JOURNAL OF THE ARNOLD ARBORETUM HARVARD UNIVERSITY VOLUME 66 NUMBER 1 ISSN 0004-2625 Journal of the Arnold Arboretum The Journal of the Arnold Arboretum (ISSN 0004-2625) is published quarterly in January, April, July, and October for $50.00 per year, plus $5.00 postage for addresses outside of the United States, by the Arnold Arboretum of Harvard University. It 1s printed and distributed by the Allen Press, Inc., 1041 New Hampshire Street, Law- rence, Kansas 66044. Second-class postage paid at Lawrence, Kansas. POSTMAS- TER: send address changes to Journal of the Arnold Arboretum, % Allen Press, Inc., P. O. Box 368, Lawrence, Kansas 66044. Subscriptions and remittances should be sent to Journal of the Arnold Arboretum, 1041 New Hampshire Street, Lawrence, Kansas 66044, U.S. A. Claims will not be accepted after six months from the date of issue. Volumes I-51, reprinted, and some back numbers of volumes 52-56 are available from the Kraus Reprint Corporation, Route 100, Millwood, New York 10546, U.S.A. EDITORIAL COMMIFTEE S. A. Spongberg, Editor E. B. Schmidt, Managing Editor P. S. Ashton K. S. Bawa P. F. Stevens C. E. Wood, Jr. Printed at Allen Press, Inc., Lawrence, Kansas COVER: The stylized design appearing on the Journal and the offprints was drawn by Karen Stoutsenberger. JOURNAL OF THE ARNOLD ARBORETUM VOLUME 66 JANUARY 1985 NuMBER | THE GENERA OF PHYTOLACCACEAE IN THE SOUTHEASTERN UNITED STATES! GEORGE K. ROGERS PHYTOLACCACEAE R. Brown in Tuckey, —_ es Congo, 454. 1818, ““Phytolaceae,” nom. (POKEWEED FAMILY) Herbs, shrubs, vines [or sometimes trees], with lateral expansion snolees or by successive cambia. Plants with betalain pigments, rich in saponins (Phy- tolaccoideae). Sieve-tube plastids usually containing globular eid. [these polygonal in Stegnosperma and cubic in Limeum]. Calcium oxalate mostly Fl ftheS United States, a long-term project made possible by see fom the National Science Foundation and currently supported by BSR-8111520 (Carroll E. Wood, Jr., principal investigator), under which this account was prepared, and BSR-8303100 (Norton G. Maes rene investigator). This treatment, the 105th in the series, follows the format established in the first paper (Jour. Arnold Arb. 39: 296-346. 1958) and continued to the present. T [ ]. References ae tr have not oe are marked with an asterisk. Special thanks are extended to my brother, James Rogers, for enthusiasm beyond mere tolerance while I collected and observed “*Phytolacca see aes a trip made to North Carolina for multiple purposes. Ihsan Al-Shehbaz, Michel Lelong, James E. Rodman, and Won S. Woo generously helped fill gaps in my information. I am indebted to Cae Staples for photographing Trichostigma in Florida. That Caen Kellogg made available her treatise on Phytolaccaceae prior to its publication Channell, Carroll Wood, and Frank C. Craighead, Jr. Supplementary materials of Petiveria came from oe from Florida in the Harvard University Herbaria (g, h, Long & Broome 2543, GH) and Puerto Rico (l-s, Wagner 1629, A). Reviews of the manuscript by Carroll Wood and Stephen Spongberg Sabian important improvements, and the paper would be poorer if not for Elizabeth Schmidt’s editorial talents. Barbara Nimblett eae the project along quickly by helping with the typing © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 1-37. January, 1985. 2 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 present as styloids (Rivinoideae) or raphides SP Ss cet sag nce [or spherical aggregates of crystals in Barbeuioideae, Microteoideae, Stegn ], and in additional forms. Leaves alternate, ome, entire, foals ly petiolate, often with crystals bulging on blades (when dry) or appearing as translucent dots; stomata anomocytic or paracytic. Inflorescences mostly ra- cemose, paniculate, or spicate, the rachises sometimes terminated by flowers, frequently bearing simple or compound lateral dichasia; bracts and bracteoles usually small. Flowers perfect [or imperfect], usually actinomorphic (regular), or slightly irregular or zygomorphic, usually with a hypogynous disc. Perianth uniseriate [or biseriate by virtue of petaloid staminodes in Stegnosperma and in Anisomeria coriacea var. petalifera fide Walter], the tepals usually 4 or 5, inconspicuous or infrequently showy, usually greenish or white, separate or slightly [or rarely strongly] coalescent basally, usually persistent. Stamens [3 or] 4 to numerous, in | or 2 whorl(s) or inserted irregularly; filaments separate or connate basally; anthers usually elongate. Pollen grains 2- (fide Davis) or 3-celled when shed, 3-colpate [3-colporoidate], pantocolpate [or pantoporate], the exine not reticulate, the tectum spinulose and usually punctate-perforate. Gynoecium of | to many [apparently separate or] connate, superior (partly inferior in Agdestis) carpels, each with | style (styles connate in Agdestis), | locule, and | adaxial-basal ovule, this (ana-)campylotropous to (among our genera, Petiveria) erect and straight with the micropyle adjacent to the funiculus, in pluricarpellate species the micropyle abaxial to the floral axis [adaxial in Stegnosperma]. [Gynoecium compound and unilocular in Microteoideae.] Fruits erries or drupes, or dry and indehiscent [or capsular, or with separate fleshy or dry carpels], sometimes winged by the persistent tepals [or with wing derived from pericarp], barbed or hooked in some genera. Seeds erect, usually com- pressed and circular to reniform in outline, sometimes elongate (Petiveria), lacking arils (or minutely arillate in Rivina) [or strongly arillate in Stegnosperma and Barbeuia]; seed coat usually smooth and dark, sometimes adherent to pericarp. Embryo annular or sharply bent, sometimes plicate. Megagameto- phyte (embryo sac) of the Polygonum type (deviating slightly in Rivina). En- dosperm formation initially nuclear. Principal nutritive tissue in mature seed perisperm. (Including Agdestidaceae Nakai, Barbeuiaceae Nakai, Petiveriaceae Agardh, Rivinaceae Agardh, Stegnospermataceae Nakai.) Type Genus: Phyto- lacca L A poorly delimited family of about 17 mostly small and often monotypic genera collectively including about 120 species. Phytolacca, with about 25 species, is the largest genus; Seguieria Loefl. is slightly smaller. Concentrated in the American tropics and subtropics, the family is represented as far north as southern. Canada. (Phytolagea. americanay..at-the southern extreme distri- butions of about half the genera include or lie within Argentina or Chile. The Old World indigens are Barbeuia Thouars in Madagascar, Monococcus F. Mueller in and near Australia, Lophiocarpus Turcz. in Africa, and species of Phytolacca in Africa and Asia. Petiveria alliacea, Rivina humilis, Trichostigma octandrum, Phytolacca americana, Agdestis clematidea, and the debatably phy- tolaccaceous Gisekia pharnacioides L. (see footnote in key) occur in the area 1985] ROGERS, PHYTOLACCACEAE 2 of the Generic Flora. Phaulothamnus spinescens SN which may or may not eae in the Phytolaccaceae, ranges as close as ytolaccaceae, clearly a family of the foe ieenticepenmac (Cary- Sei is composed of a diverse assortment of usually unarmed herbs, vines, and trees. Members usually have fairly nonsucculent, a/ternate leaves (vs. leaves mostly opposite in Caryophyllaceae, Aizoaceae, and pce nan); betalain pigments (rather than anthocyanins as in Caryophyllaceae and Mol luginaceae), and usually globular crystalloids in sieve-tube plastids (vs. crys- talloids absent in Chenopodiaceae and Amaranthaceae and polygonal in Cary- ophyllaceae). The inflorescences are predominantly racemes or racemelike but are often partly cymose (vs. more distinctly cymose in most relatives or po- tential members) and bear wnspecialized bracts (in comparison with those of Nyctaginaceae and Amaranthaceae, and the “sepals” of Portulacaceae). Phy- tolaccaceous flowers are generally perfect with nonshowy perianths (unlike Por- tulacaceae, somewhat showy in Agdestis) composed of one whorl of basally connate or separate tepals (tepals or ‘‘sepals’’ connate in Nyctaginaceae and Aizoaceae). Stamens in Phytolaccaceae vary widely in number and arrange- ment—in some genera they are numerous and inserted irregularly. With ex- ceptions, the stamens are not elaborated into attractive organs (as they are in some Aizoaceae and Molluginaceae and possibly Caryophyllaceae) and tend only slightly toward connation (thus differing from staminal tubes of some Amaranthaceae). The pollen is variable. Most genera have either a solitary carpel or several carpels with varying degrees of fusion, each carpel typically ceae, and Caryophyllaceae. With exceptions, Aizoaceae, Caryophyllaceae, Mol- luginaceae, and Portulacaceae tend to have multiplication of ovules on var- iously specialized placentas.) The six subfamilies recognized in Nowicke’s “palynotaxonomic study” (1968) of Phytolaccaceae are congruent with Heimerl’s (1934) five tribes and one set of anomalous genera. In the principal revision prior to those of Nowicke and Heimerl, Walter (1909) divided a more broadly circumscribed Phytolaccaceae into two subfamilies, three tribes, and two subtribes. All three monographers perceived Anisomeria D. Don, Ercilla A. Juss., and Phytolacca to constitute a coherent assemblage. This trio, which is characterized by raphides and multiple carpels with as many locules and styles, makes up the entire Phytolaccaceae sensu Hutchinson and the entire subfam. Phytolaccoideae in Nowicke’s treat- ment. Walter, Heimerl, and Nowicke agreed further on the boundaries of the group now known as subfam. Rivinoideae Nowicke,* characterized by styloid crystals and flowers with single carpels. a Ge 2With their authorships brought into accordance with the 1983 International Code of Botanical Nomenclature, the tribes Nowicke recognized under subfam. Rivinoideae are Seguierieae Moa. (two extralimital genera with paniculiform inflorescences and samaroid fruits) and Rivineae Endl. (seven genera, including our Petiveria, Rivina, and Trichostigma, with spikes or racemes and nonsamaroid fruits). Although some botanists attributed C. A. Agardh with the authorship of tribe Rivineae in his Aphorismi Botanici, he evidently published Rivineae as an ‘“‘order” nomenclaturally equivalent to a modern family (see Agardh, p. 61, and ICBN, 1983, Art. 18.2). 4 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 The affinities of the remaining members or potential members of the family have spawned disagreement and remain unsettled. Subfamily Microteoideae Eckardt ex Nowicke is made up of Lophiocarpus and Microtea Sw. in Nowicke’s classification. Walter did not include Lophiocarpus in the Phytolaccaceae and listed Microtea under genera anomala. Heimer! listed both as anomalous. Both Heimerl and Walter placed the three genera corresponding to Nowicke’s subfamilies Barbeuioideae Nowicke, Agdestidoideae Nowicke, and Stegno- spermatoideae H. Walter in the Phytolaccaceae at various infrafamilial ranks or among genera anomala. Other botanists have excluded them from the Phytolaccaceae as incertae sedis or as distinct families. Heimer!l, Nowicke, and most recent authors departed from Walter and from Dahlgren and colleagues by treating Achatocarpus Triana and Phaulothamnus Gray together as the family Achatocarpaceae. They further disagreed with Walter by excluding Gyrostemonaceae from Phytolaccaceae. Evidence that the former is out of place even in the Centrospermae comes from palynology, floral morphology, cytology, chemistry, and the nature of sieve-tube plastids and vacuoles in companion cells (Behnke, 1977; Goldblatt et a/.; Keighery). The foregoing historical sketch underscores the need for new research aimed toward a better circumscription of the Phytolaccaceae. The confusion comes largely from the fact that to some degree the family comprises the taxonomic residue left after the other Centrospermae are sorted into separate families based on apparent specializations. (From here it is a small jump to the common perception of the family as a phylogenetic residue left after the evolutionary radiation of other Centrospermae.) An ostensible shared absence of derived distinctions, leaving suspected ancestral traits as similarities, is at best flimsy evidence for phylogenetic relationship. Yet, even if the family Phytolaccaceae is a repository for residual unspe- cialized traits, past authors have probably overemphasized its primitiveness. Thus, a few apparently derived characters should be mentioned. Rohweder’s conclusion that ovaries in Phytolacca separate by bulging from an ontogenet- ically originally syncarpous region raises the possibility that near-apocarpy in subfam. Phytolaccoideae is phylogenetically secondary. This challenges the hypotheses that the occurrence of near-apocarpy in the Phytolaccaceae is a tie to apocarpous Ranales (see Buxbaum, 1961), and that this condition reflects the starting point for gynoecial evolution in the rest of the Centrospermae. As a second example, the racemes and racemelike inflorescences that predominate in the Phytolaccaceae are interpretable as having evolved by reduction from cymose inflorescences. Cymose arrangements characterize most other Cen- trospermae and a minority of Phytolaccaceae (mostly peripheral groups), and racemose inflorescences in the Phytolaccaceae (e.g., species of Phytolacca) sometimes have dichasial branches. (For an argument that the general evolu- tionary trend proceeds in this direction, see Stebbins.) To add a third example, Cronquist doubted that the phytolaccaceous trait of one ovule per carpel is primitive in the Centrospermae. Lastly, recent authors have noted that it is simpler to postulate that the betalain pigments of Phytolaccaceae and most other centrosperms are derived than to interpret their presence as ancestral in the order. The latter interpretation requires acceptance of the anthocyanins in Molluginaceae and Caryophyllaceae as arising anew via reversal. 1985] ROGERS, PHYTOLACCACEAE 3 Specializations are to be expected, and these do not rule out a more or less central position for Phytolaccaceae in the Centrospermae. Support for this position appears in apparent spokelike links to disparate satellite groups and centrospermous families through morphological similarities and transitional genera. As examples of the latter, Stegnosperma Bentham forms a much-dis- cussed bridge to Molluginaceae or Caryophyllaceae, and Lophiocarpus and Microtea have repeatedly been mentioned as ties to Chenopodiaceae and Ama- ranthaceae. Gisekia resembles species of Phytolaccaceae in having raphides, betalains, and gynoecia that agree developmentally, but it leans toward Mol- luginaceae in habit, cymose inflorescences, androecial morphology, nectaries, and embryology. (For comparative details see Bogle; Hofmann, 1973; Mabry et al. Note that Ehrendorfer, 1976b, placed Gisekia in Aizoaceae.) The structures termed stipules in literature on Phytolaccaceae are probably prophylls in some, if not all, genera in which they occur (Eckardt, 1964; see also Buxbaum, 1949). In Petiveria alliacea stipulelike axillary emergences can be seen to be attached like reduced leaves to developed axillary shoots, and multiple pairs of emergences appear to correspond to multiple axillary shoots. According to the sketchy data on hand, chromosome numbers in Phytolac- caceae range as polyploids, but not aneuploids, from 2” = 18 to 2n = 108. (Keighery provided a survey.) Most economic uses for members of the Phytolaccaceae appear in the generic treatments. Among extralimital genera Ercilla spicata (Bert.) Moq. is a minor ornamental, while species of Anisomeria, Gallesia Casar., Hilleria Vell., Mi- crotea, and Seguieria find uses in folk remedies. Roots of Stegnosperma scan- dens (Lunan) Standley serve as a soap in Mexico (Standley & Steyermark). REFERENCES: AGARDH, C. A. Aphorismi botanici. 246 pp. Lund. 1817. [Rivineae, 218, 219; Peti- vereae, 221; see comments on system of classification, 61. AYENSU, E. S. Medicinal plants of the West Indies. 282 pp. Algonac, Michigan. 1981. [Petiveria, Phytolacca, Rivina, 147.] BaILLON, H. Phytolaccacées. Hist. Pl. 4: 23-56. 1872. [English translation by M. M. Hartoc, The natural history of plants 4: 23-59. 1875; Phytolaccaceae with six ries. Barto, O. M., & A. F. BARBosa. Catdlogo sistematico dos pélens das plantas arbéreas . ee) Mem. Inst. Oswaldo Cruz 70: 254-259, p/. 4. 1972. [Descriptions and illustrations; includes species of Phytolacca and Petiveria (cf. BoRTENSCHLAGER BeEDELL, H. G. taxonomic and morphological re-evaluation of Stegnospermaceae (Caryophyllales). Syst. Bot. 5: 419-431. 1980 [1981]. [Wood anatomy and data from literature suggest exclusion of Stegnosperma from Phytolaccaceae.] BEHNKE, H. D. Elektronenmikroskopische Untersuchungen an Siebréhren-Plastiden und ihre Aussage tiber die pire Stellung von Lophiocarpus. (English summary.) Bot. Jahrb. 94: 114-119. Ultrastructure of siev Seen plastids in Caryophyllales oe evidence for the delimitation and classification of the order. Pl. Syst. Evol. 126: 31- 54. 1976. [See BEHNKE et a/. (1983a) for updated characterizations of sleve-tube plastids (especially for Limeum and Achatocarpaceae hloem ultrastructure and systematic position of Gyr ostemonaceae. Bot. Not. 130: 255-260. 1977. [Gyrostemonaceae with S-type sieve-tube plastids; vacuoles in 6 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 phloem resemble capparalean dilated ER cisternae (probably part of glucosinolate- myrosinase system). ,C. CHANG, I. J. Errert, & T. J. MABry. Betalains and P-type oo plastids in Petiveria and Agdestis (Phytolaccaceae). Taxon 23: 541, 542. 1 , T. J. Masry, P. NEUMANN, & W. BARTHLOTT. ae micromorpho- logical aid phytochemical evidence for a “central position” of Macarthuria (Mol- enacene) within the Caryophyllales. Pl. Syst. Evol. 143: 151-161. 1983a. ,L. Pop, & V. V. SIVARAJAN. Sieve-element plastids of Caryophyllales: additional investigations a special reference to the Caryophyllaceae and Molluginaceae. PI. Syst. Evol. 142: 109-115. 1983b. BENTHAM, G., & J. D. HOOKER. es beware Gen. Pl. 3: 78-87. 1880. [Tribes Ri- vineae, Euphytolacceae, and Gyrostemon Boc.e, A. L. The genera of Molluginaceae a Aizoaceae in the southeastern United States. Jour. Arnold Arb. 51: 431-462. 1970. [Gisekia, 435-437; G. pharnacioides “in our area, apparently as a very recent adventive’’; includes discussion of family relationships of the genus. Boxe, N. H. The cactus gynoecium: a new interpretation. Am. Jour. Bot. 51: 598-610. 1964. BORTENSCHLAGER, S. Morphologie pollinique des Phytolaccaceae. Pollen Spores 15: 227- 253. 1973. [Includes individual generic descriptions, scanning electron micrographs of pollen grains, and discussion of taxonomic implications; see BARTH & BARBOSA for contradictory observations on Petiveria A. AVINGER, A. BLAHA, & P Sion RGER. Pollen morphology of the Acha- tocarpaceae (Centrospermae), Ber. Naturw. Med. Ver. Innsbruck 59: 7-14. 1972.* {See comments in BEHNKE (1976, pp. 38, 39) concerning the significance of this BurGer, W. Phytolaccaceae. /n; W. BurGER, ed., Fl. Costaricensis. Fieldiana Bot. II. 3: 199-212. 1983. [Petiveria, Phytolacca, Rivina, Trichostigma. Bur tace, H. M. Index of plants of Texas with reputed medicinal and poisonous prop- erties. Vv + 272 pp. Austin, Texas(?). 1968. [Phytolacca, Petiveria, Rivina, 134, 135.] Buxpaum, F. Vorldufer des Kakteen-Habitus bei den Phytolaccaceen. Osterr. Bot. Zeitschr. 96: 5-14. 1949. [Based mostly on Phytolacca “‘clavigera” pene P. acinosa) Anisomeria (axillary growth resembles areoles in Pereskia), and Microtea (succu- lence, Sar branching). ] rphology of cacti. 7 B. oo Jr., ed. Sect. I. Roots and stems. 1951. Sect. I]. The ea wer. 1953. Sect. III. Fruits and seeds. 1955. [iv] + frontisp. + 223 Pasadena, California. ae seer reece to Phytolaccaceae; see criticism in — orldufige Untersuchungen tiber Umfang, systematische Stellung und Gliede- eae Caryophyllales (Centrospermae). Beitr. Biol. Pflanzen 36: 1-56. 1961. [Phy- tolacca, 8-13, ters link Caryophyllales with [/licium; refutation oo similarity between Phytolaccaceae and //licium appears in Horm 977 Corner, E. The neh Ea Guiibee Vol. 1. ix + 311 pp. Cambridge, London, New York, and Melbourne. 1976. [Phytolaccaceae, 217.] Cronauist, A. An integrated system of classification of flowering plants. xvin + 1262 pp. New York. 1981. [Phytolaccaceae, see especially 248-250; Achatocarpaceae and Gyrostemonaceae excluded, Gisekia included.] DAHLGREN, R. M. T., S. ROSENDAL-JENSEN, & B. J. NIELSEN. A revised classification of the angiosperms with comments on correlation between chemical and other char- acters. Pp. 149-204 in D. A. YounG & D. S. SEIGLER, eds., Phytochemistry and angiosperm phylogeny. New York. 1981. [Phytolaccaceae (including Achatocarpa- 1985] ROGERS, PHYTOLACCACEAE y) Pa | eae, nd Limeum), see especially 174, 200; see BEHNKE et al. (1983a) for eamncat on affinities of Limeu um.]} Davis, G. L. Systematic embryology of the angiosperms. viii + 528 pp. New York, London, and Sydney. 1966. [Phytolaccaceae and (poorly known or “embryologically unknown’’) segregates, 11, 15, 33, 36, 54, 207, 208, 210, 2 ECKARDT, T. Morphologische und systematische Auswertung der Placentation von Phy- tolaccaceen. Ber. Deutsch. Bot. Ges. 67: 113-128. p/. 3. 1954. [Concerned chiefly with question of stachyospory vs. phyllospory; Hilleria, Phytolacca, Rivina, and Trichostigma Reihe Centrospermae. In: H. Meccuior, A. Engler’s Syllabus der Pflanzenfa- milien. ed. 12. 2: 79-102. 1964. [Subfam. Phytolaccoideae with tribes Agdestideae, Barbeuieae, Phytolacceae, Rivineae; subfam. Stegnospermatoideae; subfam. Micro- teoideae; Achatocarpaceae, Gisekia, and Gyrostemonaceae excluded.] Vom Bltitenbau der Centrospermen-Gattung Lophiocarpus Turcz. Phyton Aus- tria 16: 13-27. p/. 2. 1974. [Includes taxonomic history of Lophiocarpus, affinities remain unsettled.] ee morphological features of centrospermous families. Pl. Syst. Evol. 126: 5- 25. 76. ena aa alee Pl. Syst. Evol. oy 27-30. 1976a. [Phytolaccaceae, 27, 29, “remarkably stable . in their chromosome base numbers.”’ Closing remarks: systematics and evolution of centrospermous families. bid. 126: 99-106. 1976b. GaArRCiA-BARRIGA, H. Flora medicinal de Colombia. Botanica médica. Vol. 1. 561 pp. Bogota. 1974. [Phytolaccaceae, 297-304; many uses for Petiveria alliacea ay species of Phytolacca; includes pharmacological tests of any from P. bogotensis.] GarciA-MARTINEZ, J. Phytolaccaceae. Fl. Veracruz 36: 1- 984. GOoLbBLATT, P., 1. W. Nowicke, T. J. Masry, & H. D. Sate Gyrostemonaceae: status and affinity. Bot. Not. 129: 201-206. 1976. HATSCHBACH, G., & O. GUIMARAES. Fitolacaceas do estado do Parana. Bol. Mus. Bot. Munic. Curitiba 8: 1-24. pis. J/-10. 1973. [Petiveria, Phytolacca, Rivina, Tricho- stigma. HauMAn-Merck, L. Notes sur les Phytolaccacées argentines. Anal. Mus. Nac. Hist. Nat. Buenos Aires 24: 471-516. 1913. [Substantial detail on Phytolacca dioica, which—contrary to at least one other report—is entomophilous; includes Petiveria, Rivina, and Trichostigma.] HEGNAUER, R. Chemotaxonomie der Pflanzen. Vol. 5. 506 pp. Basel and Stuttgart. 1969. [Phytolaccaceae, 305-310, 449; includes data on Petiveria (saponins not de- tected; discussion of possible presence of mustard oils), Phytolacca, Rivina (saponins not detected), and Trichostigma; presence of alkaloids not firmly established. Heimer, A. Phytolaccaceae. Nat. Pflanzenfam. III. 1b: 1-14. 1889. [Agdestideae, Gy- rostemoneae, Limeae, Phytolacceae, Rivineae, Stegnospermateae.] . Phytolaccaceae. Nat. Pflanzenfam. ed. 2. 16c: 135-164. 1934. [Delimitation of 4it F Bag HENNIG, W. Phylogenetic systematics. (English translation by D. Davis & R. ZANGERL.) [ui] + 263 pp. Urbana, Chicago, and London. 1966. [Discussion of ancestral (‘‘ple- i ) characters as taxonomic indicators, 88-93. Hormann, U. Morphologische Untersuchungen zur Umgrenzung und Gliederung der Aizoaceen. Bot. Jahrb. 93: 247-324. 1973. [Summary of characters linking Gisekia to Phytolaccaceae and Molluginaceae, 303. Centrospermenstudien 9. Die Stellung von Stegnosperma innerhalb der Cen- trospermen. (English summary.) Ber. Deutsch. Bot. Ges. 90: 39-52. 1977. [Com- parison of Stegnosperma with Caryophyllaceae, Molluginaceae, and Phytolaccaceae; best position for Stegnosperma remains unclear; comments on phytolaccaceous 8 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 66 gynoecium (augments ROHWEDER with observations on additional genera); includes descriptive detail of inflorescences of Agdestis, Petiveria, Phytolacca, Rivina, and a.] Hurtcuinson, J. The families of flowering plants. ed. 3. xviil + 968 pp. Oxford. 1973. [Phytolaccaceae, 538, 539, Agdestidaceae (monogeneric), 540, 541; Petiveriaceae (several genera usually included in Phytolaccaceae), 541, 542. KaJALe, L. B. A contribution to the embryology of the ee. II. Fertilization and the lean atl of embryo, seed and fruit in Rivina humilis Linn. and Phy- tolacca dioica Linn. Indian Bot. Soc. Jour. 33: 206-225. 1954a. [Embryogeny of R. humilis of Chenopodiad type; P. dioica with new variation of Caryophyllad type (but cf. following reference); suspensors, nutritive tissues, testa, mature embryo (Rivina), and fruit (Rivina) described and amply ne little detail on mega- gametophytes. evelopment of the embryo, endosperm and seed coat in two species of the Phytolaccaceae. Indian Sci. Congr. Assoc. Proc. 41(3-Abstr.): 140. 1954b. [Rivina humilis, Phytolacca dioica; embryogeny of both Chenopodiad type (cf previous reference). ] KEIGHERY, G. J. Chromosome numbers in the Gyrostemonaceae Endl. and the Phy- tolaccaceae Lindl.: a comparison. Austral. Jour. Bot. 23: 335-338. 1975. LAKELA, O., & F. C. CRAIGHEAD. Annotated checklist of the ee plants of ei Dade, and Monroe counties, Florida. Contr. Bot. Lab. Univ. S. Florida 15. vin 95 pp. 1965. [Agdestis, Petiveria, Phytolacca (rigida), Rivina, Trichostigma, he ae K. F., & R. FAGERSTROM. Plant toxicity and dermatitis. A manual for physicians. + 231 pp. Baltimore. 1968. [Rivina resin-containing, 27, 31, 34; PAhytolacca, 27, er Lewis, W. H., & M. P. F. E-vin-Lewis. Medical botany. Plants affecting man’s health. xv + 515 pp. 1977, [Phytolacca, 5, 90,91, 97, 98, 137, 167, 278, Petiveria, 32, 251.] Lona, R. W., & O. LAKELA. A flor Bor tropical Florida. xvii + 962 pp. Coral Gables, Florida. 1971. [Agdestis, Petiveria, Phytolacca, Rivina, Trichostigma, 392-395. sb J. A contribution to our knowledge of seedlings. Vol. 2. 646 pp. New York. 2. [Petiveria, Phytolacca, Rivina, 429-435. are TT. : The order Centrospermae. Ann. Missouri Bot. Gard. 64: 210-220. 1977. . BEHNKE, & I. J. ElFertT. Betalains and P-type sieve-element plastids in Fe L. (Centrospermae). Taxon 25: 112-114. 1976. [Position remains unsettled. ] MacsribDe, J. F. Phytolaccaceae. Jn: B. E. DAHLGREN, ed., Fl. Peru. Publ. Field Mus. Bot. 13(2): 546-558. 1937. [Petiveria, Phytolacca, Rivina, Trichostigma.] Marin, A. C. The comparative internal eras of seeds. Am. Midl. Nat. 36: 513- 660. 1946. [Petiveria, Phytolacca, Rivina, 564, Mauritzon, J. Ein Beitrag zur Embryologie der ot eee und Cactaceen. Bot. Not. 1934: 111-135. 1934. [Includes observations on Petiveria (stands apart), Phy- tolacca, Rivina, “Villamilla” (Trichostigma), emphasizes forms of ovules, nucellus, endosperm, and embryos. } METCALFE, C. R., & L. CHALK. Phytolaccaceae. Anat. Dicot. 2: 1086-1091. 1950. Moguin-TANDON, A. Ordo Phytolaccaceae. A. DC. Prodromus 13(2): 2-40. 1849. [Phy- tolaccaceae very broadly defined and divided into three suborders and eight tribes; Trichostigma (as Villamilla) included in Rivina.] Morton, J. F. Atlas of medicinal plants of Middle America. Bahamas to Yucatan. xxviii + 1420 pp. Springfield, Illinois. 1981. [Petiveria, Phytolacca, Rivina, Tri- chostigma, 198-203, figs. 88, 89. Narr, P. K. K. Pollen grains of Indian plants—II. Bull. Natl. Bot. Gard. Lucknow 60: 1-8. pl. 1. 1962. [Phytolacca acinosa, Rivina humilis, 2-4, illustrated.] NeETOLITzKY, F. Anatomie der Angiospermen-Samen. Handb. Pflanzenanat. I. Arche- n. 10. v + 364 pp. 1926. Piiolasea, Rivina, 111 (fig.), 113, 114.) Nowicke, J. W. Palynotaxonomic study of the Phytolace aceae. Ann. Missouri Bot. Gard. 55: 294-364. 1968. [Includes taxonomic revision of family; palynological 1985] ROGERS, PHYTOLACCACEAE 9 information updated in later papers by Nowicke, NowIckE & SKVARLA, and SKVAR- LA & NowIckeE.] ——. Pollen morphology in the order Centrospermae. Grana 15: 51-77. 1975 [1976]. [Phytolaccaceae, see especially 54, 55, 57 (figs.), 60, 64; includes scanning electron micrograph of Agdestis pollen; contrary to earlier reports, Phytolaccaceae lack re- ticulate pollen grains.] & SKVARLA. Pollen morphology: the potential influence in higher order systematics. Ann. Missouri Bot. Gard. 66: 633-700. 1979 [1980]. [Phytolaccaceae, 637, 641; Achatocarpaceae, 663, 697, plus scattered references; includes scanning electron micrographs of pollen of Phytolacca americana.] PECKOLT, T., & G. PECKOLT. Historia das plantas medicinaes e uteis do Brazil. Fasc. 7. Pp. 1121-1369. Rio de Janeiro. 1899. [Phytolaccaceae, 1121-1152; a major refer- ence for uses and pharmacological properties of Petiveria; also includes Me ytolacca.] POLHILL, R. M. Phytolaccaceae. Jn: E. MILNE-REDHEAD & R. M. POoLHILL, ed . Tro . Afr. 8 pp. 1971. [Phytolacca dodecandra, P. octandra, Hilleria latifolia, Rivina Aumilis.] RAEDER, K. Phytolaccaceae. Jn; R. , JR., et al., eds., Fl. Panama. Ann Missouri Bot. Gard. 48: 66-79. fee een Phytolacca, Rivina, Trichostigma.] RicHARpDsoN, P. M. Flavonoids of some controversial members of the Caryophyllales (Centrospermae). Pl. Syst. Evol. 138: 227-233. 1981. RickeTT, H. W. Wild flowers of the United States. Vol. 2. The southeastern states. Part Ix+ 322 pp. New York. 1967. [Phytolacca, Rivina, 145 (photos), 147, 148.] Rip.ey, H. N. The dispersal of plants throughout the world. Frontisp. + xx + 744 pp. Ashford, Kent. 1930. [Agdestis, 111; Phytolacca, several scattered references; Rivina (fruits at mallard ducks), 490.] RopMAaAN, J. . K. Outver, R. R. NAKAMURA, J. U. McCCLAMMEeR, JR., ee es taxonomic analysis and revised Scie of the order es mae. Syst. Bot. (in press.) [“Cohort’? Nyctaginares: Nyctaginaceae and Phytolacca- ceae; Achatocarpus, Barbeuia, Lophiocarpus, Phaulothamnus, and Stegnosperma incertae sedis in Centrospermae sedis in suborder Chenopodiineae. } Rouweper, O. Entwicklung und a a Deutung des Gynéciums bei Phyto- lacca. (English summiaty.) Bot. sie 84: 509-526. pls. 25-27. 1965. [Gynoecial development of Phytolacca acinosa P. “clavigera’ (probably P. acinosa, see NOWICKE, 1968, p. 320), and P. americana.] Roia, J. T., & J. B. AcUNA. Fitolacaceas. /n: HERMANOS LEON [J. S. Sauget] & ALAIN [E. E. Liogier], Fl. Cuba 2: 134-140. 1951. [Agdestis, Petiveria, Phytolacca, Rivina, Trichostigma.]} SANTOS, E., & B. FLASTER. Fitolacdceas. 7m: P. RAULINO RerTz, ed., Flora ilustrada Catarinense. 37 pp. Santa Catarina. 1967. [Petiveria (P. tetrandra not recognized), Phytolacca, Trichostigma SAUNDERS, E.R. Illustrations of carpel polymorphism. VI. New Phytol. 29: 81-95. 1930. [Uses floral vasculature to conclude that the ovary in ae if composed of two fused unequal carpels; cf’ JosH1 & RAo (under Rivina), SCHA ScHAEPPI, H. Zur Morphologie des Gynoeceums der Bia Flora 131: 41-59. 1936. [Petiveria, ae Rivina.] SCHERMERHORN, J. & M. W. Quimsy, eds. The Lynn index. Monograph I. Order, Centrospermae. 46 pp. Boston. 1957. [Phytolaccaceae, 42—44; presence of alkaloids in Phytolaccaceae dubious; centered on Phytolacca, including long list of contained compounds. ] ScHMIDT, J. A. Phytolaccaceae et Nyctagineae. Jn: C. F. P. von Martius, Fl. Brasil. 14(2): 325-376. pls. 73-88. 1872. [Particularly acral illustrations of Peiena and Rivina; tribes Petiverieae Endl. and Phytolacceae, each w = two subtribes. ] SKVARLA, J. J., & J. W. Nowicke. Ultrastructure of pollen exine in centrospermous families. Pl. Syst. Evol. 126: 55-78. 1976. ei ececie see especially 68.] 10 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 —— & ——. Pollen fine structure and relationships of Achatocarpus Triana and an Gray. Taxon 31: 244-249, 1982. STANDLEY, P. C. Trees and shrubs of Mexico. (Fagaceae—Fabaceae). Contr. U. S. Natl. Herb. 23: 171-515. 1922. [Agdestis, Petiveria, Rivina, Trichostigma, 263-265.] & EYERMARK. Phytolaccaceae. /n: Fl. Guatemala. Fieldiana Bot. 24(4): 192- 202. 1946. [Agdestis, Petiveria, Phytolacca, Rivina, Trichosti, gma.| Stessins, G. L. Flowering plants. Evolution above the species level. xvii + 397 pp. Cambridge, Massachusetts. 1974. [Evolution of inflorescences, 261-281.] TAKHTAJAN, A. L. Outline of the classification of flowering plants (Magnoliophyta). Bot. Rev. 46: 225-359. 1980. [Phytolaccaceae (including Agdestidaceae, Barbeuiaceae, Gisekiaceae, and Petiveriaceae; excluding Stegnospermataceae and Achatocarpa- ceae), 268; “the most primitive and generalized family of the order.” TuieretT, J. W. Seeds of some United States Phytolaccaceae and Aizoaceae. Sida 2: 352- 360. 1966. [Seeds of Rivina humilis and Phytolacca americana described and illus- trated. ] THoRNE, R. F. Proposed new realignments in the angiosperms. Nordic Jour. Bot. 3: 85- 117. 1983. [Phytolaccaceae, see especially 104; subfams. Phytolaccoideae, Gise- kioideae, Rivinoideae, Agdestidoideae, and Microteoideae; Barbeuiaceae, Achato- 3. aD see M. Las Fitolacdceas chaquefias. Notas preliminares para la flora cha- a 6: 16-25. 1974. [Petiveria (no mention of P. tetrandra), Phytolacca, Rivina.] re G. S., & G. K. Brown. Re-evaluation of the classification of Phytolac- caceae s. lat. (Abstract.) Am. Jour. Bot. 70(5, part 2): 134. 1983. [Wagner network and UPGMA cluster analysis suggested: Phytolaccaceae sensu stricto (Anisomeria, Ercilla, Gisekia, Phytolacca), Petiveriaceae (including Lophiocarpus, Microtea, Pet- iveria, Rivina, Trichostigma, and other genera); Achatocarpaceae, Agdestidaceae, Wacter, H. Die Diagramme der Phytolaccaceen. Bot. Jahrb. oe 85): 1-57. 1906. [Includes diverse anatomical data; subdivision of family, Phytolaccaceae. /n: A. ENGLER, Pflanzenr. IV. 83(Hefi a 1-154. 1909. WEBB, a 7 An Australian phytochemical survey. |. Alkaloids and cyanogenetic com- pounds in Queensland plants. Commonw. Sci. Industr. Res. Organ. Austral. Bull. 241: 1-56. 1949. [Positive tests for alkaloids in Phytolacca octandra and Rivina humilis, 39.] Witson, P. Petiveriaceae. N. Am. Fl. 21: 257-266. 1932. [‘Petiveriaceae” included Agdestis, Petiveria, Phytolacca, Rivina, Trichostigma.] sear P. Le nectaire floral chez les Phytolaccaceae. Bull. Soc. Bot. France 117: 47-260. 1970 [1971]. [Centered on Phytolacca.] KEY TO THE GENERA OF PHYTOLACCACEAE IN THE SOUTHEASTERN UNITED STATES A. Carpel |; stigma 1; style | or absent; crystals predominantly styloids. B. Inflorescences spicate or nearly so; l pubescent; fruit dry, cuneiform, armed with 4 or more > hooks at apex; a muc longer than wide. .......... 0000. etiveria. B. Inflorescences racemose; flowers actinomorphic or nearly so; ovaries are or glabrate; fruit fleshy, rounded in outline, unarmed; seed more or less lenticular. C. Plants usually herbs or subshrubs (sometimes scandent); leaf blades often deltoid; stamens 4; style well developed, stigma capitate or lobed; fruit bright red or orange; seed covered with “hairy” remnant of pericarp (this sometimes Ge ee Paste pee ee See peaaes ey Ge . Rivina woody vines, sometimes somewhat arborescent; leaf blades ovate or lanceolate to elliptic; stamens 8 or more; style absent or (@) as) ro) 3 mal yn ec mn e ad = =| [o) ion c 1985] ROGERS, PHYTOLACCACEAE 11 inconspicuous, stigma penicillate; we pecs or dark reddish; seed bare o covered with “nonhairy” remnant of pericarp. ........... : Tishostiemo. A. Carpels usually 4 or more, ee atiy a apo oases or syncarpous; stigmas and styles usually 4 or more (except Agdestis, with solitary style crowned with usually 4 con- spicuous stigmas); crystals predominantly raphides D. Plants climbing vines; leaf blades mostly cordate, often about as long as wide; ovary partly inferior, syncarpous and usually 4-locular (becoming unilocular in fruit by abortion); style solitary; fruit dry, only | per flower (not an aggregate). BE eM Ny titans hae edad kta aac cated aoa te ee 5. Agdestis. D. Plants nonclimbing herbs; leaf blades linear-oblong to elliptic or ovate, longer than wide; ovary superior, apparently apocarpous with 5 carpels or syncarpous with usually 10 ae and locules; styles as many as carpels; fruit baccate or an aggregate of nutlet E. Leaves sears usually separated by well-developed internodes, usually wid- er than | cm; inflorescence racemose, uncrowded; stamens usually 10; noecium syncarpous, carpels usually 10; Hun Dace eee l. Piyiolaeca: . Leaves one opposite or subopposite, sometim tered at nodes, narrower than | cm; inflorescence fundamentally cymose, more or less umbelliform and em crowded; stamens 5; gynoecium apparently apocarpous, car- pels 5; fruit an aggregate of warty nutlets. ...... [Gisekia Pencides L.3] ™ Subfamily PHY TOLACCOIDEAE 1. Phytolacca Linnaeus, Sp. Pl. 1: 441. 1753; Gen. Pl. ed. 5. 200. 1754. Large, perennial [or sometimes annual?], erect [or scandent or procumbent], often shrublike herbs [Phytolacca dioica and P. Weberbaueri becoming large trees], expanding laterally by successive cambia [or P. Meziana with a contin- uous ring of secondary xylem fide Wheat]. Stems and axes of inflorescences often purplish or reddish, the pith diaphragmed [or absent] in mature stems. Patterns of growth monopodial or sympodial, the branching frequently pseu- odichotomous, sometimes with multiple shoots emerging from one leaf axil. Taproots often large (reaching several dm in diameter in P. americana). Plants mostly glabrous, frequently scurfy-puberulent on axes of inflorescences [and infrequently elsewhere]. Raphide bundles usually bulging on dried specimens. Leaves petiolate [or nearly sessile], the blades thin to slightly succulent, often crisped-undulate, usually elliptic (often narrowly so) to ovate or lanceolate, mostly variously pointed apically, often asymmetric and usually tapered and decurrent onto the petiole basally; stomata anomocytic. Inflorescences termi- nal, often overtopped by axillary growth, then usually borne opposite a leaf or nearly so [infrequently axillary or arising from old growth], pedunculate [or nearly sessile], nodding to erect, the straight central rachis bearing numerous radiating much shorter [to virtually absent] pedicels, each of these subtended by a scarious elongate bract and bearing 2 small bracteoles, these sometimes subtending second- [or third-Jorder axes, especially toward the inflorescence 5 [rarely 3 or 4], white to pink or reddish [or yellowish, greenish, or purple], ’Adventive in our area. Bogle treated Gisekia for the Generic Flora under Molluginaceae. 12 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Figure 1. Phytolacea. a-h, P. americana: a, branchlet with flowers and immature fruits, x 2; b, flower, stigmas not yet receptive, x 8;c, gynoecium with receptive stigmas, low, x 22; f, mature fruit, x 3; g, seed, lateral view, funicular remnant to right, x 5; h, seed in section idiag ic, seed coat black with white stipples, embryo unshaded, perisperm in center, = 8. broad, entire or erose, persistent [or caducous], separate or nearly separate tepals. Stamens [ca. 5 to] usually 10 in P. americana [to ca. 33], usually in | [or 2] series; filaments distinct [or connate basally], broadened at the bases [to filiform]; anthers dorsifixed. Pollen grains prolate to spheroidal, 3-colpate, the tectum spinulose and punctate-perforate. Gynoecium usually of 10 [or ca. 5 to ca. 17] connate [to nearly distinct] carpels arranged in a ring, each bearing a recurved to erect style with the stigmatic surface decurrent adaxially. Fruit a smooth globose to depressed berry (sulcate when dry), usually 10-locular (P. americana) [or carpels remaining separate], usually bearing the stylar remnants, purple-black [or reddish]. Seeds usually 10 (P. americana), nearly circular to lopsided reniform [to obovate], flattened, the testas hard and shining, black or nearly so except for light-colored funicular remnants. Embryo annular. En- dosperm persisting as a vestige in the mature seed. 2n = 18, 36, 72. (Including 1985] ROGERS, PHYTOLACCACEAE 13 Sarcoca Raf., Pircunia Moq.). Lectotype species: P. americana L. (P. decandra L.); see Britton & Brown, FI. No. U.S. Canada, ed. 2. 2: 26. 1913. (Name from Greek phyton, plant, and /acca, a Latinized reference to the pigment variably known as lake, lac, or laque.) — PoKE,* POKEBERRY, POKEWEED. Approximately 25 species in three subgenera’ of two sections each, distrib- uted mostly from southeastern Canada, southward throughout most of North, Central, and South America, and in the West Indies. In the Old World a small number of species range from Africa and Madagascar into Asia Minor and eastward across southern Asia to Korea, Japan, and Taiwan. The unusually wide range of Phytolacca acinosa Roxb. (P. esculenta Van Houtte), from Pa- kistan to Japan and elsewhere, is no doubt partly attributable to its culinary history. Phytolacca dodecandra L’Hér. is widespread in Africa. Phytolacca americana, P. icosandra L., P. octandra L., and P. purpurascens r. & Bouché are adventive in scattered, usually warm regions worldwide. Outside of our area, but in the United States, P. brachystachys Mogq. is Hawaiian: P. heterotepala H. Walter, an otherwise Mexican species, appeared in San Fran- cisco, California (Howell); and P. dioica L. is grown in California. ect. PHYTOLACCA (flowers perfect) of subg. PHyTOLACCcA (carpels completely connate, styles more or less connivent) is represented in the southeastern United tates by P. americana, 2n = 36, which occurs in southern Quebec and Ontario, in every state of the United States east of or intersected by a longitudinal line crossing eastern Nebraska, and in northeastern Mexico. Populations in Arizona, Oregon, and California probably started from introductions by humans. Phy- tolacca americana is widely scattered adventively in the Old World. A possible second species in our area, Phytolacca rigida Small inhabits seaside habitats from North Carolina to Texas and extends inland across much of Florida and into Alabama (Harper). Authors are divided as to whether P. rigida ought to be recognized as distinct from P. americana. The most salient ae feature of the former, inf t (vs. usually nodding), proved to have a genetic basis in the transplant experiment reported y H. J. Rogers. A second conspicuous difference is that P. rigida has somewhat succulent leaves, a distinction undermined fu) Lloyd's (1914) wees of plasticity in leaf thickness in P. “decandra” (P. americana). My ow - servations complicate evaluation of this aia *“Poke”’ is thought to come from “pocan” or “‘puccoon,” probably an Algonquin term for a plant that contains dye. *Phytolacca subg. Pircunia (Moq.) H. Walter is a later homonym of Phytolacca subg. Pircunia Poeppig & Endl. (Nov. Gen. 1: 26. 1836, two species now placed in Anisomeria). Sections “Pircunia” and “Pircuniopsis” should be called by their older names, sects. Pircuniastrum and Pseudolacca, due to changes in the International Code of Botanical Nomenclature since Nowicke’s revision. ppeared as sections of the genus Pircunia in Moquin-Tandon (1849) and as sections of Phytolacca in Baillon (1872). (Section “Pircunia” also contradicts Art. 64.3.) n August, 1983, 1] observed Phyrolacca rigida and P. amer 7 at Emerald Isle, Carteret County, North Carolina, represented at a by G. Rogers 107 and /08. Plants of . ie at that locality had thick leaves, while those of P. americana nearby were thin, are ciate diff But indicating plasticity, two young plants of P. rigida (seeds from my no. 107) have nee only barely Sisal id ae thicker than two plants of P. americana (seeds obtained inland in Massachusetts) of the same age i 14 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Selected additional differences are that Phytolacca rigida tends to have nar- rower leaves with more gradually tapered bases (which held up on the potted plants), shorter inflorescences bearing fewer flowers, broader bracteoles, shorter pedicels (often shorter than the fruits), and peduncles with vascular cylinders of smaller diameter but with thicker xylem (broader sampling needed). Hardin compared P. americana and P. rigida in detail, and my comparison leads me to agree that differences between the two taxa are blurred by overlap. Perhaps P. rigida would be best recognized at the varietal level. The combination remains to be made. Phytolaccas are usually large herbs (or even trees) often having reddish axes, pseudodichotomous branching, diaphragmed pith, and conspicuous raphide bundles. The inflorescences are usually pedunculate, cylindrical, racemose (al- though often with lateral dichasia toward the base), fundamentally terminal, and displaced laterally by axillary growth. (Inflorescences in Frcilla usually are nearly sessile, more or less spicate, and axillary, with those of Anisomeria condensed and more obviously terminal.) Species of Phytolacca usually have five small, nonshowy, thin, and nearly equal tepals (vs. tepals fleshy and unequal in Anisomeria). Five to more than 15 carpels range from near apocarpy to pronounced syncarpy. In most species these mature into a reddish to black berry containing numerous flat, blackish seeds. (The 5(-8) or fewer carpels of Anisomeria and Frcilla usually remain separate.) Nowicke (1968) noted that interspecific hybridization, infraspecific variation, and apparent weak genetic control of many qualitative characters have obscured boundaries between species. A familiar weed, Phytolacca americana is a tolerant pioneer in disturbed sites but a poor competitor when young. Evidently limited to the north mainly by summer temperatures and to the west by dry conditions, the perimeter of the range of this species has possibly changed little in response to human activity. Nevertheless, it has certainly escaped from scattered habitats, probably mostly along streams, where the taproot has been observed to withstand flood- ing, to places disturbed by humans. Fassett & Sauer concluded that ecological disruption in Colombia broke down barriers between P. rugosa A. Br. & Bouché and P. rivinoides Kunth & Bouché. (This paragraph based largely on Sauer, 1952.) The ability of pokeweeds to become established quickly far from parental plants upon disturbance of soil and vegetation draws attention to their seeds. These remain viable in fecal deposits from birds, which undoubtedly are the primary agents of dispersal (Edmisten, Armesto e7 al.). Shown to withstand burial for almost 40 years (Toole & Brown), the seeds germinate in response to a complex set of factors or to artificial scarification. Farmer & Hall found the same pot indoors in Cambri ridge, Massachusetts. (It must be stressed that my observations on potted specimens are preliminary, based on a small number of specimens only a few inches tall.) Detracting further from 7 significance of succulent leaves, | have seen seaside plants of P. americana with thickened leaves in Hudson County, New Jersey, and Plymouth County, Massachusetts (G. Rogers 109 and 110). Plants with thickened leaves tapering at the base and with horizontal to erect inflorescences occur on Nantucket Island, Massachusetts (C. E. Wood, obs. July, 1984). 1985] ROGERS, PHYTOLACCACEAE Ie: the inability of fairly fresh seeds to sprout in the dark to be largely overcome by stratification, although a functional dimorphism appeared since some seeds required light even after stratification. Seeds from one or from different indi- viduals responded variably to a given combination of conditions (Farmer & Hall, Armesto et a/.). Thus, longevity, efficient translocation, and nonuniform requirements for germination allow pokeweed seeds to be delivered to and/or to await Se ensuring continued production of seedlings despite en- vironmental vagari Armesto and ee aise ntenpreted the ample fruit set of Phytolacca amer- icanaas a sign of autogamy; the same observation plus release of pollen followed by foley breakdown of stigmas before anthesis led Meehan to the same con- clusi othe shoots or leaves from Phytolacca “esculenta” (P. acinosa), P. amer- icana, and other phytolaccas can serve as food after being boiled once or twice to deactivate toxins. American Indians ate P. americana, and it remains a favorite wild delicacy commonly served as poke salad or “‘sallet.” It has even been marketed canned. However, pokeweed believed to have been properly prepared sickened a group of campers, according to a report cited by Edwards & Rodgers, and contemplation of the potency of pokeweed mitogens (discussed below) may dishearten would-be enthusiasts. Despite their toxicity, pokeberries have filled pies and have colored confections and wines (Braun; Shultz; Sauer, 1950). Renewed interest in derivation of food coloring from Phytolacca hinges on removal of offensive substances (e.g., see Driver & Francis, Forni ef a/.). The berries have also been employed as sources of ink, as rather poor dyes for fabrics, and (at least in certain extralimital species) as a substitute for soap. Phytolacca americana and other species have served in the Old World as ornamentals. The principal shade tree of the Pe asng: pampas, P. dioica (ombu or bella sombra), is planted in warm, dry region A formidable brew of bioactive compounds in all ae of the plants clearly lies behind most remaining roles of PAytolacca in human affairs, including its use as a narcotic and as a medicine in both hemispheres. (For amplification of the rich medicinal history of P. americana, see Byrd; Shultz; Sauer, 1950; and Steinmetz.) Even though remedies incorporating phytolaccas are obsolete, their bioactivity remains of interest as outlined in the paragraphs that follow. Phytolacca americana is a common and conspicuous toxic hazard. From the use of the root as a medicine and from its being mistaken at times for horse- radish or parsnip, the drastic and sometimes fatal consequences of eating it are well known (Ahmed et a/., Anonymous; Guthrie; Jenkins; Macht; Sauer, 1950; Shultz). The threat extends to farm animals, especially pigs, which oc- casionally dig out lethal quantities (Barnett, Hansen, Patterson). The colorful berries are dangerous, too, although they affect various people differently. In gathering data on ca. 100 ingestions of pokeberries, O’Leary uncovered only two mentions of human fatalities. One was a two-year-old child in Rhode Island (whose case Kingsbury discussed in 1980). The other is Chesnut’s old report that fruits or seeds are held to blame for deaths of a “few” children. As related in a second-hand report in Wood & Bache, a double handful killed a woman following purgation, prostration, and coma. Hansen recorded with no 16 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 elaboration another fatality from the berries; and Hardin & Arena documented the death of a five-year-old girl who drank a beverage made from the berries. On the other hand, Hardin & Arena asserted that a small number of berries is generally harmless to adults and older children. Shultz likewise noted that some people eat pokeberries with no harm, but cautioned that this is not usually the case and mentioned gastrointestinal distress suffered by others after dining on birds fed pokeberries. Individuals from a group of Boy Scouts in Kentucky variously had diarrhea, cramps (possibly due to a different cause), or no symp- toms after a meal of pokeberry pancakes and some raw berries (Edwards & Rodgers). In addition to gastric irritation, symptoms of poisoning by phytolacca berries in humans include hematological alterations and probably depression of the central nervous system with inhibition of the heart and respiration, mental aberrations, and convulsions. The three last symptoms have been induced in various experimental animals by the berries and are brought about in humans by poke root. Handling plants of Phytolacca americana and other species May cause dermatitis (Sauer, 1950). Relating the toxicity of phytolaccas to their chemistry demands continued research on the classes of bioactive compounds discussed individually below; the high concentrations of oxalic acid and con- tradictory reports concerning alkaloids (cf: Ahmed er a/., Goldstein et al., Jack ogers, Jenkins, Lascombes & Bastide, Steinmetz, Wall et al., L. Webb) should not be overlooked. A rich array of triterpenoid saponins and their free nonsugar (aglycone) components occurs in roots, fruits, and other parts of species of Phytolacca. In several papers, Woo, Kang, and Sacre reported ten “phytolacco- sides,” along with the structures of some, in P. americana and other species. Similarly, Suga and colleagues detected ee in some cases determined structures for over eight saponins in roots of P. americana and concluded that the “phy- tolaccatoxin” of earlier literature was a mixture of more than three saponins. The principal aglycone in P. americana is evidently the triterpenoid phytolac- cagenin; others sane phytolaccagenic, jaligonic, and esculentic acids. Sa- ponins from berries of P. dodecandra have aroused interest as biodegradable, ostensibly su ate. locally producible molluscicides for controlling schisto- somiasis (Lemma, Parkhurst). A set of ae chain and polymeric proteins associated with carbohydrates, designated mitogens’ due to their ability to stimulate mitotic proliferation following morphological alteration of lymphocytes, has also received muc attention in literature concerning the chemistry of Phyto/acca. Certain mitogens ’Mitogens from phytolaccas belong to the class of proteins and glycoproteins known as lectins, B-lymphocytes. That is, an antigen induces lymphocytes to enlarge into blast cells and aeeeL T-lymphocytes do so directly in response to the antigen, whereas elicciye contac! ili By phosyies and hia is usually: nee ku T-lymphocytes. Stimulated B te imulation by mitogenic lectins ifr om that st ee in that mitogens indiscriminately activate aoe numbers of lymphocyte 1985] ROGERS, PHYTOLACCACEAE Le from Phytolacca stand out among plant mitogens due to their high potency and/or ability to act upon B-lymphocytes as well as T-lymphocytes. Waxdal (1974) characterized a set of mitogens from P. americana as Pa-1 to Pa-5, among which Pa-2 probably corresponds to, or is the chief component of, the original commercially available “pokeweed mitogen” or ““PWM.” The dangers of pokeweed mitogens to humans are unclear. Accidental exposure to juices from P. americana via ingestion, breaks in the skin, and the conjunctiva has brought about hematological changes in numerous people, including research- ers studying this species (Barker et al., 1965, 1966, 1967a, 1967b). (A brief review of research on pokeweed mitogens appears in Waxdal, 1978.) Like many other plants, species of Phytolacca contain antiviral proteins. Having been detected early in the course of research on viral inhibitors in plants, and being unusually potent, pokeweed antiviral peptide (PAP) has re- ceived special attention. PAP blocks the reproductive cycle of exceedingly diverse viruses in equally diverse hosts, at least in part by interfering with protein synthesis on the hosts’ ribosomes. Coupled with an antibody, PAP may serve as a selective antitumor agent (Masuho et a/.). (For a sampling of the extensive literature concerned with PAP, see Grasso & Shepherd, Irvin, Owens et al., Tomlinson et a/., and Ussery et a/.). A second antiviral protein from P. americana recently characterized by Irvin et al. is called PAP II. REFERENCES: Under family references see BAILLON, BARTH & BARBOSA, BORTENSCHLAGER, BUXBAUM, GARCIA-BARRIGA, HAUMAN-MERCK, KAJALE, LAMPE & FAGERSTROM, Lewis & E_vin-Lewis, MARTIN, MOgQuin- ale Morton, Nowicke (1968), Nowicke & SKVARLA, POLHILL, RICKETT, ROHWEDER, SCHAEPPI, SCHERMERHORN & QuIMBY, SCHMIDT, THIERET, WALTER (1909), WEsB, ae and ZANDONELLA. AHMED, Z. F., C. J. ZUFALL, & G. L. JENKINS. A een to the chemistry and toxicology of the root of Phytolacca americana, L. Jour. Am. Pharm. Assoc. Sci. Ed. 38: 443-448. 1949. [Found no alkaloids and determined toxic principle to be a saponin; tested toxicity on animals and plants. ANoNyMous. Pokeroot poisoning. New York Med. Jour. 72: 653, 654. 1900. [Para- phrased ee of one survivor’s (C. French) experiences after eating a small quan- tity of the ARMESTO, J. 1 GP. CHEPLICK, & M. J. MCDONNELL. 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[Demonstration that pokeberries are not absolutely harmless to birds as has been believed: see also R. CATTLEY & B. BARNETT, ibid. 56: 246-248. 1977.] Bopcer, M. P., A. R. McGiven, & P. H. FirzGerAtp. Mitogenic proteins of pokeweed I. The differentiation of human peripheral blood B lymphocytes stimulated with purified pokeweed mitogens (Po-2 and Po-3) from pokeweed, Phytolacca octandra. Immunology 37: 793-799. 1979. [Includes literature review; see also 785-792 Boutin, F. C. Pokeweed. Calif. Hort. Jour. 36: 103. 1975. Braun, A. Ueber Phytolacca esculenta, eine neue Gemiisepflanze. Verh. Ver. Beford. Gartenb. Preuss. 21: 87-93. 1852 [1853]. [Includes comments on other species and the genus as a whole; discusses relationship between PAytolacca and the former genus Pircunia; synopsis of 17 species in sects. Pircunia and Phytolacca.] Burke, D. E., & P. W. Le Quesne. 3-acetyloleanolic acid from Phytolacca americana seeds. Phytochemistry 10: 3319, 3320. 1971. [Woo (1978, 146-150) explained that this is acetyl aleuritolic acid misidentified. ] Burnett, W. C., Jr., & S. B. Jones. Differential feeding of the southern armyworm on Kentucky and Florida populations of pokeweed. Am. Midl. Nat. 90: 231-234. 1973. [Larvae favored plants from Florida (where the worms are native) over plants from Kentucky. Byrp, J. W. Poke sallet from Tennessee to Texas. Tenn. Folklore Soc. Bull. 32: 48-54. 1966 CAMACHO GRANADOS, L. Estructura del tallo y ontogenia de los diafragmas caulinos en Phytolacca icosandra L. (English abstract.) Revista Biol. Trop. 27: 119-133. 1979. [Descriptions of formation of diaphragms in connection with initiation of secondary growth (cf. MIKESELL & SCHROEDER) and their ultimate disintegration; discussion of adaptive significance of diaphragms. CuesnutT, V. K. Thirty poisonous plants at United States. U. S. Dep. Agr. Farmers’ Bull. 86: 1-32. 1898. fea 9, CuHessIN, L. N., J. BOrseson, P. D. WELSH, S. D. Douac.as, & H. L. Cooper. Studies on human peripheral blood lymphocytes in vitro. I]. Morphological and biochemical studies on the Per ais of lymphocytes by pokeweed mitogen. Jour. Exper. Med. 124: 873-884. p/. 87. 1966. DatLaL, J., & J. D. Irvin. aan inactivation of a ribosomes by the pokeweed antiviral protein. FEBS Lett. 89: 257-259. Douc tas, S. D., & H. H. FupenBerG. Jn vitro developmen ot plasma ells from lymphocytes following Pe mitogen sti Exper Cell Res. 54: 277-27 . F. Horrman, J. eee & L. N. Cuessin. Studies on human peripheral blood lymphocytes im vitro: I]. Fine structural sea of lymphocyte transfor- mation by pokeweed mitogen. Jour. Immunol. 98: 1967. Driver, M. G., & F. J. FRANcis. Purification of renee (betanin) by removal of phytolaccatoxin from eee americana. Jour. Food Sci. 44: 521-523. 1979. [Procedure for removal of saponins. EpmisTen, J. Studi ae ee i icosandra. Pp. D183-D188 in H. T. Odum, ed., A tropical rain forest. A study of irradiation and ecology at El Verde, Puerto Rico. 1970. [Concerned chiefly with factors affecting germination; compared growth of P. icosandra, P. americana, and P. rigida under different light conditions; tested seeds of P. americana for effects of irradiation and scarification. aan N., & G. C. RopGers. Pokeberry pancake breakfast—or—it’s gonna be a eat day! Veterin. Hum. Toxicol. 24(Suppl.): 135-137. 1982. EMBODEN, W. Narcotic plants. Revised and enlarged. xvii + 206 pp. 54 p/s. New York 1979. [P. ene 21, 22, pl. 10, used as a narcotic by Indians of the American ls, FARMER, R. E., hice & G.C. HALL. Pokeweed seed germination: effects of environment, stratification, and chemical growth regulators. Ecology 51: 894-898. 1970. [Includes 1985] ROGERS, PHYTOLACCACEAE I literature review; effects of genotype, oe ai light, stratification time, and tem- perature, an ae of fact FARNES, P., . BAR les JE eee & H. FANGer. Mitogenic activity in Se eee americana eae Lancet 1964(2): 1100, 1101. 1964. Fassett, N. C., & . SAUER. Studies of variation in the weed genus Phytolacca. I. Hybridizing species in northeastern Colombia. Ecslikees 4: 332-339, 1950. Fornl, E., A. TriFILO, & A, PoLesELLO. Researches on the utilisation of the pigment from Phytolac cca decandra L. as a food colorant: part 1—preparation of an extract free from toxic substances. Food Chem. 10: 35-46. 1983. [‘‘Phytolaccanin” identical to betanin of beets.] FRIEDMAN, R. M., & H. L. Coorer. Stimulation of interferon production in human lymphocytes by mitogens. Soc. Exper. Biol. Med. Proc. 125: 901-905. 1967. [PWM and other mitogens induce production of interferon or similar antiviral substance. ] FUNAYAMA, S., & H. Hikino. Hypotensive principles of peers roots. Lloydia 42: 672-674. 1979 [1980]. [Hypotensive compounds gamma-aminobutyric acid (GABA) and histamine in roots of P. americana, P. “esculenta” “P. acinosa, no histamine detected), and P. japonica.] GOLDSTEIN, S. W., G. L. JENKins, & M. R. THompson. A chemical and pharmacological study of Phytolacca americana, N. F. Jour. Am. Pharm. Assoc. 26: 306-312. 1937. [Includes chemical tests (no alkaloids pein and pharmacological tests on cats.] Grasso, S., & R. J. SHEPHERD. Isolation and partial characterization of virus inhibitors from plant species taxonomically related to Phytolacca. Phytopathology 68: 199- Centrospermae yielding positive serological reaction with inhibitors from P. amer- icana,; inhibitors from Centrospermae particularly potent.] GUTHRIE, A. oe by poke root. Jour. Am. Med. Assoc. c 125. 1887. [Man chewed piece of root.] Hansen, A. ae plants injurious to livestock. Purdue Agr. Exper. Sta. Circ. 175: |- 38. 1930. [Phytolacca, 20; all parts poisonous to cattle, hogs, horses, humans, and sheep. ] Harbin, J. W. A comparison of Phytolacca americana and P. rigida. Castanea 29: 155—- 164. 1964. [Includes photos of racemes, distribution map for P. rigida, anatomical drawings, tabulation of differences, three hypotheses concerning relationship of P. rigida and P. americana.] & J. M. ARENA. Human poisoning from native and cultivated plants. ed. xii + 194 pp. Durham, North Carolina. 1974. [Phytolacca, 66, 69-73, 157.] Harper, R. M. Preliminary report on the weeds of Alabama. Geol. Surv. Alabama Bull. 53: 1-275. 1944. [P. americana, P. rigida (inland to ities ery), 99. Henprickson, J. M., & K. F. Hitsert. Pokeweed berries not an for chickens. Jour. Am. Veterin. Med. Assoc. 78: 556-558. 1931. [Cf BARNET ene J. T. A Mexican pokeberry in San Francisco, California. Leafl West. Bot. 9: 81-83. 1960. Irvin, J. D. Purification and partial characterization of the antiviral protein from Phy- tolacca americana which inhibits eukaryotic protein synthesis. Arch. Biochem. Bio- phys. 169: 522-528. 1975 , T. Ketty, & J. D. Rospertrus. Purification and properties of a second antiviral protein from Phytolacca americana which inactivates eukaryotic ribosomes. Arch. Biochem. Biophys. 200: 418-425. 1980. [PAP II from summer leaves, PAP from spring leaves.] Iron, T., T. Uetsuki, T. TAMURA, & T. Matsumoto. Characterization of triterpene 20 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 alcohols of seed oils from some species of Theaceae, Phytolaccaceae and Sapotaceae. Lipids 15: 407-411. 1980. [15 triterpene alcohols from seeds of P. americana.] Jack, L. D., & C. H. RoGers. A phytochemical and eee noe study of the berries AES americana Linné (Fam. Phytolaccaceae). Jour. Am. Pharm. Assoc. . Ed. 31: 81-84. 1942. [Preliminary investigation of canes (no alkaloids ee extracts from berries produces depression of heart and respiration in Jenkins, G. L. A preliminary report on the chemistry of Phytolacca. Jour. Am. Pharm. Assoc. 18: 573-576. 1929. [Outlines isolation of “‘alkaloid-like substance,” but see later negative results for alkaloids in GOLDSTEIN, JENKINS, & THOMPSON (and see comments in text).] oS A. Structure elucidation and molluscicide evaluation of the major saponin the berries of Phytolacca americana. Diss. Abstr. 35: 731-B. 1974. [Major oe from extract a two new triterpene aglycones identified; some glycosides molluscicidal. ] . SHimizu. Phytolaccinic acid, a new triterpene from Phytolacca americana. Tetrahedron 30: 2033-2036. 1974. [From berries, these also with phytolaccagenin and trace of oleanolic acid; also see KANG & Woo.] KasALe, L. B. A contribution to the embryology of the Phytolaccaceae I. Studies in the genus Phytolacca. Jour. Patna Univ. 1: 9-21. 1944. [P. dioica, P. acinosa, micro- and megasporogenesis, megagametophyte. ] Kana, S. S., & W. S. Woo. Triterpenes from the berries of Phytolacca americana. Lloydia 43: 510-513. 1980. [Pokeberrygenin characterized, berries also with aci- nosolic, esculentic, jaligonic, and oo acids, and phytolaccagenin; struc- tures given; also see JOHNSON & SHIMIZU.] Kincspury, J. M. One man’s poison. Blowers 30: 171-175. 1980. [Includes general discussion of pokeweed toxicity. ] & R. B. Hitman. Pokeweed (Phytolacca) poisoning in a dairy herd. Cornell Veterin. 55: 534-538. 1965. [No fatalities. ] Kraemer, H. The pith cells of Phytolacca decandra. Torreya 2: 141-143. 1902 Lascomses, S., & A. BAstipe. Recherche d’alcaloides dans Phytolacca decandra L. (Phytolacca americana ol (English summary.) Pl. Méd. Phytothér. 10: 182-187. 1976. [Their summary: “The authors were not able to identify alkaloids with cer- tainty. However, their Gadings confirm that numerous osidic compounds are ex- tracted when the tartric acetone procedure is effected. These compounds show the characteristic reactions of alkaloids.”’ Includes 19th-century references to alkaloids in Phytolacca.] Lemma, A. Will pokeweed extract control the number ic di ? Naval Res. Rev. 26(6): 1-10. 1973. [Includes field test on Sa from P. dodecandra, endod, applied as molluscicide in Ethiopia. ,D. EMAN, & H. Kioos, eds. Studies on the molluscicidal and other prop- erties of the endod plant, Phytolacca dodecandra. University of California, San Francisco. 1979.* Lewis, I. F. Notes on the development of Phytolacca decandra L. sete Hopkins Univ. Circ. 178: 34-42. 1905. [Describes microsporogenesis, young ovule, and embryo sac (8-nucleate, development not traced), formation of Epes embryogenesis, perisperm, and germination. Lioyp, F. E. Responses of Phytolacca decandra to various environmental conditions. Carnegie Inst. Yearb. 13: 71-73. 1914. [P. americana grown at Tucson and in Santa Catalina Mts., Arizona, and at Carmel, California.] . Critical flowering and fruiting temperatures ce Phytolacca decandra. P|. World 20: 121-126. Macnt, D. I. A pharmacological study of Phytolacca. Jour. Am. Pharm. Assoc. 26: 594-599. 1937. [Poke root and pokeberries obsolete and dangerous as medicines.] Masuno, Y., K. Kisuipa, & T. HARA. Targeting of the antiviral protein from a americana with an antibody Biochem. Biophys. Res. Commun. 105: 462-469. 1982. o 1985] ROGERS, PHYTOLACCACEAE 21 Mattick, F. Die Wurzelscheibe von Phytolacca dioica und andere Beispiele von Schei- benwurzeln. (English summary.) Bot. Jahrb. 86: 38-49. pis. 7, 2. 1967. [Includes general information on this species; large discoid base on trunk formed by coales- cence of roots.] McDonne t_, M., E. Stites, G. CHEPLICK, & J. ARMESTO. Bird-dispersal of Phytolacca americana L. and the influence of fruit removal on subsequent fruit development. Am. Jour. Bot. 71: 895-901. 1984. Vee A. Pokeweed and other lymphocyte mitogens. Pp. 83-102 in A. D. KING- nN, ed., Toxic plants. New York. 1979. ie ae Contributions to the life-histories of plants. No. . Proc. Acad. Nat. Sci. Phil. 1890: 266-277. 1890. [P. ‘‘decandra,” autogamy in MIKESELL, J. E. Anomalous secondary thickening in Phyielaces americana L. (Phyto- laccaceae). Am. Jour. Bot. 66: 997-1005. 1979. [Several rings of xylem in taproot and hypocotyl, one in stem.] & SCHROEDER. Development of chambered pith in stems of Phytolacca americana L. (Phytolaccaceae). Am. Jour. Bot. 67: 111-118. 1980. [Lysigenous and schizogenous activities form cavities: cf’ CAMACHO GRANADOS.] Munz, P. A., & D. D. Keck. A California flora. Frontisp. + [11] + 1681 pp. Berkeley and Los Angeles. 1959. [P. americana, 388.] NouGarebE, A., & P. Ronper. Aspects of growth in branches of Phytolacca decandra L. Abstr. Int. Bot. Congr. 11: 161. 1969. Modalites de croissance des plants du Phytolacca decandra ie en geons souterrains. Compt. Rend. Acad. Sci. Paris, D. 277: 2481 -2484. pis. | 2: 1973. Ocinuma~, K., R. TANAKA, & K. Suzuki. Karyomorphological studies on three species of Phytolacca of Japan. Chromosome Inf. Serv. 29: 6-8. 1980. [P. japonica (indig- poe 2n = 72; P. “esculenta” (naturalized), 2n = 72; P. americana (naturalized), = 36 (and mentions isolated report of n = 9 by Hsu, Taiwania 13: 125. 1967); in "all three species chromosomes intergrade smoothly in length and have median or submedian centromeres; includes photographs of chromosomes from each species. ] OGzEWALLA, C. D., H. E. Mosspera, J. Beck, & O. FARRINGTON. Studies on the toxicity of poke berries. Proc. Okla. Acad. Sci. 43: 54-57. 1963. [Pulp and seeds mildly toxic to mice O'Leary, S. B. Poisoning in man from eating poisonous plants. Arch. Environ. Health 9: te 242. 1964. [P. americana, 230, 231, 236, 239, 240. Owens, R., G. BRUENING, & R. SHEPHERD. A possible mechanism for the inhibition of plant viruses by a peptide from Phytolacca americana. Virology 56: 390-393. 1973. PALMA, S. Consideraciones fitogeograficas y sistematicas de las especies Chilenas de la tribu Phytolacceae. Bol. Soc. Biol. Concepcién 50: 53-71. 1976. [Includes world- wide distribution map for Phytolacca ParKHuRsT, R. M. The chemotaxonomy of Phytolacca species. Indian Jour. Chem. 13: 757, 758. 1975. [Outdated review of literature on saponins in species of Phytolacca, structures for several saponins provided, concerned especially with P. dodecandra, but with data on P. americana and other species. PATTERSON, F. D. Pokeweed causes heavy losses in swine herd. Veterin. Med. 24: 114. 1929, [Accidental and experimental poisonings.] ReIsFELD, R. A., J. BORJESON, L. N. CHessin, & P. A. SMALL, JR. sae and char- acterization of a mitogen from pokeweed (Phytolacca americana). Proc. Natl. Acad. i. U.S.A. 58: 2020-2027. 1967. [According to WAXDAL (1978), this. is Pa-2.] See W.G. The Peruvian yumbi. Calif. Hort. Jour. 36: 104, 105. 1975. [P. We- be oe seems to hybridize with P. dioica, cultivated in Lima.] Rocers, H. J. Variations in the racemes of PAytolacca americana L. (Abstract.) ASB Bull. 22: 77. 1975. [Root (undoubtedly of P. rigida, although this name not m 22 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 tioned) transplanted inland from Roanoke Island to pee, North Carolina, ‘continues to produce stubby erect racemes” after ca. five ye as W. The Argentine umbu. Calif. Hort. Jour. 36: 106, 107, 1975. [Phytolacca “the only tree native to the Argentine pampas’’; mentions anemophily (but oe ae MERCk).] SAUER, J. D. Pokeweed, an old American herb. Missouri Bot. Gard. Bull. 38: 82-88. 950. [Major reference for P. americana in human affairs. . Studies of variation in the weed genus Phyrolacca. U1. Latitudinally adapted seats Sips a North American species. Evolution 5: 273-279. 1951. [Trans- plantation of P. americana from Texas and Wisconsin to Missouri revealed genet- ically pee differences. ] A geography of pokeweed. Ann. Missouri Bot. Gard. 39: 113-125. 1952. [In- cludes distribution map, list of places where pokeweed is naturalized, with discussion of uses that have led to relocation; population at one locality described and revisited er three years.] SHEPHERD, R. J., J. P. Futton, & R. J. WAKEMAN. Properties ofa virus causing pokeweed mosaic. reece 59: 219-222. 1969. SHuLtz, B. An inaugural botanico-medical dissertation, on the Phytolacca decandra of Linnaeus. Frontisp. + [v] + 55 pp. Philadelphia. 1795. [Includes old common names, early investigation of chemistry, berries as a source of dye, biological effects, and medicinal use STEINBAUER, G. P., & B. GricsBy. an of Thermepenod, light, and substrate in the germination of seeds of pokeweed, Phy unericana L. Pl. Physiol. 31(Suppl.): 36, 37. 1956. STEINMETZ, a F. Phytolacca americana. Acta Phytotherap. 7: 181-187. 1960. [Medicinal and additional uses for P. americana and other species, common names; mentions alkaloid ““ombuine.”’] STOCKBARGER, C, Testa of the seeds of Phytolacca. Bot. Gaz. 11: 274, 275. pl. 8 (part). 1886. Stout, G. H., B. M. MaLorsxy, & V. F. Strout. Phytolaccagenin: a light atom x- i structure ne using chemical ae aaron. Jour. Am. Chem. Soc. 86: 957, 958. ae [See also SuGA et al. SUGA . Y. MARUYAMA, 8S. KAWANISHI, & J. SHON. Studies on the constituents of ae nee plants. I. On the structures of phytolaccasaponin B, E and G from the roots of Phytolacca americana L. Chem. Pharm. Bull. 26: 520-525. 1978. [Over eight phytolaccasaponins detected; includes brief review of literature on this subject for P. americana, structures of some saponins illustrated. ] TOMLINSON, J.. V. M. WALKER, T. H. Flewerr, & G. R. BARCLAY. The inhibition of infection by cucumber mosaic virus and influenza virus by extracts from Phytolacca americana. Jour. Gen. Virol. 22: 225-232. 1974. Tooce, E. H., & E. BRown. Final results of the Duvel buried seed experiment. Jour Agr. Res. 72: 201-210. 1946. [P. americana, 205, 208, 209, 81-90% Seroiidiion after almost 40 years. ] Ussery, M. A., J. D. IRvin, & B. Harpesty. Inhibition of poliovirus replication by a plant antiviral peptide. Ann. N. Y. Acad. Sci. 284: 431-440. 1977. [PAP from P. ] WAKABAYASHI, S., T. Hase, K. Wapa, H. MArsuBaArRaA, & K. Suzuki. Amino acid sequences of two ferredoxins Gam: Piniélae ca esculenta. Gene duplication and spe- ciation. Jour. Biochem. Tokyo 87: 227-236. 1980. [The unusual trait of having two ferredoxins (vs. one) in one individual is true of P. americana and P. “esculenta” (acinosa). (Phytolacca japonica, with three ferredoxins, remains inadequately stud- ied.) The two ferredoxins appear to be coded by different loci, which the authors believe to have become separate after Phytolacca diverged as a genus but before divergence of P. americana and P. oo. Watt, M. E., C. S. Fenske, J. W. Gat JJ. J. WILLAMAN, Q. Jones, B. G. SCHUBERT, 1985] ROGERS, PHYTOLACCACEAE 2 & H.S. Gentry. Steroidal sapogenins LV. Survey of plants for steroidal sapogenins and other constituents. Jour. Am. Pharm. Assoc. Sci. Ed. 48: 695-722. 1959. [P. americana negative for alkaloids, 715.] WaxDAL, M. Isolation, ae ore and biological activities of five mitogens from pokeweed. Biochemistry 13: 3671-3677. 1974. . Pokeweed mitogens. /n: V. ane iRG, ed., Methods in enzymology 50: 354- Wess, D. A. Phytolacca L. In: T. G. Tutin, V. H. Heywoon, et al., eds., Fl. Europaea 1: 112. 1964. LP. americana in southern and central Europe, P. ‘ esculenta” (acinosa) possibly more or less naturalized in Romania; P. dioica locally naturalized in Med- iterranean region. ] Weser, W. T. Direct evidence the response of B and T cells to pokeweed mitogen. Cell. ue 9: 482-487. 1973. Wueat, D. Successive cambia in the stem of Phytolacca dioica. Am. Jour. Bot. 64: 1209- 1217. 1977. [Includes a on P. Weberbaueri and P. Meziana.] Waite, J. W. The mysterious ombi. Nature Mag. 41: 412-414. 1948. [P. dioica.] Woo, W. S. Steroids and eaten triterpenoids from Phytolacca americana. Phy- tochemistry 13: 2887-2889. 4. The chemistry and ee ae of terpenoids of eee plants. Annual Rep. Nat. Prod. Res. Inst. 17: 113-159. 1978. [An important monograph including summary of medicinal and other uses, chemistry Sasa structures for aglycones of ten phytolaccosides and chemistry of seeds and fruits), and | tests. ] S: New phenolic aldehyde from the ee of Ph ytolacca americana (Abstract.) Korean Jour. Pharm. 10: 192, 193. 1979. [Original in ibid. 1 1979.* Seeds with 3-acetylaleuritolic acid, americanin A, and (new) caffeic eee , O. SELIGMANN, V. M. CHari, & H. WAGNER. The structure of new lignans from the seeds of Phytolacca americana. Tetrahedron Lett. 21: 4255-4258. 1980. [Structures for americanins A, ] . WAGNER, O. SELiGMaNN, & V. M. CHari. Triterpenoid saponins from the roots of Phytolacca americana. Planta Med. 34: 87-92. 1978. Woop, G. B., & F. BACHE. The dispensatory of the United States of America. ed. 18. Revised by H. C. Woop et al. xlv + 1998 pp. Philadelphia. 1899. eeiolaece 1030, 031 ] Woopcock, E. F. Observations on the morphology of the seed in Phytolacca. Pap. Mich. Acad. Sci. Arts Lett. I. 4: 413-418. pls. 20, 21. 1925. [P. americana, includes anatomical drawings and cs aa of young embryo, perisperm, testa, starch, and eae of endosperm.] Wyatt, 8. D., & R. J. naa Isolation and characterization of a virus inhibitor from nee americana. Phytopathology 59: 1787-1794. 1969. YOKOYAMA, K., T. TERAO, & T. OSAWA. en ay eas specificity of pokeweed mitogens. Biochim. Hone Acta 538: 384-396. Subfamily RIVINOIDEAE Nowicke Tribe RIVINEAE Endl. 2. Trichostigma A. Richard in Sagra, Hist. Fis. Cuba 10: 306. 1845.8 Climbing, shrubby, or somewhat arborescent woody plants, without succes- sive cambia (Trichostigma octandrum, stems to 15 cm thick in this species). Plants glabrous or puberulent to hirsute-pilose on young stems, leaves, petioles, This work was issued in French (7richostigma, p. 627, 1851?) and evidently a second time in Spanish (Trichostigma, 2: 306. 1853!). 24 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 and inflorescence axes. Calcium oxalate present primarily as styloid crystals. Leaves petiolate, the blades sometimes crisped-crenulate, ovate or lanceolate to elliptic, usually pointed and sometimes apiculate apically, mostly cuneate to rounded [or cordate] basally. Racemes borne at ends of minor (or sometimes major) leafy branches or axillary [sometimes displaced by sympodial growth to a pseudolateral position in 7. peruvianum], sometimes clustered, axes be- coming reddish, the slender central rachises bearing many shorter pedicels, each subtended by and usually adnate to one subulate, deciduous or persistent bract and bearing a pair of minute bracteoles. Flowers perfect, fragrant, with 4 subequal, concave, whitish to yellowish or greenish (becoming reddish with age) [sometimes reported as brownish or externally brownish in 7. peruvia- num], separate, oblong-elliptic or tapered tepals, these reflexed or spreading in fruit. Stamens 8-13 (rarely more) [—-many]; filaments + filiform; anthers linear, cleft at the bases. Pollen grains subprolate to spheroidal, mostly 3-colpate [or 1 1- to 15-colpate], the tectum spinulose. Gynoecium unicarpellate and uni- locular; ovary subglobose to elliptic or flask shaped, compressed; style absent or very short, stigma penicillate. Fruit fleshy, nearly globose, black or reddish. Seed lenticular, often plump, dark, glossy and bare or with adherent pericarp tissue. lar sili Ruiz & Pavon,’ Villamilla Auct.) Type species: T. rivinoides A. ard, nom. illegit. (= 7. octandrum (L.) H. Walter, Rivina octandra L.). (Name from Greek ¢trichos, hair, and stigma, in reference to the brushlike stigma.) A small genus of three species distributed throughout most of tropical Amer- ica. Trichostigma polyandrum (Loes.) H. Walter (Rivina polyandra Loes.) is found in rain forests from southern Nicaragua to western Panama (for a recent treatment see Burger). Limited to Peru and Ecuador, 7. peruvianum (Moq.) H. Walter likewise inhabits shady forests, possibly favoring rocky sites. 7ri- chostigma octandrum ranges from Argentina northward across South and Cen- tral America and the West Indies to a spare representation in Florida only as far north as Collier County (Big Cypress National Preserve, Chokoloskee Island) and Dade County. Trichostigma octandrum is variously described as a vine, a shrub, or rarely a tree. Numbers of stamens, shapes of tepals, and lengths of racemes fluctuate. Individuals of this species are fone markedly pubescent, a condition that prompted Kitanov to propose “7. octandrum forma hirsutum” from Cu where this tendency is pronounced. 7richostigma octandrum and T. peniion: um differ from 7. polyandrum in having 12 or fewer stamens (vs. over 20) with filaments usually longer than 1.2 mm and (in 7. octandrum) persistent in *Villamillia tinctoria Ruiz & Pavon, Fl. Peru. Chil. 4: p/. 402! (= Trichostigma peruvianum) entered the botanical literature among a set of plates distributed sometime before 1830 and thus prior to Richard’s publication in 1845 of Trichostigma and its generally acknowledged type species. According to the 1983 International Code of Botanical Nomenclature, Art. 42, the names of a genus and a species “may be” simultaneously validated, and a plate published before 1908 with analysis “‘is acceptable” for that purpose (the plate in question contains analysis as explicitly defined therein). I h ted Villamillia tinctoria as validly published, which appears to be an option implied in the Sear 7 the article. 1985] ROGERS, PHYTOLACCACEAE 2 fruit (vs. under | mm and not persistent). Racemes in 7. octandrum only rarely attain 15(—20) cm in length—those of 7. peruvianum usually exceed 20 cm, and lengths in 7. polyandrum are intermediate. Large leaves cordate at base distinguish 7. peruvianum from its congeners. Trichostigma is most similar to Rivina, in which earlier botanists included all three species, a placement that Burger thought perhaps to be best, although he did not formally merge the genera. A number of characters distinguish the two. Trichostigmas tend to be shrubs or robust climbers to several meters tall with ovate or lanceolate to elliptic leaf blades, as opposed to the herbaceous or suffrutescent, sometimes vinelike Rivina, which only rarely grows as tall as two meters and often has deltoid leaf blades. Flowers of Trichostigma have 8 to many stamens (vs. 41n Rivina) and sessile or nearly sessile penicillate stigmas (vs. capitate on well-defined styles in Rivina). In contrast with Buxbaum’s (1955, pp. 209, 210) mention of indument on seeds of Trichostigma (‘‘Villa- milla’), a well-known peculiarity of Rivina, I found no “hairy” seeds in any of the three species of Trichostigma (herbarium specimens at A and GH). Some seeds of Trichostigma do resemble those of Rivina in remaining covered by pericarp tissue after most of the flesh of the fruit falls away. With corroborative survey needed, secondary growth in 7richostigma is normal and sometimes accumulates massively, unlike the weaker anomalous secondary growth of Rivina, which reportedly occurs in thick stems (Metcalfe & Chalk; Walter, 1909; specimen of 7. octandrum, Abbott 1083, Gu). The sole chromosome count for Trichostigma, 2n = 72 for T. peruvianum, is two-thirds of the 2” = 108 reported repeatedly in Rivina The extensive distribution of Trichostigma octandrum is matched by its ecological breadth. In Florida this species grows in or on the margins of ham- mocks, on swampy ground, on disturbed sites, and in moist woods. Among i habitats throughout its range are gallery forests along tropical rivers, wet evergreen forests, tropical swamps, coastal grassy areas, coastal Laguncularia formations, tidal flats, limestone outcrops, and dunes. Rocky and scrubby places predominate, and ruderal sites are not infrequent. Trichostigma is palynologically heterogeneous. Nowicke (1968) described grains of 7. octandrum as 3-colpate and those of the other two species as having five colpi at each pole and five more at the equator. Acetolyzed grains from one collection of 7. octandrum'® are mostly 3-colpate, but infrequently have four equatorial colpi; they sometimes have extra, perpendicular, polar apertures, thereby approaching grains as described from the other species. Instead of a total of 15 colpi, Bortenschlager counted 12 arranged like the edges of a cube on pollen from 7. peruvianum. My observations fail to confirm the presence of minute, deciduous stipules in Trichostigma sporadically mentioned in the literature. Uses of Trichostigma are few. In Colombia leaves of 7. octandrum have been applied to wounds, and in Haiti a decoction of the leaves has been used to counter suffocation or choking. The thin, flexible stems find applications in ‘Harvard Palynological Collection, s/ide 6300, Panama, 1940. 26 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 basketry and as barrel hoops in the West Indies (Marie-Victorin & Le6n, Morton, Standley). Fruits of 7. peruvianum have been used for coloring linen, and the dense wood is suitable for handles (Ruiz & Pavon) REFERENCES: Under family references see BORTENSCHLAGER, BURGER, BUXBAUM (1955), HATSCH- BACH & GUIMARAES, HAUMAN-MERCK, HOFMANN (1977), LAKELA & CRAIGHEAD, LONG & LAKELA, MACBRIDE, MAURITZON, METCALFE & CHALK, Morton, Nowicke (1968), RAEDER, STANDLEY, STANDLEY & STEYERMARK, WALTER (1909), and WILSON. Austin, D. F.,& D.M. McJunkin. Anethnoflora of Chokoloskee Island, Collier County, Florida. Jour. Arnold Arb. 59: 50-67. 1978. [7. octandrum, 64.] Back, D. W., & S. BLAcK. Plants of Big Cypress National Preserve. A preliminary checklist of vascular plants. S. Florida Res. Center Rep. T-587. 28 pp. Homestead, Florida. 1980. [7. octandrum, 22, rare. Hircucock, A. S. List of plants in my Florida herbarium. Part |. Trans. Kansas Acad. Sci. 16: 108-157. 1899. [Rivina (Trichostigma) octandra, Chokoliska Is., 150.] Kiranov, B. Novedades en la flora Cubana. I. (English summary.) Annu. Univ. Sofia Fac. Biol. 64: 59-64. 1972. [“Trichostigma octandra (L.) H. Walt. f. Airsuta Kitan. (n. f.),”? 59; holotype not designated.] Marie-VICTORIN, Frere [J. L. C. Kirouac], & Frere Leon [J. S. SAuGeT]. Itinéraires botaniques dans l’ile de Cuba. Deuxiéme série. 410 pp. Montreal. 1944. [7. octan- drum, 205, 274, 286, 338. Mo -penke, H. A contribution to our knowledge of the wild and cultivated flora of Florida—I. Am. Midl. Nat. 32: 529-590. 1944 [1945]. [7. octandrum, swampy ground along roadside, Miami, 537. RaTTer, J. A., & C. MiLNe. Some angiosperm chromosome numbers. Notes Bot. Gard. Edinburgh 32: 429-438. p/. 10. 1973. [T. peruvianum, 435, 36 bivalents.] Ruiz, H., & J. PAVoNn. Fl. Peruviana Chilensis 4(4): 117-241. 1957. [Villamillia tinctoria (T. ae 143, 144; see discussion in Stafleu & Cowan.] STarLeu, F. A., & R.S. Cowan. Taxonomic literature. ed. 2. Vol. 4: P-Sak. 1x + 1214 pp. Utrecht, Antwerp, The Hague, and Boston. 1983. [Ruiz & Pavon, Vol. 4, 984.] — 3. Rivina Linnaeus, Sp. Pl. 1: 121. 1753; Gen. Pl. ed. 5. 57 (“Rivinia’). 1754. Often highly branched, perennial (or probably occasionally annual), some- times scandent herbs, subshrubs, or shrubs, thickening by successive cambia especially at the base, the thin stems with single xylem cylinders. Pattern of branching frequently pseudodichotomous, often with 3 or more shoots arising from | node (such branching often taking the form of an inflorescence or vegetative branch, frequently abortive, centered between 2 + equal divaricate branches). Plants glabrous or scurfy to densely pilose or hispid(ulous) on most organs. Calcium oxalate present primarily as styloid crystals. Leaves alternate or infrequently subopposite, petiolate, the blades usually elliptic or lanceolate to deltoid, generally acuminate apically, the bases usually acute to truncate; stomata rubiaceous or anomocytic. Inflorescences at ends of branches or ax- illary-lateral, narrow racemes with short pedicels radiating from elongate, straight, central rachises; bracts lanceolate or subulate, bracteoles 2 per pedicel, minute. Flowers perfect. Tepals nearly equal, 4, lingulate to elliptic or oblan- ceolate, upright to reflexed in fruit. Stamens 4, alternating with and shorter than or about as long as tepals; filaments filiform; anthers oblong-elliptic, 1985] ROGERS, PHYTOLACCACEAE a By DES FiGureE 2. Rivina. a—j, R. humilis: a, tip of flowering shoot, x '4; b, flower, 2 anthers removed, x12; c, gynoecium in vertical section—note basal ovule, x 6; d, very young fruit, x 6; e, mature fruit, x 6; f, mature fruit, longitudinal section, note hairy endocarp, fleshy mesocarp, and liquid-filled space between mesocarp and endocarp—note that “bumps” in mesocarp fit into ‘‘areoles” on very thin endocarp, x 6; g, seed, x 6; h, seed in vertical section, radicle of embryo at micropyle, perisperm stippled, x 6; 1, embry oriented as in “h,” x 6; j, section through center of cotyledons of embryo, ae as ssiew x 1 in dorsifixed. Pollen grains spheroidal to prolate, the tectum spinulose. Gynoe- clum unicarpellate; ovary superior, unilocular, compressed, nearly circular to elliptic in outline, grooved adaxially; style filiform, inserted obliquely, (sub)terminal to distinctly eccentric, curved, shorter than to about as long as the ovary; stigma capitate, sometimes irregularly lobed. Drupe bright red or orange, nearly globose, compressed, crowned with the remnant of the style. Seed more or less lenticular, black beneath “hairy” covering derived from pericarp, minutely arillate. Embryo annular, the cotyledons convolute. En- dosperm persisting as a cap around the radicle. Megagametophyte (embryo sac) fundamentally of the Polygonum type, although the antipodal cells some- times proliferating. Type species: R. humilis L. (Name commemorating Au- gustus Quirinus Rivinus (Bachmann), 1652-1723, professor of botany, medicine, and chemistry at Leipzig, early user of binomial nomenclature.) — BLOODBERRY, ROUGE PLANT, BABY PEPPER. 28 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 A single polymorphic species ranging from mid-Argentina northward across South and Central America and the West Indies to Mexico and the southern United States; introduced into warm regions elsewhere, including Africa, Asia, Australia, Madagascar, the Malay Archipelago, and scattered islands in the Atlantic and Pacific. In the continental United States, Rivina humilis is found across most of Florida and in Louisiana, Arkansas (fide Smith), Oklahoma, Texas, New Mexico, and Arizona. I have seen no documentation of the oc- currence of Rivina in Mississippi or Alabama. It is naturalized in Hawaii. Rivinas are paleo or shrubby, often conspicuously woody only at the base, and prawling. Branching tends to be divaricate; often multiple axes arise from a er node. Pubescence 1s absent or variable. Diverse in shape and size, the leaf blades are frequently deltoid. The small flowers bear four stamens alternating with four tepals. The single compressed carpel is topped with a well-defined, curved style inserted obliquely and generally off center, and the stigma is capitate or lobate. The most outstanding characteristic is the bright reddish, juicy fruit containing one lenticular and “hairy” endocarp. Rivina has been collected from dunes, rocks, cliffs, waste grounds, stream beds and banks, prairies, roadsides, thickets, ae canyons, swampy meadows, hammocks, and ‘‘dense,”’ “wet,” and “‘rain”’ forests. It invades cul- tivated areas. Sites are frequently shaded but also may be open—some are rich and moist, others dry. Flowering proceeds year-round in Florida. By excluding 7richostigma and by broadening species concepts, modern monographers reduced the number of species in Rivina as compared with nineteenth century treatments. Walter (1909) recognized R. humilis, R. por- tulaccoides Nutt.,!' and R. purpurascens Schrader, separated in his key by the relative lengths and degrees of erectness of the inflorescences and by the colors and lengths of the tepals. Nowicke (1968), H. Harms (note in Heimerl, 1934), Standley, and others perceived only one species, for which Raeder listed 37 synonyms. Agreement is general that Walter’s (1909) division of his already narrowly defined R. humilis into three plus the typical varieties based chiefly on pubescence is excessive splitting (discussion in Raeder) Repeated counts have yielded 2” = 108 as the chromosome number for Rivina humilis. Joshi’s illustration reveals the chromosomes to be short and of fairly uniform length at diakinesis. Pollen grains from one collection’? of Rivina humilis show that discrepancies in the literature relating to numbers of colpi result from insufficient sampling. Most grains in this collection have five equatorial colpi plus five perpendicular colpi encircling each pole. Also common are grains with 12 colpi arranged similarly, but in fours. Scanning electron micrographs in Bortenschlager show microspines on the tectum and perforations in the endexine. Nuclei in cells from Rivina humilis contain rod-shaped or short-prismatic ‘Although in Nuttall’s protologue “R. portulaccoides” does not sound in some respects like a species of Rivina, a specimen so named and labeled ‘“‘Verdigris” from Nuttall’s herbarium at BM is clearly R. humilis. "Harvard Palynological Collection, slides 344, Texas, 1936. 1985] ROGERS, PHYTOLACCACEAE 29 protein bodies in clusters of up to 10 near nucleoli. As described by Carniel, these may be solid, hollow, or septate and are composed of granular subunits. Kajale (1954a) determined that cells of the inside ovarian hypodermis elon- gate radially and differentiate into hairs between the outer tissues of the ovary and the inside epidermis, with the latter adhering to the seed coat. Hence the seed remains covered with a thin shaggy coat after the bulk of the pericarp falls away. (Netolitzky interpreted the “hairy” covering as belonging to the outer integument.) Because of its attractive divaricate pattern of branching and bright red fruits, Rivina humilis is sometimes cultivated as an ornamental, a use dating as far back in Europe as the late seventeenth century. From the very little information that is available, the fruits and other parts are considered toxic (Burlage, Perkins & Payne, Lampe & Fagerstrém). Rivina taints milk of cows that eat it (White). Medicinal uses are listed in Ayensu and in Morton. Red juice from the fruits is said to have been used for dyeing, as rouge and ink, and for coloring cut flowers. REFERENCES: Under family references see AYENSU, BORTENSCHLAGER, BURGER, BURLAGE, HEIMERL, HOFMANN (1977), KAJALE, LAMPE & FAGERSTROM, LuBBocK, MACBRIDE, MARTIN, MAU- RITZON, Morton, Nair, NeTouitzKy, NowicKe (1968), PoLuitt, RAEDER, RIDLEY, SAUNDERS (1930), SCHAEPPI, STANDLEY, STANDLEY & STEYERMARK, THIERET, WALTER (1909), and Wess. CarnieL, K. Zur Kenntnis des Feinbaues der Proteinkristalle in den Zellkernen von Rivina humilis. (English summary.) Osterr. Bot. Zeit. 118: 580-590. 1970. ImMPERATO, F. Betanin 3’-sulphate from Rivinia [sic] humilis. Phytochemistry 14: 2526, 27. 1975. [Fruits contain the betacyanins betanin, isobetanin, and betanin 3'-sulphate (= rivinianin of an earlier report Josui1, A. C. A contribution to the embryology and cytology of Rivina humilis Linn. Jour. Indian Bot. Soc. 15: 91-103. pls. 9, 10. 1936. [Describes development of single carpel (cf. papers by SAUNDERS), micro- and megasporogenesis, megagametophyte; comments on endosperm; chromosomes.] & V.S. Rao. Floral anatomy of Rivina humilis L., and the theory of carpel polymorphism. New Phytol. 32: 359-363. 1933. [Contrary to SAUNDERS (1930), anatomical evidence indicates that ovary of Rivina is unicarpellate (reply in SAUNDERS, 1934). Knock, F. Rivina—the plant with red berries. Back to Eden 12(7): 6. 1946. Nemec a Collections towards a flora of the Territory of Arkansas. Hie Am. Philos. oc 5: 139-203. 1835-1836. [R. portulaccoides, 167 (published 1835), near ae of Verdigris and Arkansas rivers. PERKINS, K. D., & W. W. Payne. Guide to the poisonous and irritant plants of Florida. Florida Coop. Ext. Serv. Univ. Florida Circ. 441: 1-91. 1980. [R. humilis, 45.] ee ININI, B. G. Rivina humilis. Interesante planta oe cultivada para ornamento n la Republica Argentina. Publ. Tech. Inst. Bot. Buenos Aires, I. 12: [Includes instructions for cultivation and nee showing habit, eral details, Saunpers, E, R. On some recent contributions and criticisms dealing with morphology in angiosperms. New Phytol. 31: 174-219. 1932. [Rivina, 180-182, 186; comments and illustrations concerned with floral anatomy and coloration.] 30 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 —., A note on the floral anatomy of Rivina en L. Ibid. 33: 66, 67. 1934. [Reply to Josn1 & Rao’s criticism of SAUNDERS’s earlier work; maintains that Rivina and et genera are bicarpellate (in 1936, JosH1 still thought Rivina to be unicarpel- lat SMITH, : B. An atlas and annotated list of the vascular plants of Arkansas. iv + 592 pp. Fayetteville, Arkansas. 1978. [Rivina humilis, 517; two reports mentioned; robably rare in state.”’] VILI heen M. Un caso teratolégico en Rivina humilis L. Lilloa 32: 319-321. 1966. [Describes and iiasinales Argentinian specimen with highly branched inflores- cences. Wuite, C. T. Rivina (Rivina laevis). Queensland Agr. Jour. II. 25: 274, 275. 1926. Witson, P. Rivina humilis. Bloodberry. Addisonia 12: 51. pl. 470. 1927. 4. Petiveria Linnaeus, Sp. Pl. 1: 342. 1753; Gen. Pl. ed. 5. 160. 1754. Herbs, subshrubs, or shrubs, sometimes sprawling, thickening by successive cambia (in root only?). Multiple shoots rising from | sometimes rhizomelike root. Branching sparse, multiple axes occasionally branching from | node. Plants with garliclike odor. Axes of inflorescences, young stems, petioles, and major foliar veins usually puberulent or tomentose to pilose or villous, addi- tional organs also sometimes pubescent (abaxial surfaces of leaf blades often densely so). Calcium oxalate present primarily as styloid crystals. Leaves pet- iolate, the blades mostly elliptic to oblanceolate, infrequently rounded to usually acuminate at both ends, often apiculate at the apices; stomata usually with irregular subsidiary cells parallel to the guard cells. Axillary buds flanked by 2 stipulelike (probably foliar) bristles. Inflorescences axillary or terminal, com- posed of | or more long, thin, wandlike, uncrowded spicate axes tending to nod with the apogee of the bend near the youngest open flower, more erect in fruit; when branched, with a small number of lateral axes inserted toward the base of the similar main axis; bracts small, ovate-lanceolate to deltoid, the 2 bracteoles minute. Flowers nearly sessile, zygomorphic, ascending. Tepals 4, glabrous or pubescent abaxially at the bases, elliptic-oblong to narrowly lan- ceolate or narrowly deltoid, slightly connate basally and slightly adnate to bases of filaments, white or tinged with yellow, green, or pink, becoming green and erect in fruit. Stamens 4—-6(-8), unequal, shorter than to about as long as tepals; anthers cleft at both ends. Pollen grains spheroidal or nearly so, 12- (or 15-)colpate [or 12-porate], or reportedly sometimes acolpate, the tectum spi- nulose and without punctate perforations (fide Bortenschlager). Gynoecium unicarpellate; ovary densely pubescent, bearing a set of hooks at the apex (these Figure 3. Petiveria. a-s, P. a/liacea: a, tip of stem with inflorescence—note bend in rachis at point where flower at anthesis, x '; b, up of inflorescence, showing anther- bearing flower at bend, 2 flowers after anthers have fallen (below), and flower buds (above), x 3; c, detail of tip of inflorescence in “‘b’’—note 2 hooks on ovary, x | adaxial view of flower—note stigma on ovary (unshaded triangular area indicates< scar where younger portion of inflorescence removed), x 10; e, f. adaxial and abaxial views of anthers, x 12; g, h, polar and equatorial views (respectively) of pollen grains, pollen 12-colpate with 4 colpi around each pole and 4 perpendicular to the polar colpi around the equator, x 1000; i, side view of gynoecium, style absent, stigma penicillate — 1985] ROGERS, PHYTOLACCACEAE 31 note 2 hooks to left, x 12; j, ovule, attachment point indicated by open circle at bottom left, x 12; k, nearly mature fruit (an achene), with hooks above and persistent achene, x 3; 0, abaxial cous of embryo, x 6; p, side view of embryo, x 6; q, vertical section of embryo, x 6; r, embryo with longer (inner) cotyledon removed and shorter (outer) one unfolded, x 3. s, mafic longer cotyledon of embryo in 32 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 enlarging considerably in fruit); style absent; stigma penicillate, facing the ra- chis; ovule straight, the micropyle alongside the funiculus. Fruit dry, indehis- cent, cuneiform, longitudinally ribbed, pubescent, armed apically with 4 (or 5) [-13] sharp, stout barbs inserted on 2 lobes and bent back along the surface of the fruit for ca. “4-2 its length, sometimes with an extra, straight barb rising vertically between the lobes. Seed shaped like the fruit, the testa thin. Embryo with the cotyledons unequal, one wrapped around the other: the outer markedly auriculate basally, wider and shorter than the inner, this rolled into a tube; embryo bent double at about the middle of the inner cotyledon and near the apex of the outer one. Type species: P. alliacea L. (Named for James Petiver, ca. 1660-1718, British naturalist and apothecary, Fellow of the Royal Society, noted collector and prolific author.) — GUINEA-HEN WEED, GARLIC WEED. One variable species distributed across most of Florida and occurring from southern Texas southward through Mexico, Central America, the West Indies, and South America to approximately Buenos Aires, Argentina. Pefiveria alli- acea has escaped from cultivation to a limited extent in warm parts of the Old World. Long, slender, uncrowded, unbranched or sparsely branched, spicate inflo- rescences allow recognition of Petiveria from a distance. Fresh plants have a skunky or garlicky odor when injured. The small, four-tepaled flowers have a variable number of unequal stamens and a distinctive, densely pubescent ovary bearing hooks at the apex but no style. The brushlike stigma is more or less lateral. The unmistakable long, narrow, tapered, dry fruit 1s topped by four or more stout hooks. The odd bent embryo has two unequal cotyledons, one wrapped longitudinally around the other. Investigating different sets of characters, Baillon and Walter (1906) each uncovered evidence suggestive of affinity between Petiveria and Monococcus. Baillon encountered similarities in vegetative organs, inflorescences, floral or- ganization, and general construction of the embryos. Walter observed that the completely straight (gerade) ovules of the two distinguish them together from other Rivineae, in which the funiculus is inserted at the middle of the trans- versely overlaid nucellus (see Mauritzon for embryological details of Petiveria). Walter also mentioned that both genera have tepals overlapping so that one is outside at both edges, one is inside at both edges, and two have one edge inside and the other outside (a trait that reappears in Seguierieae). Further, in 1909, he mentioned similarity in their “Stipularorgane,” their seed coats, and the general forms of their embryos Petiveria differs from Monococcus in having perfect (vs. imperfect or polyg- amous) flowers rotated 45 degrees relative to those of Monococcus, spines terminal on (vs. covering) the fruits, fewer stamens, longer fruits, more dissim- ilar cotyledons, less nutritive tissue in the seed (see especially Baillon), and possibly anomalous secondary growth. (Monococcus probably lacks anomalous secondary growth; this is restricted to the root in Petiveria according to Holm, 1915: see also Metcalfe & Chalk, and Walter, 1909.) ng the diverse habitats occupied by Petiveria are wet, tropical, evergreen forests, thickets, fields, and even savannas. Soils may be rich or not. Disturbed 1985] ROGERS, PHYTOLACCACEAE 33 sites, such as banks of streams, are common. Habitats reported in Florida, where P. alliacea flowers year-round, include cultivated land, waste places, hammocks, moist woods, and the top ofa limestone cliff. This species at times becomes a weedy pest. Distribution by animals is clearly effected by the hooks on the fruits. Ormond & Pinheiro (1974) induced autogamy in Brazilian specimens. In 1909 Walter recognized Petiveria tetrandra Gomes as a distinct species, in his key distinguished from P. alliacea by six (vs. four) hooks on the fruits, glabrous inflorescence axes (a very unreliable character), and shorter tepals. Petiveria tetrandra is centered in or restricted to southern Brazil, northern Argentina, and Paraguay. Hauman-Merck and Nowicke (1968) reduced it to a variety of P. alliacea; after studying it at the heart of its range, Santos & Flaster and Hatschbach & Guimaraes denied it any taxonomic status. As the result of a multifaceted investigation focused on the problem of the status of alliacea differed from the one they believed probably to represent var. fe- trandra in having a somatic chromosome number of 72 (vs. 36), four hooks per fruit (vs. 5 or more!?), and several organs larger, as well as in other ways. The two entities remained phenotypically distinct under uniform cultivation. Crosses in both directions yielded some fruits, a result requiring careful inter- pretation in view of the alleged difference in chromosome number. Nowicke (1968) raised the possibility of apomixis by suspecting partial sterility in var. tetrandra as indicated by apparently acolpate pollen “notwithstanding the set- ting of fruit’ (p. 344). Complicating the palynological picture, Bortenschlager observed ae grains in “P. tetrandra”’ and grains with elongate apertures in “P. allia The ee odor that gave Petiveria alliacea its name, and the enthusiasm for this species in folk medicine, underscore the desirability of chemical studies. Pietschmann obtained evidence of mustard oils in roots and stems, and various other authors have ascribed them to the genus. However, Ettlinger & Kjaer dismissed Pietschmann’s evidence as “meaningless”; their own tests on the garlicky seeds were negative for myrosinase and glucosinolates. The odor most likely comes from sulfur-containing compounds other than mustard oils: Von Szczepanski and colleagues established an antimicrobial oil from roots and stems of P. alliacea as benzyl-2-hydroxyethyl-trisulfide; Adesogan character- ized another sulfur-containing compound from the roots as cis-3,5- diphenyl- 1,2,4-trithiolan (‘‘trithiolaniacin’’). Segelman & Segelman isolated 1 related compounds, and potassium nitrate from leaves. (For the chemistry of Petiveria see also Dias da Silva, Hegnauer, Loustalot & Pagan, Rocha, and Rocha & Da Silva.) '3Specimens displaying the sharpest distinguishing trait of P. alliacea var. tetrandra, more than four hooks per fruit, occur ale the = daries given above. For example, fruits on Bartlett 10787 (GH) from Mexico have 4, 5, or 6h 34 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 In view of the odor, antimicrobial properties, reputed narcotic effects (Dias da Silva), noxiousness, and toxicity (see symptoms of poisoning in Peckolt & Peckolt) of Petiveria alliacea, it 1s unsurprising that plants of this species are valued and sometimes marketed as a folk remedy. Its attributed benefits are available in numerous references, among them Ayensu, Dias da Silva, Morton, Peckolt & Peckolt, Sorari & Bandoni, Standley, and Wong. This species is reputed to degrade the milk and meat of cattle, in which it also induces abortion. (The last-mentioned effect applied to humans is one of the most frequently mentioned medicinal uses.) Griffith recounted that a nauseating infusion of roots of P. “‘foetida’’ in rum was employed in the West Indies to instill disgust for liquor. Somewhat insecticidal, Petiveria has been used to free woolen goods and chickens of vermin. Harms (note in Heimerl, 1934) and the label of the Brazilian collection Krukoff’s 6th Expedition ... 7638 (A) mentioned Petiveria as an ingredient in curare poison. As related by Peckolt & Peckolt, P. alliacea has been used to poison fish. The hooks on the fruits can puncture human skin. REFERENCES: Under family references see AYENSU, BAILLON, BARTH & BARBOSA, BEHNKE et al. (1974), BORTENSCHLAGER, BURGER, BURLAGE, GARCIiA-BARRIGA, HATSCHBACH & GuIMARAES, HAUMAN-MERCK, HEGNAUER, HEIMERL, HOFMANN (1977), LEwis & E._vin-Lewis, LUpBock, MARTIN, MAURITZON, METCALFE & CHALK, MorTON, NOWICKE (1968), PECKOLT & PECKOLT, RAEDER, pablo SAUNDERS, SCHAEPPI, STANDLEY STANDLEY & STEYERMARK, WALTER, and WIL ApesoGan, E. K. Trithiolaniacin, a novel trithiolan from Petiveria alliacea. Jour. Chem. Soc. Chem. Commun. 1974: 906, 907. 1974 [From root; molecular structure given. ] ANGELY, J. Flora analitica e fitogeografica do estado de Sado Paulo. Vol. |. xlviii + 240 + 32 pp. Sao Paulo. 1969. [Petiveria, xlvii, 62, 64; includes distribution map for “‘P. hexagloxin var. tetandra AVILA DE ARAUJO, A. O pipi “ emansa-senhor.” Petiveria tetrandra. Chacaras e Quintais 65: 191, 192. 1942.* Dias pa Siva, R. A. Pipi. Revista Fl. Med. 1: 477-487. 1935. [P. “tetrandra”: common names, relationships, description, illustration, structure of root, therapeutic prop- erties, instru s for use, description of poisoning; crude chemistry of root of P. “‘hexaglo a Gab petiverine, an alkaloid?; cf LousrALot & PAGAN, ROCHA & Da SiLva).] ea, M.G., & A. KuAer. Sulfur compounds in plants. Pp. 59-144 in T. J. Masry, E. ALston, & V He oo eds., Recent advances in phytochemistry. Vol. Sets [P. alliacea 4.] ae R. E. Petiveria oem Jour. Phila. Coll. Pharm. 6: 203. 1834. Hom, T. Medicinal plants of North America. 95.—Petiveria alliacea L. Merck’s Rep. 24: 266-270. sere ar of morphology and anatomy; anomalous thickening restricted to roots t cf WALTER (1909, p. 4). . Sciaphilous a aaa Beih. Bot. en 44: 1-89. pis. 1-3. 1927. [P. alliacea, 56; structure of le Lousta.oT, A. J., & C. PAGAN Toca “fever” plants tested for presence of alkaloids. El Crisol 3(5): 3-5, 1949.* eee in Chem. Abstr. 44: 2179, 2180. 1950; tests for alkaloids on leaves and stems — s alliacea negative. ) ORMOND, W.T., & M.C. B. PINHEIRO Ati l6gi de Petiveria alliacea L. (English eee Revista Brasil. Biol. 34: 123-142. 1974 1985] ROGERS, PHYTOLACCACEAE 35 [1975]. [Autogamy, transplant experiments, morphology, seedlings, chromatogra- phy, crosses, germination; literature review emphasizing taxonomic history of Pet- iveria. > —_.. a elemento a mais para o esclarecimento taxinémico de Petiveria alliac . Namero de cromossomas. (English abstract.) Ibid. 35: 39-43. 1975, ete ae eee and drawings of chromosomes. PIETSCHMANN, Zum aoa Nachweis der Senféle. Mikrochemie 2: 33- . 1924. [See ora in HEGNAUER and in ETTLINGER oe AER. Rocua, A. B. VWariedades quimicas de “ Petiveria alliacea’’ L. Bol. Soc. Quim. Peru 39: 55 229. 1973 [1974]. ane of roots of 19 Fae from different localities yielded os heterogeneous results & J. AS nalise cr romatografica em camada delgada de alguns prin- cipios ativos da raiz de Petiveria alliacea L. Revista Fac. Farm. Odont. Araraquara 3: 65-72. 1969.* [Abstract in Chem. Abstr. 72: 39788. 1970. Roots contained no tannins, essential oils, mucilages, anthracene derivatives, saponins, alkaloids, phy- tosterols, triterpenoids, or flavonoids: thin-layer alae ect showed 19 cou marins (in 1974 RocHa mentioned “posible existencia de rinas’’). SEGELMAN, F. P., & A. B. SEGELMAN. Constituents of Petiveria as L. (Phytolac- caceae). I. Isolation of isoarborinol, isoarborinol acetate and isoarborinol cinnamate from the leaves. (Abstract.) Lloydia 38: 537. 1975. [Collected near Iquitos, Peru; potassium nitrate also isolated; related abstract in Diss. Abstr. Int. 35: 3842B. 1975.] SorARU, S. B., & A. L. BANDOoNI. Plantas de la medicina popular seman 153 pp. Buenos Aires. 1978. [P. alliacea, 58, 59; includes chemistry, common names, de- scription, distribution, habitat, illustration, synonymy, and uses.] SzCZEPANSKI, C. von, P. ZGORZELAK, & G. A. Hoyer. Isolierung, ee und Synthese einer antimikrobiell wirksamen Substanz aus Petiveria alliacea L. (English summary.) Arzneimittel-Forsch. 22: 1975, 1976. 1972. [Structure illus. ” TrIMEN, H., & W. T. THIseELTON Dyer. Flora of Middlesex. Map + xh + 428 pp. London. 1869. [Biography of Petiver, 379-386. Wonca, W. Some folk medicinal plants from Trinidad. Econ. Bot. 30: 103-142. 1976. [P. alliacea, 119.] Subfamily AGDESTIDOIDEAE Nowicke 5. Agdestis Mocifio & Sessé ex A. P. de Candolle, Syst. Nat. 1: 511, 543. 1817 (“1818’). Slightly woody, twining, pungent-smelling vines, sometimes with large na- piform taproots. Sieve-tube plastids with globular crystalloids. Plants puber- ulent on axes of inflorescences, abaxially on leaf blades, and sometimes lightly on young stems. Calcium oxalate present primarily as raphide bundles. Leaves petiolate, the blades suborbicular to usually cordate, rounded to acute and often mucronate apically, often about as wide as long; slender petioles about as long as leaf blades; stomata anomocytic. Inflorescences mostly axillary, sometimes terminal, lax, composed of main axes bearing simple or compound lateral dichasia, or bearing single flowers in axils of bracts (some axes exclusively with such single flowers), or bearing branches resembling the main axes; bracts and bracteoles inconspicuous, subulate to lanceolate. Flowers perfect, pedicellate, strongly scented. Tepals 4 (5 or rarely more), white, elliptic or oblong to ob- lanceolate, separate or slightly coalescent basally. Stamens 15-30; filaments slender, unequal, shorter than to slightly longer than tepals, threadlike, inserted 36 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 irregularly; anthers cleft at both ends. Pollen grains subspheroidal to subprolate, ae the tectum spinulose and punctate-perforate. Gynoecium syncar- ous; Ovary semi-inferior, (3- or) 4-locular; stigmatic lobes (3 or) 4, thick, aie adaxially, recurved, shorter than to slightly longer than the single conical, stocky style. Fruit small, dry, indehiscent, obconical, ribbed, surround- ed by the enlarged, greenish, spreading, winglike, prominently veined tepals, unilocular and |-seeded by abortion. Seed with thin testa adherent to pericarp. Embryo annular, the cotyledons linear, slightly wider than radicle. TyPE SPECIES: A. clematidea Mocino & Sessé ex A. P. de Candolle. (Named for a disagreeable hermaphroditic monster because of the anomalous original position of the plant in the dioecious Menispermaceae. '*) A single species distributed from Texas southward through Mexico to Gua- temala, reported from Honduras and Nicaragua, and escaped from cultivation in warm places elsewhere. Agdestis clematidea is cultivated at least as far north as Jacksonville, Florida, and occurs outside of cultivation in disturbed sites and hammocks in the southern half of Florida. Several distinctive attributes allow ready recognition of Agdestis and isolate it from other Phytolaccaceae. It is a slender vine capable of forming dense tangles and climbing over shrubs and high into trees. (Taylor estimated growth to be as fast as 40 or 50 feet per year.) The turnip-shaped taproot protrudes above the surface of the ground and, according to Taylor, may weigh as much as 150 pounds (Heimerl, 1934, says six pounds). The cordate leaf blades are highly distinctive. Observers describe odors from the foliage and root as gar- licky, skunklike, reminiscent of cabbage, or fetid. Descriptions of the floral scent include “very sweet-scented” (Taylor) and “‘more fetid than those of the carrion-flower or skunk-cabbage”’ (Britton). Mexia (8947, Gu) recorded the stench to have caused headaches. The white flowers in simple or compound dichasia (vs. mostly racemose inflorescences in other Phytolaccaceae) each have four tepals, generally four stigmatic lobes on one compound style (most Phy- tolaccaceae have one style per carpel), and usually four locules in the ovary, with three aborting. The partly inferior ovary is unique in the family. The single seed adheres to the pericarp of the small indehiscent fruit encircled by spreading tepals. Bortenschlager found Agdestis to agree palynologically with other Phytolac- caceae. While not favoring affinity with Phytolaccaceae in particular, the pres- ence of betalains and P-type sieve-tube plastids confirms Agdestis as a member of the Centrospermae (Behnke er a/., 1974), The morphological peculiarity of Agdestis is reflected in the taxonomic po- sitions assigned it by different authorities. Most regard Agdestis as an isolated member of the Phytolaccaceae. Walter (1909) listed it among genera anomala; Heimer! (1934) treated it as the sole genus of tribe Agdestideae Heimer]; and Nowicke (1968) established for it the monogeneric subfamily Agdestidoideae ‘According to one version of the Phrygian myth, Cybele—embodied as the Agdus Rock—gave birth unwillingly to Agdestis despite her having thwarted rape by Jupiter. Blood that spilled when the gods tricked the arrogant Agdestis into drunkenness and bound him/her to a tree spawned a second tree, this yielding fruits responsible for the conception of Attis in the princess Nana. 1985] ROGERS, PHYTOLACCACEAE 37 Nowicke. Hutchinson recognized it as the single member of the Agdestidaceae al. Agdestis resembles other Phytolaccaceae 1 in its weediness, preferring naturally and artificially disturbed sites. It grows in such diverse habitats as tropical forests, dry thickets, rocky places, and clearings. Ridley (p. 111) observed that a number of taxonomically disparate woody climbers of ‘“‘rather open jungles in the tropics” produce usually small, one- seeded fruits surrounded by spreading winglike sepals that cause the fruit to rotate rapidly while falling. Among his examples is Agdestis. That the falling fruits indeed whirl like the blades of a helicopter is readily demonstrated with fruits from herbarium specimens. Observations on the nature of secondary growth are contradictory, with the balance tipped toward the presence of successive cambia (cf Cobau; Heimerl, 1934; Metcalfe & Chalk; Walter, 1909). Agdestis has limited application as an ornamental in circumstances where its odor is not objectionable. It forms a thick cover sometimes used to decorate buildings and hide eyesores. REFERENCES: Under family references see BEHNKE ef al. (1974), BORTENSCHLAGER, HEIMERL (1934), HorMANN (1977), HUTCHINSON, METCALFE & CHALK, NowIcKE, RIDLEY, Roic & ACUNA, STANDLEY & STEYERMARK, and WALTER (1909). Britton, N. L. Agdestis clematidea Moc. & Sessé. Torreya 4: 24. 1904. a E. Co aia all’anatomia della “Agdestis clematidea vie et Sessé.”’ Boll. o Bot. eee 111-122. 1898 ee nee W. Botany. Vols. 1-5 in F. D. GopMaAn & O. SALvin, eds., Biologia oe ee a London. 1879-1888. a. 1: 22; 3: 30; 4: 83, 259: 5: pl. cade 7 Notulae ad plantas Asiae Orientalis (XVIII). Jour. Jap. Bot. 18: 91-120. 1942, laa region 104.] Taytor, N. Agdestis. In: L. H. Baitey, ed., Standard cyclopedia of horticulture. ed. 2. : 239, 1925 VERMASEREN, M. J. The legend of Attis in Greek and Roman art. Vol. 9 ie M. J. VERMASEREN, Etudes préliminaires aux religions orientales dans |’Empire romain. Frontisp. + 59 pp. + 40 pls. Leiden. 1966. [Includes legend of Agdestis (Aedistis) ARNOLD ARBORETUM HARVARD Soca 22 Divinity AVEN CAMBRIDGE, Meuse 02138 SCHMIDT, INDEX TO AUTHORS AND TITLES a9 JOURNAL OF THE ARNOLD ARBORETUM INDEX TO AUTHORS AND TITLES, VOLUMES 51-65 (1970-1984) ELIZABETH B. SCHMIDT In 1973 the Journal of the Arnold Arboretum published an “Index to Authors and Titles, Volumes | through 50, 1919-1969,” which included a brief history of the Journal. Since then 15 years have passed, during which 15 volumes, 326 papers, and 8638 pages have been published. This index is a supplement to the first one; it covers the material published in volumes 61-65 and brings the history up to date. During this period there have been many changes, some readily visible to readers and some less so. Bernice Schubert, whose capable, tactful, and me- ticulous direction of the Journal began in 1963, stepped down as Editor in 1979, to be succeeded by Stephen Spongberg. An Editorial Committee, orig- inally comprising Bernice Schubert (Chairman), Stephen Spongberg, Peter Ste- vens, and Carroll Wood, was established in 1975 to redistribute some of the editorial burden. Although committee members have provided reviews and advice and have helped to determine policy, a single botanist must supervise to maintain consistency of policy and quality. Today’s committee consists of Stephen Spongberg, Elizabeth Schmidt, Peter Ashton, Kamaljit Bawa (outside member), Peter Stevens, and Carroll Wood. The amount of assistance available to the editor has increased greatly during this period. In 1970 the only help was a circulation manager; this position was upgraded to editorial assistant, assistant editor, and finally managing editor. These posts have been held by Dulcie Powell (1967-1971), Ellen Bernstein (1971-1973), Kathleen Claggett (1973-1976), and Elizabeth Schmidt (1976- present). After many years with the Harvard University Printing Office, we changed to Edwards Brothers (Ann Arbor, Michigan) for Volume 61. With this move we hoped to achieve better results at a considerably lower price, we changed from hot to cold type, and we gained sharper reproduction of photographs. Not completely satisfied, however, we changed to Allen Press (Lawrence, Kan- sas) for Volume 63 and have been extremely pleased with the results. Circu- lation management has recently been given to Allen Press, as well. The appearance of the Journal has changed considerably over the past 15 years. Basically the same for the first 50 volumes, the cover was redesigned in 1970. From 1972 through 1982, the cover was changed annually, a process that became increasingly expensive and time consuming. In 1981 we had what was to become the Journal logo embossed on off-white stock, and we have © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 39-72. January, 1985. 40 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 retained this cover ever since. Color plates were included for the first time in 1984—an event perhaps even more exciting for us than for the author! Other, less visible changes have also taken place. Although still primarily a staff organ, the Journal has been accepting an increasing number of papers from outside authors. Consequently, instructions for authors were drawn up— informally (photocopied and sent to authors on request) in 1977, and formally (printed in the back of the Journal) in 1983. The review process has also been formalized and tightened, with outside reviewers playing a more and more active role. The length of papers submitted has been increasing over time. Consequently, fewer papers are published, but several of them have been extremely long. The publication of Peter Stevens’s 573-page “A Revision of the Old World Species of Calophyllum (Guttiferae)” in 1980 marked the culmination of this trend: three galley readers were never heard from again, and the next six issues ap- peared off schedule! To offset skyrocketing costs, we have instituted various measures over the past 15 years. Regretfully, we have had to raise the subscription rate several times: from $10.00 to $16.00 in 1972; to $25.00 in 1978; to $30.00 in 1983: and finally to $50.00 in 1984. Additionally, we added a foreign postage charge of $5.00 and halved agents’ discounts. We initiated page charges for manu- scripts received after | March 1980: however, we have been careful to ensure that inability to pay such charges in no way influences our handling of a manuscript. We are unfortunately no longer able to provide outside authors with free offprints. In years to come, we hope to continue to offer solid scientific work contained in a carefully produced journal. Despite time, money, and staffing constraints, we Strive to provide personalized service to both authors and subscribers. Any comments and suggestions will be gratefully received. DATES OF ISSUE, VOLUMES 51-65 VoL. No. PAGES DATE VoL. No. PAGes DATE 1 1-132 16 Jan. 1970 55 1-124 30 Jan. 1974 123-330 26 April 1973 331-418 16 July 1973 419-493 19 Nov. 1973 73-192 25 May 1977 193-348 9 Aug. 1977 349-463 10 Nov. 1977 2 133-256 14 April 1970 2 125-332 30 May 1974 3 257-430 13 July 1970 3 333-524 24 Sept. 1974 4 431-560 19 Oct. 1970 4 525-695 3 Dec. 1974 52 | 1-204 4 Feb. 1971 56 | 1-184 16 April 1975 2 205-368 16 April 1971 2 185-264 13 June 1975 3. 369-522 16 July 1971 3. 265-374 2 Sept. 1975 4 $23-717 27 Oct. 1971 4 375-478 24 Nov. 1975 53 l 1-140 10 Jan. 1972 57 1 1-128 4 March 1976 2 141-272 19 April 1972 2 129-216 9 June 1976 3. 273-408 4 Aug. 1972 3. 217-404 17 Sept. 1976 4 409-582 13 Nov. 1972 4 405-548 30 Dec. 1976 54 1 1-122 Oo Feb... 1973 58 ] 1-72 4 March 1977 2 2 3 3 4 4 1985] Voit. No. PAGES DATE 59 1 1-104 24 Jan. 1978 2 105-196 May 1978 3 197-310 26 July 1978 4 311-429 30 Nov. 1978 60 1 1-166 31 Jan. 1979 2 167-322 1 May 1979 3 323-402 24 July 1979 4 403-542 17 Dec 1979 61 1 1-116 21 March 1980 2 117-424 19 Dec 1980 3. 425-700 19 Dec 1980 4 701-783 24 April 1981 62 1 1-128 12 June 1981 2 130-266 21 Aug 1981 3 267-436 17 Nov. 1981 4 437-561 11 Jan. 1982 63 1 1-101 22 March 1982 2 103-198 13 April 1982 3 199-336 27 July 1982 4 337-530 30 Dec 1982 64 1 1-169 11 Jan 1983 2 171-332 8 April 1983 3 333-490 19 July 1983 4 491-665 20 Oct 1983 65 l 1-148 11 Jan 1984 2 149-254 16 April 1984 3 255-428 7 July 1984 4 429-592 12 Oct. 1984 ABBE, ERNST C., AND RoBert B. KAu Inflorescence architecture and aioe in the Fagaceae, 65: 375-401 Abies amabilis x lasiocarpa: Sargent’s fir hybrid, 58: 52-59 Acanthaceae in the southeastern United States, The genera of, 51: 257-309 Acanthopanax, Eleutherococcus vs., 61: 107-111 Acer saccharum, in northern Cape Breton Island, Silvical characteristics of sugar maple, 58: 307-324 Acer, Shoot growth and heterophylly in, : 240-266 Acmena (Myrtaceae), A revision of the Pa- puasian species of, 58: 325-342 Acradenia (Rutaceae), A revision of the ge- nus, 58: 171-181] Acronychia (Rutaceae), A revision of the genus, 55: 469-523, 525-567 Acrotrema, Additional notes on. Compar- SCHMIDT, INDEX TO AUTHORS AND TITLES 4] ative morphological studies in Dilleni- aceae, VII, 52: 319-333 ADAMS, PRESTON, AND CARROLL E. Woon, Jr. The genera of Guttiferae (Clusi- aceae) in the southeastern United States, 57: 74-90 Additional new taxa and new combina- tions in Hymenaea (Leguminosae, Caes- alpinioideae), 55: 441-452 Additional notes on Dimorphanthera (Er- icaceae), 58: 437-444 Additional notes on the genus Flindersia (Rutaceae), 56: 243-247 Additional notes on the Malesian species of Zanthoxylum (Rutaceae), 51: 423-426 Additions and changes in the Neotropical Convolvulaceae—notes on Merremia, Operculina, and Turbina, 64: 483-489 Agarista (Ericaceae), A taxonomic revision American species of, 65: 255-342 AIELLO, ANNETTE. A reexamination of Portlandia a and associated taxa, 60: 38- Airosperma ey Notes on, with a new species from Fiji, 61: 95-105 Aizoaceae in the southeastern United States, The genera of Molluginaceae and, 51: 431-462 Algae of Pico del Oeste, The. The ecology of an elfin forest in Puerto Rico, 14, §2: 86-109 Alismataceae in the southeastern United States, The genera of, 64: 383-420 ALMEDA, FRANK, JR. Systematics of the Neotropical genus Centradenia (Mela- 108 A. The tribes of Cru- ciferae (Brassicaceae) in the southeastern United States, 65: 343-373 Alsophila (Cyatheaceae) in the Americas, A revision of the genus, 64: 333-382 Amaranthaceae in the southeastern United States, The genera of, 62: 267-313 Amentotaxus, The secondary phloem of, 5§: 119-122 Amentotaxus, The wood of, 54: 111-119 American grasses, Notes on, 60: 320, 321 ares species of Agarista (Ericaceae), A taxonomic revision of the, 65: 255- 342 Americas, A revision of the genus AI- sophila (Cyatheaceae) in the, 64: 333- 382 Analysis of the complex vascularity in stems of Dioscorea composita, 51: 228-240 42 JOURNAL OF THE ARNOLD ARBORETUM Anatomy of stem abscission in the genus Smilacina (Liliaceae), 65: 563-570 Anatomy of the palm Rhapis excelsa, VIII. Vessel network and vessel-length distri- bution in the stem, 63: 83-95; IX. Xylem structure of the leaf insertion, 64: 599- X. Differentiation of stem con- ducting tissue, 65: 191-214 ANDERSON, LoRAN C. Studies on Bige- lowia (Asteraceae), II. Xylary compari- sons, woodiness, and paedomorphosis, 53: 499-514 Andromedeae (Ericaceae), Generic rela- tionships in the, 60: 477-503 Andropogon virginicus complex (Gramin- a8), Syslemalics of the, 64: 171-254 A (Gesneriaceae), The genus, 56: 364-368 a A second species of Nem- opanthus in the southern, Ilex collina, 55: 435-44 Araceae of the Lesser Antilles, Nomencla- tural notes on the, 60: 272-289 Aralia spinosa (Araliaceae), The architec- ture of devil’s walking stick, 65: 403-418 Araliaceae, What is the primitive floral structure of, 52: 205-239 Architecture of devil’s walking stick, Ara- lia spinosa (Araliaceae), The, 65: 403- 418 Asarum (Aristolochiaceae), A synopsis of the Chinese species of, 64: 565-569 Ascarina (Chloranthaceae) in the southern Pacific, The genus. Studies of Pacific is- land plants, XX XIII, 57: 405-425 Asia and in cultivation, The genus Neillia (Rosaceae) in mainland, 52: 137-158 Asiatic- eee Australian species of Erythrina, Notes on, II, 53: 128-139 Ateleia ie from the Bahamas, A new species of, 62: 261-263 Aublet’s generic names by his contempora- ries and by present-day taxonomists, The treatment of, 65: 215-242 Aublet’s Histoire des Plantes de la Guiane Francoise, The plates of, 64: 255-292 AusTIN, DANIEL F., AND Davip M. Mc- JUNKIN. An ethnoflora of Chokoloskee Island, ees County, Florida, 59: 50-67 AUSTIN, DANIEL F., AND Royce L. OLIver. Sisyrinchium solstitiale oo a Florida endemic, 55: 291-299 AUSTIN, DANIEL F., AND G. W. STAPLES. Additions as changes in the Neotrop- ical Convolvulaceae—notes on Merre- [VOL. 66 mia, Operculina, and Turbina, 64: 483- 489 Australasia, Rhizophora in—some clarifi- cation of taxonomy and distribution, 59: 156-169 Australia, The genus Piper (Piperaceae) in New Guinea, Solomon Islands, and, 1, 53: 1-25 AYENSU, Epwarp S. Analysis of the com- plex vascularity in stems of Dioscorea composita, 51: 228-240 Baas, PieTER. Vegetative anatomy and the taxonomic status of Ilex collina and Nemopanthus (Aquifoliaceae), 65: 243- 250 Bahama Islands, Gomphrenoideae (Ama- ranthaceae) of the, 58: 60-66 Bahamas, A new species of Ateleia (Le- guminosae) from the, 62: 261-263 Bahamas, Caesalpinia subgenus Guilan- dina in the, 55: 425-430 Bahamas, Caicos and Turks islands, New species and a new combination from the, 58: 40-51 Bahamas, Caicos and Turks islands, New species and varieties from the, 60: 154— 162 Bahamian species of Bursera (Bursera- ceae), Systematic anatomy of, 60: 163- 165 Balsaminaceae in the southeastern United States, The, 56: 413-426 Bamboo classification, Present status and problems of, 54: 293-308 BARGHOORN, Exso S., ELISABETH WHEE- LER, AND RICHARD A. Scott. Fossil di- cotyledonous woods from Yellowstone National Park, 58: 280-306; II, 59: 1-31 BARRINGER, KER Cubitanthus, a new genus o ie Ce from Brazil, 65: 145-14 ee ee B., D. E. BouFForp, A. L. CHANG, a CHENG, T. . DubL_ey, S. A. He, Y. X. Jin, Q. Y. Li, J. L. Lureyn, S.A. Sroncnen, 8. C. re N, Y.C. TANG, J. X. WAN, AND T. S. Yin. The 1980 Sino-American botaniesl expedition to western Hubei er People’s Re- public of China, 64: 3 BARTHOLOMEW, B., ee E. BOUFFORD, AND STEPHEN A. SPONGBERG. Metase- quoia glyptostroboides—its present sta- tus in central China, 64: 105-128 1985] Bataceae in the southeastern United States, The, 63: 375-386 ce maritima (Bataceae), Chromosome mber and its significance in, 57: 526- 330 Bauerella (Rutaceae), ee taxonomic Ssta- -170 tus of the genus, 56: Bawa, K. S. Chromosome numbers of ee species ofal 54: 422-434 Bawa, K. S., AND Otto T. SoLsric. Iso- zyme variation in ae ~ Prosopis (Leguminosae), 56: 398-4 BELL, ADRIAN. Rhizome an in relation to vegetative spread in Medeola virginiana, 55: 458-468 Belliolum (Winteraceae) and a note on flowering, Wood anatomy of, 64: 161- 169 Betulaceae and Salicaceae, Notes on West Himalayan, 54: 412-418 BHANDARI, N. N. Embryology of the Mag- noliales and comments on their rela- tionships, 52: 1-39, 285-304 Bipincer, J. M., M. J. LAPIANA, G. J. PER- SINOS, AND S. K. Curistig. The ecology ofan elfin forest in Puerto Rico, 13. Phy- tochemical screening and literature sur- vey, 51: 540-546 Bigelowia (Asteraceae), Studies on, II. Xy- odiness, and pae- 4 Bigelow’s “American Medical Botany,” 55: 6-5 Biosystematic revision of Bommeria, A, 60: 445-476 Boa ie, A. Linn. Floral morphology and vascular anatomy of the Hamamelida- ceae: the apetalous genera of Hamameli- doideae, 51: 310-366 Boc_e, A. Linn. The genera of Mollugi- naceae and Aizoaceae in the southeast- ern United States, 51: 431-462 Bocie, A. Linn. The genera of Nyctagi- naceae in the southeastern United States, 1-3 — Bruce A., Scott W. scp RICH- pb J. Hespa, AND P. F. STEVENS. Ge- neric limits in the tribe Cis ee (Ericaceae), and its position in the Rho- dodendroideae, 59: 311-341 Bommeria, A biosystematic revision of, 60: 445-476 Boraginaceae of West Pakistan and Kash- mir, A revision of the, 51: 133-184, 367- SCHMIDT, INDEX TO AUTHORS AND TITLES 43 402, 499-520; 52: 110-136, 334-363, 486-522, 666-690 Boreal and western North American plants in the late Pleistocene of Vermont, 60: 167-218 Borneo, Two unusual Chionanthus species from, and the position of Myxopyrum in the Oleaceae, 64: 619-626 Borreria from New Guinea, A new name in Spermacoce for two species of, 64: 628 Bosistoa (Rutaceae), A revision of the ge- nus, 58: 416-43 BouFrFoRD, DAvip E. Notes on Peperomia (Piperaceae) in the southeastern United States, 63: 317-325 Bourrorp, Davip E., A. L. CHANG, ie CHENG, T. R. ee S. A. He, Y Jin, Q. Y , J. L. Luteyn, S. x SPONGBERC, "i C. Sun, Y. C. TANG, J. Wan, T. S. YING, AND B. Bar- THOLOMEW. The 1980 Sino-American botanical expedition to western Hubei Province, People’s Republic of China, 64: 1-103 BOUFFORD, AN SPONGBERG. Gentes floridus (Cal- ycanthaceae)—a nomenclatural note, 62: 265, 266 Bourrorp, Davip E., STEPHEN A. SPONGBERG, AND BRUCE BARTHOLOMEW. Metasequoia glyptostroboides — its pres- ent status in central China, 64: 105-128 BouFFORD, Davip E., TsUN-SHEN YING, AND SUSUMU TERABAYASHI. A mono- ae of Diphylleia (Berberidaceae), 65: 7. Brass, ee (1900-1971), an appre- ciation [obituary, with portrait], 52: 695— 698 Brazil, A new species of Ormosia from, 51: 29-131 Brazil and Guyana, New taxa from, in the enus eee eee Caesal- pinioideae), 54: 94-104 Brazil, Cubitanthus, A new genus of Ges- des to Perezia mpositae, Mutisieae), Transfer of the, 59: 352-359 Breeding mechanisms in trees native to tropical Florida—a morphological as- sessment, 55: 269-290 Brim, Scott W., RICHARD J. HEBDA, P. F. STEVENS, AND Bruce A. Boum. Generic 44 limits in the tribe sien pi (Eri- hodo- dendroideae, 59: 311-341 Bromeliaceae in the partes United States, The genera of, 56: 375-397 BRoomME, C. R., i. W. J. HaybDen, W. T Gtuts, AND D.E. STONE. Systematics and palynology of Picroden- dron: further evidence for relationship with the Oldfieldioideae (Euphorbi- aceae), 65: 105-127 BUCHHEIM, GUNTHER. Bigelow’s ““Amer- ican Medical Botany,’ 55: 46-50 Buchnera (Scrophulariaceae) from Colom- bia, A spectacular, 59: 298 Buck, WILLIAM R., AND MICHAEL J. Huet. Two new species of Euphorbia subgenus Agaloma from Mexico, 58: 343-348 Bulbostylis from the West Indies, A new combination in, 60: 322 Bunt, J. S., R. B. Primack, N. C. DUKE AND P. B. ToMLinson. Lumnitzera ro- sea (Combretaceae) — its status and floral morphology, 59: 342-351 Burcu, I. H., AND S. A. SPONGBERG. Lar- dizabalaceae hardy in ne North America, 60: 302- BuRKART, ARTURO. A monograph of the genus Prosopis (Leguminosae subfam. Mimosoideae), 57: 219-249, 450-525 Burkart, Arturo; a personal appreciation Bursera urseraceae), Systematic anato- myo amian species of, 60: 163-165 Burtt, B. L. sie ae _ Staur- anthera (Ges ae) New Sa with paneer a on ar genus, 65: -133 Caesalpinia subgenus Guilandina in the Bahamas, 55: 425-430 Caesalpinioideae (Leguminosae) in the southeastern United States, The genera of, 57: 1-53 Caicos and Turks islands, New species and a new combination from the Bahamas, 58: 40-51 Caicos and Turks islands, New species from the Bahamas, 60: 154-162 California, A possible magnolioid floral axis, Loishoglia bettencourtil, from the Upper Cretaceous of central, 65: 95-104 California, Dicotyledonous wood from the JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Upper Cretaceous of central, 60: 323- 349: II, 61: 723-748: III. Conclusions, 62: 437-455 Calliandra haematocephala: history, mor- phology, and taxonom : 69-85 Calophyllum (Guttiferae), sep of the Old World species of, 61: Calophyllum (Guttiferae), es Old World species of. 1. The Mascarene species, 57: 7-1] Calycanthus floridus (Calycanthaceae)—a nomenclatural note, 62: 265, 266 CAMPBELL, CHRISTOPHER S. Systematics of the Andropogon virginicus complex (Gramineae), 64: 171-254 Cannabaceae in the southeastern United States, The genera of, 51: 185-203 CANTINO, PHILIP D., AND OTTo T. SOLBRIG. Reproductive adaptations in Prosopis (Leguminosae, Mimosoideae), 56: 185- 210 wn ty — Breton Island, lee Srentocunr sugar maple, Acer um ea 58: 307-324 Caricaceae in the southeastern United States, The, 63: 411-427 CARLQUIST, SHERWIN. Wood anatomy of Belliolum (Winteraceae) and a note on flowering, 64: 161-169 CARLQUIST, SHERWIN. Wood anatomy of Myrothamnus flabellifolia (Myrotham- naceae) and the problem of multiperfo- rate perforation plates, 57: 119-126 Caroline islands, The genus Cyrtandra in the Ryukyu and, 54: 105-110 Caryophyllus cotinifolius, What and whence was Miller’s, 56: 171-175 CASSENS, DANIEL L., AND REGIS B. MILLER. Wood anatomy of the New World Pithe- cellobium (sensu lato), 62: 1-44 Casuarinaceae in the southeastern United States, The, 63: 357-373 Catesby’s plants, The modern names for, 64: 511-546 niente (Melastomataceae), System- s of the Neotropical genus, 58: 73- 1 Central America, Notes on the genus Gal- e new species of Pic- ramnia (Simaroubaceae) from, 54: 315- 321 Central American Heliconia (Heliconi- aceae) with pendent inflorescences, Sys- tematics of, 65: 429-532 1985] aes American taxa of Heliconia (Hel- iconiaceae), New, 62: 243-260 eooapn ines hardy in temperate North Am -376 Cestrum (Solundcede) from southern Co- lombia, A new species of, 61: 113-115 CHANG, A. L., Z. CHENG, T. R. DUDLEY, S. A. HE, Y. X. Jin, Q. Y. Li, J. L. LUTEyn, S. A. SPONGBERG, S.C. Sun, Y. C. TANG, J. X. Wan, T. S. Yinc, B. Bar- THOLOMEW, AND D. E. BouFForpD. The 1980 Sino-American botanical expedi- tion to western Hubei Province, People’s 3 review ae (Hamamelidaceae), 58: 382- cnt (Melastomataceae) in the Lesser Antilles, Notes on Tibouchina and, 53: 399-402 CHENG, CHING-YUNG, AND CHUN-SHU YANG. A synopsis of the Chinese oe of Asarum (Aristolochiaceae), 64: 5 597 CHENG, Z., T. . ae S. A. He, Y. X. Jin, Q. Y. Li, J. L. Luteyn, S. A. SPONGBERG, i C. Sun, Y. C. TANG, J. xX. Wan, T. S. YING, B. BARTHOLOMEW, D. E. BOUFFORD, AND A. L. CHANG. The 1980 Sino-American botanical expedi- tion to western Hubei Province, People’s Republic of China, 64: 1-103 CHew, WEE-LEK. The genus Piper (Piper- aceae) in New ee Solomon Islands, and Australia, 1, 53: China, central, saan glyptostro- ides—its present status in, 64: 105- China, People’s Republic of, The 1980 Sino-American botanical expedition to western Hubei Province, 64: 1-103 Chinese species of Asarum (Aristolochi- ceae), A synopsis of the, 64: 565-597 Chionanthus species from Borneo, Two unusu i and the position of Myxopy- rum in the Oleaceae, 64: 619-626 eee. S. K., J. M. Bipincer, M. J. La- PIANA, ap G. J. PErsiNos. The ecology ofan elfin forest in Puerto Rico, 13. Phy- tochemical screening and literature sur- vey, 51: 540-546 Chromosome counts in cultivated juni- pers, 54: 369-376 Chromosome number and its significance SCHMIDT, INDEX TO AUTHORS AND TITLES 45 in Batis maritima (Bataceae), 57: 526- 530 Chromosome numbers in the Juglanda- ceae, 51: 534-539 Chromosome numbers of tree species of a lowland tropical community, 54: 422- 34 Chromosomes and relationships of Meta- sequoia and Sequoia (Taxodiaceae), The: an update, 65: 251-254 Chrysobalanaceae in the southeastern United States, The genera of, 51: 521- 28 CHAOS, pees: of blind vein-endings in mous venation of, 51: 70-88 erases (Verbenaceae), Dioecism in, 53: 386-389 Citharexylum (Verbenaceae), Dioecism in: an addendum, 54: 120 Cladocolea (Loranthaceae), The genus, 56: 65-335 sree harerias (Ericaceae), Generic limits n the tribe, and its position in the Rho- ide ee 59: 311-341 CLARK, Ross C. Ilex collina, a second species of Nemopanthus in the southern Appalachians, 55: 435-440 CLAUSEN, KRISTIN S., WILLIAM T. GILLIS, JR., AND RICHARD A. Howarpb. William Hamilton (1783-1856) and the Pro- dromus Plantarum Indiae Occidentalis (1825), 62: 211-242 CLAUSEN, KRISTIN §., AND RICHARD A. Howarpb. The Soule plant of St. Vincent, 61: 765-7 Clayton, Temple, ae and amateur botanist, aah [obituary, with portrait], 65: 1-4 ee ee Reinstatement of, 60: 515-522 Colombia, : new species of Cestrum (So- nem from southern, 61: 113-115 Colom spectacular Buchnera ee from, 59: 298 Colombia, The vegetation of the Serrania de Macuira, _ Guajira: comes laos arid est, 63: 1-30 Colombian cloud forest, The ecological, h some implications for island biogeography, 63: 31-61 Comparative anatomy and systematics of Moutabeae (Polygalaceae), 58: 109-145 46 Comparative anatomy and systematics ot Picrodendron, genus incertae sedis, 257-279 Comparative anatomy of Ulmaceae, 52: 523-585 p phological Dil- leniaceae, V. Leafanatomy, 51: 89-113; VI. Stamens and young stem, 51: 403- 422; VII. Additional notes on Acrotre- ma, 52: 319-333 CoNnaNT, Davin S. A revision of the genus Alsophila (Cyatheaceae) in the Ameri- cas, 64: 333-382 Conpe, Louis F., AND DONALD E. STONE. Seedling morphology in the Juglanda- ceae, the cotyledonary node, 51: 463- 477 CONSTANCE, LINCOLN, AND MILDRED E. MartTHIAs. A new species of Oreomyr- rhis (Umbelliferae, Apiaceae) from New Guinea, 58: 190-192 Contribution to the knowledge of cytology in Magnoliales, A, 55: 453-457 Convolvulaceae, the Neotropical—notes on ; Operculina, and Turbina, 64: 483-489 Convolvulaceae of the Lesser Antilles, The, 60: 219-271 Cordyline (Agavaceae), Morphological studies in, I. Introduction and general morphology, 52: 459-478; II. Vegetative morphology of Cordyline terminalis, 53: 113-127 Cordyline terminalis, Vegetative mor- phology of. Morphological studies in Cordyline (Agavaceae) II, 53: 113-127 Cornus (Cornaceae), Some observations on the reproductive biology of three species of, 65: pee CorRELL, DONOVAN S. A new species of Ateleia ee from the Baha- mas, 62: 261-263 CORRELL, DONOVAN S. New species and a new combination from the Bahamas, Caicos and Turks islands, 58: 40-51 CorRELL, DONOVAN 8S. New species and varieties from the Bahamas, Caicos and Turks islands, 60: 154-162 aie i gala A review , 58: 382-415 Additions and changes 1 In Costa Ric e genus ee (Contianacea in, 53: 553-55 Cottonwoods (Populus, Seen of sec- tions Abaso and Aigeiros, North Amer- ican, 58: 193-208 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ee BARBARA, RAY STOTLER, AND MarG elfin forest in Puerto Rico, Hepaticae of Pico del Oeste, 51: 56-69; 15. A study of the leafy hepatic flora of the Luquillo Mountains, 52: 435-458 Crassulaceae in the southeastern United States, The genera of, 59: 198-248 CRAVEN, L. A., AND T. G. HartLey. A revision of the ease species of Ac- mena (Myrtaceae), 58: 3 Criscl, JoRGE Victor. A armen: taxo- nomic study of the subtribe Nassauvi- inae (Compositae, Mutisieae), 55: 568- 610 Criscl, JoRGE Vicror. Marticorenia: a new nus of Mutisieae (Compositae), 55: -45 Crisct, JORGE VICTOR, AND CLODOMIRO MARTICORENA. Transfer of the Brazili- an Trixis eryngioides to Perezia (Com- positae, Mutisieae), 59: 352-359 CRITCHFIELD, WILLIAM B. Sargent’s fir hy- brid: Abies amabilis x lasiocarpa, 58: 2-5 CRITCHFIELD, WILLIAM B. Shoot growth and heterophylly in Acer, 52: 240-266 CROWLEY, WEBSTER R., MARION T. HALL, AND APARNA MUKHERJEE. Chromo- some counts in cultivated junipers, 54: 369-376 Cruciferae (Brassicaceae) in North Amer- ica, Weeds of the, 62: 517-540 Cruciferae (Brassicaceae) in the southeast- ern United States, The tribes of, 65: 343- 373 Cruciferae of western North America, Studies in the, 64: 491-510 Cubitanthus, a new genus of Gesneriaceae from Brazil, 65: 145-147 CuLLEN, J. The genus Neillia (Rosaceae) in mainland Asia and in cultivation, 52: 137-158 Cunoniaceae, Fruits and seeds of the, 65: 149-190 Cussonia spicata (Araliaceae), Develop- of the digitately compound leaf in, 56: 256-263 Cycads, Taxonomy of the West Indian, 61: 701-722 Cyclanthaceae, Two new species and a new subgenus of, 59: 74-102 Cyrtandra in the Ryukyu and Caroline is- lands, The genus, 54: 105-110 1985] Cytological studies in Ulmaceae, Mora- ceae, and Urticaceae, 55: 663-677 Cytological studies on Himalayan Meli- aceae, 53: 558-568 Cytology and evolution in Hamamelida- ceae, 58: 67-71 Cytology of West Indian Betulaceae and Salicaceae, 54: 412-418 C hol f Moraceae, 53: 216-225. Cytotaxonomic notes on some Gentiana- ceae, 56: 211-222 DANIEL, THOMAS F. Systematics of Hol- ographis (Acanthaceae), oe 129-160 Darwin, STEVEN P. ecies of Ti- monius (Rubiaceae) ath Papuasia, 64: 611-618 Darwin, STEVEN P. Notes on Airosperma (Rubiaceae), with a new species from Fiji, 61: 95-105 DARWIN, STEVEN P. The genus Lindenia (Rubiaceae), "37; 426-449 DaRWIN, STEVEN P. The genus and dendron (Rubiaceae), 58: 349- Darwin, STEVEN P., AND ALBERT C, iaie Studies of Pacific island plants, XX VIII. The Guttiferae of the Fijian region, 55: 215-263 Dates of publication of Sargent’s Silva of North eee 59: 68-73 Davis, J.S., AND P. B. TOMLINSON. A new species of ee in high salinity in Western Australia, 55: 59-66 Derris from the Solomon Islands, A new species of. Studies in the Leguminosae, 11, 51: 251-254 Development of the digitately compound leaf in Cussonia spicata (Araliaceae), 56: 56-263 Duar, UsHA, AND M. R. VJAYARAGHAVAN. Kadsura heteroclita— microsporangium and pollen, 56: 176-182 DICKISON, WILLIAM C. Comparative stud- ies in Dilleniaceae, V. Leaf anatomy, 51: 89-113; VI. Stamens and young stem, 51: 403-422: VII. Additional notes on Acrotrema, 52: 319-333 DickIsoN, WILLIAM C. Fruits and seeds of the Cunoniaceae, 65: 149-190 DICKISON, 1AM C., AND PHILLIP M. Rury. Leaf venation patterns of the ge- nus Hibbertia (Dilleniaceae), 58: 209- 256 SCHMIDT, INDEX TO AUTHORS AND TITLES 47 DickisoNn, WILLIAM C., PHILLIP M. Rury, AND EDYARD STEBBIN Ns. Xylem anatomy of Hibbertia (Dilleniaceae) in relation to ecology and evolution, 59: 32-49 DickISON, WILLIAM C., AND WILLIAM E., SCHADEL. Leaf anatomy and venation patterns of the Styracaceae, 60: 8-37 Dicotyledoneae, The stem-node-leaf con- tinuum of the, 55: 125-181 Dicotyledonous wood from the Upper Cre- taceous of central California, 60: 323- 349; II, 61: 723-748; III. Conclusions, 62: 437-455 Dicotyledons, Observations of reaction fi- bers in leaves of, 63: 173-185 Dilleniaceae, ae morphological studies in, V. Leaf anatomy, 51: 89-113; VI. Stamens and young stem, 51: 403- 422; VII. Additional notes on Acrotre- ma, 52: 319-333 Dimorphanthera (Ericaceae), Additional notes on, 58: —444 Dioecism in Citharexylum (Verbenaceae), 53: 386-389 Dioecism in Citharexylum (Verbenaceae): n addendum, 54: 120 Dioscorea composita, Analysis of the com- plex vascularity in stems of, 51: 228-240 Diospyros (Ebenaceae) in Fiji, Samoa, and Tonga, The genus. Studies of Pacific is- land plants, XXIII, 52: 369-403 Diphylleia (Berberidaceae), A monograph of, 65: 57-94 Dominica, Notes for the flora of: Sper- macoce confusa and Schradera exotica (Rubiaceae), 58: 445-450 Dracaena draco—dragon’s blood tree, The growth of, 55: 51-58 Dracaena fragrans (Agavaceae), The vas- cular system in the axis of, 2. Distribu- tion and development of secondary vas- cular tissue, 51: 478-491 Drury, WILLIAMC., AND IANC. T. NISBET. Succession, 54: 331-368 - ie) | Sino-American botanical expedition to western Hubei Province, People’s Re- public of China, 64: 1-103 Duke, N. C., P. B. ToMuinson, J. S. BuNT, 48 AND R. B. Primackx. Lumnitzera rosea (Combretaceae)—its status and_ floral morphology, 59: 342-351 Ebenaceae hardy in temperate North America, 58: 146-160 ECKENWALDER, JAMES E. North American cottonwoods (Populus, Salicaceae) of sections Abaso and Aigeiros, 58: 193- 208 ECKENWALDER, JAMES E. Taxonomy of the West Indian cycads, 61: 701-722 Ecological, geographic, and taxonomic re- lationships of the flora of an isolated Co- lombian cloud forest, The, with some si for island biogeography, 63: 1-61 see of an elfin forest in Puerto Rico, , 10. Notes on two species of Marc- oe 51: 41-55; 11. The leafy ere icae of Pico del Oeste, 51: 56-69; new species of Gonocalyx eee a 221-227; 13. Phytochemical screening and literature survey, 51: 540-546; 14. The algae of Pico del Oeste, 52: 86-109; 15. A study of the leafy hepatic flora of tation ofits seasonality, 52: 586-613; 17. Epiphytic mossy vegetation of Pico del Oeste, 58: 1-24 Elephantorrhiza elephantina, The mor- y and germination of the seed of, 28 Eleutherococcus vs. Acanthopanax, 61: 107-111 Elfin forest in Puerto Rico, The ecology of an, 10. Notes on two species of Marc- gravia, 51: 41-55; 11. The leafy ca icae of Pico del Oeste, 51: 56-69; 12. A of Gonocalyx 8 5]. ; 13. Phytochemical ets and literature survey, 51: 540-546; The algae of Pico del tee 52: 86- ie 15. A study of the leafy iap flora of the Luquillo Mountains, 52: 8; 16. The flowering cycle and an ee tation ofits seasonality, 52: 586-613; 17. Epiphytic mossy vegetation of Pico del Oeste, 58: 1-24 Evias, THOMAS S. Notes on the genus Gal- ipea (Rutaceae) in Central America, 51: 27-430 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Eias, THOMAS S. The genera of Fagaceae in the southeastern United States, 52: 159-195 Euias, THomAs S. The genera of Juglan- daceae in the southeastern United States, 53: 26-51 Euias, THOMAS S. The genera of Mimo- soideae (Leguminosae) in the southeast- ern United States, 55: 67-118 Euias, THomas 8. The genera of Myrica- ceae in the southeastern United States, 52: 305-318 ELias, THOMAS S. The genera of Ulmaceae in the southeastern United States, 51: 18-40 ae THOMAS S., AND Lorin I. NEVLING, Calliandra haematocephala: history, napisy, and taxonomy, 52: 69-85 Embryology of the Magnoliales and com- ments on their relationships, 52: 1-39, -304 Enpress, PETER K., AND PETER GOLD- BLATT. Cytology and evolution in Ham- amelidaceae, 58: 67-71 Enumeratio and Selectarum of Nicolaus von Jacquin, The, 54: 435-47 Ephedra, Venation patterns in the leaves of, 53: 364-385 Erythrina, Notes on Asiatic-Polynesian- Australian species of, I], 53: 128-139 Ethnoflora of Chokoloskee Island, Collier County, Florida, An, 59: 50-67 Eugenia, Floral anatomy of Myrtaceae, II, 53: 336-363 Eugenia maire (Myrtaceae) of New Zea- and, A new combination in Syzygium for, 60: 396-401 Euphorbia (Euphorbiaceae) from southern Mexico, A remarkable new dimorphic, 63: 97-101 Euphorbia subgenus Agaloma from Mex- ico, Two new species of, 58: 343- aan Eype, RICHARD H., AND CHARLES C, TSEN¢ hat is the primitive floral structure of Araliaceae, 52: 205-239 Fagaceae in the ee United States, The genera of, 52: -195 Fagaceae, A ara architecture and evolution in the, 65: 375-401 ee PRISCILLA, AND P. B. TOMLIN- Dioecism in Citharexylum (Ver- ee. 53: 386-389 Features of pollen flow in Gelsemium sem- pervirens (Loganiaceae), 60: 377-381 1985] FERNANDEZ, P., OZANO, AND E. MARTINEZ- SHER NEE: Pollen of trop- ical trees, I. Tiliaceae, 59: 299-309 Fiji, Notes on Airosperma (Rubiaceae), with a new species from, 61: 95-105 Fiji, Samoa, and Tonga, The genus Dio- spyros (Ebenaceae) in. Studies of Pacific island plants, X XIII, 52: 369-403 Fijian region, The Guttiferae of the. Stud- ies of Pacific island plants, XXVIII, 55: 215-263 Fijian region, The Myrsinaceae of the. Studies of Pacific island plants, XXV, 54: 1-41, 228-292 oe otras of Stauranthera (Gesneri- w Guinea, The, with gen- at se on ae genus, 65: 129-133 FISHER, J. B., AND P. B. TOMLINSON. Mor phological de in Cordyline (hea: vaceae) I. Introduction and general mor- phology, 52: 459-478; Vegetative morphology of Cordyline terminalis, 53: 113-127 Flacourtiaceae, Systematic anatomy of the xylem and comments on the relation- ships of, 56: 20-102 Flindersia (Rutaceae), ae notes on the genus, 56: 243-2 Floral anatomy of ae II. Eugenia 53: 336-363 Floral morphology and vascular anatomy of the Hamamelidaceae: the apetalous genera of Hamamelidoideae, 51: 310- 366 Floral structure and relationships of the Florida, Dredge 16 mechanisms in trees na- Florida endemic, A: Sisyrinchium solsti- tiale (Iridaceae), 55: 291-299 FOERSTER, JOHN W. The ecology ofan elf- in forest in Puerto Rico, 14. The algae of Pico del Oeste, 52: 86-109 Foliar trichomes of Quercus subgenus Quercus in the eastern United States, 60: 350-366 Form of the perforation plates in the wide vessels of metaxylem in palms, 59: 105- 128 Fossil dicotyledonous woods from Yellow- tone National Park, 58: 280-306; II, 59: 1-31 SCHMIDT, INDEX TO AUTHORS AND TITLES 49 FosTeR, ADRIANCE S. Types of blind vein- endings in the dichotomous venation of Circaeaster, 51: 70-88 FosTeR, ADRIANCE Venation patterns _ in the leaves of Ephedra, 53: 364-385 Malesia and Southeast Asia. Studies in Malesian Pan- danaceae, 19, 64: 309-324 Fropin, D Studies in Schefflera (Ara- liaceae): the Cephaloschefflera complex, 56: 427-448 Fruits and seeds of the Brandon Lignite, V. Rutaceae, 61: 1-40; VI. Microdiptera (Lythraceae), 62: 487-516 Fruits and seeds of the Cunoniaceae, 65: FrRYXELL, PAUL A new Herissantia (Malvaceae) from the West Indies, 60: 316-319 FrYXELL, PAuL A. Revision and expan- sion of the Neotropical genus Wercklea (Malvaceae), 62: 457-486 ULFORD, MARGARET, BARBARA CRAN- leafy Hepaticae of Pico del Oeste, 51: 56- 69; 15. A study of the leafy hepatic flora of the Luquillo Mountains, 52: 435-458 Galipea (Rutaceae) in Central America, Notes on the genus, 51: 427-430 Garay, LestiE A. On the origin of the Orchidaceae, II, 53: 202-215 Garay, LESLIE A., AND HERMAN R. SWEET. Notes on West Indian orchids, I, 53: 390-398; III, 53: 515-530 GARNOCK-JONES, P. J., AND W. R. SYKES. A new combination in apraeeee for Eu- genia maire as of New Zea- land, 60: 396-4 Gaultheria swartzii, nom. nd th combinations in Be eaeicli S bined. tor, 56: 240-242 Gelsemium (Loganiaceae), Poe systemat- ics and breeding system of, 51: 1-17 Gelsemium sempervirens ene Features of pollen flow in, 60: 377-381 Genera of Acanthaceae in the southeastern United States, The, 51: 257-309 Genera of Alismataceae in the southeast- ern United States, The, 64: 383-420 maranthaceae in the south- ern United States, The, 56: 375-397 50 JOURNAL OF THE ARNOLD ARBORETUM Genera of Burmanniaceae in the south- eastern United States, The, 64: 293-307 Genera of Caesalpinioideae (Leguminosae) in the southeastern United States, The, 57: 1-53 Genera of Cannabaceae in the southeastern United States, The, 51: 185-203 Genera of Chrysobalanaceae in the south- eastern United States, The, 51: 521-528 Genera of Crassulaceae in the southeastern United States, The, 59: 198-248 Genera of Fagaceae in the southeastern United States, The, 52: 159-195 Genera of Gentianaceae in the southeast- ern United States, The, 63: 441-487 Genera of Geraniaceae in the southeastern United States, The, 53: 182-201 Genera of Guttiferae (Clusiaceae) in the southeastern United States, The, 74-9 Genera of Haemodoraceae in the south- eastern United States, The, 57: 205-216 Genera of Juglandaceae in the southeastern United States, The, 53: 26-51 Genera of Lactuceae (Compositae) in the southeastern United States, The, 5 42-9 Genera of Melastomataceae in the south- eastern United States, The, 63: 429-439 Genera of Menyanthaceae in the south- eastern United States, The, 64: 431-445 Genera of Mimosoideae (Leguminosae) in the southeastern United States, The, 55: -118 Genera of Molluginaceae and Aizoaceae in the southeastern United States, The, 51: 431-462 Genera of Myricaceae in the southeastern United States, The, 52: 305-318 Genera of Nyctaginaceae in sa southeast- ern United States, The, 55: 1-37 Genera of Olacaceae in the en United States, The, 63: 387-399 Genera of Orobanchaceae in the south- eastern United States, The, 52: 404-434 Genera of Rosaceae in the southeastern United States, The, 55: 303-332, 344- 401, 611-662 Genera of Saxifragaceae in the southeast- n United States, The, 53: 409-498 Genera of Ulmaceae in the southeastern United States, The, 51: 18-40 Genera of the Urticaceae in the southeast- ern United States, The, 52: 40-68 Genera of Vernonieae (Compositae) in the [VOL. 66 southeastern United States, The, 63: 489-— 507 Genera of Zygophyllaceae in the south- eastern United States, The, 53: 531-552 Generic Flora of the Southeastern United Generic limits in the tribe Cladothamneae (Ericaceae), and its position in the Rho- dodendroideae, 59: 311-341 Generic limits in the Xeroteae (Liliaceae sensu lato), 59: 129-155 Generic relationships in the Andromedeae (Ericaceae), 60: 477-503 Gentianaceae, Cytotaxonomic notes on some, 56: 211-222 Gentianaceae in the southeastern United States, The genera of, 63: 441-487 Genus Anetanthus (Gesneriaceae), The, 56: 4-3 Genus Cladocolea (Loranthaceae), The, 56: 265-335 Genus Cyrtandra in the Ryukyu and Car- oline islands, The, 54: 105-110 Genus Gymnocladus and its tropical affin- ity, The, 57: 91- Genus Lindenia (Rubiaceae), The, 57: 426- 449 Genus Macrocarpaea (Gentianaceae) in Costa Rica, The, 53: 553-557 Genus Mastixiodendron (Rubiaceae), The, 58: 349-381 Genus Neillia (Rosaceae) in mainland Asia and in cultivation, The, 52: 137-158 Genus Phyllocladus (Phyllocladaceae), The, —273 Genus Piper (Piperaceae) in New Guinea, Solomon Islands, and Australia, The, |, 53: 1-25 Geraniaceae in the pre United States, The genera of, 53: —201 Gesneriaceae from cera Cobian a new genus of, 65: 145- GIDEON, OsiA. A new name in Sperma- coce for two species of Borreria from New Guinea, 64: 627, 628 GILL, B.S., AND P. N. MEHRA. Cytological studies in Ulmaceae, nes and Ur- ticaceae, 55: 663-677 LETT, GEORGE W. Lenbrassia an Queensland, 55: 431 -434 GILLETT, GEORGE W. The genus Cyrtan- dra in the Ryukyu and Caroline islands, 54: 105-110 1985] GILLETT, GEORGE W. The taxonomic sta- tus of Protocyrtandra (Gesneriaceae), 51: —246 GILLIS, WILLIAM T., JR., RICHARD A. HowarD, AND KristTIN A. CLAUSEN. William Hamilton (1783-1856) and the Prodromus Indiae Occidentalis (1825), 62: 211-242 GILLIS, WILLIAM T., AND JAMES A. MEARS Gomphrenoideae (Amaranthaceae) of the Bahama Islands, 58: Ee GILLIs, WILLIAM T., D GEORGE R. PROCTOR. eee. meee Gui- landina in the Bahamas, 55: 425-430 GILLis, WILLIAM T., D. E. Stone, C. R. Broome, G. L. WEBSTER, AND W. AYDEN. Systematics and palynology of etre further evidence for re- lationship with the Oldfieldioideae (Eu- phorbiaceae), 65: 105-127 GOLDBLATT, PETER. A contribution to the knowledge of cytology in Magnoliales, 55: 453-457 GOLDBLATT, PETER. Chromosome num- ber and its significance in Batis maritima (Bataceae), 57: 5 GOLDBLATT, PETER, AND PETER K. ENDRESS. Cytology and evolution in Hamameli- daceae, 58: 67-71 GOMEz-Pompa, ARTURO, AND SERGIO GUEVARA S. Seeds from surface soils in a tropical region of Veracruz, Mexico, §3: 312-335 Gomphrenoideae (Amaranthaceae) of the Bahama Islands, 58: 60-66 Gonocalyx (Ericaceae), A new species of. The ecology of an elfin forest in Puerto Rico, 12, 51: 221-227 GouLb, FRANK W. Notes on American ce 60: 320, 321 GRAHAM, S. A., AND C. E. Woop, Jr. The ian aes in the southeastern United States, 56: 456-465 Green, P. S. Notes relating to the floras of Norfolk and Lord Howe islands, 51: 204-220 GREENIDGE, K. N. H. Silvical character- istics of sugar maple, Acer saccharum, in northern Cape Breton Island, 58: 307- 324 Grosser, D., AND W. LiEsE. Present status and problems of bamboo classification, 54: 293-308 Growth of Dracaena draco, The—dragon’s blood tree, 55: 51-58 SCHMIDT, INDEX TO AUTHORS AND TITLES 51] Grubbs, P. J.,. AND E. V. J. TANNER. The iioHtne forests and soils of Jamaica: a reassessment, 57: 313-368 Guadeloupe, 1977-1979, The post-erup- tive vegetation of La Soufriére, 61: 749- 764 GUEVARA §S., SERGIO, AND ARTURO Gomez-Pompa. Seeds from surface soils in a tropical region of Veracruz, Mexico, 53: 312- GUNATILLEKE, C. V. S., AND I. A. U. N GUNATILLEKE. Some observations on the reproductive biology of three species of Cornus (Cornaceae), 65: 419-427 GuNATILLEKE, I. A. U. N., AND C. V. S. GUNATILLEKE. Some observations on the reproductive biology of three species of nus (Cornaceae), 65: 419-427 Guttiferae (Clusiaceae) in the southeastern United States, The genera of, 57: 74-90 Guttiferae of the Fijian region, The. Stud- ies of Pacific island plants, XX VIII, 55: 215-263 Guyana, New taxa from Brazil and, in the enus See (Leguminosae, Caesal- pinioideae), 54: 94-104 Gymnocladus its tropical affinity, The genus, 57: 91-112 Haemodoraceae in the southeastern United some counts in cultivated junipers, 54: 369-376 Hamamelidaceae, Cytology and evolution in, 58: 67-71 Hamamelidaceae, Floral morphology and vascular anatomy of the: the apetalous genera of Hamamelidoideae, 51: 310-— ee the apetalous genera of: Floral morpho Hamilton, William (1783- 1856), and the Prodromus Plantarum Indiae Occiden- talis (1825), 62: 211-242 Hans, A. S. Chromosome numbers in the Juglandaceae, 51: 534-539 Hans, A. 8. Cytomorphology of arbores- cent Moraceae, 53: 216-225 Haploid and diploid pollen in Hypericum patulum, 51: 247-250 Harpin, JAMES W. Hybridization and in- trogression in Quercus alba, 56: 336-363 52 JOURNAL OF THE ARNOLD ARBORETUM HartLey, THOMAS G. A new species of Zanthoxylum (Rutaceae) from New Guinea, 56: 369-373 HARTLEY, THOM . A revision of the genus peers ee 58: 171-181 HartLey, THOMAS G. A revision of the genus Acronychia (Rutaceae), 55: 469- 523, 525-567 Hart.Ley, THomMas G. A revision of the genus ce ‘eaten 58: 416-436 Hartley, THOMAS G. A revision of the genus aan (Rutaceae), 60: 127- 153 HartLey, THOMAS G. Additional notes on the Malesian species of Zanthoxylum (Rutaceae), 51: 4 HARTLEY, THOMAS G. The taxonomic sta- tus of the genus Bauerella (Rutaceae), 56: 70 HARTLEY, THOMAS G., AND L. A. CRAVEN. A revision of the Series Oe of Acmena (Myrtaceae), 58: 3 AND B. P. Additional notes on the genus Flindersia (Rutaceae), 56: 243-247 HARTLEY, THOMAS G., AND L. M. Perry. A provisional key and enumeration o species of Syzygium (Myrtaceae) from Papuasia, 54: 160-227 HAUFLER, CHRISTOPHER H. A biosystem- atic revision of Bommeria, 60: 445-476 Haypben, W. JOHN. Comparative anato- my and systematics of Picrodendron, ge- nus incertae sedis, 58: 257-2 , W. Joun, W. T. Gittis, D. E. R. BROOME, AND L. WERSTER. “Systematics and palynology of Picrodendron: further evidence for re- lationship with the oe (Eu- phorbiaceae), 65: 105- aa puaueel R. ne Najadaceae in astern United States, 58: 161- a 170 Haynes, Rosert R. The Potamogetona- ceae in the southeastern United States, 59: 170-191 He, S.A., Y. X. Jin, Q. Y. Li, J. L. Luteyn, S.A. ; SrocnenG ©: C. Sun, Y.C. TANG, dt Wan, T. S. Yinc, B. BaAr- THOLOMEW, D. E. Bourrorp, A. L. NG, Z. CHENG, AND T. R. DUDLEY. The 1980 Sino-American botanical ex- pedition to western Hubei Province, People’s Republic of China, 64: 1-103 [VOL. 66 HEspbA, RICHARD J., P. F. Stevens, BRUCE A. Boum, AND Scott W. Brim. Generic limits in the tribe Cladothamneae (Eri- caceae), and its position in the Rhodo- dendroideae, 59: 311-341 Heliconia (Heliconiaceae), New Central merican taxa of, 62: 243-260 Heliconia (Heliconiaceae) with pendent in- florescences, Systematics of Central American, 65: 429-532 Hepatic flora of the Luquillo Mountains, A study of the leafy. The ecology of an elfin forest in Puerto Rico, 15, 52: 435- 458 Hepaticae of Pico del Oeste, The leafy. The ecology of an elfin forest in Puerto Rico 11, 51: 56-69 Henscantia (Malvaceae) from the West In- dies, A new, 60: 316-319 Heterostyly in Oplonia (Acanthaceae), 60: 382-3 Hibbertia (Dilleniaceae) in relation to ecol- ogy and evolution, Xylem anatomy of, : 32-49 Hibbertia (Dilleniaceae), Leaf venation patterns of the genus, 58: 209-256 tology of West, 54: 412-418 Himalayan Meliaceae, Cytological studies on, 53: 558-568 Hinton, George B., collector of plants in southwestern Mexico, 53: 141-181 Holographis (Acanthaceae), Systematics of, 129-160 Howarp, E. S., AND R. A. Howarp. The West Indian taxa in Solander’s ‘‘Florula Indiae Occidentalis,”’ 63: 63-8 1 Howarb, RicHArD A. David Sturrock (1893-1978)—mentor ae ie [obit- uary, with portrait], 60: Howarb, RICHARD A. © anes swart- Zil, nom. nov., and the combinations in Raeuschel’s Peano 56: 240-242 Howarp, RICHé . Karl Sax, 1892- 1973 one ae portrait], 55: 333- 343 Howarp, RicHArD A. Lazella Harenberg , 1900-1973 [obituary], 54: Howarpb, RICHARD A. Lindernia brucei, a new West Indian species of the Asian section Tittmannia, 56: 449-455 Howarpb, RIcHARD A. Nomenclatural notes on some Lesser Antillean Mono- cotyledoneae, 60: 290-301 1985] Howarp, RicHArpD A. Nomenclatural notes on the Araceae of the Lesser An- anes an 272-289 Ho , RicHArD A. Nomenclatural Aas on the Lauraceae of the Lesser An- tilles, 62: 45-61 Howarp, RicHAarD A. Notes on the Pi- peraceae of the Tey Antilles, 54: 377- 411 Howarb, RicHARD A. Notes on Tibou- china and Charianthus (Melastomata- ceae) in the Lesser Antilles, 53: 399-402 two species of Marcgravia, 51: 41-55 Howarp, RICHARD A Enumeratio and Selectarum of Nicolaus von Jacquin, 54: 435-470 Howarb, RICHARD A. The genus Anetan- thus (Gesneriaceae), 56: 364-368 Howarp, RICHARD A. The plates of Au- blet’s Histoire des Plantes de la Guiane stem-node-leaf continuum of the Dicotyledoneae, 55: 125-181 Howarp, RICHARD A., AND KRISTIN S. CLAUSEN. The Soufriére plant of St. Vincent, 61: 765-770 Howarb, RICHARD A., KRISTIN S. CLAU- SEN, AND WILLIAM T. GILLIS, JR. Wil- liam Hamilton (1783-1856) and the Prodromus Plantarum Indiae Occiden- talis (1825), 62: 211-242 Howarb, RICHARD A., AND E. S. HOWARD. The West Indian taxa in Solander’s “Florula Indiae Occidentalis,” 63: 63-8 Howarpb, RICHARD A., JACQUES PorR- TECOP, AND PIERRE DE MONTAIGNAC. The post-eruptive vegetation of La Sou- friére, Guadeloupe, 1977-1979, 61: 749- 764 Howarpb, RICHARD A., AND GEORGE W. STAPLES. The modern names for Cates- by’s plants, 64: 511-546 Hu, SHiu YinG. Eleutherococcus vs. Acanthopanax, 61: ee aa Hu, SuHiu YING. sequoia flora and its Se ec a 61: 41-94 Hurt, MicHaer J. A remarkable new di- morphic Euphorbia (Euphorbiaceae) from southern Mexico, 63: 97-101 Hurt, MicHae_ J., AND WILLIAM R. Buck. SCHMIDT, INDEX TO AUTHORS AND TITLES 53 Two new species of Euphorbia subgenus —348 Cestrum (Solanaceae) from southern Co- lombia, 61: 113-115 Hybridization and introgression in Quer- cus sea 56: 336-3 HyYLAN Additional notes. on the genus Flindersia (Rutaceae), 56: 243-247 Hymenaea (Leguminosae, Caesalpinioi- deae), Additional new ew combinations in, 55: 441-452 Hymenaea (Leguminosae, Caesalpinioi- deae), New taxa from Brazil and Guyana in the genus, 54: 94-104 Hypericum patulum, Haploid and diploid pollen in, 51: 247-250 Ilex See a second species of Nemo n the southern Appalachians, 55: 435-4 440 Ilex collina and Nemopanthus (Aquifoli- aceae), Vegetative anatomy and the taxonomic status of, 65: 24 Inbreeding depression in Metasequoia, 64: 475-48 1 Indexes to papers | to 100 published as parts of the Generic Flora of the South- eastern United States, 64: 547-563 Inff hit t qd latian in the Fagaceae, 65: 375-401 Isozyme variation in species of Prosopis (Leguminosae), 56: 398-412 Jacquin, The Enumeratio and Selectarum of Nicolaus von, 54: 435-470 Jamaica, ew species of Reynosia (Rhamnaceae) from, 52: 364-367 Jamaica, More additions to the flora of, 63: 199-315 Jamaica, The montane forests and soils of: a reassessment, 57: 313-368 Jamaican gamopetalous plants, Taxonom- ic and nomenclatural notes on, 52: 614- 648 Jin, Y. X., Q. Y. Li, J. L. Luteyn, S. A. SroncHens, S.C. SUN, Y.C. TANG, J. X. Wan, T. S. Yinc, B. BARTHOLOMEW, D. E. Bee JFFORD, A. L. CHANG, Z. CHENG, T. R. Dubey, AnD S. A. He. The 1980 Sino-American botanical expedition to western Hubei Province, People’s Re- public of China, 64: 1-103 JouNson, L. C., S. E. SCHLARBAUM, AND 54 JOURNAL OF THE ARNOLD ARBORETUM T. Tsucuiya. The chromosomes and relationships of Metasequoia and Se- quoia (Taxodiaceae): an update, 65: 25 1- 2 54 JOHNSTON, MARSHALL C. A new species of Reynosia (Rhamnaceae) from Jamai- ca, 52: 364-367 JOHNSTON, MARS LC. Revision of Kentrothamnus ian 54: 47\- 473 JONES, SAMUEL B., Jr. The genera of Ver- nonieae (Compositae) in = southeast- erm United States, 63: 489-507 Jubb, WALTERS. A aaa oe (Ericaceae), 62: 63-209, 315-4 Jupp, WALTER S. A tax cara ies of Pieris erage a 63: 103- Jupp, WAL A eats ane of the oe. species of Agarista (Er- icaceae), 65: 255-342 JUDD, WALTER 8. Generic relationships in the Andromedeae (Ericaceae), 60: 477- 503 Juglandaceae, Chromosome numbers in -539 Juglandaceae in the southeastern United States, The genera of, 53: 26-51 ta Seedling morphology in the, the cotyledonary node, 51: 463-477 Junipers, Chromosome counts in cultivat- ed, 54: 369-376 Kadsura_ heteroclita—microsporangium and pollen, 56: 176-182 Kashmir, A revision of the Boraginaceae of West Pakistan and, 51: 133-184, 367- 402, 499-520; 52: 110-136, 334-363, 486-522, ne 690 KaAuL, Ropert B., AND Ernst C. ABBE. arene architecture and evolution in the Fagaceae, 65: 375-401 Kazi, S. M. A. A revision of the Borag- inaceae of West Pakistan and Kashmir, 51: 133-184, 367-402, 499-520: 52: 110-136, 334-363, eee 522, 666-690 KEEFE, JOSEPH M., D MAYNARD F. MOSELEY, Tr. Wood a aa and phy- logeny of Paeonia section Moutan, 59: —297 KEELEY, STERLING C. A revision of the West Indian vernonias (Compositae), 59: 360-413 NG, Hsuan. The genus Phyllocladus (Phyllocladaceae), 59: 249-273 [VOL. 66 Kentrothamnus (Rhamnaceae), Revision of, 54: 471-473 MEHRA, AND T. S. N. Cytological studies on Hima- layan Meliaceae, 53: 558-568 Two unusual Chionanthus species from Borneo and the position of Myxopyrum in the Oleaceae, 64: 619- 626 Aw = Or: n z >: ac) Kotz, Larry H. Form of the perforation plates in the wide vessels of metaxylem in palms, 59: 105-128 oe bipinnata, a misnomer for: ocarya esquirolii, 58: 189 rato (Sapindaceae), A revision of the genus, 57: 129-166 Koyama, TETSUO. A new combination in Bulbostylis from the West Indies, 60: 322 KraL, RoBert. The Xyridaceae in the ine eae United aan 64: 421-429 KRAL, Ro J WURDACK. The ae Ta ay Tenens in the southeastern United States, 63: 429-439 Krameriaceae in the southeastern United States, The, 54: 322- od Kress, W. JoHN. New tral American taxa of Helicon (Heliconiaceae), 62: 243-260 Kress, W. JOHN. Systematics of Central American Heliconia (Heliconiaceae) with pendent inflorescences, 65: 429-532 Krukorr, B. A. Notes on Asiatic-Polyne- sian-Australian species of Erythrina, II, 53: 128-139 Kupirzkl, K., H. Kurz, Anp H. G. Ricu- TER. Reinstatement of Clinostemon (Lauraceae), 60: 515-522 Kuurt, Jos. The genus Cladocolea (Loran- -335 Kurz, H., H. a. AND K. Reinstatement of Clinoste- mon (Lauraceae), 60: 515-522 Kuser, JOHN. Inbreeding depression in Metasequoia, 64: 475-48 1 Lactuceae (Compositae) in the southeast- ern United States, The genera of, 54: 42-93 LaFrankie, James V., Jr. Anatomy of stem abscission in the genus Smilacina (Lili- aceae), 65: 563-570 LANGENHEIM, JEAN H., AND YIN-TSE LEE. 1985] Additional new taxa and new combi- nations in Hymenaea (Leguminosae, Caesalpinioideae), 55: 441- LANGENHEIM, JEAN H., AND YIN-TSE LEE. New taxa from Brazil and Guyana in the enus Hymenaea (Leguminosae, Caesal- Sonera? - 94- LAPIANA, . J. Persinos, S. K. CHRISTIE, AND J. M. Brpincer. The ecology of an elfin forest in Puerto Rico, 13. Phytochemical screening and litera- ture survey, 51: 540-546 Lardizabalaceae hardy in temperate North America, 60: 302-31 Lateglacial plants and plant communities in northwestern New York State, 54: 123- 159 Lauraceae hardy in temperate North America, 56: 1-19 Lauraceae of the Lesser Antilles, Nomen- clatural notes on the, 62: 45-6 Leaf anatomy and venation patterns of the Styracaceae, 60: 8-37 Leaf venation patterns of the genus Hib- bertia (Dilleniaceae), 58: 209-256 Lee, YiIN-Tse. The genus Gymnocladus and its tropical aes 57: 91-112 N H. LANGENHEIM. nations in Hymenaea (Leguminosae, Caesalpinioideae), 55: 441-452 Lee, YIN-TseE, AND JEAN H. LANGENHEIM. New Taxa from Brazil and Guyana in the genus Hymenaea (Leguminosae, Caesalpinioideae), 54: 94-104 Lee, YIN-TSE, AND KENNETH R. ROBERT- SON . The genera of Caesalpinioideae (Leguminosae) in the southeastern United States, 57: 1-53 Leguminosae, Studies in, 1 1. A new species of Derris from The Solomon Islands, 51: 251-254 Leguminosae, Two new species of, 52: 691- 694 pees Sousa a new genus en- orth Queensland, 55: 431-434 Lesser Antilles, Nomenclatural notes on the Araceae of the, 60: 272-289 Lesser Antilles, Nomenclatural notes on the Lauraceae of the, Lesser Antilles, Notes on the Piperaceae of the, 54: 377-411 SCHMIDT, INDEX TO AUTHORS AND TITLES 53 Lesser Antilles, Notes on Tibouchina and Charianthus (Melastomataceae) in the, 53: 399-402 Lesser Antilles, The Convolvulaceae of the, 0: 219-271 Leucaena and Lysiloma, A reinterpreta- tion of, 57: 113-118 Li, Q. Y., J. L. Luteyn, S. A. SPONGBERG, S.C. SuN, Y.C. TANG, J. X. Wan, T.S. The 1980 Sino-American botanical ex- pedition to western Hubei Province, People’s Republic of China, 64: 1-103 Liese, W., AND D. Grosser. Present status and problems of bamboo classification, 54: 293-308 Linaceae in the southeastern United States, The, 52: 649-665 Lindenia (Rubiaceae), The genus, 57: 426- 449 Lindera (Lauraceae) from North America, A new, 64: 325-331 Lindernia brucei, a new West Indian species of the Asian section Tittmannia, 56: 449- 455 Lisianthus (Gentianaceae), A revision of the Neotropical genus, 53: 76-100, 234— 311 Loishoglia bettencourtii, A possible mag- nolioid floral axis, from the Upper Cre- taceous of central California, 65: 95-104 LonGc, Ropert W. The genera of Acan- thaceae in the southeastern United States, 51: 257-309 Lord Howe islands, Notes relating to the floras of Norfolk and, 51: 204-220 Lozano, S., E. MARTINEZ-HERNANDEZ, AND P. FERNANDEz. Pollen of tropical trees. I. Tiliaceae, 59: eae 309 tus and floral ae es 59: 342. 351 Luteyn, J. L., S. A. SPONGBERG, S. C. SUN, . TANG, J. X. Wan, T. S. YING, B. BARTHOLOMEW, D. E. BoUFFORD, A. L CHANG, Z. CHENG, T. R. DUDLEY, S. A. He, Y. X. Jin, AND Q. Y. Li. The 1980 Sino-American botanical expedition to western Hubei Province, People’s Re- public of China, 64: 1-103 Lyonia (Ericaceae), A monograph of, 62: 63-209, 315-436 56 JOURNAL OF THE ARNOLD ARBORETUM Lysiloma, A reinterpretation of Leucaena and, 57: 113-118 pa esurraie a in Costa CHAEL, AND aes TIFFNEY. The seeds of the Menicie their morphology and fossil record, 57: 185-204 Magnoliaceae hardy in temperate North America, 57: 250-312 Magnoliales, A contribution to the knowl- edge of cytology in, 55: 453-457 Magnoliales, Embryology of the, and com- on their relationships, 52: 1-39, 285-304 MAGUIRE, BASSETT, AND RICHARD E. WEAVER, e Neotropical genus Tachia Coane. 56: 103-125 ies in Malesian Pandanaceae, 19, 64: 309- 324 Malesian species of Zanthoxylum (Ruta- ceae), Additional notes on the, 51: 423- 426 Malpighiaceae in the southeastern United States, The, 53: 101-112 Marcgravia, Notes on two species of. The ecology of an elfin forest in Puerto Rico, 10, 51: 41-55 Margaritaria (Euphorbiaceae), A revision 403-444 CORENA, CLODOMIRO, AND JORGE Vicror Crisci. Transfer of the Brazilian Trixis eryngioides to Perezia (Compos- itae, Mutisieae), 59: 3 9 . FERNANDEZ, S. Lozano. Pollen of tropical trees. I. Tiliaceae, 59: 299-309 Martyniaceae in the southeastern United States, The, 58: 25-39 Mascarene species, The. e Old World species of oe ee cS I, 57: 167-184 Mastixiodendron (Rubiaceae), The genus, 349-38 1 MATHIAS, MILDRED E., AND LINCOLN CONSTANCE. A new species of Oreo- myrrhis Cae ae Apiaceae) from New Guinea, 58: 190-192 Mayacaceae in the ice United States, The, 56: 248-255 [VoL. 66 McCug, Kenr F., JoHN S. SPERRY, AND MartTIN H. ZIMMERMANN. Anatomy of the palm Rhapis excelsa, VIII. Vessel network and vessel-length distribution 95 McJUNKIN, Davip M., AND DANIEL F. Austin. An ethnoflora of Chokoloskee Island, Collier County, Florida, 59: —67 McVauGu, Rocers. Notes on West In- dian Myrtaceae, 54: 309-314 McVaAuGH, ROGERS. was Miller’s Caryophyllus cotinifolius, 56: 171-175 Mears, JAMES A., AND WILLIAM T. GILLIS. tne I Bahama Islands, 58: 60-66 Medeola virginiana, Rhizome organiza- tion in relation to vegetative spread in, 55: 458- MenrA, P.N., AND B.S. GILL. Cytological studies in Ulnxaceae, vee and Ur- ticaceae, 55: Roe zy! 7 MenraA, P.N., T.S.SAREEN. Cytology of West Himalayan Betulaceae and Sal- icaceae, 54: 412-418 EHRA, P. N., T. S. SAREEN, AND P. K. KHOosLA. Cytological studies on Hima- layan Meliaceae, 53: 558-568 Melastomataceae in the southeastern United States, The genera of, 63: 429- 439 Meliaceae, Cytological studies on Hima- layan, 53: 558-568 £41 AT tne INCw World, 63: 145-171 MENNEGA, ALBERTA M. W. Stem structure of the New World Menispermaceae, 63: 145-171 Menyanthaceae in the southeastern United States, The genera of, 64: 431-445 Merremia, Operculina, and Turbina, notes on— Additions and changes in the Neo- tropical Convolvulaceae, 64: 483-489 Metasequoia and Sequoia (Taxodia cee: The chromosomes and relationships of: an update, 65: 251-254 Metasequoia flora and its phytogeographic significance, The, 61: Ai Rides KA Acent ent status in central China, 64: 105-128 Metasequoia, Inbreeding depression in, 64: 475-481 Mexico, A new species of Parietaria (Ur- ticaceae) from northeastern, 51: 529-533 1985] Mexico, A remarkable new dimorphic Eu- phorbia eee from southern, Mexico, ae on Salvia Wace in, with three new species, 65: 135-14 Mexico, Notes on the genus ae in the United States and, 60: 504-514 Mexico, Seeds from surface soils in a trop- ical region of Veracruz, 53: 312-335 Mexico, Two new species of Euphorbia subgenus Agaloma from, 58: 343-348 Meyer, F. G. A revision of the genus Koelreuteria eee 57: 129-166 Meyer, F.G. ocarya esquirolii, a mis- nomer for sane bipinnata, 58: 189 Mever, F.G. Sinoradlkofera: a new genus of Sapindaceae, 58: 182-188 Microdiptera (Lythraceae), Fruits and seeds of the Brandon eee VI, 62: 487-516 Miter, H. A., KeitH W. RUSSELL. The ecology of an elfin forest in Puerto Rico, 17. Epiphytic mossy vegetation of Pico del Oeste, 58: 1-24 MILLer, Howarp J. The wood of Amen- totaxus, 54: 111-119 Mi.ver, Norton G. A new species of Pa- rietaria (Urticaceae) from northeastern Mexico, 51: 529-533 MILter, Norton G. Lateglacial plants and lant communities in northwestern New York State, a 123-159 MILLER, Nort Caricaceae in the pean United States, 63: 41 1- 427 MiLiter, Norton G. The genera of the Cannabaceae in the southeastern United States, 51: 185-203 MILLER, Norton G. The genera of the Urticaceae in the southeastern United States, 52: 40-68 ee NORTON G. The Polygalaceae in eastern United States, 52: 267- 284 a Ne G., ey Boy WwW. apie the Allegheny Plateau of New York on 57: 369-403 MILLER, Norton G., AND GARY G THompson. Boreal and western North American plants in the late Pleistocene of Vermont, 60: 167-218 MILLER, Recis B. Systematic anatomy of the xylem and comments on the rela- tionships of Flacourtiaceae, 56: 20-102 Miter, REcis B., AND DANIEL L. CASSENS. SCHMIDT, INDEX TO AUTHORS AND TITLES a Wood anatomy of the New World Pithe- cellobium (sensu lato), 62: 1-44 Mimosoideae (Leguminosae) in the south- eastern United States, The genera of, 55: 67-118 Mittak, W.L., AND J. P. PERRY, JR. Pinus tribution, 60: 386-395 Modern names for Catesby’s plants, The, 64: 511- MOHLENBROCK, ROBERT H., AND PAUL M. HOMSON. Foliar trichomes of Quercus subgenus Quercus in the eastern United States, 60: 350-366 Molluginaceae and Aizoaceae in the south- eastern United States, The genera of, 51: 1- Monocotyledoneae, Nomenclatural notes on some Lesser Antillean, 60: 290-301 Monograph of Diphylleia (Berberidaceae), A, 65: 57-94 Monograph of Lyonia (Ericaceae), A, 62: 63-209, 315-436 Monograph of the genus Prosopis (Legu- minosae subfam. Mimosoideae), A, 57: 219-249, 450-525 Monstereae, Th s of the: their mor- phology and a record, 57: 185-204 MONTAIGNAC, ERRE DE, RICHARD A. eon AND TaCQUES Portecop. The vegeta tion of La Soufriére, ae ae 1977-1979, 61: 749-764 Montane forests and soils of Jamaica, The: a reassessment, 57: 313-368 Moraceae, and Urticaceae, Se studies in Ulmaceae, 55: 663-677 Moraceae, Cytomorphology of arbores- cent, 53: 216-225 More additions to the flora of Jamaica, 63: 9-31 Mor Ley, BRIAN, AND JEW-MING CHAO review of Corylopsis (Hamamelidaceae), 58: 382-415 Morphological studies in Cordyline (Aga- morphology of Cordyline terminalis, 53: 113-127 Morphology and germination of the seed of Elephantorrhiza elephantina, The, 51: 8 MoseLey, MAYNARD F., JR., AND JOSEPH M. Keere. Wood anatomy and phylog- eny of Paeonia section Moutan, 59: 274— 297 58 JOURNAL OF THE ARNOLD ARBORETUM Moutabeae (Polygalaceae), Comparative tomy and systematics of, 58: 109- MUKHERJEE, APARNA, WEBSTER R. CRow- LEY, AND Marion T. HALL. Chromo- some counts in cultivated junipers, 54: 369-376 Mutisieae Cae a new genus of: Marticorenia, 55: 38—4 Myricaceae in the southeastern United States, The genera of, 52: 305-318 Myrothamnus flabellifolia (Myrothamna- ceae) and the problem of multiperforate perforation plates, Wood anatomy of, 57: 119-126 Myrothamnus flabellifolius (Myrotham- naceae), The nodal anatomy of: another example of a “‘split-lateral” condition, 59: 192-196 Myrsinaceae of the Fijian region, The. Studies of Pacific island plants, XXV, 54: 1-41, 228-292 Myrtaceae, Floral anatomy of, II. Eugenia, 53: 336-363 Myrtaceae, Notes on West Indian, 54: 309- 314 Myxopyrum in the Oleaceae, Two unusual Chionanthus species from Borneo and the position of, 64: 619-626 Najadaceae in a se as United States, The, 58: 170 Nassauviinae eins Mutisieae), A numerical-taxonomic study of the sub- tribe, 55: 568-610 Neillia (Rosaceae) in mainland Asia and in cultivation, The genus, 52: 137-158 Nemopanthus (Aquifoliaceae), Vegetative anatomy and the taxonomic status of Ilex collina and, 65: 243-250 Nemopanthus in the southern Appala- chians, A second species of, Ilex collina, 55: 4 0 Neotropical genus Tachia (Gentianaceae), The, 56: 103-125 NEVLING, aoe I., Jk. The ecology — elfin forest in Puerto Rico, 12. An species of Gonocalyx (Ericaceae), SI: 221-227; 16. The flowering cycle and'an interpretation ofits seasonality, 52: 586— 613 Nevling, Lorin I., Jr., and Thomas S. Elias. Calliandra haematocephala: history, morphology, and taxonomy, 52: 69-85 [VOL. 66 New Central American taxa of Heliconia (Heliconiaceae), 62: 243-260 New combination in Bulbostylis from the West Indies, A, 60: 322 New combination in Syzygium for Eugenia maire (Myrtaceae) of New Zealand, A, 60: 396-401 New Guinea, A new name in Spermacoce for two species of Borreria from, 64: 627, 8 62 New Guinea, A new species of Oreomyr- rhis (Umbelliferae, Apiaceae) from, 58: 190-192 New Guinea, A new species of Zanthoxy- lum (Rutaceae) from, 56: 369-373 New Guinea, Solomon Islands, and Aus- tralia, The genus Piper (Piperaceae) in, 1, 53: 1 a New Guinea, The first species of Staur- New Lindera (Lauraceae) from North America, A, 64: 325-331 New name in Spermacoce for two species of Borreria from New Guinea, A, 64: 627, 628 New species and a new combination from the Bahamas, Caicos and Turks islands, 58: 40-51 New species and varieties from the Baha- mas, Caicos and Turks islands, 60: 154- 162 New species of Ateleia (Leguminosae) from the Bahamas, A, 62: 261-263 New species of Cestrum (Solanaceae) from southern Colombia, A, 61: 113-115 New species of Oreomyrrhis (Umbellifer- ae, Apiaceae) from New Guinea, A, 58: 190-192 New species of Ormosia from Brazil, A, 51: 129-131 New species of Parietaria (Urticaceae) from 5 New species of Ruppia in high salinity in Western Australia, A, 55: 59-66 New species of Timonius (Rubiaceae) from Papuasia, 64: 611-618 New species of Zanthoxylum (Rutaceae) from New Guinea, A, 56: 369-373 New World Menispermaceae, Stem struc- ture of the, 63: 145-171 1985] New World Pithecellobium (sensu lato), Wood anatomy of the, 62: 1-44 New York State, A radiocarbon dated pol- len diagram from the Allegheny Plateau of, 57: 369-403 New York State, Lateglacial plants and plant communities in northwestern, 54: 123-159 New Zealand, A new combination in Sy- zygium for Eugenia maire (Myrtaceae) of, 60: 396-401 NICOLSON, DAN ox es for the flora of Dominica: Sp e confusa and Schradera ae (eabiacee). 58: 445- 450 NisBet, IAN C. T., AND WILLIAM H. Drury. Succession, 54: 331-368 Nodal anatomy of Myrothamnus flabelli- folius (Myrothamnaceae), The: another example of a “‘split-lateral’’ condition, 59: 192-196 Nomenclatural notes on some Lesser An- tillean Monocotyledoneae, 60: 290-301 Nomenclatural notes on the Araceae of the Lesser Antilles, 60: 272-289 Nomenclatural notes on the Lauraceae of the Lesser Antilles, 62: 45-61 Norfolk and Lord Howe islands, Notes re- lating to the flora of, 51: 204-220 North America, A new Lindera (Laura- ceae) from, 64: 325-331 North America, Cercidiphyllaceae hardy in temperate, 60: 367-376 North America, Ebenaceae hardy in tem- perate, 58: 146-160 North America, Lardizabalaceae hardy in temperate, 60: 302-315 North ge Lauraceae hardy in tem- perate, 56: 1-19 North ee Magnoliaceae hardy in temperate, 57: 250-312 North America, Studies in the Cruciferae of western, 64: 491-510 North America, Styracaceae hardy in tem- perate, 57: 54—- North America, Weeds of the Cruciferae (Brassicaceae) in, 62: 517-540 North American cottonwoods (Populus, Salicaceae) of sections Abaso and Ai- geiros, 58: 193-208 North American plants in the late Pleis- tocene of Vermont, Boreal and western, 67-218 Notes for the flora of Dominica: Sperma- SCHMIDT, INDEX TO AUTHORS AND TITLES oY coce confusa and Schradera exotica (Ru- biaceae), 58: 445-450 Notes on Airosperma (Rubiaceae), with a 95-105 Notes on Asiatic-Polynesian-Australian species of Erythrina, II, 53: 128-139 Notes on Peperomia (Piperaceae) in the southeastern United States, 63: 317-325 Notes on Salvia (Labiatae) in Mexico, with three new species, 65: 135-143 Notes on the genus Galipea (Rutaceae) in Central America, 51: 427-430 Notes on the genus Polygala in the United States and Mexico, 60: 504-514 Notes on the Piperaceae of the Lesser An- tilles, 54: 377-411 Notes on Tibouchina and Charianthus (Melastomataceae) in the Lesser An- tilles, 53: 399-402 Notes on West Indian Myrtaceae, 54: 309- Notes on West Indian orchids, II, 53: 390- 398; II, 53: 515-530 Notes relating to the floras of Norfolk and Lord Howe islands, 51: 204-220 Numerical-taxonomic study of the sub- tribe Nassauviinae ener Muti- sieae), A, 55: 568-610 Nyctaginaceae in the southeastern United tates, The genera of, 55: 1-37 Observations of reaction fibers in leaves of dicotyledons, 63: 173-185 Olacaceae in the southeastern United States, The genera of, 63: 387-399 Old World species of rue ae (Gut- tiferae), A revision of the, 61: 117-699 Old World species of Siar ae (Gut- tiferae), The. I. The Mascarene species, 57: 167-184 Oldfieldioideae (Euphorbiaceae), further evidence for relationship with the: Sys tematics and vate of Piecden: — hae 7 Olea Two unusual Chionanthus serie ee Borneo and the position of Myxopyrum in the, 64: 619-626 OLIver, Royce L., AND DANIEL F. AUSTIN. Sisyrinchium solstitiale (Irdaceae): a Florida endemic, 55: 291-299 ikea and Turbina, notes on Mer- mia—Additions and changes in the eres Convolvulaceae, 64: 483- 489 60 JOURNAL OF THE ARNOLD ARBORETUM Oplonia (Acanthaceae), Heterostyly in, 60: 382-385 Orchidaceae, On the origin of the, II, 53: —215 Orchids, Notes on West Indian, II, 53: 390- 398; III, 53: 515-530 Oreomyrrhis (Umbelliferae, Apiaceae) Guinea, A new species of, 58: 190-192 Origin of the Orchidaceae, On the, IH, 53: 202-215 Ormosia from Brazil, A new species of, 51: 129-131 OrNDUuFF, RosertT. Features of pollen flow in Gelsemium sempervirens (Logani- aceae), 60: 377-381 OrRNDUFF, RoperT. Heterostyly in Oplo- nia (Acanthaceae), 60: 382-385 OrnNbuFF, Ropert. Relationships in the Piriqueta caroliniana—P. cistoides com- plex (Turneraceae), 51: 492-498 OrnpburF, Rospert. The systematics and breeding hie of Gelsemium (Loga- niaceae), 5 paneuey aad uthea United States, The genera of, 52: 404— 434 Outer, R. W. DEN, AND E. Togs. The sec- ondary eee a seer rene 55: 119- 122 Oxalidaceae in the southeastern United States, The, 56: 223-239 Pacific island plants, Studies of, XIII. The genus Diospyros (Ebenaceae) in Fiji, Sa- moa, and Tonga, 52: 369-403; XXV. The Myrsinaceae of the Fijian region, 54: 1- 41, 228-292: XXVIII. The Guttiferae of the Fijian region, 55: 215-263; X XXIII. The genus Ascarina (Chloranthaceae) in the southern Pacific, 57: 405-425 Pacific, The genus Ascarina (Chlorantha- ceae) in the southern. Studies of Pacific island plants, XX XIII, 57: 405-425 Paeonia section Moutan, Wood anatomy and phylogeny of, 59: 274-297 PAGE, VIRGINIA M. A possible magnolioid floral axis, Loishoglia bettencourtii, from the Upper Cretaceous of central Califor- nia, 65: 95-104 Pace, VIRGINIA M. Dicotyledonous wood from the Upper Cretaceous of central California, 60: 323-349; II, 61: 723-748; II. Conclusions, 62: 437-455 Pakistan and Kashmir, A revision of the Boraginaceae of West, 51: 133-184, 367- [VOL. 66 402, 499-520; 52: 486-522, 666-690 Palm stems, Vascular patterns in: varia- tions of the Rhapis principle, 55: 402— 110-136, 334-363, Palms, Form of the perforation plates in the wise vessels of metaxylem in, 59: 105— 28 Panama, Three new species of Zanthoxy- lum (Rutaceae) from Darién Province, 53: 403-408 Pandanaceae, Studies in Malesian, 19. New species of Freycinetia and Pandanus from Malesia and Southeast Asia, 64: 309- 324 fi Malesi 1 Sout! Asia New species of Freycinetia and. Studies in Malesian Pandanaceae, 19, 64: 309- 324 Papuasia, A provisional key and enumer- ation of Neorg oo (Myrtaceae) from, 54: Papuasi Nes species of Timonius (Ru- biaceae) from, 64: 611-618 Papuasia, Three new species of Phaleria (Thymelaeaceae) from, 55: 264- Papuasian species of Acmena (Myrtaceae), A revision of the, 58: 325-342 Parietaria (Urticaceae) from northeastern Mexico, A new species of, 51: 529-533 Peperomia (Piperaceae) in the southeast- ern United States, Notes on, 63: 317 Perezia (Compositae, Mutisieae), Transfer of the Brazilian Trixis eryngioides to, 59: 352-359 Perry, J. P., Jr. The taxonomy and chem- istry of Pinus estevezii, 63: 187-198 Perry, J. P., Jk., AND W. L. Mittak. Pi- distribution, 60: 386-395 Perry, Lity M. Leonard J. Brass (1900— 1971), an appreciation [obituary, with portrait], 52: 695-6 G. Hartiey. A enumeration of ., S. K. Curistie, J. M. Bi- . J. LapiaAna. The ecol- ogy of an elfin forest i in Puerto Rico, 13. Phytochemical screening and literature survey, 51: 540-54 Phaleria (Thymelaeaceae) from Papuasia, Three new species of, 55: 264-268 1985] Puitcox, D. A spectacular Buchnera ee from Colombia, 59: 298 Phrymaceae in the southeastern United States, The, 53: 226-233 abe ecoaes i a ea The genus, ae Pico del one Epiphytic mossy vegetation of. The ecology of an elfin forest in Puer- to Rico, 17, 58: 1-24 Pico del Oeste, The algae of. The ecology of an elfin forest in Puerto Rico, 14, 52: -109 Pico del Oeste, The leafy Hepaticae of. The ecology of an elfin forest in Puerto Rico, 11, 51: 56-69 Picramnia (Simaroubaceae) from Central merica, Three new species of, 54: 315- Picrodendron, genus incertae sedis, Com- ibs i A + +s t 58: Picrodendron, Systematics and palynology of: further evidence for relationship with the Oldfieldioideae (Euphorbiaceae), 65: 105-127 Pieris (Ericaceae), A taxonomic revision of, : 103-144 Pinus estevezii, The taxonomy and chem- ate of, 63: 187- 198 L. edit banen 60: 386-395 Piper (Piperaceae) in New Guinea, Solo- nds, and Australia, The genus, 1, 53: 1-25 Piperaceae of the Lesser Antilles, Notes on e, 77-411 Piriqueta caroliniana—P. cistoides complex (Turneraceae), Relationships in the, 51: 92-498 Pithecellobium (sensu lato), Wood anato- ew World, 62: 1-44 Plantaginaceae in the southeastern United States, The, 65: 533-562 Plates of Aublet’s Histoire des Plantes de American plants in the late, 60: 167-218 Podostemaceae in the southeastern United States, The, 56: 456-465 Pollen of tropical trees, I. Tiliaceae, 59: 299-309 Polygala in the United States and Mexico, Notes on the genus, 60: 504-514 SCHMIDT, INDEX TO AUTHORS AND TITLES 61 Polygalaceae in the southeastern United tates, The, 52: 267-284 PortTecop, JACQUES, PIERRE DE Mon- TAIGNAC, AND RICHARD A. Howarp. The post-eruptive vegetation of La Souf- riére, Guadeloupe, 1977-1979, 61: 749- 764 PoRTER, DUNCAN M. The genera of Zy- gophyllaceae in the southeastern United States, 53: 531-552 PorRTER, DUNCAN M. Three new species of Picramnia (Simaroubaceae) from Central America, 54: 315-321 e, Panama, 53: 403 Sornds Ree and associated taxa, A reexamination of, 60: 38-126 Possible ee floral axis, Loishoglia bettencourtii, from th per Creta- ceous of central California, A, 65: 95- 4 Post-eruptive vegetation of La Soufriére, Guadeloupe, 1977-1979, The, 61: 749- 764 Potamogetonaceae in the southeastern United States, The, 59: 170-191 PoweL_, DutcieE A. The Convolvulaceae 271 sobalanaceae in the southeastern United States, 51: 521-528 Present status and ee of bamboo classification, ae 308 PRIMACK C. Du P. B. TOMLINSON, con S, Bun. Dona. era rosea (C floral seca 59: 342-351 Proctor, GEORGE R. More additions to the flora of lama, ee 199-315 Proctor, GEO ND WILLIAM T. GILLIS. Cicwipile Te Guilan- dina in the Bahamas, 55: 425-4 Prosopis (Leguminosae), Isozyme varia- tion in species = 56: 398-412 Prosopis (Leguminosae, Mi sa a Reproductive adaptors in, 56: 210 Prosopis (Leguminosae subfam. Mimo- soideae), A monograph of the genus, 57: 219-249, 450-525 Protocyrtandra (Gesneriaceae), The taxo- nomic status of, 51: 241-246 Provisional key and enumeration of species 62 ee oe from Papuasia, 60- ean pee rolil, a misnomer for Koelreuteria bipinnata, 58: 189 Puerto Rico, The ecology of an elfin forest in, 10. Notes on two species of Marc- gravia, 51: 41-55; 11. The leafy Hepat- icae of Pico del Oeste, 51: 56-69; 12. A new species of Gonocalyx (Ericaceae), 51: 221-227; 13. Phytochemical screening and literature survey, 51: 540-546, 14. The algae of Pico del Oeste, 52: 86-109; 15. A study of the leafy hepatic flora of the Luquillo Mountains, 52: 435-458: 16. The flowering cycle and an interpre- tation of its seasonality, 52: 586-613; 17. Epiphytic mossy vegetation of Pico del Oeste, 58: 1-24 Purr, CHRISTIAN. The nodal anatomy of Myrothamnus flabellifolius (Myrotham- naceae): another example of a ‘‘split-lat- eral” condition, 59: 192-196 Queensland, A new genus endemic to north: Lenbrassia (Gesneriaceae), 55: 431-434 Quercus alba, Hybridization and introgres- sion in, 56: 336-363 Quercus subgenus Quercus in the eastern United States, Foliar trichomes of, 60: 350-366 Radiocarbon dated pollen diagram from the Allegheny Plateau of New York State, A, 57: 369-403 Raeuschel’ S eee Gaultheria he combina- RAMAMOORTHY, T. P. Notes on Salvia (Labiatae) in Mexico, with three new species, 65: 135-143 Raup, HuGH M. Species versatility in shore habitats, 56: 126-163 Reduction of Rusbyanthus and the tribe Rusbyantheae (Gentianaceae), The, 55: —302 Reexamination of Portlandia oa and associated taxa, A, 60: 38-126 So of ee oenen ae ceae), 60: 515-522 Reinterpretation of oe and Lysilo- ma, A, 57: 113-118 Relationships in the Piriqueta caroliniana— P. cistoides complex (Turneraceae), 51: 492-498 Remarkable new dimorphic Euphorbia JOURNAL OF THE ARNOLD ARBORETUM 66 [VOL. ree tia from southern Mexico, A, 63: 97-101 Reproductive adaptations in Prosopis (Le- guminosae, Mimosoideae), 56: 185-210 Review Corylopsis (Hamamelidaceae), A, 58: 382-415 Review of deciduous-leaved species of Ste- wartia (Theaceae), A, 55: 182-214 Revision and expansion of the Neotropical genus Wercklea (Malvaceae), 62: 457- 486 Revision of Kentrothamnus (Rhamna- ceae), 54: 471-473 Revision of Margaritaria (Euphorbiaceae), A, 60: 403-444 Revision of Stenopetalum (Cruciferae), 53: -75 Revision of the Boraginaceae of West Pa- kistan and Kashmir, A, 51: 133-184, 367-402, 499-520; 52: 110-136, 334- 363, 486-522, 666-690 Revision of the genus Acradenia (Ruta- ceae), A, 58: 171-181 Revision of the genus Acronychia (Ruta- ceae), A, 55: 469-523, 525-567 Revision eer genus Alsophila (Cyathea- ceae) in the Americas, A, 64: 333-382 Revision ae genus Bosistoa (Rutaceae), 6 Revision of the genus Koelreuteria (Sap- indaceae), A, 57: 129-166 Revision of the genus Tetractomia (Ruta- ceae), A, 60: 127-153 Revision of the Neotropical genus Lisian- thus (Gentianaceae), A, 53: 76-100, 234— 311 Revision of the Old World species of Cal- ophyllum (Guttiferae), A, 61: 117-699 Revision of the Papuasian species of Ac- mena (Myrtaceae), A, 58: 325-342 Revision of the West Indian vernonias (Compositae), A, 59: 360-413 5 AND H. P. VAN DER F. Development of the digitately decompound leaf in Cussonia spicata (Araliaceae), 56: 256-263 Reynosia (Rhamnaceae) from Jamaica, A new species of, 52: 364-367 Rhapis excelsa, Anatomy of the palm, VIII. Vessel network and vessel-length distri- bution in the stem, 63: 83-95; IX. Xylem structure of the leaf insertion, 64: 599- meee of stem con- ducting. tissue, 65: 191-214 Rhizome pole in relation to vege- 1985] tative spread in Medeola virginiana, 55: 458-468 Rhizophora in Australasia—some clarifi- cation of taxonomy and distribution, 59: 156-169 Rhododendroideae, Generic limits in the tribe Cladothamneae (Ericaceae), and its position in the, 59: 311-341 RICHTER, H. , K. Kusitzkl, AND H. Kurz. Re instatement of Clinostemon 2 nera of United States, 62: 267-313 ROBERTSON, KENNETH R enera of Geraniaceae in the southeastern United States, 53: 182-201 ROBERTSON, KENNETH R. The genera of Haemodoraceae in the southeastern United States, 57: 205-216 ROBERTSON, KENNETH R enera of Olacaceae in the southeastern United States, 63: 387-399 RoBERTSON, KENNETH R. The genera of Rosaceae in the southeastern United cee 55: 303-332, 344-401, 611-662 ROBERTSON, KENNETH R e Krameri- aceae in the southeastern United States, 54: 322-327 ROBERTSON, KENNETH R. The Linaceae in the southeastern United States, 52: 649- 665 ROBERTSON, KENNETH R. The Malpighi- aceae in oe southeastern United States, 53: 101-112 alee KENNETH R. The Oxalida- ceae in the eae United States, 56: 223-239 ROBERTSON, Lee. The KENNETH R., AND YIN-TSE genera ee Cicaalpinioidese e southeastern Rocers, GEORGE K. The Bataceae in the southeastern United States, 63: 375-386 ROGERS, GEORGE Casuarinaceae in the southeastern United States, 63: 357-373 RoGers, GeorGE K. The genera of Alis- mataceae in the southeastern United lie 64: ae 420 GERS, GEORGE Stemonaceae in ne southeastern Oe States, 63: 327- 336 RoGeERS, GEOR K. The Zingiberales (Cannaceae, ee and Zingiber- SCHMIDT, INDEX TO AUTHORS AND TITLES 63 aceae) in the southeastern United States, 65: 5-5 Rotuins, Reep C. Studies in the Crucif- erae of western North America, 64: 49 1- 510 Ro. ins, REEDC. Weeds of the Cruciferae (Brassicaceae) in North America, 62: 517-540 Rosaceae in the southeastern United States, The genera of, 55: 303-332, 344-401, 611-662 RosaTtl, THomas J. The Plantaginaceae in the southeastern United States, 65: 533-562 RUDENBERG, LILy, AND RICHARD E. WEA- VER, JR. otaxonomic notes on some Gentianaceae, 56: 211-222 Ruppia in high salinity in Western Austra- lia, A new species of, 55: 59-66 Rury, PHILtuipe M., AND WILLIAM C. DicKk- ison. Leaf venation patterns of the ge- nus Hibbertia (Dilleniaceae), 58: 209- 256 Rury, PHituipe M., G. LEDYARD STEBBINS, AND WILLIAM C. Dickison. Xylem anatomy of Hibbertia (Dilleniaceae) in relation to ecology and evolution, 59: -49 Rusbyantheae (Gentianaceae), The reduc- tion of Rusbyanthus and the tribe, 55: 300-302 Rusbyanthus and the tribe Rusbyantheae (Gentianaceae), The reduction of, 55: 300-302 Russe__, KeirH W., AND H. A. oa The ecology of an elfin forest in Puert Rico, 17. eae mossy vegetation of Pico del Oeste, 58: 1-24 Rutaceae, Fruits onal seeds of the Brandon Lignite, V, 61: 1-4 Ryukyu and Caroline islands, The genus Cyrtandra in the, 54: 105-110 RzEDOWSKI, J., AND JAMES HINTON. George B. Hinton, collector of plants in south- western Mexico, 53: 141-181 St. Vincent, The Soufriére plant of, 61: 765- 770 Salicaceae, Cytology of West Himalayan tulaceae and, 54: 412-418 Salvia (Labiatae) in Mexico, Notes on, with three new species, 65: 135-143 Samoa, and Tonga, The genus Diospyros (Ebenaceae) in Fiji. Studies of Pacific is- land plants, XXIII, 52: 369-403 64 JOURNAL OF THE ARNOLD ARBORETUM SAMPSON, F. B., AND PETER K. ENDRESS. Floral structure and relationships of the Trimeniaceae (Laurales), 64: 447-473 Sapindaceae, a new genus of: Sinoradlko- fera, 58: 182-188 SAREEN, T. S., . KHOSLA, AND P. N. MEHRA. Cytological studies of Hima- layan areata 55 2a oa SAREEN, T.S., AN A. Cytology of West Tadian cee oe Salica- ceae, 54: 412-418 Sargent’s fir hybrid: Abies amabilis x la- siocarpa, 58: 52-59 Sargent’s Silva of North America, Dates of publication of, 59: 68-73 Saururaceae in the southeastern United States, The, 52: 479-485 Sax, Karl, 1892-1973 [obituary, with por- trait], 55: 333-343 Saxifragaceae in the southeastern United States, The genera of, 53: 409-498 SCHADEL, WILLIAM E., AND WILLIAM C. Dickison. Leaf anatomy and venation patterns of the Styracaceae, 60: 8-37 Schefflera (Araliaceae), Studies in: the Ce- phaloschefflera complex, 56: 427-448 ScuiFF, H. P. vAN DER, AND W. REYNEKE. Development of the digitate- ly decompound leaf in Cussonia spicata (Araliaceae), 56: 256-2 ScHiFF, H. P. VAN DER, AND L. SNYMAN. The morphology and germination of the seed of Elephantorrhiza elephantina, 51: 114-128 SCHLARBAUM, S. E., T. TSuCHIYA, AND L. C. JOHNSON. The chromosomes and rela- tionships of Metasequoia and Sequoia (Taxodiaceae): an update, 65: 251-254 SCHMID, RUDOLF. Floral anatomy of Myr- taceae, II. Eugenia, 53: 336-363 Schradera exotica (Rubiaceae), Sperma- coce confusa and: Notes for the flora of Dominica, 58: 445-450 SCHUBERT, B.G. Temple Clayton, chemist and amateur botanist, 1914-1978 [obit- -4 HAW. A rein- terpretation of Leucaena and Lysiloma, 7: 113-118 Schwarten, Lazella 7 1900-1973 [obituary], 54: 4 Scott, RICHARD . ee S. BARGHOORN, AND ELISABETH WHEELER. Fossil dicot- yledonous woods from Yellowstone Na- tional Park, 58: 280-306; II, 59: 1-31 [VOL. 66 Secondary phloem of Amentotaxus, The, 55: 119-122 Seedling morphology in the Juglandaceae, the cotyledonary node, 51: 463-477 Seeds from surface soils in a tropical region of Veracruz, Mexico, 53: 312-335 Seeds of the Monstereae, The: their mor- phology and fossil record, 57: 185-204 Sequoia (Taxodiaceae), The chromosomes and relationships of Metasequoia and: an update, 65: 251-254 SHaw, E. A. Revision of Stenopetalum (Cruciferae), 53: 52-75 SHaw, E. A., AND B. G. ScHuBERT, A rein- terpretation of Leucaena and Lysiloma, 57: 113-118 Shoot growth and heterophylly in Acer, 52: 240-266 Silvical characteristics of sugar maple, Acer saccharum, in no rm Cape Breton Is- land, 58: 307-324 Sino-American botanical expedition to western Hubei Province, People’s Re- public of China, The 1980, 64: 1-103 Sinoradlkofera: a new genus of Sapinda- ceae, 58: 182-188 Sisyrinchium solstitiale (Iridaceae): a Flor- ida endemic, 55: 291-299 Smilacina (Liliaceae), Anatomy of stem -570 . The genus Diospyros (Ebenaceae) in Fiji, Samoa, and Tonga 52: 369-403; XXV. The Myrsinaceae of the Fijian region, 54: 1-41, 228-292: XX XIII. The genus Ascarina (Chloran- thaceae) in the southern Pacific, 57: 405-— 425 SMITH, ALBERT C., AND STEVEN P. Darwin. Studies of Pacific island plants, XX VIII. The Guttiferae of the Fijian region, 55: 215-263 SMITH, LYMAN B., AND CARROLL E. Woop, Jr. The genera of Bromeliaceae in the southeastern United States, 56: 375-397 NYMAN, L., AND H. P. VAN DER SCHIJFF. The morphology and germination of the seed of Elephantorrhiza elephantina, 51: 114-128 Solander’s “‘Florula Indiae Occidentalis,” The West Indian taxa in, 63: 63-81 SOLBRIG, Otto T. Arturo Burkart: a per- sonal appreciation [obituary, with por- trait], 57: 217, 21 SOLBRIG, OTTO T., AND KAMALJIT S. BAWA. 1985] Isozyme variation in species of Prosopis (Leguminosae), 56: 398-412 SoLBRIG, OTTO T., AND PHitip D. CANTINO. Reproductive adaptations in Prosopis (Leguminosae, Mimosoideae), 56: 185- 210 Solomon Islands, A new species of Derris from the. Studies in the Leguminosae, 11, "51: 251- Solomon Islands, and Australia, The genus Piper (Piperaceae) in New Guinea, 1, 53: 1-25 Some observations on the reproductive bi- ology of three species of Cornus (Cor- naceae), 65: 419-427 SORENSEN, PAuL D. Dates of publication of Sargent’s Silva of North America, 59: -73 Soufriére plant of St. Vincent, The, 61: 765-770 Southeast Asia, New species of Freycinetia and Pandanus from Malesia and. Studies in Malesian Pandanaceae, 19, 64: 309- 324 Southeastern United States, Indexes to pa- pers 1 to 100 published as parts of the Generic Flora of the, 64: 547-563 Southeastern United States, The Balsami- naceae in the, 56: 413-426 Sa eae United States, The Bataceae in the, 63: 375-386 Sines enna aes The Caricaceae in the, 63: 411-427 Southeastern United States, The Casuari- naceae in the, 63: 357-373 Southeastern United States, The genera of Acanthaceae in the, 51: 257-309 Southeastern United States, The genera of Alismataceae in the, 64: 0 Southeastern United States, The genera of Amaranthaceae in the, 62: 267-313 Southeastern United States, The genera of Bromeliaceae in the, 375- Southeastern United States, The genera of Burmanniaceae in the, 64: 293-307 Southeastern United States, The genera of ee (Leguminosae) in the, : 1-53 eee United States, The genera of the Cannabaceae in the, 51: 185-203 Southeastern United States, The genera of Chrysobalanaceae in the, 51: 521-528 Southeastern United States, The genera of Crassulaceae in the, 59: 198-248 SCHMIDT, INDEX TO AUTHORS AND TITLES 65 Southeastern United States, The genera of agaceae in the, 52: 159-195 Southeastern United States, The genera of Gentianaceae in the, 63: 441-487 Southeastern United States, The genera of Geraniaceae in the, 53: 182-201 Southeastern United States, The genera of Guttiferae (Clusiaceae) in the, 57: 74-90 Southeastern United States, The genera of Haemodoraceae in the, 57: 205-216 Southeastern United States, The genera of Juglandaceae in the, 53: 26-51 Southeastern United States, The genera of Lactuceae (Compositae) in the, 54: 42-93 Southeastern United States, The genera of Melastomataceae in the, 63: 429-439 Southeastern United States, The genera of Menyanthaceae in the, 64: 431-445 Southeastern United States, The genera of Mimosoideae (Leguminosae) in the, 55: 7-118 Southeastern United States, The genera of Molluginaceae and Aizoaceae in the, 51: -4 Southeastern United States, The genera of Myricaceae in the, 52: 305-318 Southeastern United States, The genera of Nyctaginaceae in the, 55: 1-37 Southeastern United States, The genera of Olacaceae in the, 63: 387-399 Southeastern United States, The genera of obanchaceae in the, 52: 404-434 Southeastern United States, The genera of Rosaceae in the, 55: 303-332, 344-401, 611-662 Southeastern United States, The genera of Saxifragaceae in the, 53: 409-498 Southeastern United States, The genera of Ulmaceae in the, 51: 18-40 Southeastern United States, The genera of the Urticaceae in the, 52: 40-68 Southeastern United States, The genera of Vernonieae (Compositae) in the, 63: 489- 507 Southeastern United States, The genera of Zygophyllaceae in the, 53: 531-552 Southeastern United States, The Krame- riaceae in the, 54: 322-327 Southeastern United States, The Linaceae in the, 52: 649-665 Southeastern United States, The Malpigh- iaceae in the, 53: 101-112 Southeastern United States, The Martyn- iaceae in the, 58: 25-3 66 JOURNAL OF THE ARNOLD ARBORETUM Southeastern United States, The Mayaca- ceae in the, 56: 248-255 Southeastern United States, The Najada- ceae in the, 58: 161-170 Southeastern United States, The Oxalida- ceae in the, 56: 223-239 Southeastern United States, The Phryma- ceae in the, 53: 226-233 Southeastern United States, The Planta- ginaceae in the, 65: -562 Southeastern United States, The Podo- stemaceae in the, 56: 456-465 Southeastern United States, The Polyga- laceae in the, 52: 267-284 Southeastern United ae The Potamo- getonaceae in the, 59: 170-191 Southeastern United cans The Saurura- ceae in the, 52: 479-485 Southeastern United States, The Sparga- niaceae in the, 63: 341-355 Southeastern United States, The Staphy- leaceae in the, 52: 196-203 Southeastern United States, The Stemona- ceae in the, 63: 327-336 Southeastern United States, The tribes of Cruciferae (Brassicaceae) in the, 65: 343- 373 Southeastern United States, The Viscaceae in the, 63: 401-410 Southeastern United States, The Xyrida- ceae in the, 64: 421-429 Southeastern United States, The Zingiber- ales (Cannaceae, Marantaceae, and Zin- giberaceae) in the, 65: 5-55 acing in the southeastern United s, The, ee 355 ae Rav W., D Norton G. MILLER. A radiocarbon ee pollen diagram from the Allegheny Plateau of New York State, 57: 369-403 Species versatility in shore habitats, 56: 126-163 gl eae Buchnera (Scrophulariaceae) mbia, A, 59: 298 See ead Anew name in, for two species of Borreria from New Guinea, 64: 627, 628 nd Schrade “(Rubiaceae): notes for the flora of Do- minica, 58: 445-450 SPeRRY, JOHN S. Anatomy of the palm Rhapis excelsa, VIII. Vessel network and vessel-length distribution in the stem, 63: 83-95 [VOL. 66 SPERRY, JOHN S. Observations of reaction fibers in leaves of dicotyledons, 63: 173- 185 SPERRY, JOHN S., AND MARTIN H. ZIM- ERMANN. Anatomy of the palm Rha- pis excelsa, IX. Xylem structure of the leaf insertion, 64: 599-609 SPONGBERG, STEPHEN A. A review of de- ciduous-leaved species of Stewartia (Theaceae), 55: 182-214 SPONGBERG, STEPHEN A. Cercidiphylla- ceae hardy in temperate North America, 60: 367-376 SPONGBERG, STEPHEN A. Ebenaceae hardy in temperate North America, 58: 146- 1 SPONGBERG, STEPHEN A. Lauraceae hardy in temperate North America, 56: 1-19 SPONGBERG, STEPHEN A. Magnoliaceae hardy in temperate North America, 57: 250-312 SPONGBERG, STEPHEN A. Styracaceae hardy in temperate North America, 57: 54-73 SPONGBERG, STEPHEN A. The genera of Crassulaceae in the southeastern United States, 59: 1 8 SPONGBERG, Senden A genera of Saxifragaceae in the southeastern United States, 53: 409-498 SPONGBERG, STEPHEN A. The Staphyle- ay in the southeastern United States, 52: —203 Se STEPHEN A., BRUCE BAR- THOLOMEW, AND Davip E BOUFFORD. Metasequoia g its pres ent status in central China, 64: 105-128 SPONGBERG, STEPHEN A., AND D. E. Bourrorp. Calycanthus floridus (Caly- canthaceae)—a nomenclatural note, 62: 265, 266 SPONGBERG, STEPHEN A., AND I. H. Burcu. Lardizabalaceae hardy in temperate North America, ae 302-315 pEanGuEnG. STEPHEN A., S. C. Sun, Y. C. T : ne T. S. Yina, B. Bar- THOLOMEW, E. BouFFrorp, A. L oe Z. CHENG, T. R. DOPE S. A The 1980 Sino- American polanical ex- Staphyleaceae in the southes ein United States, The, 52: 196-203 StTap_Les, G. W., AND D. F. Austin. Ad- 1985] ditions and changes in the Neotropical Convolvulaceae—notes on Merremia, paabapng a Turbina, 64: 483-489 STAPLES, G. ND RICHARD A. How- ARD. The a names for Catesby’s plants, 64: 511-54 Stauranthera (Gesneriaceae) from New Guinea, The first species of, with general notes on the genus, 65: 129-133 STEARN, WILLIAM T. Taxonomic and no- menclatural notes on Jamaican gamo- petalous plants, 52: 614-648 STEBBINS, G. LEDYARD, WILLIAM C, DIck- ISON, AND PHILLIP M. anato omy of Hibbertia (Dilleniaceae) in relation to ecology and evolution, 59: 32-49 Stem-node-leaf continuum of the Dicoty- ledoneae, The, 55: 125-181 Stem structure of the New World Meni- spermaceae, 63: 145-171 Stemonaceae in the southeastern United States, The, 63: 327-336 Stenopetalum (Cruciferae), Revision of, 53: 52-75 STEVENS, P. F. A revision of the Old World species of Calophyllum (Guttiferae), 61: -699 STEVENS, P. F. Additional notes on Di- See Cou onagnae 58: 437-444 STEVENS, P. F c limits in the Xe- roteae es sensu lato), 59: 129- Stevens, P. F. The Old World species of Calophyllum (Guttiferae). - The Mas- carene species, _ 167-18 STEVENS, P. F. new oe of Pha- leria Cinymeacacess) from Papuasia, 55: —268 STEVENS, P. F., BRUCE A. — Scott W. BRIM, AND RICHARD J. Hespa. Generic limits in the tribe A eee (Eri- caceae), and its position in the Rhodo- dendroideae, 59: 311-341 STEVENSON, DENNIS WM. Systematic anat- omy of Bahamian species of Bursera (Burseraceae), 60: 163-165 Stewartia (Theaceae), A review of decid- Southeast Asia, 64: 309-324 STONE, D. C. R. Broome, G. L. SCHMIDT, INDEX TO AUTHORS AND TITLES 67 WesstTer, W. J. HAYDEN, AND W. T. : lye and palynology of Picrodendron: further evidence for re- lationship with the Oldfieldioideae (Eu- phorbiaceae), 65: 105-127 Stone, D. E., AND Louis F. ConpDeE. Seed- ling morphology i in the Juglandaceae, the cotyledonary node, 51: 463-477 elfin forest in Puerto Rico. 11. The leafy Hepaticae of Pico del Oeste, 51: 56-69; 15. A study of the leafy hepatic flora of the Luquillo Mountains, 52: 435-458 Studies in Malesian Pandanaceae, 19. New species of Freycinetia and Pandanus from Malesia and Southeast Asia, 64: 309- 324 Studies in Schefflera (Araliaceae): the Cephaloschefflera complex, 56: 427-448 Studies in the Cruciferae of western North America, 64: 491-510 Studies in the Leguminosae, 11. A new species of Derris from the Solomon Is- lands, 51: 251-254 Studies of Pacific isang eee Secbeare The genus Di in Fiji, Sa- moa, and Tonga, 52: 369-403: XXV. The Myrsinaceae of the Fijian region, 54: 1- 41, 228-292; XXVIII. The Guttiferae of the Fijian region, 55: 215-263; XX XIII. The genus Ascarina a ere in the southern Pacific, 5 ss age on Bigelowia rs II. Xy- mparisons, woodiness, and pae- noni is, 53: 499-514 Surock David (1893-1978)—mentor and d [obituary, with portrait], 60: 1-7 an CHARLES H. Comparative anato- my and systematics of Moutabeae (Po- lygalaceae), 58: 109-145 Styracaceae hardy in temperate North America, 57: 54-73 Styracaceae, Leaf anatomy and venation erns of the, 60: 8-37 Succession, 54: 331-368 UGDEN, ANDREW M. The ecological, geo- forest, with some eae for island biogeography, 63: 31- SUGDEN, ANDREW M. oe vegetation of the Serrania de Macuira, Guajira, Co- 68 lombia: a contrast of arid lowlands and an isolated cloud ea 63: 1-30 Sun, 8S. C., Y. C. TANG, J. X. Wan, T. S. YING, B. eee a. D. E. biter A. L. CHANG, Z. Page T.R. Dub ey, S. A. HE, Y. X. Jin, Q. Y. Li, J.L. pea AND S. A. SPONGBERG. The 1980 Sino-American botanical expedi- tion to western Hubei Province, People’s Republic of China, 64: 1-103 SWEET, HERMAN R., AND LESLIE A. GARAY. Notes on West Indian orchids, II, 53: 390-398; III, are $15-530 SWEITZER, EDWA Comparative anatomy of ie 52: 523-585 Sykes, W. R., AND P. J. GARNOCK-JONES. Anew combination in Syzygium for Eu- genia maire (Myrtaceae) of New Zea- land, 60: 396-401 Symon, D. E. The growth of Dracaena draco—dragon’s blood tree, 55: 51-58 Synopsis of the Chinese species of Asarum (Aristolochiaceae), A, 64: 565-597 Systematic anatomy of Bahamian species ments on the relationships of Flacour- tiaceae, 56: 20-102 as na and breeding jae of Gel- semium (Loganiaceae), 51: 1-17 ae and palynology = Picroden- dron: further evidence for relationship with the Oldfieldioideae (Euphorbi- aceae), 65: 105-127 Systematics of Central American Helico- nia (Heliconiaceae) with pendent inflo- rescences, 65: 429-532 Systematics of Holographis (Acanthaceae), -160 Systematics of the Andropogon virginicus complex (Gramineae), 64: 171-254 Systematics of the Neotropical genus Cen- tradenia (Melastomataceae), 58: 73-108 Syzygium for Eugenia maire (Myrtaceae) of New Zealand, A new combination in, 60: 396-401 Syzygium (Myrtaceae) from Papuasia, A provisional key and enumeration of species of, 54: 160-227 Tachia a The Neotropical genus, 56: 103-12 , J. X.; a T. S. YING, BaKTHOLOMEW, D. E. BouFFoRD, Ne L. ANG, Z. CHENG, T. R. DUDLEY, S. A. JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 He, Y. X. Jin, Q. Y. Li, J. L. Lutreyn, S. A. SeONCEE RS. AND §. C. SuN. The 1980 Sino-American botanical expedi- tion to western Hubei ae People’s Republic of China, 64: 1-103 TANNER, E. V. J., AND P. J. ee The montane forests and soils of Jamaica: a reassessment, 57: 313-368 Taxa from Brazil and Guyana in the genus Hymenaea (Leguminosae, Caesalpinioi- deae), New, 54: 94-104 Taxonomic and nomenclatural notes on Jamaican gamopetalous plants, 52: 614- 648 Taxonomic revision of Pieris (Ericaceae), A, 63: 103-144 Taxonomic revision of the American species of Agarista (Ericaceae), A, 65: -342 axonomic status of Protocyrtandra (Ges- neriaceae), The, 51: 241-246 Taxonomic status of the genus Bauerella (Rutaceae), The, 56: 164-170 Taxonomy and chemistry of Pinus estev- ezil, The, 63: 187-198 Taxonomy of the West Indian cycads, 61: 701-722 TERABAYASHI, SUSUMU, DAvip E. Bour- FORD, AND TSUN-SHEN YING. A mono- a of Diphylleia (Berberidaceae), 65: oe (Rutaceae), A revision of the , 60: 127-153 THIERET, JOHN W. The genera of Oroban- pee in the southeastern United States, 52: 404-434 pms JOHN e Martyniaceae in the southeastern United States, 58: 25-39 THIERET, JOHN W. The Mayacaceae in the southeastern United States, 56: 248-255 THIERET, JOHN W. The Phrymaceae in the southeastern United States, 53: 226-233 THIERET, JOHN parganiaceae in the southeastern United States, 63: 341- 355 THomas, JoAB L. Haploid and diploid pollen in Hypericum patulum, 51: 247- 250 THOMPSON, GARY G., AND Norton G. MILLER. Boreal and western North American plants in the late Pleistocene 18 THOMSON, PAuL M., AND Ropert H. MOHLENBROCK. Foliar trichomes of 1985] Quercus subgenus Quercus in the eastern United States, 60: 350-36 THOTHATHRI, K. Studies in the Legumi- nosae, 11. A new species of Derris from the Solomon Islands, 51: 251-254 Three new species of Phaleria (Thymelae- aceae) from Papuasia, 55: 264-268 Three new species of Picramnia (Simarou- baceae) from Central America, 54: 315- 321 Three new species of Zanthoxylum (Ru- taceae) from Darién Province, Panama, 53: 403-408 Tibouchina and Charianthus (Melasto- mataceae) in the Lesser Antilles, Notes on, 53: 399-402 TIFFNEY, BRucE H. Fruits and seeds of the Brandon Lignite, V. Rutaceae, 61: 1-40; VI. Microdiptera (Lythraceae), 62: 487- 516 TIFFNEY, BRUCE H., AND MICHAEL MApI- ON. The seeds of the Monstereae: their morphology and fossil record, 57: 185- 204 Tiliaceae. Pollen of tropical trees. I, 59: 299-309 Timonius (Rubiaceae) from Papuasia, New species of, 64: 611-618 Toes, E., AND R. W. DEN OuTER. The sec- ondary phloem of Amentotaxus, 55: 1 19- 122 ToMLINson, P. B. Breeding mechanisms in trees native to tropical Florida—a hological assessment, 55: 269-290 TomLinson, P. B ioecism in Citharex- ylum (Verbenaceae): an addendum, 54: 120 TomLinson, P. B. Rhizophora in Austra- lasia—some clarification of taxonomy and distribution, 59: 156-1 Tomuinson, P. B., J. S. Bunt, R. B. Pri MACK, AND N. C. Du UKE. Lumnitzera ro- sea (Combretaceae) — its status and floral . Davis. Anew species of Ruppia in high salinity in Western ee 55: 59-66 TomLINson, P. B., AND PRISCILLA FAw- ETT. Dioecism in ceateeeee (Ver- benaceae), 53: oe 389 TOMLINSON, P. B DJ. B. FisHer. Mor- phological ati in Cordyline (Aga- vaceae) I. Introduction and general mor- phology, 52: 459-478; II. Vegetative SCHMIDT, INDEX TO AUTHORS AND TITLES 69 morphology of Cordyline terminalis, 53: 113-127 ToMLINSON, P. B., AND J. R. VINCENT. Anatomy of the palm Rhapis excelsa, X. Differentiation of stem conducting tis- sue, 65: 191-21 Tomunson, P. B., Dp M. H. ZIMMER- MANN. The vascular system in the axis of Dracaena fragrans (Agavaceae) 2. Dis- tribution and development of secondary vascular tissue, 51: 478-491 Tomuinson, P. B., . ZIMMER- MANN. Vascular patterns in palm stems: variations of the Rhapis principle, 55: Tonga, The genus Diospyros (Ebenaceae) island plants, X XIII, 52: 369-403 Transfer of the Brazilian Trixis eryngioides to Perezia (Compositae, Mutisieae), 59: —359 Treatment of Aublet’s generic names by his contemporaries and by present-day tax- onomists, The, 65: 215-242 Tribes of Cruciferae (Brassicaceae) in the southeastern United States, The, 65: 343-— 373 Trimeniaceae (Laurales), Floral structure and relationships of the, 64: 447-473 Trixis eryngioides to Perezia (Compositae, Mutisieae), Transfer of the Brazilian, 59: 352-359 TsENG, CHARLES C., AND RICHARD H. EyDE. What is the primitive floral structure of Araliaceae, 52: 205-239 Tsucutva, T., L. C. JOHNSON, AND S. E. SCHLARBAUM. The chromosomes and relationships of Metasequoia and Se- quoia (Taxodiaceae): an update, 65: 251- 254 Turbina, notes on Merremia, Operculina, and— Additions and changes in the Neo- tropical Convolvulaceae, 64: 483-489 Turks islands, New species and a new com- bination ee the Bahamas, Caicos and, Turks ae New species and varieties from the Bahamas, Caicos and, 60: 154- 162 Two new species and a new subgenus of Cyclanthaceae, 59: 74-102 Two new species of Euphorbia subgenus Agaloma from Mexico, 58: 343-348 Two new species of Leguminosae, 52: 691- 694 70 JOURNAL OF THE ARNOLD ARBORETUM Two unusual Chionanthus species from Borneo and the position of Myxopyrum in the Oleaceae, 64: 619-626 Types of blind vein-endings in the dichot- omous venation of Circaeaster, 51: 70— 8 Ulmaceae, Comparative anatomy of, 52: 23-585 Ulmaceae in the southeastern United States, The genera of, 51: 18-40 Ulmaceae, Moraceae, and Urticaceae, Cy- tological studies in, 55: 663-677 United States and Mexico, Notes on the nus Polygala in the, 60: 504-514 United States, Foliar trichomes of Quercus subgenus Quercus in the eastern, 60: 350— 366 United States, Notes on Peperomia peraceae) in the southeastern, 63: 2 Upper Cretaceous of central California, A possible magnolioid floral axis, Lois- hoglia bettencourtil, from the, 65: 95- 104 Upper Cretaceous of central California, Dicotyledonous wood from the, 60: 323- 349; II, 61: 723-748: III. Conclusions, 62: 437-455 Urticaceae, Cytological studies in Ulma- raceae, and, 55: 663-677 Urticaceae in the southeastern United States, The genera of the, 52: 40-68 eas patterns in palm stems: varia- s of the Rhapis principle, 55: 402- Vascular system in the axis of Dracaena fragrans (Agavaceae), The, 2. Distribu- tion and de ee of secondary vas- cular tissue, 51: 478-491 Vegetation of the ener de Macuira, Guajira, Colombia, The: a contrast of arid lowlands and an isolated cloud for- est, 63: 1-30 Vegetative anatomy and the taxonomic status of Ilex collina and Nemopanthus (Aquifoliaceae), 65: 243-250 Venation patterns in the leaves of Ephedra, 53: 364-385 Vernonias (Compositae), A revision of the West Indian, 59: 360-413 Vernonieae (Compositae) in the south- [VOL. 66 eastern United States, The genera of, 63: 489-507 VIJAYARAGHAVAN, M. R., AND USHA DHar. Kadsura heteroclita— microsporangium and pollen, 56: 176-182 VINCENT, J. R., D P. B. TOMLINSON. Anatomy of the mie Rhapis excelsa, X. Differentiation of stem conducting tis- sue, 65: 191-214 Viscaceae in the southeastern United States, The, 63: 401-410 VUILLEUMIER, BERYL SIMPSON. The genera of Lactuceae (Compositae) in the south- eastern United States, 54: 42-93 Wan, J. X., T. S. YInc, B. BARTHOLOMEW, D. of BouFrFrorb, A, L. CHANG, Z. CHENG, T. R. Duptey, S. A. He, Y. X. Jin, Q. Y. Li, J. L. Luteyn, S. A. SPONGBERG, S.C. Sun, AND Y. C. TANG. The | Sino-American botanical expedition to western Hubei Province, People’s Re- public of China, 64: 1-103 WEAVER, RICHARD E., JR. A revision of the Neotropical genus Lisianthus (Gen- tianaceae), 53: 76-100, 234-311 WEAVER, RICHARD he genus Mac- rocarpaea (Gentianaceae); in Costa Rica, 53: 553-557 WEAVER, RICHARD E., Jr. The reduction of Rusbyanthus and the tribe Rusbyan- theae (Gentianaceae), 55: 300-302 WEAVER, RICHARD E., JR., AND BASSETT Macuire. The Neotropical genus Ta- chia (Contneae, 56: 103-125 aii RICHARD E., Jr., AND Lity RU- G. Cyto taxonomic notes on some jaa 56: 211-222 WEAVER, RICHARD E., JR., AND CARROLL E. Woop, Jr. The genera of Gentiana- ceae 7 the southeastern United States, 63: 441-487 WEBSTER, ee A revision of Mar- garitaria Euphorbiaceae) ies 403-444 WEBSTER, G. N, W. T. GIL- tis, D. E. sane AND "C. - BROOME. Systematics and palynology of Picroden- dron: further evidence for relationship with the Oldfieldioideae (Euphorbi- aceae), 65: 105-127 Weeds of the Cruciferae (Brassicaceae) in North America, 62: 517-540 WeEnDT, Tom. Notes on the genus Polygala 1985] in the United States and Mexico, 60: 504— Wercklea (Malvaceae), Revision and ex- pansion of the Neotropical genus, 62: 457-486 West Indian cycads, Taxonomy of the, 61: 701-722 West Indian Myrtaceae, Notes on, 54: 309- 314 West Indian orchids, Notes on, IT, 53: 390- 398; III, 53: 515-530 West Indian species of the Asian section Tittmannia, a new, Lindernia brucei, 56: 449-455 West Indian taxa in Solander’s ‘“‘Florula Indiae Occidentalis,” The, 63: 63-81 West Indian vernonias (Compositae), A re- vision of the, 59: 360-41 West Indies, A new combination in Bul- bostylis from the, 60: 322 West Indies, A new Herissantia (Malva- ceae) from the, 60: 316-319 Western Australia, A new species of Rup- pia in high salinity in, 55: 59-66 What and whence was Miller’s Caryophyl- lus cotinifolius, 56: 171-175 What is the primitive floral structure of Araliaceae, 52: 205-239 WHEELER, ELISABETH, RICHARD A, SCOTT, AND Eso S. BARGHOORN. Fossil dicot- ledonous woods from Yellowstone Na- tional Park, 58: 280-306; II, 59: 1-31 Wuite, Peter S. The architecture of dev- il’s walking stick, Aralia spinosa (Arali- 8 WILDER, GEORGE J. Two new species and a new subgenus of Cyclanthaceae, 59: 74— 102 WorrorpD, B. EUGENE. A new Lindera Pere from North America, 64: -331 tia anatomy and es oe of Paeonia section Moutan, 59: 274-297 Wood anatomy of Belliolum (Winteraceae) and a note on flowering, 64: 161-169 Wood anatomy of Myrothamnus flabelli- folia (Myrothamnaceae) and the prob- lem of multiperforate perforation plates, 57: 119-126 Wood anatomy of the New World Pithe- cellobium (sensu lato), 62: 1-44 Wood of Amentotaxus, The, 54: 111-119 D, CARROLL E., Jr. Indexes to papers 1 to 100 published as parts of the Ge- SCHMIDT, INDEX TO AUTHORS AND TITLES 71 ric Flora of the Southeastern United 563 e Balsamina- ceae in the southeastern United States, 56: 413-426 Woop, CARROLL E., Jr. The genera of urmanniaceae in the southeastern United States, 64: 293-307 Woop, Carrot E., Jr. The genera of Menyanthaceae in the southeastern United States, 64: 431-445 Woop, CARROLL E., JR. The Saururaceae in the southeastern United States, 52: 479-485 Woop, CARROLL E., JR., AND PRES ADAMS. The genera of Guttiferae (Clu. siaceae) in the southeastern United States, Woop, CARROLL E., JR., AND S. A. GRA- HAM. The Podo stemaceae in the south- eastern United States, 56: 456- se Woop, CARROLL E., JR., AND LyM SmitH. The genera of Be rcliaoae in the southeastern United States, 56: 375- 397 Woop, CARROLL E., JR., AND RICHARD E. WEAVER, JR. The genera of Gentiana- ceae in the southeastern United States, 63: 441-487 WuRDACK, JOHN J., AND ROBERT KRAL. The genera of Melastomataceae in the southeastern United States, 63: 429-439 Xeroteae (Liliaceae sensu lato), Generic limits in the, 59: 129-155 Xylem anatomy of Hibbertia (Dilleni- aceae) in relation to ecology and evolu- tion, 59: 32-49 Xyridaceae in the southeastern United States, The, 64: 421-429 YAKOVLEV, G. P. A new species of Or- mosia from Brazil, 51: 129-131 YAKOVLEV, Two new species of Le- ND CHING-YUNG A synopsis of the Chinese species . Asarum (Aristolochiaceae), 64: wine ca National Park, Fossil dicot- yledonous woods from, 58: 280-306; II, 31 YING B. BARTHOLOMEW, D. E. Boueeoan. "A L. CHANG, Z. CHENG, T. R. ce JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Dub ey, 8S. A. He, Y. X. Jin, Q. Y. Li, McCue, AND JOHN S. SPERRY. Anatomy . L. Luteyn, S. A. — S.C. see palm Rhapis excelsa, VIII. Vessel Suni. Y.C. TANG, AND J. X The 1980 Sino-American ea eens tion to western Hubei province, People’s Republic of China, 64: 1-103 Yinc, T. S., Susumu TERABAYASHI, AND AviID E, BourFForRD. A monograph of Diphylleia (Berberidaceae), 65: 57-94 Zanthoxylum (Rutaceae), Additional notes on the Malesian species of, 51: 423-426 Zanthoxylum (Rutaceae) from Darién Province, Panama, Three new species of, 53: 403-408 Zanthoxylum (Rutaceae) from New Guinea, A new species of, 56: 369-373 ZARUCCHI, JAMES L. The treatment of Au- blet’s generic names by his contemporar- ies and by present-day taxonomists, 65: 215-242 ZIMMERMANN, MartTIN H., Kent F. ARNOLD Fae arena 22D ITy AVENUE Speen MASSACHUSETTS 02138 network and vessel-length distribution in i stem, 63: 83-95 ZIMMERMANN, MARTIN H., AND JOHN S. PERRY. Anatomy of the palm Rhapis excelsa, IX. ae structure of the leaf 9 ZIMMERMANN, eens H., AND P. B. The vascular system in the axis of Draciens fragrans (Agavaceae) 2. Distribution and development of sec- ondary vascular tissue, 51: 478-491 ZIMMERMANN, MartTIN_ H., TOMLINSON. Vascular patterns in palm stems: variations of the Rhapis princi- ple, 55: 402-424 Zingiberales (Cannaceae, Marantaceae, and Zingiberaceae) in the southeastern United States, The, 65: 5-55 Zygophyllaceae in the southeastern United States, The genera of, 53: 531-552 1985] TIFFNEY, FLORISTIC SIMILARITY 73 PERSPECTIVES ON THE ORIGIN OF THE FLORISTIC SIMILARITY BETWEEN EASTERN ASIA AND EASTERN NORTH AMERICA! Bruce H. TIFFNEY THE FLORISTIC SIMILARITY between eastern Asia and eastern North America has been recognized since the time of Linnaeus (see Graham, 1972a; Boufford & Spongberg, 1983) and was emphasized through the work of Asa Gray (1840, 1859). Scientific study of this pattern has continued, and its importance in current botanical thought is shown by the several symposia recently convened on the topic, most notably those at the XI International Botanical Congress in Seattle and the Japanese-American meeting in Corvallis in 1969 (Graham, 1972b), at the Missouri Botanical Garden in 1982, and at the Japanese-Amer- ican conference held at the Cary Arboretum of the New York Botanical Garden in 1983 In general, presentations at these conferences have followed one of three approaches: enumeration of taxa exhibiting this pattern; discussion of some aspect of the biology (e.g., anatomy, ecology, cytology, chemistry) of a taxon or taxa exhibiting this pattern; or examination of the paleontological aspects of this question, involving postulated routes of movement or changes over time in one geographic area. However, two major questions have never been directly addressed and have only rarely been alluded to in these symposia: first, is the pattern of similarity between eastern Asia and eastern North America real, and second, if it is, what are all the possible ways by which the pattern might have arisen? A proper solution to the first question requires a rigorous examination of the patterns of similarity between eastern Asia and eastern North America in light of the larger biogeography of the Northern Hemisphere. In particular, “‘three-area” tests of the variety suggested by cladistic biogeographers need to be made and analyzed to determine whether the eastern Asian-eastern North American similarity is a unique pattern or simply a distinctive subset of a larger pattern. From a paleontological perspective, I suspect that the latter is both the more correct assumption and the better working hypothesis. I believe that this conclusion is also inherent in reviews of modern angiosperm bio- geography (e.g., Thorne, 1972). However, it is the second of the two questions that I wish to explore in depth here, as it places the following paper (Tiffney, \This is the first of two related papers. The second, entitled “The Eocene North Atlantic Land Bridge: Its Importance in Tertiary and Modern Phytogeography of the Northern Hemisphere,” will be published in the April, 1985, issue of the Journal of the Arnold Arboretum. © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 73-94. January, 1985. 74 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 1985) on the importance of early Tertiary North Atlantic land bridges in the historical context of all possible origins of the eastern Asian-eastern North American floristic similarity. For this purpose I will assume that the pattern is ““real’”’; I do not think that this assumption biases the inquiry into its origins. The purpose of this paper is to call attention to the diverse historical com- ponents of this biogeographic pattern and to emphasize that it did not arise as a result of a single historical event. Scientists working with this problem rec- ognize that it is complex but have not presented a logical explanation of its components. A clear exposition of the range of biogeographic factors involved in the origin of the eastern North American—eastern Asian floristic similarity would make it possible to evaluate the individual histories of plant taxa that contribute to the pattern. This information should in turn enhance our knowl- edge of other aspects of the biology of the plants under investigation. As a general survey, this paper may prove wrong in its particulars but will provide a starting point for an examination of the variables involved. PATTERNS AND PROCESSES The origin of the floristic similarity of eastern Asia and eastern North Amer- ica involves an interplay of three factors: changing geography, changing climate, and evolving (both phylogenetically and ecologically) biota. The last factor is not completely independent of the former two, as physical events are important in both allopatric speciation and natural selection. Before the interaction of these three factors and the range of possible ways by which the eastern Asian-eastern North American similarity arose can be discussed, three other biogeographic questions must be considered: the concept of a “center of origin” of the flora that now displays this distribution pattern, the nature of past plant movements in general (specifically, the distinction between the dispersal of “floras” and “individuals’’), and the biogeographic history of herbaceous angiosperms. These topics have had a strong influence, whether perceived or not, on thought concerning the origin of the eastern Asian— eastern North American floristic pattern. ELEMENTS OF PALEOPHY TOGEOGRAPHY CENTERS OF ORIGIN AND ASSOCIATED PROBLEMS The similarity of the extant floras of eastern Asia and eastern North America arose through movements of taxa in the geologic past. Gray (1878), considering the geographic arrangement of the Northern Hemisphere, proposed that the pattern developed due to a glacially induced southward movement of an earlier thermophilic flora with a polar distribution. This perspective was developed by Chaney (1947) and refined by Axelrod (e.g., 1966) as the “geofloral hy- pothesis.”’ Subsequent workers have found no evidence of a Late Cretaceous/ early Tertiary circum-Arctic flora similar to that of the temperate regions of eastern North America and eastern Asia today (see Hickey et a/., 1983; Hickey, pers. comm.). 1985] TIFFNEY, FLORISTIC SIMILARITY 1S Wolfe (1975, 1977) argued from paleobotanical evidence that the origin of the similarity of the floras of eastern Asia and eastern North America involved the evolution of a large number of modern taxa in the latest Cretaceous and early Tertiary. These first appeared in the mid-latitudes of the Northern Hemi- sphere and spread by existing land bridges, ultimately forming a relatively homogeneous early Tertiary flora. Both paleoclimatological data (Kennett, 1977; Buchardt, 1978; Collinson et a/., 1981) and the taxonomic composition of this early Tertiary flora demonstrate that early Tertiary climates were at least par- atropical in the mid-latitudes of the Northern Hemisphere. For this reason, and to distinguish this assemblage from coeval floras in the Southern Hemi- sphere (Wolfe, pers. comm.), Wolfe (1975) referred to these newly evolved plants as forming a ‘“‘boreotropical flora.” Wolfe (1975, 1977) did not cite a specific “center of origin” for the boreo- tropical flora, but certain aspects of its composition and distribution have been taken to suggest such a center. The greatest diversity of modern taxa derived from this early Tertiary flora is now found in eastern Asia. Similarly, the affinities of many fossil representatives of the boreotropical flora found in Europe and North America lie with extant taxa found in Japan, China, northern India, Indomalaysia, and some western Pacific islands. These include plants of temperate, subtropical, and tropical environments. Further, the modern eastern Asian flora includes a host of taxa that are presumed to be phyloge- netically primitive, with many occurring as monotypic families or genera (Wang, 1961). These factors all lead to the common perception that southeastern Asia was the evolutionary source area both of the angiosperms as a whole and of the modern flora of the Northern Hemisphere (e.g., Takhtajan, 1969; Smith, 1970). The interpretation of southeastern Asia as the place of origin of the angiosperms has been rejected in recent years (e.g., Raven & Axelrod, 1974), and its role as the sole source for the boreotropical flora similarly disintegrates under scru- tiny. In both cases the alternative interpretation that southeastern Asia was a great refugium or “museum” appears to be correct. Perhaps more importantly, the dismissal of this “‘center of origin” should not imply the necessity of locating a new one. I agree with Wolfe (1975) that the boreotropical flora probably had a diffuse origin involving several areas of the Northern Hemisphere. Evaluation of the status of southeastern Asia, and of the latter suggestion, requires an examination of what distinguishes southeastern Asia from other areas of the Northern Hemisphere in the past and the present, as well as of what evidence exists for other places of origin of the boreotropical flora. The latter further requires the distinction between a localized center of origin and a diffuse origin of this flora. Little paleobotanical evidence is available for southeastern Asia in the early Tertiary. Guo (1980) and Hsii (1983) have reviewed evidence of the Late Cretaceous and Tertiary flora and vegetation of China. Although Hsii includes some palynological data, generally at the family level, both reviews are largely dependent on evidence from fossil leaves. Hickey (1973) and Wolfe (see Hickey & Wolfe, 1975) have indicated that many existing identifications of fossil leaves are erroneous and in need of revision. Thus, the composition of these Chinese 76 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 floras is unclear. Muller’s (1968) report on early Tertiary palynology of Borneo indicates that several typical elements of the modern flora did not arrive at the sample site until after the Eocene. This suggests that the extant flora of this area developed through the Tertiary and is not the product of a single, local, early Tertiary origin. Vertebrate evidence (Li & Ting, in press; see also McKenna, 1983b) indicates that the Chinese Paleocene fauna was distinct from that of the rest of the Northern Hemisphere; the same may have been true of its early Tertiary flora. Circumstantial evidence further suggests that southeastern Asia is well suited to preserve taxa of tropical to warm-temperate affinity. During the early to middle Tertiary, it was linked with central Asia and Europe by the Tethys Seaway (see Tiffney, 1985, map 6), and to western North America via the Bering land bridge. Southeastern Asia is topographically diverse and was presumably equally so in the later Tertiary, encompassing a wide range of habitats and climates. Further, it was and is protected from invasion of Arctic air masses by east-west oriented mountains that had sufficient gaps to permit the southward movement of plants from the north. In short, southeastern Asia could be expected to serve as a refugium for thermophilic plants in an ice age. With respect to the second question, the other possible areas of origin of the boreotropical flora involve the Late Cretaceous—early Tertiary low latitudes, high latitudes, and mid-latitudes of the Northern Hemisphere. No real data are available on plant evolution in the tropics at this time; this is one of the challenges to angiosperm paleobotany. Recent evidence (Hickey, 198 1a; Hickey et al., 1983; Hickey, pers. comm.) from high latitudes indicates the presence of a species-poor, deciduous flora. Although several components of this flora (e.g., Betula L., Cercidiphyllum Sieb. & Zucc., Metasequoia Miki, Juglandaceae) are members of the boreotropical flora, the latter unit did not evolve here. For the mid-latitudes the evidence is less direct, but suggestive. In the Late Cretaceous, palynological data indicate that the Northern Hemisphere was broadly divided into two primary floristic provinces: the Aquillapollenites Rouse province of western North America and eastern Asia, and the Normapolles province of eastern North America and Europe (Muller, 1970; Srivastava, 1981), which reflect the geography of the time—eastern Asia and western North America were linked by the Bering land bridge, and eastern North America and Europe were linked by a North Atlantic land bridge. Separated by the Turgai Straits and other seaways through central Asia and eastern Europe (Vinogradov, 1967-1968; see Tiffney, 1985), and by the Midcontinental Seaway through central North America, these provinces disintegrated at the end of the Cretaceous (Muller, 1970), shortly before the rise of the boreotropical flora. With their different floristic compositions, they each probably contributed distinctive elements to the succeeding boreotropical flora. The paleogeography of the early Tertiary also suggests other possible mid- latitude sources of the boreotropical flora. In particular, the island chains of the European and Middle Eastern portions of the Tethys Seaway seem likely to have been excellent sources for the evolution of new taxa through allopatric speciation. The great longitudinal span of the Tethys, from eastern Asia to Europe and west at least as far as Caribbean North America, may have provided a natural route for taxa that evolved in a limited area of the seaway. Certainly 1985] TIFFNEY, FLORISTIC SIMILARITY det both classic boreotropical floras (e.g., the London Clay Flora of England (Reid & Chandler, 1933; Chandler, 1964), the Geiseltal Flora of Germany (Mai, 1976), the Haselbach Flora of Germany (Mai & Walther, 1978), the Burgas Flora of Bulgaria (Palamarev, 1973), the Clarno Flora of Oregon (Scott, 1954; Chandler, 1964; Manchester, 1981la, 1983)) and modern refugia rich in bo- reotropical elements (Central America, southeastern North America, the Cau- casus, the Himalayas, southeastern Asia) lie along the ancestral path of the Tethys. Other mid-latitude areas of the early Tertiary may also have provided the geographic diversity necessary for allopatric speciation. In North America the early Tertiary rise of the Rocky Mountains resulted in an increasingly diverse landscape and was associated with many floristic changes (Leopold & MacGinitie, 1972), which probably involved the evolution of new taxa in situ rather than their movement in from other areas. In summary, no paleontological evidence exists to support the concept of eastern Asia as the sole center of origin of the modern flora of the Northern Hemisphere. A limited number of boreotropical taxa have been recognized in the early Tertiary of the Arctic; geographic considerations suggest that other areas in the mid-latitudes of the early Tertiary could well have served as diffuse centers of origin and speciation. Resolution of the sources of the boreotropical flora will require careful analysis of the geographic history of its specific com- ponent lineages (e.g., Manchester’s (1981b) survey of the Juglandaceae). THE BALANCE OF FLORAS AND INDIVIDUALS IN “MIGRATION” Discussion of the origin of the modern flora of the Northern Hemisphere invariably entails consideration of the “‘migration” of ancestral communities or floras. This idea can be traced to Darwin (1859) and Gray (1878). However, the first modern concepts of the community can be ascribed to the ecological work of Clements (1916, 1928), who considered the community to be the basic structural unit of the earth’s vegetation. He regarded individual communities as tightly interdependent groupings of plants united through adaptation to a particular climate and environment and having almost organismlike emergent properties. Clements argued his case cogently, and his ideas had a strong in- fluence on American botany for many years. One of those influenced was R. W. Chaney, who saw in this approach an ecological explanation to patterns observed in the fossil record. From this arose the geofloral concept—the hy- pothesis that past phytogeographic changes involved the movement of mono- lithic “‘climax”? communities of set taxonomic composition across the face of the earth in response to climatic stimuli (Chaney, 1947). In particular, he believed that the present similarity of the floras of eastern Asia and eastern North America resulted from the early Tertiary southward movement from a polar source of a temperate ‘““Arcto-Tertiary Geoflora’”’ of modern floristic and vegetational composition. Viewed in the context of contemporary science, this was an up-to-date, biological explanation of the observed facts. However, the Clementsian concept of the community as a monolithic unit was not without its detractors. In particular, H. A. Gleason (1926) countered the community concept of plant ecology with what he termed the “indivi- 78 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 dualistic concept.”’ Gleason contended that plant species acted independently, that range expansions and contractions occurred on the level of individual organisms, and that the “communities” of Clements were nothing more than chance aggregations of species sharing some common physiological require- ments and tolerances. In some senses the individualistic approach is the dom- inant perspective in modern community ecology, as reflected both in Whit- taker’s concept of gradients (1967) and in the general sense that Clementsian “climax”? communities do not exist. The paradox of the Clementsian-Gleasonian debate is that both sides are right. Communities do not move in lockstep, but neither are plant groupings totally completely random associations of species. Davis (1976, 1981) has demonstrated that several taxa that are found together in portions of the modern temperate deciduous forest of eastern North America moved into these com- munities after the Pleistocene from different refugial sources and following different routes of dispersal. However, although plants disperse as individuals, different taxa may be constrained by similar environmental factors such as moisture, temperature, soils, or dispersal agents in such a way that ‘“‘commu- nities” of mutual tolerance are maintained as loose but recognizable units. With the loss of resolution dictated by the nature of the fossil record, it is not surprising that paleontologists perceive a pattern involving “‘floras” rather than individuals. The danger lies in accepting this perception at face value without seeking the dynamic biological factors that underlie it The critical response to the geofloral hypothesis has nl necessarily followed the community-individual debate, but elements of that discussion are present. Wolfe (1969, 1975, 1977) surveyed the fossil record and found no evidence of a polar Arcto-Tertiary Geoflora, or of phytogeographic evolution of the North- ern Hemisphere involving the mass movement of unit floras. However, he has demonstrated the early Tertiary appearance of a floristic unit that he termed the “boreotropical flora.” Although Wolfe never envisioned this flora as uni- form in its composition, its name conveys the impression that it was fairly homogeneous. This raises conceptual problems, as it might appear that the sole difference between the Arcto-Tertiary Geoflora and the boreotropical flora is that the latter did not “migrate” but simply appeared. In a sense this is true, but the real distinction between the two lies in their internal dynamics. The geofloral hypothesis assumed a stable community with a static composition: the boreotropical flora concept, a constant internal flux of taxonomic com- position, both in its origin and during its existence. Thus, the boreotropical flora is envisioned not as sweeping out from a single source but as rapidly accumulating through the dispersal of separately derived taxa into common areas. Although the reason for the initial appearance of so many boreotropical taxa during the early Tertiary 1s unclear (but see Tiffney, in press, for a possible explanation), the unique proximity of Northern Hemisphere continents in the early Tertiary, together with the warm climates of that time, explains their rapid spread. Similarly, after its establishment the boreotropical flora probably displayed considerable internal variation. I suspect that during the times of maximum land connection in the Northern Hemisphere, although the flora was characterized by a few distinctive taxa that were known from all or most 1985] TIFFNEY, FLORISTIC SIMILARITY 79 KA ves = of the range of the flora (e.g., Nypa Steck, Icacinaceae ), individual species generally occupied only a portion of the range at any one time. As time progressed and climate and geography altered, this level of variation gave way to allopatric speciation and increased local differentiation. Finally, some word is appropriate regarding one antithesis of floral ‘“‘migra- tion’’—the hypothesis that the floristic similarity of eastern North America arose largely through chance long-distance dispersal (e.g., Iltis, 1982, 1983). This hypothesis is at odds with paleobotanical evidence for the existence of a boreotropical flora. Further, biotas resulting from long-distance dispersal are often dysharmonic; that is, they contain an imbalance of ecological constituents (Carlquist, 1974). The floras (and faunas) of eastern Asia and eastern h America contain a diverse array of constituents and could not have resulted entirely or in large part from the effects of long-distance dispersal. Finally, while long-distance dispersal is significant in explaining the past and present distri- bution of individual taxa, it is a counterproductive and anarchic hypothesis when used to explain patterns involving entire biotas. A dispersal hypothesis eliminates the ability to make predictive hypotheses and reduces the science of biogeography to chance. THE DIFFERENTIAL APPEARANCE OF TAXA Analogous to simplistic models of ‘single centers of origin” and “migration of unit floras” is the all-too-human tendency to seek a single time for the origin of the similarity of the floras of eastern Asia and eastern North America. Although Wolfe’s boreotropical-flora model of the early Tertiary provides much to explain the extant phytogeography of the Northern Hemisphere, I believe that it has given the unintended impression that the eastern elas North American similarity is a function ofa single time-limited historical event. However, analyses of phytogeographic patterns reveal that the individual taxa involved appeared in the fossil record at different times (which may reflect their evolution at different times), have different ecological adaptations, par- ticularly as reflected in physiognomy, and are presently adapted to different climatic regimes. In short, the observed similarity of the two modern floras involves a range of taxa with rather different histories, habitats, and habits. This suggests that the similarity did not arise as the result of a single past event. Closer examination of the fossil record supports this contention. I will look at three particular aspects: the time of origin of specific families; the time of origin of herbaceous angiosperms, many of which are included in this pattern; and the nature of the different climatic tolerances of taxa constituting the modern eastern Asian—eastern North American pattern. ORIGINS AND AFFINITIES. Some of the plants now having an eastern Asian— eastern North American distribution pattern belong to families that appeared in the fossil record at different times in the Tertiary. As a sample of the plants now showing this geographic pattern, I take those described in the classic work of H. L. Li (1952, 1972) and those mentioned by participants in the symposium that prompted the present paper, together with a few assembled from other sources (see TABLE 1). For the first occurrences of modern families in the fossil 80 JOURNAL OF THE ARNOLD ARBORETUM TABLE 1. a and eastern North Americ [VOL. 66 Age of origin of some families held in common laa the floras of eastern REPRESENTATIVE REFER- FRUIT AND FAMILY# GENERA? ENCE® POLLEN DATES SEED DATE® Aquifoliaceae Tlex L. 5 Turonian Paleocene Buxaceae Pachysandra Mi- 4 Campanian Mid-Miocene chaux Juglandaceae Carya Nutt. 4 Campanian Paleocene Leguminosae Gymnocladus 4 Maastrichtian Paleocene Lam., Cladras- tis Raf, Wiste- ria Nutt., Apios Medikus Symplocaceae Symplocos Jacq. 5 Maastrichtian Early Eocene Theaceae Gordonia Ellis, 4 Early Eocene Late Cretaceous Stewartia L. Aceraceae Acer 5 Oligocene Paleocene Anacardiaceae Rhus L 5 Paleocene Early Eocene Araliaceae Panax L. 4 Paleocene Mid-Eocene Caprifoliaceae Triosteum L., 4 Mid-Eocene Paleocene Diervilla Miller, Weigela Thunb. Cyperaceae Carex L., Schoe- 3 Mid-Eocene Paleocene noplectus (Reichb.) Palla Hamamelidaceae Hamamelis L. 4 Paleocene Early Eocene Nyssaceae Nyssa Gronov. ex 4 Paleocene Early Eocene L. Polygonaceae Antenoron Raf., 4,5 Paleocene Late Eocene Polygonum i. Rosaceae Rhodotypos Sieb. 4 Oligocene Paleocene & Zucc., Kerria DC., Neviusia A. Gray Lauraceae Sassafras Trew, 4 Paleocene Late Paleocene Lindera Thunb. Ericaceae Pieris D. Don, 4 Pliocene Late Paleocene Lyonia Nutt., Epigaea L Rutaceae Zanthoxylum L. 5 Pliocene’ Late Paleocene Vitaceae Vitis L., Partheno- 5,11 Oligocene Late Paleocene cissus Planchon Araceae Symplocarpus 4 Late Miocene Early Eocene Salisb. Celastraceae Celastrus L. 5 Oligocene Early Eocene Cornaceae Cornus L. 6 No data Early Eocene Ebenaceae Diospyros L. > Early Eocene Early Eocene Magnoliaceae a ea L., 4 Mid-Eocene Early Eocene nolia 1985] TIFFNEY, FLORISTIC SIMILARITY 81 TABLE | (continued). REPRESENTATIVE EFER- FRUIT AND FAMILY? GENERA? ENCE‘ POLLEN DATE4 SEED DATES Menispermaceae Menispermum L. 4 No data Early Eocene Santalaceae Cee a 4 Early Eocene Mid-Eocene a Mi- Staphyleaceae Staphylea L. 1] Pliocene Early Eocene Styracaceae Halesia J. Ellis ex 4,5 No data Early Eocene rax L Umbelliferae Sanicula L. 5 Early Eocene Mid-Miocene Bignoniaceae Campsis Lour., 4 Mid-Eocene Mid-Eocene Catalpa Scop Oleaceae Chionanthus L. 4 Oligocene Mid-Eocene Rubiaceae ee L., Gali- 4,7 Late Eocene Mid-Eocene Acanthaceae ten = Diclip- 11 Early Miocene Late Eocene tera Jus Guttiferae Ascyrum ‘ 4 No data Late Eocene Liliaceae Tribe Helonieae 9 Late Eocene No data Ranunculaceae eee 4 Early Miocene Oligocene scher & Mey- the closely related era Hydras- tis Ellis ex L. . Am.) and Glaucidium ieb. & Zucc. (E. ae Labiatae Stachys L., Aga- 11 Pliocene Mid-Oligocene ere eee ene Brit- Primulaceae ane L., Sa- 11 Pliocene Mid-Oligocene lus , Lysi- machia L Saururaceae Saururus L. 4 No data Mid-Oligocene Compositae 19 genera in com- 2 Oligocene Mid-Miocene mon Verbenaceae Callicarpa L., 11 Early Miocene No data Clerodendrum L., Vitex L Loganiaceae Gelsemium Juss. 4 No data Mid-Miocene Scrophulariaceae Veronicastrum 4 Mid-Miocene® Mid-Miocene Moench Saxifragaceae pace hts L., As- 4 No data Mid-Miocene tilbe B Ham., HT wdiahe gea L 82 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 TABLE | (continued). REPRESENTATIVE REFER- FRUIT AND FAMILY? GENERA? ENCES POLLEN DATE? SEED DATES Berberidaceae Jeffersonia Bar- 4 No data Late Miocene tram, Podophyl- L., Diphyl- leia Michaux, C oe yllum Cruciferae Pe _ > raba 11 Pliocene Late Miocene a Ca rda amine Crassulaceae Pethoran Gro- 4 No data Quaternary .ex L Phytolaccaceae pee aie L. 10 No data Quaternary ‘Listed in order of ag th Iphabeti hen of similar age. Age of first appearance is determined from fossil records of pollen and of fruits ee seeds; where the two differ, the older age | is used to order ine famili tern Asian—eastern North American distribution pattern. Reference(s) to modern distribution pattern by number: 1) Constance, 1972; 2) H. Koyama, 1983; 3) T. Koyama, 1983); 4) H , 1952; 5) H. L. Li, 1972; 6) Sharp, 1972; 7) Shimizu, 1983; 8) Tamura, 1983; 9) Utech, ee ie Wada & Ihara, 1983; 11) personal dat: ‘Earliest date recorded for family, based on pollen records (Muller, en Stratigraphy according to individual author’s citations, arranged after Van Eysinga (1975). ‘Earliest date recorded for family, based on fruit and seed records (B. H. Tiffney, unpubl. data). Stratigraphy according to fe author’ s citations, arranged after Van Eysinga (1975). Lignite of Vermont (Oligocene’?). ®*Muller indicates (1981) that some Paleocene pollen may ultimately prove to have affinities with the Scrophulariaceae. record, I refer to Muller’s (1981) compilation of the palynological record and to similar unpublished data of my own on fossil fruits and seeds. Such “first occurrence” data are suspect and open to revision with the discovery of new material. Further, Muller queries several of the identifications that he reports; on is no guarantee that all of the individual reports will stand the test of me. However, the parallelism between the two records suggests that these can are useful, and that the general patterns will hold even if specific cases are found to be in error Many of the taxa belong to families known in the fossil record by the Early Eocene (see TABLE 1) and could thus have been members of the boreotropical flora. However, many other taxa sharing the modern eastern Asian-—eastern North American distribution belong to families that arose long after the boreo- tropical flora is assumed to have been broken up by drifting continents and cooling climates. These must have had a geographic history separate from that of the more classic early Tertiary taxa, although they share this modern dis- tribution pattern. 1985] TIFFNEY, FLORISTIC SIMILARITY 83 HERBS AND TREES. This pattern of different times of origin of different taxonomic groups has a parallel in the histories of herbaceous and woody plants. Many herbaceous taxa (e.g., members of the Araceae, Araliaceae, Compositae, Cy- peraceae, Liliaceae, Polygonaceae, Primulaceae, Ranunculaceae, Rubiaceae, Santalaceae, Umbelliferae) have an eastern Asian-eastern North American distribution. In general, the paleobotanical literature (e.g., Muller’s (1981) data on first appearances, which basically agree with my data on fruits and seeds) tends to emphasize the appearance of herbaceous families in the mid-Tertiary. These herbs are generally assumed to have evolved through neoteny from woody ancestors (Takhtajan, 1976) in response to increasing seasonality in rainfall and/or temperature. Often these herbs were important in the expanding grass- dominated biomes of the time, the prairies and savannas. However, this picture is misleading, because herbs were present before the Miocene and may be presumed to have occupied unstable sites or to have formed forest-floor as- sociations in angiosperm and gymnosperm communities. Evidence for this is the occurrence of individual taxa (e.g., Ranunculus L., Polanisia Raf.) and even entire groups (e.g., the Monocotyledoneae, which are inherently herbaceous) in early Tertiary floras. Thus, all herbaceous angiosperms sharing an eastern Asian—eastern North American distribution may not have hada similar history. Some may have spread with the boreotropical flora as forest-floor herbs or as early successional colonists of disturbed sites. Others may have evolved in the later Tertiary and spread either by continuous range expansion within the deciduous communities of the Bering or North Atlantic land bridges or by chance long-distance dispersal. This separation of historical types among herbs is both a complication for paleophytogeographic inquiry and an opportunity to break such a study into component parts. Individual groups will have individual histories, but I suggest that at least four broadly overlapping historical patterns (reflecting, in part, the ecologies of the plants involved) can be predicted for herbs. First would be the plants of the forest-floor association. While some members of this group (par- ticularly those adapted to flowering before leaves of the forest canopy appear in the spring) would be expected to evolve with the diversifying mixed-me- sophytic forest of the mid-Tertiary, others were likely present in the early Tertiary. These would belong to lineages with at least a Paleogene fossil record, and they would probably be rhizomatous perennials adapted to stable, low- light environments (see Li, 1952). The long fossil history of monocots (Doyle, 1973) suggests that they would play an important role in this group. Second would be plants of disturbed forest sites. Again, these might belong to lineages with a Paleogene fossil record, but they might be biennials or shorter-lived perennials with good dispersal and other adaptations to the patchy and transient nature of disturbed forest sites. Plants in these groups could also have attained an eastern North American-eastern Asian distribution quite early. The third group, which would include plants adapted to continually disturbed or stressed environments, would comprehend herbs of many different life-histories and would be dominated by groups that evolved in the mid-Tertiary (e.g., Com- positae). A fourth and unique group would be composed of aquatic angio- 84 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 sperms. Their adaptation to the common, stable but patchy and short-lived habitats of lakes and other bodies of fresh water suits them to a broad distri- bution. This mode of existence has been present almost since the origin of the angiosperms (Doyle & Hickey, 1976; Hickey & Doyle, 1977), and the inclusion of aquatics in the eastern Asian-eastern North American pattern may predate the boreotropical flora. These categories are general; variants and intergradations will occur, partic- ularly since members of each category have undoubtedly evolved throughout the Tertiary, although at greater rates during some periods than during others. Further, the fossil record and the biology of individual plants will constrain the success with which these categories can be recognized. For example, Jef- fersonia Barton, Podophyllum L., and Diphylleia Michaux (Berberidaceae), and Dicentra Borkh. (Papaveraceae) all exemplify the first category of rhizomatous forest-floor herbs that might be expected to trace their eastern Asian—eastern North American distribution to the early Tertiary. However, pollen of Ber- beridaceae is not known in the fossil record and fruits and seeds appear only in the Late Miocene (TaBLe 1), while no record is available for the Papavera- ceae. Either the fossil record is incomplete or these taxa moved after the early Tertiary. For the Berberidaceae the fossil record of pollen, fruits, and seeds may be shown to be incomplete since leaves of Mahonia Nutt. are known from Late Eocene-earliest Oligocene sediments in the American West (Leopold & MacGinitie, 1972). However, this extension fails to push the family back to the warmest climates of the Early Eocene, possibly indicating that it expanded after the spread of the boreotropical flora. Although this suggestion of groupings is speculative, it establishes a per- spective. More importantly, it emphasizes that herbaceous plants sharing a common distribution pattern in the modern day need not have attained this distribution in the same way or at the same time. The ecology, phylogeny, and fossil record of individual taxa must be studied before an informed hypothesis about the biogeographic history of a group can be made. BIOGEOGRAPHIC HISTORY AND CLIMATIC REQUIREMENTS. The climate of the past 65 million years has ranged from the widespread, equable conditions of the early Tertiary that brought tropical taxa to far northern latitudes (Reid & Chandler, 1933; Chandler, 1964; Wolfe, 1975) to the glacial maxima of the Pleistocene. The pattern of change from one extreme to the other was not directional and gradual in any but the broadest sense; continued paleoclimatic research (Kennett, 1977; Buchardt, 1978; Wolfe, 1978; Keller, 1983) demon- strates that the overall cooling trend of the Tertiary was marked by fluctuations. The interplay between climatic fluctuations and changing intercontinental geo- graphic connections through the Tertiary has determined the availability of “migration”’ routes to plants. The climatic history of the Northern Hemisphere Tertiary commences with temperate (Hickey, 1981b) or cool-paratropical conditions (Wolfe, pers. comm.) in the mid-latitudes from the Cretaceous-Tertiary boundary through the Pa- leocene. Temperatures warmed, with fluctuations, into the Early and Middle Eocene, supporting tropical vegetation in equable climates at high latitudes, 1985] TIFFNEY, FLORISTIC SIMILARITY 85 although perhaps with a simultaneous reduction of average annual equatorial temperatures (Shackleton, 1981). In the Middle to Late Eocene, climates grad- ually cooled, leading to a sharp decline in the latest Eocene or at the Eocene- Oligocene boundary (Kennett, 1977; Buchardt, 1978; Wolfe, 1978; Collinson et al., 1981). Although we have less knowledge of Oligocene climates, evidence suggests a generally cooler period, with a warming trend beginning in Late Oligocene time and extending into the Miocene. Miocene climates were gen- erally equable and fairly warm, but not as warm as those of the Eocene. More importantly, they were characterized by a series of fluctuations (Kennett, 1977, Wolfe, 1978; Mai, 1980) between warmer and cooler temperatures, leading to increasingly cooler climates in the later Miocene. From the Late Miocene through the Pliocene to the Pleistocene, climates cooled off, with fluctuations, to a situation approximating that of the present day. Changing climates have had a direct effect upon the evolution and distri- bution of Tertiary plant communities. In particular, Mai (1964) and Wolfe (1969) both discuss the development of the mixed mesophytic forest as a function of Miocene climatic fluctuations. Szafer (1961), Leopold (1967), and Friis (1975) detail the effect of increasing seasonality in the Late Miocene, Pliocene, and Pleistocene on European plant communities. It is clear from such studies that the climatic tolerances of many angiosperm taxa could not be altered; these taxa either moved via dispersal or became extinct. Others were able to adapt to the cooler, more seasonal climates of the later Tertiary, adding to the growth of deciduous communities (Mai, 1964; Wolfe, 1969). In general, the fossil record suggests that the direction of evolution of tolerance was from paratropical to temperate climates; there is no suggestion that paratropical taxa consistently crossed temperate barriers by evolving temperate forms and then reevolving paratropical ones. We may safely assume that the eastern Asian— eastern North American pattern among evergreen or thermophilic taxa arose at a time when these plants could move directly between the two areas and is not a result of parallel evolution from widespread, deciduous, temperate com- mon ancestors The font similarity between eastern Asia and eastern North America involves “tropical” evergreen and thermophilic taxa, temperate decid and boreal and alpine taxa. Tropical taxa require no frost, adequate cae and sufficient year-round light to support an evergreen physiology. These en- vironmental constraints were met in the Early Eocene when the congruence of warm climates and the availability of the North Atlantic bridges and perhaps the southern margin of the Bering bridge (Wolfe, 1978, in press; Tiffney, 1985) provided a connection between the Old and New worlds. We may assume that evergreen or obligate thermophilic taxa with an eastern Asian-eastern North American pattern in the present day generally attained this distribution as part of the boreotropical flora. The situation is less clear for temperate taxa with this geographic pattern. I see three possible ways in which such taxa could have achieved this distribution. First, as Hickey has implied (Hickey ef a/., 1983), temperate elements could have evolved near the early Tertiary North Pole, developing a deciduous habit in response to annual fluctuations in day length. These taxa could have moved 86 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 southward with cooling temperatures in the later Eocene, attaining a ‘‘boreo- tropical” distribution in the process. Some taxa certainly followed this route, but the known early Tertiary Arctic floras are species poor and do not account for all of the temperate taxa presently shared between the Old and New World portions of the Northern Hemisphere. Second, as Wolfe (1969, 1977) suggests, these temperate-adapted taxa could have evolved in parallel in the Old and New worlds from thermophilic ancestors that attained their distribution with the Eocene spread of the boreotropical flora. It seems unlikely to me that this could account for the entire temperate floristic similarity of eastern Asia and eastern North America. However, in many cases (e.g., oaks) where there are good tropical relatives of the temperate taxa in the modern day and/or where a transition from a tropical ancestor to a temperate descendant can be dem- onstrated in the fossil record (see Wolfe, 1969), this is a reasonable supposition. The third possible explanation is that these temperate taxa evolved in post- Eocene time in one portion of the Northern Hemisphere and moved to other regions during the mid-Tertiary, when temperate vegetation was still present at high latitudes (Wolfe, 1972). Such an exchange could have occurred via the Bering land bridge, which was present through the Tertiary and was closed to temperate plants by climatic barriers only in the latest Tertiary or Quaternary. It is also possible that some exchange could have occurred across the post- Eocene North Atlantic by “island hopping” (see, for example, Heie & Friedrich, 1971; McKenna, 1983b), but supporting evidence for this is less clear. I believe that the similarity in temperate taxa between eastern Asia and eastern North America has arisen through some combination of (at least) these three patterns. Researchers interested in temperate taxa shared between these areas should examine the history and affinities of individual taxa to see if they fit one of these patterns. Finally, although the fossil record of boreal and alpine taxa is virtually nonexistent, we may assume that many of these plants evolved in the later Tertiary and Quaternary in response to cooling world climate. Particularly since the Bering bridge lay at a high latitude and was functional in the later Tertiary and Quaternary, there is little difficulty in ascribing the similarities of Asian and western North American montane floras to direct exchange. How- ever, workers should be sensitive to the possibility of parallel evolution of montane taxa in the two areas from related temperate ancestors, as well as to long-distance dispersal. MAJOR HISTORICAL DISTRIBUTION PATTERNS AND EASTERN ASIAN-EASTERN NORTH AMERICAN FLORISTIC SIMILARITY In the preceding section perspectives and physical variables involved in the origin of the similarity of the floras of eastern Asia and eastern North America were explored. The apparent independent nature of these factors (e.g., climate, geography, evolution) could be expected to predispose me to the view that the history of this floristic pattern involves so many permutations that it would change continuously through time and not be divisible into stages. However, 1985] TIFFNEY, FLORISTIC SIMILARITY 87 while the variables are “‘continuous” in one sense, they are often grouped and form coherent patterns. In particular, climatic variation may be seen as oc- curring in several “stages” during the Tertiary, and the variables of geography and evolution are not fully independent of climate. Geography may influence climatic change (e.g., moving continents and oceanic currents— Kennett (1977), Berggren (1982)), and climatic change and geography certainly influence evo- lution. Therefore, one can discern a series of stages in the evolution of the floristic similarity between eastern Asia and eastern North America. These are offered as hypotheses for a not as final conclusions destined to replace existing hypotheses or conclusio At the outset, it is ene : list the variables. GEOGRAPHY. Two major routes connect the Old and New worlds: the Bering and the North Atlantic land bridges. The former was available throughout the Tertiary, although with occasional breaks enforced by climatic change. The latter involved at least four geographic links, two between North America and Greenland, one between Greenland and Fennoscandia, and one between Green- land and southwestern Europe (McKenna, 1983a, 1983b). Cimates. As detailed above, world climate was cool or, at most, moderately warm at the beginning of the Tertiary. It warmed into the Early Eocene to an Early to mid-Eocene maximum, commenced cooling in the mid-Eocene with a sharp drop in the Late Eocene, remained cool through most of the Oligocene, and then warmed into the Miocene, although not to the degree achieved in the Eocene. A cooling trend began in the Late Miocene and has continued to the present. These general climatic trends were overlain by a secondary pattern of fluctuation that affected the floras of specific times, but not the broad pattern under discussion. MAJOR PERIODS OF EVOLUTION. Two distinct periods in which modern angio- sperm families appeared at an accelerated rate occurred during the Tertiary (see Muller, 1981; Tiffney, 1981, and unpubl. data). From the Cretaceous- Tertiary boundary to the Early Eocene, many modern families appeared. These were largely families dominated by trees. The Late Oligocene and Miocene saw a second diversification, this time largely involving families dominated by herbs. It must be emphasized that, from the Cretaceous to the present, new families were always appearing. The two specific times cited are only times of ‘““increased”’ rate of family appearance. POSSIBLE GENERAL PATTERNS Taking geography, climate, and evolution as the three variables, I suggest that at least five historical patterns contribute to the floristic similarity between eastern Asia and eastern North America. PRE-TERTIARY. Our knowledge of pre-Tertiary angiosperm evolution and bio- geography is limited, but the existence of the Normapolles and Aquillapollenites floristic provinces in the later Cretaceous suggests that some Tertiary biogeo- graphic patterns could stem from Cretaceous antecedents. This might be par- 88 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ticularly true of aquatic angiosperms and monocots. I suspect that many co- nifers (perhaps excluding some Pinaceae, a family that shows modernization concomitant with that of the angiosperms—Miller (1976)) and some bryo- phytes and pteridophytes may also have attained an eastern Asian—eastern North American distribution at this time. Earcy Eocene. The basic components of the boreotropical flora evolved in the Paleogene. The combination of warm climates at high latitudes and the existence of the Bering and North Atlantic land bridges made available the boreal land routes necessary for its spread. I expect that the majority of ev- ergreen taxa presently fitting into the eastern Asian-eastern North American pattern (e.g., Magnoliaceae, Lauraceae, Theaceae) attained their distribution at this time via the North Atlantic bridges. These arborescent taxa were prob- ably accompanied by many herbs of the forest floor or disturbed forest sites. Some deciduous trees may have spread about the hemisphere at this time, perhaps occupying marginal sites in the primarily evergreen boreotropical for- est LaTE EocENE-OLIGOCENE. As the climates cooled during this period, the de- ciduous taxa of the polar realms (Hickey et al., 1983) spread southward; some may already have spread to marginal sites earlier in the Eocene. The North Atlantic bridges broke up in the Early Eocene (McKenna, 1983a), cutting off direct movement between Europe and North America. Taxa adapted to cooler, more seasonal sites may have moved via the Bering bridge. Miocene. The Bering bridge remained a viable route, but the temperatures at high latitudes dictated that only temperate deciduous plants could be exchanged between Asia and North America. The North Atlantic land bridges may have existed as a series of island “‘stepping stones” into the mid- Tertiary and might have permitted the passage of some deciduous taxa. Many deciduous tree lineages evolved during this time (Wolfe, 1969). With regard to the origin of the similarity of the deciduous elements of eastern Asia and eastern North America, it is unclear how many of these evolved in one area and moved via the Bering bridge to the other, and how many evolved in parallel in the two separate areas from common ancestors in the boreotropical flora. This period also saw the evolution of many herbaceous angiosperm groups. Many of these exhibit an eastern Asian-eastern North American distribution, which might have arisen in one of two ways: movement via the Bering bridge by colonization of disturbed sites in the existing forests or development of open communities, or spread by long-distance dispersal, a character common in such plants. I think the latter explanation is less important in view of prevailing wind direc- tions. LATE TERTIARY—QUATERNARY. With the advent of cold climates in the polar region and on high mountains in the latest Tertiary, it is likely that modern Arctic-alpine forms evolved. The widespread high mountains of Asia and western North America and their point of “meeting” in the northern Pacific provide ample explanation for the movement of these taxa from one area to the other. Some of these taxa may also prove to be derived from common 1985] TIFFNEY, FLORISTIC SIMILARITY 89 herbaceous ancestors that spread to occupy an eastern Asian—North American range earlier in time. OTHER. In any such generalized series of categories, there must be a repository for organisms that do not fit the other classes. Taxa that fit into this category may be unique in their history or may represent another pattern that I have failed to suggest. EXHORTATION Investigators working on specific plants with an eastern Asian-eastern North American distribution should attempt to determine which of these patterns (if any) their taxon exhibits. They should seek out the assumed geologic time of origin of that taxon and ascertain its climatic and ecological affinities. From such data it is possible to hypothesize the earliest time at which the taxon attained its present distribution. Such information will enhance the value of research on individual taxa. For example, knowledge of which pattern most closely agrees with the history of a taxon will provide an approximate time of separation of its eastern Asian and its eastern North American members. This in turn permits the estimation of rate—perhaps of karyotypic or chemical differentiation, perhaps of morphological or ecological evolution. Such data also aid the paleontologist to understand past floristic movements and ulti- mately to assess the validity of the five models suggested above. It should be clear that the study of this pattern on a geographic basis is not the province of the paleontologist and phytogeographer alone, but requires knowledge from all associated fields. SUMMARY Discussion of Southeast Asia as the cradle or the grave of the modern flora of the Northern Hemisphere, and of angiosperms, is misleading; this area is a giant refugium. However, this implies that another “center of origin” is to be sought. I do not think that such a center exists. I suggest that the antecedent of the modern flora of the Northern Hemisphere (the boreotropical flora of Wolfe) had its origins from several separate sources. The debate whether plants move in communities or only as individuals is fallacious. Plants disperse as individuals. Plants having similar ecological tol- erances generally respond to similar environmental stimuli in a similar manner. The myopic perspective induced by the fossil record makes it likely that, as environmental factors change through geologic time, the paleontological ob- is thus reasonable but must always be tempered by the knowledge of the underlying biological pattern of the dispersal of individuals. The early Tertiary boreotropical flora developed in a unique geographic situation involving two sets of land bridges (Bering and North Atlantic) existing at different latitudes in a time of warm and equable climates. This permitted a free movement of newly evolved taxa and the development of a hemispheric flora. No evidence exists for monolithic “geofloras” in the classic sense. The 90 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 boreotropical flora was not homogeneous; local differentiation existed. Indi- vidual plant migrations resulted in most taxa occurring in some portion of the range of the boreotropical flora at some time, but few taxa occurring in all of the range of the flora all of the time. Taxa exhibiting the eastern Asian—eastern North American distribution in- clude forms that evolved in both the early and later portions of the Tertiary. The modern similarity of the two areas is the product of more than one bio- geographic event. The perception of herbaceous angiosperms as primarily a phenomenon of the mid-Tertiary is wrong. Aquatic herbs and monocotyledons have existed almost since the origin of the angiosperms. Forest-floor herbs existed in the Early Eocene boreotropical flora. While the mid-Tertiary did witness a major diversification of herbaceous taxa adapted to disturbed sites, these were not the first, nor the only important, angiosperm herbs. The modern eastern Asian—eastern North American pattern of distribution did not arise through a single historical event but is the result of a layering of many events. Some aspects of the similarity may trace their roots to pre-Tertiary times. A large number of taxa, many evergreen, achieved this distribution in the warm climates of the Early and Middle Eocene. Deciduous taxa may have accompanied these floras, moved later in the Tertiary during times of cooler climate, or evolved in parallel from evergreen ancestors inhabiting both areas. Herbaceous forms may have achieved the distribution at various times, de- pending on their particular ecological affinities. All of these observations complicate our understanding of the origin of this biogeographic pattern and the mechanisms underlying it. However, if the ques- tion is broken down into component parts, it may be easier to address the overall pattern. ACKNOWLEDGMENTS I wish to thank Leo J. Hickey (Peabody Museum of Natural History, Yale University), Karl J. Niklas (Cornell University), Stephen A. Spongberg (Arnold Arboretum, Harvard University), Scott L. Wing (U. S. Geological Survey, Washington, D. C.), Malcolm C. McKenna (American Museum of Natural History), Alan Graham (Kent State University), and Jack A. Wolfe (U. S. Geological Survey, Denver, Colorado) for comments and criticisms on the content of this paper, and Willard W. Payne, Thomas S. Elias, and Tetsuo M. Koyama (all then at the New York Botanical Garden) for organizing the con- ference that spurred me to consider this line of thought. Research was supported in part by NSF grants DEB 79-05082 and BSR 83-06002. LITERATURE CITED AXELROD, D. I. 1966. The evolution of flowering plants. Pp. 227-305 in S. Tax, ed., Evolution after Darwin. Vol. 1. Univ. Chicago Press, Chicago. BERGGREN, W. A. 1982. Role of ocean gateways in climate changes. Acta Univ. 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III. 155. 1891 Herbaceous annuals [biennials, or perennials, very rarely shrubs], glabrous or with simple trichomes only [very rarely with furcate hairs]. Inflorescence a terminal raceme or corymb, laxly or densely flowered, often ebracteate. Sepals equal at base (infrequently strongly saccate), erect or spreading, rarely reflexed [or sometimes forming an urceolate, flask-shaped, or slightly bilabiate calyx]. Petals often differentiated into claw and blade [occasionally undifferentiated or attenuate to a clawlike base], usually crisped or channeled. Stamens long- exserted, sometimes slightly protruding [rarely included], equal in length or slightly tetradynamous, rarely in 3 pairs of unequal length; anthers often sag- ittate at base, linear [or occasionally oblong or ovate], usually coiling circinately after dehiscence; filaments not appendaged, free, or the median ones connate in pairs. Siliques dehiscent, linear, several to many times longer than broad, flattened parallel to the septum [or terete], often borne on a distinct gynophore, rarely subsessile. Styles obsolete or evident in fruit. Stigmas entire or slightly [to strongly] 2-lobed; lobes opposite the valves [or replum] in fruit. Seeds winged or wingless, not mucilaginous when wet; cotyledons accumbent [or incumbent]. Base chromosome numbers 10, 11, 12, 13, 14, 15. (Including Stanleyeae Rob- ee oy | Can ‘Prepared for tl United States, a long-term project made possible by grants from the National Science Foundation and currently eas by BSR-8111520 (C. E. Wood, Jr., principal investigator), under which this research was done, and BSR-8303100 (N. G. Miller, principal investigator). This account, the 106th in the series, log: the format established in the first paper (Jour. Arnold Arb. 39: 296-346. 1958) and continued to the present. The eneric Fl gia, Florida, Te Alabama, Mississippi, Arkansas, and Louisiana. The descriptions are based primarily on the plants of this area, with information aia extraregional members of a family or genus in brackets [ ]. The reference that I have not verified is marked with an asterisk. I am most indebted to Carroll Wood for his continuous guidance, help, and critical review of the present paper. Seah eae ae is extended to ee ed C. Rollins for his notes on the distribution of Warea, and to N n G. Miller and Geor, . Rogers, as well as to Barbara Nimblett for the typing of the manent I am grateful to ee B. Schmidt and Stephen A. Spongberg for their editonal advic or an account of the family and its tribes, see I. A. Al-Shehbaz, The tribes of Cruciferae (Bras- Rae in the southeastern United States. Jour. Arnold Arb. 65: 343-373. 1984. © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 95-111. ae 1985. 96 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 a ox ee Be The nine Southeastern States, showing distributions of species of Warea. Each symbol represents a county record. inson, Romanschulzieae O. E. Schulz, Streptantheae O. E. Schulz.) Type GENus: Thelypodium Endl. A natural tribe of 11 genera and some 110 species, distributed primarily in North America from the Pacific States eastward to a line extending from North Dakota to Texas, occurring in all the Southeastern States except Tennessee and Mississippi, and from Mexico to Panama, but most numerous in California, Nevada, and Utah, where more than 60 species occur. Macropodium R. Br. (two species; Japan, Mongolia, and Siberia) is the only member of the tribe distributed outside North America. Nearly all of the typically tropical repre- sentatives of the Thelypodieae belong to Romanschulzia O. E. Schulz, the 14 species of which are found mainly at altitudes of 1200-3500 meters (4000- 11,500 feet) in wet forests of Mexico (Nuevo Leén to Oaxaca), Guatemala, Costa Rica, and Panama. The tribe is represented in the southeastern United States by seven indigenous species of Streptanthus Nutt. and Warea Nutt. The latter is the only endemic genus of Cruciferae in our area (see MAp). Members of the Thelypodieae can easily be distinguished from those of other tribes by a combination of the following characters: anthers usually exserted, sagittate at base, often linear, usually coiled after dehiscence; filaments equal 1985] AL-SHEHBAZ, THELY PODIEAE 97 in length, sometimes in 3 unequal pairs, or slightly tetradynamous; gynophore present, usually more than | mm long; petals crisped or channeled, usually with a distinct claw; and plants glabrous or with simple trichomes. On the basis of similarities in floral morphology (particularly the presence of a gynophore, exserted stamens of equal length, obsolete styles, spreading parts, and equal sepals) and in several aspects of the fruit (dehiscent, 2-valved, much longer than broad, and many seeded), many authors have postulated that the subfamily Cleomoideae (Capparaceae) is the direct progenitor of the Cruciferae through the intermediate link Thelypodieae. The palynological evi- dence (Al-Shehbaz, 1973), however, does not support such a direct connection, and it is more likely that the two families evolved from a common ancestor. Any assumptions regarding the ties between the two families must account for members of the Thelypodieae. Some genera of the tribe undoubtedly possess characters more primitive than those found elsewhere in the family, but it is not entirely clear how the Thelypodieae relate to the rest of the Cruciferae. A few authors (Cronquist; Dvorak, 1973) have suggested that the most primitive extant Cruciferae probably occur in central Asia, an assumption apparently lacking a solid morphological foundation and most likely influenced by the hypothesis that the center of greatest taxon diversity and generic endemism represents the center of origin. The assumption has been based primarily on the presence of multicellular glands in some species of Cleome L. and the occurrence of their morphological equivalents in some genera of the Hesper- ideae. Glandular papillae are found on the inflorescences ofall species of Warea, but whether or not these are anatomically similar to those of Cleome remains to be determined. Relict genera of the family are found throughout the world, but almost all of those listed by Hedge are undoubtedly advanced. Except for two pairs of genera of Thelypodieae, the others are all morpho- logically well defined and can easily be separated by several characters. The- lypodium is very close to Thelypodiopsis Rydb. and is distinguished primarily by its entire stigmas (two-lobed in the latter genus). The boundaries between Streptanthus and Caulanthus S. Watson overlap, and the two are separable by a few characters that are sometimes continuous (see the treatment of Strep- tanthus). The relationships among members of the tribe have recently been studied by Hauser and Crovello (1982), who used phenetic and cladistic anal- yses. Their conclusions coincide in many ways with those reached earlier by Al-Shehbaz (1973), who defined the limits of the tribe primarily on the basis of the nearest sister relatives of its component genera. Chromosome numbers have been reported for 46 species in nine genera (see Rollins, 1966; Rollins & Riidenberg). The most common base number is 14, found in Caulanthus, Stanleya Nutt., Streptanthella Rydb., and Streptanthus. Other genera have x = 10, 11, 12, 13 (Thelypodium), and 15 (Macropodium). No cytological data are available for Romanschulzia or for Chlorocrambe Rydb., a monotypic genus endemic to Oregon and Utah. The great diversity in floral morphology found among members of the Thely- podieae is not paralleled in any other tribe of the Cruciferae. Floral characters are very useful in distinguishing most of the genera. Although a wide range of variation in the shape, orientation, size, and color of floral parts can occasionally 98 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 be found within some genera (e.g., Streptanthus and Thelypodium), unfortu- nately very little is known about the floral biology of either these genera or the rest of the tribe. Nearly all of the Thelypodieae are herbaceous. A woody habit is known only in Romanschulzia apetala Rollins, a shrub to 3 m tall endemic to Costa Rica, and in Stanleya pinnata (Pursh) Britton, a subshrub of the western United States. Wood anatomy of the latter species was studied by Carlquist, who suggested that the woody habit da have evolved as an adaptation to warmer regions with long growing seaso Except for Caulanthus lasiophyllus (Hooker & Arnott) Payson and Strep- tanthella longirostris (S. Watson) Rydb., both of which have become weedy in the Pacific and Mountain states and in northern Mexico (Rollins, 1981), the tribe has no economic importance. REFERENCES: Under family references in At-SHEHBAz (Jour. Arnold Arb. 65: 343-373. 1984), see AVETISIAN (1983), BusCH, CARLQUIST, CRONQUIST, DvoRAK (1971, 1973), Giro & CHLER, HAYEK, HEDGE, JANCHEN, PRANTL, ROLLINS (1966, 1981), RoLLINS & RU- DENBERG (1971, 1977, 1979), ScHULz, and VILLANI AL-SHEHBAZ, I. A. The biosystematics of the genus Thelypodium (Cruciferae). Contr. Herb. 204: 3-148. 1973. [Generic limits and evolutionary trends within the Thelypodieae; pollen of selected Capparaceae. ] Rollinsia, a new genus of Cruciferae from Mexico. Taxon 31: 421, 422. 1982. —. The tribes of Cruciferae aaa in the southeastern United States. Jour. Arnold Arb. 65: 343-373. 19 Hauser, L. A. Quantitative pile ei and phytogeographic studies in the Thely- podieae (Brassicaceae). vill + 260 pp. Unpubl. Ph.D. Thesis, Univ. Notre Dame, Indiana Phy “lo ogenetic relationships and phenetic similarities among species of Thely- ees and Thelypodium (Brassicaceae). (Abstr.) Am. Jour. Bot. 70(5, part 2): 116. 1983. . Systematic studies in the genus Stanleya (Brassicaceae). (Abstr.) Ibid. 71(5, part 2): 170. 1984. & . CROVELLO. Phylogeny, character trends, and distribution patterns in the Thelypodieae tribe (Brassicaceae). (Abstr.) Bot. Soc. Am. Misc. Ser. 160: 69. 1981. & Numerical analysis of generic relationships in Thelypodieae (Bras- sicaceae). Syst. Bot. 7: 249-268. 1982. [Phenetic and cladistic analyses. ] KrAL, R. A report on some rare, threatened, or endangered forest-related vascular plants of the South. U. S. Dep. Agr. Forest Serv. South. Reg. Tech. Publ. R8-TP2. Vol. 1.x + 718 pp. 1983. [Streptanthus squamiformis, 528-532; a eerie W. Carteri, and W. sessilifolia, 533-544; descriptions, habitats, m LicHvaAr, R. W. Evaluation of varieties in Stanleya pinnata patie ate vou Basin Nat. 43: 684-686. a [Reduces S. pinnata var. gibberosa to synonymy under 5S. pinnata var. bipinnat MUuSCHLER, R. eae Andinae. Bot. Jahrb. 40: 267-277. 1908. [Describes four species of Thelypodium and Streptanthus from Bolivia and Peru; these are presently assigned to other genera; see AL-SHEHBAZ (1973), GitG & MUSCHLER. Payson, E. B. Species of Sisymbrium native to America north of Mexico. Uni oming Publ. 1: 1-27. 1922. [Treatment of 11 species; transferred to Thelypodiopsis and Schoenocrambe, see Rollins, 1982.] monographic study of The/lypodium and its immediate allies. Ann. Missouri 1985] AL-SHEHBAZ, THELYPODIEAE 99 Bot. Gard. 9: 233-324. 1923. [Caulanthus, Chlorocrambe, Stanleyella, Streptan- thella, Thelypodium, Warea.]| RAVEN, P. H., & D. I. AXELROD. Origin and relationships of the California flora. Univ. Calif. Publ. Bot. 72. vi + 134 pp. + 2 pls. 1978. [Thelypodieae, 30.] Rosinson, B. L. Cruciferae. Pp. 98-180 in A. Gray & 8S. WaTson, Synoptical flora of North America. Vol. 1. 1895. [Thelypodieae (listed as Stanleyeae), 105, 167-180.] Ro.uins, R. C. The cruciferous genus Stanleya. Lloydia 2: 109-127. 1939. [Ongin of Cruciferae from Capparaceae-Cleomoideae, 110-112. —. A tentative revision of the genus Romanschulzia. Contr. Dudley Herb. 3: 217- 226. 1942. [Suggests that ae be placed with Thelypodium in same tribe rather than in a unigeneric tribe. Some new primitive Mexican Cruciferae. Rhodora 58: 148-157. 1956. [Com- nents on Romanschulzia and descriptions of three new species. ] . Miscellaneous Cruciferae of Mexico and western Texas. ie 59: 61-71. 1957. Some sisymbriums (Cruciferae) native to Texas and northeastern Mexico. [bid. 62: 55-60. 1960. [Four species presently assigned to There see ROLLINS, 1982 —— s on Mexican Cruciferae. Contr. Gray Herb. 206: 3-18. 1976. [Thely- eres ee Thelypodium, 11-17.] . Th elypodiopsis and Schoenocrambe (Cruciferae). Ibid. 212: 71-102. 1982. [Rec- e. Studies on Mexican Cruciferae IJ. Ibid. 214: 19-27. ee {[Romanschulzia Correllii, R. Rzedowskii, and net aes Breedloveii, spp. RybBERG, P. A. Studies on the Rocky Mountain flora— XVIII. Bull ey Bot. Club 34: 417-437. 1907. [Discussion of ae key, and original descriptions of the segregates Thelypodiopsis, nei Hesperidanthus, Stanleyella, Heter- othrix, and Sallie 428 J WELSH, S.L., & N. D. Arwoop. An andecened species of Thelypodiopsis (Brassicaceae) from the Uinta Basin, Utah. Great Basin Nat. 37: 95, 96. 1977. [T. argillacea, sp. nov.; transferred by Rollins (1982) to Schoenocrambe KEY TO THE GENERA OF THELYPODIEAE IN THE OUTHEASTERN UNITED STATES Sepals reflexed, rarely spreading; floral buds clavate or pyriform: gynophore slender, (3—) 5-14 mm long; petal claws slender, papillose or pubescent; stamens equal in length; aah. oaeg deciduous from the rachis, often leaving elevated scars; — ae WINGlESS meee AB Ss dhe ead ie Mia Boe eek alee attach ty Warea Sepals — or ascending; floral buds oval or lanceolate; gynophore stout, | oe mm long; petal claws broad, flat, glabrous; stamens slightly tetradynamous or in 3 pairs of unequal length; fruiting pedicels persistent; seeds minutely reticulate, winged. ...... . Streptanthus. 1. Warea Nuttall, Jour. Acad. Nat. Sci. Phila. 7: 83. 1834. Glabrous and occasionally glaucous annual herbs; stems slender, often branching above, leafless below. Lowermost leaves undescribed; middle and upper ones entire, short-petiolate or sessile. Inflorescence a short, ebracteate, corymbiform, terminal raceme, slightly elongating in fruit. Pedicels slender, sometimes filiform, straight, with 2 lateral, gland-tipped papillae at the base. Floral buds clavate or pyriform. Sepals linear to spatulate, not saccate at base, strongly reflexed and subappressed to pedicel, rarely widely spreading, green or same color as petals. Petals spreading, white, pink, or deep purple, clawed; 100 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 blades orbicular or obovate, equal or rarely slightly unequal, often abruptly narrowed to claw, sometimes cuneate or attenuate at base; claws minutely papillose to conspicuously pubescent, often slightly dilated at base. Glandular tissue subtending bases ofall stamens, usually developed into 6 teeth alternating with filaments, the 4 teeth adjacent to the lateral stamens larger than the 2 alternating with the median ones. Stamens spreading, long-exserted, equal in length; filaments filiform, glabrous, often slightly dilated at base; anthers linear, Sagittate at base, usually coiling circinately when fully dehisced. Ovary borne on a long gynophore; style obsolete; stigma entire. Fruiting pedicels often de- ciduous from the infructescence axis, usually leaving elevated, disclike scars. Siliques dehiscent, narrowly linear, glabrous, flattened parallel to the septum, horizontal or reflexed, straight or arcuate; valves with a prominent midnerve extending full length; gynophores slender, (3—)5—14 mm long. Seeds uniseriately arranged, wingless, brown, longitudinally striate, not mucilaginous when wet; cotyledons accumbent. Type species: Stanleya amplexifolia Nutt. = W. am- plexifolia (Nutt.) Nutt.; see Payson, 1923. (Name commemorating Nathaniel A. Ware, 1789-1853, a teacher in South Carolina who traveled widely in the southeastern United States.) A very well-defined genus of four species endemic to the southeastern United States in North and South Carolina, Georgia, Alabama, and Florida (see Map). Species of Warea are restricted to the southeastern Coastal Plain, where they grow primarily on sandy soils in pinelands, dry open Quercus woods or scrub, and sandhills. Flowering and fruiting generally occur in the spring and summer, but under favorable conditions successive generations of a given species may be produced throughout the year. All four species are a and geographically distinct. No infrageneric subdivisions are recognized. The most widely distributed species of the genus is Warea ee (Muhl.) Nutt. (Cleome cuneifolia Muhl., Stanleya gracilis DC.), which occurs in certain counties of Florida (Liberty and Gadsden), Alabama (Pike), Georgia (Talbot, Ben Hill, Pierce, Montgomery, Richmond, Long, Taylor, Pulaski, Laurens, Wheeler, Bacon, Emanuel, Bulloch, Tattnall, and McIntosh), South Carolina (Jasper, Allendale, Aiken, Lexington, Richland, Kershaw, Darlington, and Chesterfield), and North Carolina (Harnett). The nearest relative of W. cunei- folia is W. Carteri Small, 2n = 24, which is endemic to southern peninsular Florida (Brevard, Polk, Highlands, De Soto, Glades, Broward, and Dade coun- ties). Both species have short-petiolate, cuneate, oblanceolate, or linear leaves and white flowers. The former is characterized by its glabrous or minutely papillose petal claws and by gynophores that are longer than the fruiting ped- icels; the latter is easily recognized by its densely pubescent or somewhat fimbriate claws and by gynophores that are shorter than the fruiting pedicels. A few authors (e.g., Patman) have reduced W. Carteri to synonymy under W. cuneifolia, but such action is totally unwarranted, as is evidenced by the dis- tinctive morphology and distribution of the two species Warea amplexifolia (Nutt.) Nutt. (Stanleya amplexifolia Nutt., W. auricu- lata Shinners) is a rare species confined to central peninsular Florida (Lake, Orange, Polk, and Osceola counties). It differs from the other species of Warea 1985] AL-SHEHBAZ, THELYPODIEAE 101] in having deeply auriculate and amplexicaul, ovate to lanceolate or oblong cauline leaves. Flower color is generally white changing to light purple Warea sessilifolia Nash is similar to W. amplexifolia in having sessile, ovate or lanceolate cauline leaves, but the leaves are not amplexicaul and are without auricles (or are rarely minutely auriculate), and the flowers are dark purple. It is distributed throughout the panhandle of Florida (from Leon and Wakulla counties westward through Escambia County) and in Alabama (Pike County). All reports of W. amplexifolia from areas outside central peninsular Florida are based on misidentifications of plants of W. sessilifolia. Nuttall’s original description of Stanleya amplexifolia was based on a fruiting specimen collected by Nathaniel Ware from “east” Florida (actually the central peninsular area). He transferred this species in 1834 to his new genus Warea after acquiring flowering material from “‘west” Florida (the panhandle area). Nuttall did not realize that he was dealing with two distinct entities, and that the flowering material and its illustration, which accompanied the original description of the genus, clearly belong to a different species (described later by Nash as W. sessilifolia). Without studying any of Nuttall’s specimens, Shin- ners mishandled the nomenclature of both species, believing that Nuttall made a mistake in the locality (east vs. west), that both the flowering and fruiting specimens were collected from West Florida, and that Nuttall did not have a mixture of two species. Shinners reduced W. sessilifolia to synonymy under W. amplexifolia and redescribed the plants of central peninsular Florida as W. auriculata. (See Channell & James for further details. Warea is very well defined morphologically and is apparently without im- mediate relatives among the Thelypodieae. Both Stan/eya Nutt. and Roman- schulzia O. E. Schulz resemble it in several aspects of the flowers and fruits, but no close ties are found between any two of these genera (see Hauser & Crovello). Furthermore, it is highly unlikely that Warea is ancestral to Strep- tanthus Nutt., as was suggested by Hayek. The characters that in combination easily distinguish Warea from the other genera of the Cruciferae are corymbose inflorescences, clavate buds, spreading floral parts, slender and papillate or pubescent petal claws, long-exserted stamens of equal length, long gynophores, striate seeds, and fruiting pedicels that are deciduous from the rachis (see Al- Shehbaz, 1984, fig. 2, a, b Hardly anything is known about the chemistry, embryology, anatomy, ge- netics, or ecology of Warea. Chromosome counts (m = 12, 2n = 24) for W. Carteri are known from a single collection (Rollins & Riidenberg, 1977). The adaptive value and the phylogenetic significance of the g papillae found in the inflorescence of all species of Warea are unknown. With the exception of W. cuneifolia, the species of the genus are listed as endangered or threatened in Florida and Alabama. The genus has no economic value. Warea sessilifolia has very showy inflo- rescences and might well be used as an ornamental REFERENCES: Under family references in AL-SHEHBAZ (Jour. Arnold Arb. 65: 343-373. 1984), see HayEK, PATMAN, RADFORD eft a/., RICKETT, ROLLINS & RUDENBERG (1977), SCHULZ, and 102 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 SMALL. Under tribal references see AL-SHEHBAz (1973), HAUSER & CROVELLO (1982), KRAL, PAYSON (1923), and RoBINSON AHLES, H. E., C. R. BELL, & A. E. RADForD. Species new to the flora of North or South Carolina. Rhodora 60: 10-32. 1958. [W. cuneifolia from Harnett County, North Carolina, 16.] AyENSU, E. S., & R. A. DeFivipps. Endangered and threatened plants of the United States. xv + 403 pp. Washington, D. C. 1978. [W. amplexifolia and W. Carteri endangered in Florida, W. sessilifolia threatened in Alabama and Florida.] CHANNELL, R. B., & C. W. James. Nomenclatural and taxonomic corrections in re (Cruciferae) Rhodora 66: 18-26. 1964. [Excellent account of the historical back- ground of neeeneren discrepancies in Warea, key to species, distributions; see SHINNERS, SMALL (1896).] Dean, B. E., A. Mason, & J. L. THomas. Wild flowers of Alabama and adjoining states. Xx + 230 pp. University, hicpana. 1973. [W. cuneifolia and W. sessilifolia, 72, 73 4 Duncan, W. H., & L. E. Foote. Wild flowers of the southeastern United States. vii + 296 pp. Athens, Georgia. 1975. [Warea, colored photo of W. sessilifolia (not W. cuneifolia, as stated), 50.] FREEMAN, J. D., A. S. Causey, J. W. SHort, & R. R. HAynes. Endangered, threatened, and special concern plants of Alabama. 25 pp. Auburn, Alabama. 1979. [W. ses- silifolia, threatened, reported from Pike County, 12, fe. 28, W. amplexifolia, a misidentification of the former species, 25.] Harper, R. M. The “pocosin” of Pike County, Alabama, and its bearing on certai problems of succession. Bull. Torrey Bot. Club 41: 209-220. 1914. [W. Aedes addition to the state flora, 212; record needs verification. ] A preliminary list of the endemic flowering plants of Florida. ec Jour. Florida Acad. Sci. 12: 1-9. 1950. [W. amplexifolia and W. sessilifolia, 7, KraL, R. Some notes on the flora of the Southern States, particula = Alabama a middle Tennessee. Rhodora 75: 366-410. 1973. [First record of W. sessilifolia aoe Alabama, listed as a synonym of W. amplexifolia, 389. LakeLA, O., & F.C. CRAIGHEAD. Annotated checklist of vascular plants of Collier, Dade, and Monroe counties, Florida. Bot. Lab. Univ. S. Florida Contr. 15. viii + 95 pp. a Gables, Florida. 1965. [W. C arteri (listed as W. cuneifolia) in Dade oa 41.) Lona, R. W., & O. Laketa. A flora of tropical Florida. xvii + 962 pp. Coral Gables, Florida. ‘1971. [Warea, 432; suggestion that W. Carteri may be conspecific with Nasu, G. Notes on some Florida plants.—II. Bull. Torrey Bot. Club 23: 95-108. 1896. ay sessilifolia sp. nov., 101.] NUuTTAaLt, T. A description of some of the rarer or little known plants indigenous to the 83-85; Warea and ae represent a natural ‘‘order’’ intermediate between the Cruciferae and Capparace Ro.uins, R. C. The need for care in choosing lectotypes. Taxon 21: 635-637. 1972. [Comments on Shinners’s mishandling of the typification of W. amplexifolia; see SHINNERS. SHINNERS, L. H. Warea auriculata instead of W. amplexifolia of Small Soueaa Sida 1: 105, 106. 1962. [Misinterpretation of Nuttall’s Se upon which W fonplesaiolia was originally based; see CHANNELL & JAM s.] SMALL, J. K. Studies in the botany of the southeastern United States— VIL Bull. Torrey Bot. Club 23: 405-410. 1896. [Warea, 408, 409; see CHANNELL ES. ] . Additions to the flora of peninsular Florida. I. Native species. Ibid 36: 159- 164. 1909. [W. Carteri, sp. nov., 159, 160.] 1985] AL-SHEHBAZ, THELYPODIEAE 103 WUNDERLIN, R. P. Guide to the vascular plants of central Florida. 472 pp. Tampa and other cities, Florida. 1982. [Warea, 195.] 2. Streptanthus Nuttall, Jour. Acad. Nat. Sci. Phila. 5: 134. 1825. Annual [biennial or perennial], often glaucous, glabrous or sparsely [to dense- ly] hispid [or hirsute], taprooted herbs. Basal and lowermost cauline leaves usually absent in flowering specimens [rarely forming a definite rosette], pet- iolate or subsessile, thin [sometimes coriaceous or somewhat fleshy], dentate or pinnatifid to pinnatisect [runcinate or divided into linear or filiform seg- ments]. Upper cauline leaves usually sessile, amplexicaul [or auriculate], some- times short- [or long-]petiolate, linear, lanceolate, ovate, oblong [or of other shapes], entire or dentate. Inflorescence an ebracteate [very rarely bracteate], dense or lax, many- [or few-]flowered raceme [or panicle]; rachis straight [rarely flexuous], elongating in fruit; flowering pedicels ascending, divaricate, or re- flexed [rarely secund]. Flowers actinomorphic or slightly [to strongly] zygo- morphic, all fertile [occasionally the terminal cluster of flowers sterile, having larger and showier sepals than those of the fertile ones, and with other floral parts aborted or lacking]. Calyx regular [or irregular], campanulate, subcylin- drical [or usually flask shaped, somewhat bilabiate, or urceolate], open [or closed] at apex; sepals equal or unequal at base, all or only the inner pair saccate, lanceolate to oblong [ovate or rarely orbicular], erect or ascending, separate [or connivent], herbaceous [or somewhat fleshy or membranaceous], acute or obtuse, cucullate [or not] at apex, usually scarious at margin, with straight or recurved tips, purple or green [white, yellow, red, or purplish black], glabrous or sparsely to densely hairy or setose [rarely with a subapical tuft of stiffhairs], round [or prominently keeled], uniform in size [or the adaxial (upper) sepal smaller than or markedly larger than and subtending the other 3]. Corolla cruciform, usually becoming slightly [to strongly] bilabiate by the divergence of petals in opposite pairs; petals always strongly differentiated into blade and claw, equal in size, shape, and color [or the adaxial pair smaller than or much larger than the abaxial one, or differing in color and/or shape], lavender or light to dark purple or magenta [green, yellow, white, brown, red, or purplish black]; blades broadly obovate, 2—4 times wider than the claw, or linear to oblanceolate or oblong [or spatulate] and as broad as or narrower than the claw, entire or partly [to wholly] undulate or crisped, usually reflexed, uniformly colored or with the center and/or veins darker; claws included, spatulate or oblanceolate, crisped, usually channeled. Stamens equal in length, somewhat tetradynamous, or in 3 unequal pairs (with the adaxial pair usually the longest), exserted to slightly protruding, or the outer pair [or all] included; filaments free, or those of | (the adaxial) or both median pairs partially to completely connate, straight or recurved; anthers linear or oblong, apiculate or obtuse, sagittate at base, all polliniferous, or those of the adaxial pair of stamens abortive and much shorter than the others. Glandular tissue flat, subtending the bases of all or only the lateral stamens. Siliques narrowly [to broadly] linear, somewhat [to very strongly] flattened parallel to the septum [very rarely sub- terete], 1-7 mm wide, smooth [or torulose], erect, divaricate [or pendent]; 104 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 valves obscurely [to prominently] |-nerved from base to apex, glabrous [hispid or setose]; style short or obsolete in fruit; stigma entire or 2-lobed, the lobes always opposite the valves; gynophore short [rarely exceeding 4 mm]; septum somewhat thick [or membranaceous and translucent]. Seeds oblong to orbic- ular, not mucilaginous when wet, usually minutely reticulate [or nearly smooth], brown, winged [rarely wingless]; wing narrow [or to 1-1.5 mm wide], completely surrounding the seed [or restricted to the distal end]; funiculus free or partially [to completely] adnate to the septum, slender or flattened; cotyledons accum- bent or obliquely so. Base chromosome number 14. (Including Agianthus Greene, Cartiera Greene, Disaccanthus Greene, Euklisia (Nutt. ex Torrey & Gray) Rydb. ex Small, 1903 (Euclisia (Nutt. ex Torrey & Gray) Greene, 1904), Ician- thus Greene, Mesoreanthus Greene, Microsemia Greene, Mitophyllum Greene, Pleiocardia Greene.) Tyre species: S. maculatus Nutt. (Name from Greek, streptas, twisted, and anthos, flower, in reference to the petals.) —TwisT-FLOWER, JEWEL FLOWER. A genus of about 35 species in three subgenera and probably more than seven sections, distributed from Louisiana and Arkansas westward through Kansas and all the southwestern United States, the Mountain States (except Montana), and the Pacific States (except Washington), as well as in northern Mexico (Baja California, Chihuahua, and Coahuila). The great majority of the species (26) occur in California, and 14 of these are found in the western part of the state, particularly in the counties of the Coast Ranges north and south of San Francisco Bay. A few other species are endemic to the serpentine out- crops of the Sierra Nevada foothills from Shasta County to Fresno County. Streptanthus cordatus Nutt. is distributed in all the Mountain and Pacific states except Washington and Montana. Five species are endemic or primarily re- stricted to south-central or western Texas (Big Bend National Park and sur- rounding counties); one, S. platycarpus Gray, is localized in northern Mexico, and another, S. carinatus Wright, is widely distributed in New Mexico and Arizona. Streptanthus 1s represented in the southeastern United States by three species distributed in southwestern Arkansas and northwestern Louisiana, as well as in adjacent Texas, Oklahoma, and Kansas. Infrageneric groups in Streptanthus have not been satisfactorily treated; for- mal sectional classification has been published only for subgenus Eucuisia Nutt. ex Torrey & Gray (Kruckeberg & Morrison). Rodman and colleagues provided an informal provisional nomenclatural synopsis of Streptanthus in which they followed Jepson in reducing Caulanthus to two subgenera of Streptanthus. However, several authors (see Rollins, 1971; Al-Shehbaz; Rollins & Holmgren) have clearly demonstrated that, in order to obtain a workable classification in this group, both genera must be recognized. Strongly diverging from Jepson’s position, Schulz recognized 11 genera (including Caulanthus) in this complex and retained only three species in Streptanthus. In this he followed Greene’s splitting of the genus into nine segregates that are largely based on minor differences in the flower. Neither Schulz’s nor Jepson’s opposing generic con- cepts are practical, and they cannot be accepted. Two species of Streptanthus occurring in the Southeast belong to subgenus 1985] AL-SHEHBAZ, THELYPODIEAE 105 STREPTANTHUS (Eustreptanthus Endl.), a group of six or seven species distrib- uted in Texas and its neighboring states and in northern Mexico. Plants of this subgenus are characterized by having petal blades usually broadly obovate and often more than twice the width of the claw; stamens free, tetradynamous or in three unequal pairs, with the anthers all fertile; stigmas strongly 2-lobed; siliques (2-)4-7 mm wide; flowers actinomorphic, rarely zygomorphic; and calyx usually regular, open at the apex. No sections have been proposed in subgenus STREPTANTHUS, but it is clear that at least two or probably three can be recognized. Streptanthus maculatus Nutt. (S. obtusifolius Hooker, Brassica Washitana Muhl., Stanleya Washitana (Muhl.) DC.) is confined to rocky bluffs and moist woodlands in northeastern Texas, southeastern Oklahoma (McCurtain and Pushmataha counties), and southwestern and central Arkansas (Pike, Mont- gomery, Garland, Hot Springs, Saline, and Pulaski counties). With its broadly obovate, reflexed, purple petals of equal size, each with a central magenta spot, its glabrous and purplish sepals, its ovate or oblong, amplexicaul cauline leaves, and its divaricately ascending siliques that are 6-10 cm long and 2-2.5 mm wide, this is the most attractive and one of the most distinctive species in the genus. A very close relative and a member of the same subgenus, Streptanthus squamiformis Goodman is endemic on sandstone and soft shale in Pinus- Quercus-Carya forests (see Kral for further details) of southeastern Oklahoma (McCurtain County) and southwestern Arkansas (Polk, Howard, and Sevier counties). The remarkable similarities between the two species in every respect except the pubescence and the sepals may support considering them as con- specific. The pedicels and sepals in S. squamiformis are characteristically pu- bescent with trichomes that are 1-2 mm long, thick, widely spreading, and (upon drying) scalelike; the sepals are generally long-cucullate. In S. maculatus the sepals are glabrous and not cucullate (or with only the outer pair bearing short cuculli). There is some variation in the amount of pubescence and in the thickness of trichomes on the sepals and pedicels of S. squamiformis, but in the absence of any field studies and crossing experiments between this and S. maculatus, the two are best treated as distinct species. Streptanthus hyacinthoides Hooker (Icianthus hyacinthoides (Hooker) Greene, Euklisia hyacinthoides (Hooker) Small, S. glabrifolius Buckley, I. glabrifolius (Buckley) Greene) grows primarily on sand in Pinus, Quercus, or Carya woods, open areas, roadsides, grassy sandhills, and sand dunes in northwestern Lou- isiana (Winn, Caddo, and Bienville parishes), southwestern Arkansas (Nevada and Ouachita counties), eastern Texas, central and northwestern Oklahoma, and adjacent Kansas (Barber and Comanche counties). The linear-lanceolate, short-petiolate or subsessile cauline leaves, the pendent or horizontally spread- ing, deep-purple or magenta (rarely lavender) flowers, the open calyx, and the fused median filaments with aborted adaxial anthers serve to distinguish this species from all the others of the genus. The subgeneric disposition of Streptanthus hyacinthoides is problematic. Earlier authors such as Gray and Watson (1871) placed it in subgenus EUcLIsIA Nutt. ex Torrey & Gray, while Rodman and associates assigned it to subgenus 106 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 STREPTANTHUS. Subgenus Euc.isiA 1s characterized by zygomorphic flowers; reduced petal blades as wide as or narrower than the claw; three unequal pairs of stamens with the filaments of one or both pairs of the median stamens partially to completely connate; anthers of the upper (adaxial) stamens sterile; entire (rarely 2-lobed) stigmas; and narrow siliques 1-2 mm wide. All of these features are found in S. Ayacinthoides, and they clearly support its placement in subgenus Eucuisia. However, it clearly deviates from the 14 species of this subgenus, which are exclusively Californian and primarily serpentine endemics, by its open calyx that is regular and neither flask shaped nor urceolate. From members of subgenus STREPTANTHUS, S. Ayacinthoides differs in having entire stigmas, narrow petal blades, connate median filaments, sterile adaxial anthers, and narrow siliques. Greene (1906a), who was the first to point out the differ- ences between the typical members of Euclisia and S. hyacinthoides, proposed Icianthus to accommodate the species. Perhaps the best disposition for this species would be in a monotypic section, not yet proposed, of subgenus Ev- CLISIA. Subgenus PLEIOcARDIA (Greene) Jepson, not represented in our area and primarily distributed in California, accommodates the remaining species of the genus. Members have slightly zygomorphic flowers, three usually unequal, free pairs of stamens with all anthers fertile, usually entire stigmas, and narrow petal blades often as wide as the claw. The genera most closely related to Streptanthus are Streptanthella Rydb. and Caulanthus S. Watson. From these, Streptanthus is distinguished by its accumbent cotyledons, usually winged seeds, and flattened siliques. Caulanthus species usually have incumbent cotyledons, wingless seeds, and terete fruits. The line separating the last two genera, however, is not as well defined as it may seem, and there are few species that could be accommodated in either genus without drastically altering the generic limits. Nevertheless, a more prac- tical taxonomy of the group can be achieved by maintaining both genera. Many other pairs of closely related genera with equally arbitrary boundaries are found in the Cruciferae. The monotypic Streptanthella is separated from Streptanthus by its incumbent cotyledons and its beaked siliques in which the valves remain undehisced in the beak area. Hauser and Crovello suggested that these two genera probably evolved from Caulanthus. Several species of Streptanthus are highly polymorphic in flower color and pubescence. The most notable example is S. glandulosus Hooker, which has an enormous array of morphologically discrete forms that are apparently cor- related with the spatial isolation of populations. As many as nine species have been described in this complex, but these were shown to be interfertile (Krucke- berg, 1957, 1958). Because of the importance of the flowers in the taxonomy of the genus, careful field notes should be made, particularly with respect to color, degree of irregularity, and petal size and orientation. The remarkable diversity of the flowers of Streptanthus is certainly unpar- alleled in any genus of the Cruciferae. The specific epithets of S. hyacinthoides and S. polygaloides are indicative of the strong superficial resemblance of the flowers of these plants to those of the genera Hyacinthus L. (Liliaceae) and 1985] AL-SHEHBAZ, THELY PODIEAE 107 Polygala L. (Polygalaceae). As shown in the generic description above, the calyx and corolla vary greatly in color, shape, size, orientation of parts, and symmetry. The androecium, too, is highly evolved and shows a wide range of variability, particularly with respect to the length, color, orientation, and degree of connation of the median stamens, and the fertility or sterility of the adaxial anthers. These patterns undoubtedly represent adaptations to certain pollina- tors, about which hardly anything is known. Kruckeberg (1957) observed bees, butterflies, beetles, and even hummingbirds visiting the flowers of S. glandu- losus, but no attempt was made to identify the species of these pollinators. Self-incompatibility and protandry were demonstrated in Streptanthus car- inatus and S. Cutleri Cory (Rollins, 1963). In both species flower odor reaches its peak during anther dehiscence, while nectar secretion coincides with the maturation of the gynoecium. Both devices are nicely coordinated to fulfill the requirements for insect attraction. Selfing is reduced or prevented in many taxa of subgenus Eucuisia by protandry and the curvature of the filaments away from the stigma during full anthesis. Data on the reproductive biology of the majority of species are needed. A uniform haploid chromosome number of 14 has been reported for at least 18 species (Kruckeberg, 1958; Rollins, 1966; Rollins & Riidenberg, 1977; Kruckeberg & Morrison). Earlier counts of m = 12 for Streptanthus cordatus may have been in error, or the species may have a deviant chromosomal race. No chromosome counts are available for the three species occurring in our area. Extensive hybridization experiments have been conducted within sections Euc.isiA, INSIGNES Kruckeberg & Morrison, and HESperipes Kruckeberg & Morrison. In all cases species of a given section can be crossed, but the artificial hybrids either are inviable or suffer from reduced pollen fertility (Kruckeberg, 1957; Kruckeberg & Morrison). No visible meiotic irregularities during mi- crosporogenesis were observed that explain the low degree of pollen viability. Natural hybridization in Streptanthus was first reported between two subspecies of S. carinatus (Kruckeberg et al.). Forty species of Streptanthus and Caulanthus have been analyzed for their seed glucosinolates, and 26 compounds have been identified (Rodman et a/.). In general, the glucosinolate profiles have been shown to be species specific, but the two genera are chemically indistinguishable. The serpentine endemics are apparently as complex and diverse in their glucosinolates as the nonser- pentine taxa. Although infraspecific variability in these compounds js signifi- cant in six species, only S. cordatus shows a clear correlation, with morpho- logical discontinuities corresponding to recognizable infraspecific taxa. Seeds of S. hyacinthoides contain two volatile compounds (3-butenyl as the major component and allyl glucosinolate in smaller concentrations) and two non- volatiles, with 4-methylsulfinylbutyl as the major constituent and 2-hydroxy- 3-butenyl glucosinolate as the minor. Streptanthus maculatus (listed as S. or- bicularis), by contrast, contains two volatiles, with allyl glucosinolate as the dominant constituent and 3-butenyl glucosinolate as the minor one. Of the 32 species of Streptanthus and Caulanthus analyzed for nickel content 108 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 (Reeves et al.), S. polygaloides is the first known hyperaccumulator in the New World, with values in the range of 3300—14,800 parts per million of dry weight. Other serpentine-tolerant species had nickel values of only 10-100 ppm. Greene (1904) established the monotypic genus Microsemia for this species on the basis of its very broad, bannerlike, adaxial sepal that subtends the other sepals in bud, a feature not encountered elsewhere in the Cruciferae. The nickel data may support Greene’s position, but in floral and fruit morphology the species fits well in Streptanthus. Edaphic factors probably play a major role in the localized distribution of most species of Streptanthus. Although many species are restricted to limestone, shale, sand, clay, and granite gravel and rocks, by far the narrowest endemism is shown by the serpentine inhabitants. Kruckeberg’s pioneering studies on serpentine tolerance show that some species (such as S. glandulosus, S. tor- tuosus Kellogg, and S. cordatus) are broad generalists adapted to different soils, while others (at least 22 taxa of 15 species) are serpentine endemics. Ecotypic differentiation in the form of several serpentine-tolerant and intolerant races is now well documented in S. glandulosus. Kruckeberg believes that evolu- tionary diversification in Streptanthus may have resulted from the reduced gene flow between edaphic races accentuated by spatial and edaphic isolation, particularly in serpentine habitats, and that the serpentinophytes probably represent the end product of a process of biotype depletion in which the ser- pentine intolerants were eliminated by competition pressure, leaving only the serpentine obligates. REFERENCES: Under family references in AL-SHEHBAZ (Jour. Arnold Arb. 65: 343-373. 1984), see Hayek, Ro. ins (1966), ROLLINS & RUDENBERG (1977), and ScHuLz. Under tribal ref- erences see AL- SHEHBAZ (1973), HAUSER & CROVELLO (1982), KRAL, MUSCHLER, RAVEN & AXELROD, and RoBINSON Brooks, R. E., R. L. McGrecor, & L. A. HAUSER. are plants new to the state of Kansas. Tech. Publ. State Biol. Surv. Kansas 1: 1-12. 1976. [S. Ayacinthoides in Comanche and Barber counties, 4.] Brown, C. A. Wildflowers of Louisiana and adjoining states. xl + 247 pp. Baton Rouge, Louisiana. 1972. LS. hyacinthoides growing on deep sand in Winn Parish, 59.] Cory, V. L. A new pea from the Big Bend of Texas. Rhodora 45: 258-260. 1943. [S. Cutleri, sp. no Goopman, G. J. A new ae of Streptanthus. ie 58: 354, 355. 1956. [S. squami- formis, sp. nov., from Oklahoma and Arkansas.] Gray, A. On Streptanthus, Nutt., and the plants each have been referred to that genus. Proc. Am. Acad. Arts Sci. 6: 182-188. 1864. [Two subgenera recognized: Eustrep- tanthus, three species, and Euclisia, 13 species.] GREENE, E. L. Certain West American Cruciferae. Leafl. Bot. Obs. Crit. 1: 81-90. [Euclisia, Pleiocardia, Mitophyllum, Microsemia, and Mesoreanthus segregated yas Streptanthus. —. Icianthus and Sprengeria. Ibid. 197-199. 1906a. —. Four streptanthoid genera. bid. 224-229. 1906b. [Disaccanthus, Cartiera, Guil- lenia, and Agianthus segregated from Streptanthus and Thelypodium HERMANN, F. J. Notes on western range forbs: Cruciferae through Compositae: U.S. 1985] AL-SHEHBAZ, THELYPODIEAE 109 Dep. Agr. Forest Serv. Agr. Handb. 293: 1-365. 1966. [S. tortuosus said to be palatable to sheep, 17. HorrMan, F. W. Studies in Streptanthus. A new Streptanthus complex in California. Madrofio 11: 189-220. 1952. [Key to the subgenera of Streptanthus (including Cau- lanthus); key to the groups of section Euclisia; S. Morrisonii and S. brachiatus, spp. nov Hoores: W. zi Streptanthus obtusifolius. Blunt-leaved streptanthus. Bot. Mag. 61: pi. 3317. 18 ——_. eet is hyacinthoides. Hyacinth-flowered streptanthus. Jbid. 63: pl. 3516. 1836. Howe, J. T. The Tompkins-Tehipite expedition of the California Academy of Sci- nces. Leafl. West. Bot. 9: 181-187. 1961. [S. fenestratus, key to related species, 184, 185.] . Anew variety of Streptanthus cordatus. Ibid. 10: 31. 1963. The juvenile leaves of a California jewel flower. Jbid. 135, 136. 1964. [S. polygaloides. | . Anew Sierran Streptanthus. Ibid. 182, 183. 1965. [S. Farnsworthianus, sp. nov.] JePs0N, Aue L. A flora of California. Vol. 2. Frontisp. + 684 pp. Berkeley. 1936. [Rec- zes 25 species in four subgenera of Streptanthus, Caulanthus reduced to two KRUCKEBERG, A. R. Intraspecific variability int to serpentine soil. Am. Jour. Bot. 38: 408-419. 1951. ean of S. ee strains to serpentine and nonserpentine soils, the role of biotype depletion in the origin of serpentine endemics.] . The ecology of enna soils. III. Plant species in relation to serpentine soils. Ecology 35: 267-274. 1954. [Tolerance and intolerance to serpentine among strains of S. glandulosus.] ariation in fertility of hybrids between isolated populations of the serpentine species, Streptanthus glandulosus Hook. Evolution 11: 185-211. 1957. [Artificial hybridization between members of 32 populations in 334 combinations; interfertility studies eee the reduction of the le Species 3 in the complex to thr ee.] The taxono 14; 217-227. 1958, lInterfetility relationships recognizes RY anos (three eae and three varieties), S us (two subspecies), and S. n The mplication of ecology He cee systematics. Taxon 18: 92. “00. 1969a. [Edaphic Bee tion of Streptanthus, 97, 98. —. Soil oe and the distribution of plants, with examples from western North merica. Madrono 20: 129-154. 1969b. [Obligate serpentine endemics of Strep- tanthus, | ae & RRISON. New Streptanthus taxa (Cruciferae) from California. Ma- seers 30: 930-244, 1983. [Five new sections in subgenus Fuclisia; S. drepanoides, sp. ; S. insignis subsp. Lyonii, subsp. nov.; crosses among some members of ee ieee nes. ODMAN, & R. D. WORTHINGTON. Natural aan between Strep- fants. arizonicus and S. carinatu ise e). Syst. 7: 291-299, 1982. [First report of natural hybridization in Streptanthus, eae karyology, and glu- cosinolate chemistry support the nein of S. arizonicus to a subspecies of S. Martin, P. S., & C. M. Drew. Scanning electron photomicrographs of Southwestern pollen grains. Jour. Arizona Acad. Sci. 5: 147-176. 1969. [Pollen of S. arizonicus is prolate, tricolpate, and with visible columellae, 150, fig. alte D.) Morrison, J. L. Studies in the genus Streptanthus Nutt. I. Two new species in section eae Nutt. Madrofio 4: 204-208. 1938. [S. batrachopus and S. callistis, spp. ov.] 110 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 A monograph of the section me pie of Streptanthus Nutt. Unpubl. Ph.D. Thesis, Univ. California, Berkeley. 194 Muwz, P. A., & D. D. Keck. A California ie Frontisp. + 1681 pp. Berkeley and Los Angeles. 1959. [Streptanthus, 216-221.] NutTAa._, T. Description of two new genera of the natural order Cruciferae. Jour. Acad. Nat. Sci. Phila. 5: 132-135. 1825. [Streptanthus, 134, 135, pl. 7. Reeves, R. D., R. R. BRooxs, & R. M. MACFARLANE. Nickel uptake by Californian Streptanthus and Caulanthus with ae reference to the hyperaccumulator S. sag a (Brassicaceae). Am. Jour. Bot. 68: 708-712. 1981. Ropmaw, J. E., & A RUCKEBERG. a of seed glucosinolate variation in the genus Sireptantus (Cruciferae). (Abstr.) Bot. Soc. Am. Misc. Ser. 158: 96. 1980. —_——— AL-SHEHBAZ. Chemotaxonomic diversity and complexity in seed a a of Caulanthus and Streptanthus (Cruciferae). Syst. Bot. 6: 197- 222. 1981. [Glucosinolates of 89 collections of 40 species; 26 compounds identified; phenogram of 38 species based on glucosinolate profiles; provisional nomenclatural synopsis of paced (including pee ae serpentine taxa are chemically as diverse and complex as nonserpenti Ro uins, R. C. Some new or aaa Neth ‘American Cruciferae II. Contr. Dudley Herb. 3: 366-373. 1946. [S. oliganthus, sp. nov., 7 Protandry in two species of Streptanthus (Cruciferae). Rhodora 65: 45-49. 1963. [Protandry, self-incompatibility, and zygomorphy in S. Cutleri and S. carinatus.] . Notes on Streptanthus and Erysimum (Cruciferae). Contr. Gray Herb. 200: 190- 10. 1971. [Generic limits of Streptanthus and Caulanthus; argument for caning both genera. ] . BANERJEE. Pollens of the Cruciferae. Publ. Bussey Inst. Harvard Univ. 1979: 33- 64. 1979. [S. carinatus, S. platycarpus, and S. hyacinthoides; pollen prolate; interspecific differences in the size and abundance of lumina, 48- & OLMGREN. A new species of Caulanthus (Cruciferae) from Nevada. Brittonia 32: 148-151. 1980. [C. Barnebyi, sp. nov.; a brief comment on main- taining both Caulanthus and Streptanthus.] —,E. A. SHaw, & R. J. Davis. Cruciferae. Pp. 671-706 in D. S. Correct & M . JOHNSTON, Manual of the vascular plants of Texas. Renner, Texas. 1970. [Strep- tanthus, 676, 677.] RypserG, P. A. Studies on the Rocky Mountain flora—XVI. Bull. Torrey Bot. Club 33: 137-161. 1906. [The typification and limits of Euklisia, 142.] — ae" SHAPIRO, A. M. Egg-mimics of Streptanthus (Cruciferae) deter oviposition by Pieris sisymbrii pe re wae aa Oecologia 48: 142, 143. 1981. [Orange-pigmented callosities on the leaves of S. Breweri and S. slandulosus mimic in shape, size, and color the eggs of P. cisymbril these affect the egg-laying of the insect, which visually assesses the egg load on individual host plants before ovipositing. SIOLUND, R. D., & T. E. Weiter. An ultrastructural study of chloroplast structure and diferentiation in a cultures of Streptanthus tortuosus (Cruciferae). Am. Jour. Bot. 58: 172- ie 197 Smitu, E. B. An s and ee list of the vascular plants of Arkansas. iv + 592 pp. Fete, as 1978. [S. hyacinthoides, S. maculatus, S. squamiformis, 135, 136. THIERET, ; W. Twenty-five species of vascular plants new to Louisiana. Proc. Louisiana Acad. Sci. 32: 78-82. 1969. [S. hyacinthoides from Bienville and Caddo parishes, 79. ] Torrey, J., & A. Gray. A flora of North America. Vol. 1. xiv + 711 pp. New York. near ae eee 75-78 (1838), 666 (1840).] Watson, S. y. U.S. Geol. Expl. Fortieth Parallel 5. liti + 525 pp. + 40 pls. 1871. ei aes 19, 430, 431; Caulanthus, 27, 28.] 1985] AL-SHEHBAZ, THELY PODIEAE 11] —. Contributions to American botany. 1. Miscellaneous notes upon North Amer- ican plants, chiefly of the United States, with descriptions of new species. Proc. Am. Acad. Arts Sci. 25: 124-163. 1890. [Streptanthus, grouping of 22 species, 125-127.] ARNOLD ARBORETUM 22 Divinity AVENUE CAMBRIDGE, MASSACHUSETTS 02138 COX, MERYTA 113 THE GENUS MERYTA (ARALIACEAE) IN SAMOA PAUL ALAN Cox THE GENUS MERYTA, a group of araliaceous trees of the islands of the south- western Pacific, New Guinea, Micronesia, and Australia, was proposed by J. R. and G. Forster (1775) on the basis of a staminate collection made at an unspecified site during the second voyage of Captain Cook. According to Willis (1973), the genus includes 16 species; according to Harms (1937), it includes 38. Consisting of dioecious trees or shrubs with simple leaves and with flowers either solitary or borne in heads, the genus remains poorly understood and has yet to be monographed. Intrageneric relationships are particularly obscure, and limits between species are difficult to define. The genus occurs in all of the major archipelagoes of Polynesia except Hawaii, although it is rare in Fiji, where prior to 1971 it was believed to be completely absent (Smith & Stone, 1968). At present, the Fijian species Meryta tenuifolia A. C. Smith is known only from the type collection from Viti Levu (Smith, 1971). The ecological and biogeographic factors responsible for the present distribution of the genus remain unknown. It is hoped that a clarification of the status of the genus in Samoa will prove useful to those concerned with the Samoan flora, as well as to those dealing with the Araliaceae in general. Of the Araliaceae known to be extant in Samoa, species of Reynoldsia A. Gray, Polyscias J. R. & G. Forster, and Schefflera J.R. . Forster have been collected in addition to Meryta Two species, Meryta macrophylla (Rich ex A. Gray) Seon and M. ca- pitata Christoph., have been described from Samoa (Seemann, 1862; Chris- tophersen, 1935). However, an analysis of the type specimens and descriptions, as well as of recent and old collections of Meryta from Samoa, reveals the existence of two additional taxa and some confusion concerning the two known taxa. The first species of Meryta from Samoa was described as Botryodendrum macrophyllum Rich ex A. Gray, based on an unnumbered specimen collected at an unspecified site in Samoa by the U. S. Exploring Expedition. Gray’s description (1854, p. 732) was characteristically brief (““B. foliis obovato-lan- ceolatis basi attenuatis membranaceis ad apicem ramorum confertis’’), and it is apparent from his discussion (ibid.) that he regarded the specimen as inad- equate: “‘This is said to be ‘a simple shrub, from 10 to 25 feet high.’ Whether it is really distinct from the preceding species Botryodendrum taitense cannot be satisfactorily determined from the present materials which consist of foliage, some badly preserved fertile flowers, a detached portion of male inflorescence (which perhaps belongs to B. taitense), and mature fruit.” © President and Fellows of Harvard College, Pes of the Arnold Arboretum 66: 113-121. ue 1985. 114 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 All of the species in the genus Botryodendrum Endl. were transferred by Seemann (1862) to the genus Meryta. Subsequently, numerous specimens of a common species of Meryta in Samoa have been placed in M. macrophylla. However, examination reveals the type to have little in common with these specimens. The fruits of the type specimen are completely free or united only at the base, have sessile stigmas and prominent ridges, and do not exceed 1 cm in length. This contrasts greatly with the fruits of the common Samoan Meryta, which are fused to half of their length within the heads, lack prominent ridges, and exceed 1.5 cm in length. It is thus clear that although the most common species of Meryta in Samoa has been called M. macrophylla, it is actually an undescribed species. It is here designated Meryta mauluulu (de- scribed below). The status of Meryta macrophylla remains uncertain because of the possi- bility, mentioned by Gray, that the type is a composite specimen. Only one of the Meryta specimens I have examined from Samoa (Bristo/ 2118 (Bisu), from Salamumu, Upolu) can possibly be ascribed to this species. I cannot exclude the possibility that the type specimen represents a very early developmental stage, although Gray’s dissection led him to declare the fruit mature. Another specimen (Setchell 1253 (BisH)), in which only one fruit per capitulum devel- oped, shows ridges on the fruits similar to those of the U. S. Exploring Ex- pedition specimen, although the fruits themselves are much larger. Meryta mauluulu can readily be distinguished from the other common Sa- moan species, M. capitata: the fruits of the former species are fused along the lower half only, while those of the latter are completely fused. After periodic observation of several tagged trees in Upolu in 1978 and 1979, Iam convinced that M. capitata and M. mauluulu are indeed different and not merely devel- opmental stages of the same species. The similarity of the erect entomophilous terminal inflorescences of these two sympatric species raises interesting eco- logical questions concerning the nature of the isolating mechanisms. Perhaps M. mauluulu is a relatively recent introduction from Tonga or, alternatively, M. mauluulu spread to Tonga from Samoa but M. capitata did not. With regard to the latter possibility, it is of interest to note the occurrence of “leaky dioecy”’ (Baker & Cox, 1984) in M. mauluulu: Christopherson 1254 has both staminate and pistillate flowers borne in different fascicles on the same inflo- rescence. Meryta malietoa (described below) can easily be distinguished from the other Samoan species of Meryta by its greater degree of ramification, its fruits that are free or united only at the base, and its prominently exserted stigmas. It is apparently confined to the mountain forests of Savaii, although Whistler 1047, a specimen collected from Mt. Mariota in Upolu and lacking fruits, may be referable to M. malietoa. (In 1980, I climbed Mt. Mariota but did not find any plant similar to M. malietoa.) The four Samoan species of Meryta are difficult to distinguish vegetatively. Meryta malietoa has a much greater degree of ramification than M. capitata or M. mauluulu, both of which appear to approximate Chamberlain’s model (Hallé et al., 1978). Obtaining decisive foliar characteristics is particularly problematic. Although laminas of M. capitata and M. mauluulu are somewhat 1985] COX, MERYTA 115 Meryta Leaf Parameters 23.8. 22.5) e 28.8 e¢ ry = 17.5) e . e 5 %} ¢ 00 ¢ } —, 15.8] e ra "eee Uo 12.5 geoet? 3 ¢¢ 2 +0,% = o 18.8) eee % i | oot 0 7.5] o *¢ oan _ o¢ ff, a B 5.8L a a M. macrophy!!ea a M. mal letoa 2.5) @ M. mauluulu eM. capitate .) + + + + + + + + 4 s = s 8 © &® @ &£ & R lamina length (cm. ) Ficure |. Lamina lengths plotted against lamina widths for species of Meryta in longer than those of M. malietoa or M. macrophylla, this character is highly variable (see TABLE 1). Leaves of M. malietoa and M. macrophylla do appear to be considerably narrower, however (see TABLE 1). A plot of lamina lengths and widths (FiGure 1) effectively divides the four species into two separate groups, with M. capitata and M. mauluulu having identical length/width quo- tients of 3.5, and M. malietoa and M. macrophylla having quotients of 4.4 and 4.2, respectively (TABLE 1). Thus, while these four species are very similar vegetatively, my observation of tagged individuals over a one-year period leaves little doubt that they are distinct. There was no variation in fruit char- acters observed through time within any individual, and intermediate fruit character states have not been found. The overall vegetative similarities be- tween these species is perhaps not surprising, given the climatic and relative ecological homogeneity of their habitats (with the exception of the montane M. malietoa). The ecological factors that maintain the integrity of these species 116 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 TABLE |. Leaf characteristics of Samoan species of Meryta. SPECIES : M. M. capitata mauluulu _maliietoa macrophylla CHARACTERISTICS (N= 26) (N=27) (N=19) (N = 6) Mean lamina length (cm)/S.D. 46.9/13.2 43.1/17.2 34.1/6.7 33.8/6.4 Mean lamina width (cm)/S.D. 13.3/3.7 12.1/3.4 8.0/1.6 7.8/1.6 Lamina length-width quotient/S.D. 3.5/0.4 3.5/0.7 4.4/0.9 4.2/0.4 Mean petiole length (cm)/S.D. 8.5/4.9 9.2/4.3 11.8/3.9 7.6/1.2 Lamina length-petiole length quotient/S.D. 9.3/11.8 6.0/5.7 3.2/7.33 4.4/0.6 and the relationships of Samoan species to the rest of the genus await further study KEY TO THE SAMOAN SPECIES OF MERYTA 1. Fruits free or united only at base 2. Fruits less than | cm long; stigmas SESSIIG: 2.05. degu eh cnicaus 2. M. macrophylla. 2. Fruits greater than 1 cm long; stigmas ea exserted. ...3. M. malietoa. 1. Fruits completely or partially fused into hea 3. Fruits completely fused along entire lengt . ee ee cee ene 1. M. capitata. 3. Fruits fused only along lower half, the upper half free. ....... 4. M. mauluulu. 1. Meryta capitata Christoph. Bernice P. Bishop Mus. Bull. 128: 161. 1935. Few-branched tree 5 m high, with leaves inserted near ends of branches. Leaves with lamina oblanceolate, 20-80 by 6-25 cm, apex short acuminate, base decurrent, margin slightly undulate, glabrous. Infructescence terminal, racemose, with fruits borne in heads. Fruits sessile or short pedicellate, com- pletely fused except for the 2- to 3-mm conical apex, green, with 8 to 12 persistent stigmas. Type. Western Samoa, Savaii, edge of forest back of Vaipouli, 150 m alt., 7 July 1931, Christophersen & Hume 1913 (holotype, BisH!; isotypes, A!, BISH!, us}). SPECIMENS EXAMINED. Western Samoa. Sava: Falealupo, Christophersen 2802 (BISH); Manase, Christophersen 2369 (sis), Taga, Bristol 2219 (Bish, GH, Us), Christophersen 2839 (BIsH, US); Patamea, 280 m alt., Bristol 2365A (sisH); Vaipouli, 75 m alt., Chris- tophersen & Hume 1837 (a, BISH); road to Papa, Whistler 2184 (sis); Fatuvalu, ‘Cox 10 (GH). Upotu: Tapatapao, 700 m alt., Cox 78:(GH). American Samoa. Tau: top of island, Whistler 3204 (sisH); 100 m alt., Yuncker 9162 (pisH); 600 ft alt., Garber 622 (BISH). Oru: Yuncker 9545 (pisH). OLOSEGA: 1700 ft alt., Garber 622 (BISH). A tree common throughout Samoa, called “‘lau fagufagu” in Samoan. 2. Meryta macrophylla (Rich ex A. Gray) Seemann, Bonplandia 10: 294, 295. 1862 “Small tree 10 to 25 feet high” (Gray, 1854, p. 732). Leaves with petiole 6- 1985] COX, MERYTA ig 10 cm long; lamina oblanceolate, 20-40 by 6-10 cm. Fruits free or united only at base, 0.8-1 cm long, with prominent longitudinal ridges, stigmas sessile. Type. “Samoan or Navigator Islands, Herbarium of the U. S. Exploring Ex- pedition, under the command of Captain Wilkes, U.S.N., 1838-1842” (us!). SPECIMEN EXAMINED. Western Samoa. Upo.u: Lefaga-Salamumu, Bristol 2118 (isn). 3. Meryta malietoa P. A. Cox, sp. nov. FIGURE 2. Infructescentia bracteata paniculata, fructibus parum pedicellatis vel sessi- libus, solitariis vel in capitulis a ae Fructus virides, discreti vel basi tantum conjuncti, diametro 1-1.2 cm, globosi vel ovoidei, cristis longitudi- nalibus prominentibus 5-8 instructi, baci pericarpio carnosulo 5-6 pyre- nibus instructi; calyce, stylo, et stigmatibus persistentibus, stigmatibus 6-8, prominentibus, 3-5 mm longis, stylo 2 mm exserto. Few-branched tree 6 m high, with leaves inserted near ends of branches. Leaves with petiole 10-20 cm long; lamina obovate to oblanceolate, 36-43 by 8-9 cm, apex short acuminate, base decurrent, margin slightly undulate par- ticularly near apex, glabrous, coriaceous, with lateral nerves 25 to 30 on each side, prominent. Infructescence solitary, paniculate, bracteate, with fruits borne singly or aggregated into heads. Fruits short pedicellate or sessile, free or united only at base, baccate, globose to ovoid with 5 or 6 prominent longitudinal ridges, 1-1.2 cm in diameter, green, with calyx, style, and stigmas persistent (stigmas 6 to 8, prominent, 3-4 mm long, styles exserted 2 mm); pericarp fleshy; pyrenes 5 or 6, asymmetrically oblong, 11 by 6 by | mm, hard. Seed with 3 or 4 wings, 7 by 3 by 0.2 mn, testa soft, with circular red layer in transection; ovule solitary, pendulous, anatropous; endosperm copious. Type. Western Samoa, Savaii Island, Mt. Silisili, Letui side, above salafa toward summit, 1800 m alt., in cloud forest, 27 June 1979, Cox 279 (holotype, Uc; isotypes, BISH, GH). SPECIMENS EXAMINED. Western Samoa. SAVAII: above Matavanu, wet forest, 1400 m alt., Christophersen & Hume 2199 (uc); W of Mt. Silili, 1600 m alt., Whistler 2678 (us); o west, Asau forestry, 300 m alt., Whistler 1770 (us); inland from Asau, 500 m alt., Whistler 1047 (us). The specific epithet of Meryta malietoa comes from the chiefly title of His Highness, the Head of the State of Western Samoa, Malietoa Tanumafili IJ, and is used with his permission. It is hoped that the association of his kingly title with this plant will add impetus to the establishment of a national park in the interior forests of Savaii to which this plant is confined. 4. Meryta mauluulu Cox, sp. nov. FIGURE 3. Fructus virides, infra conjuncti supra liberi, 5-7 mm alti, calyce persistent, plerumque 8-partito, stigmatibus persistentibus, plerumque 8, sessilibus, pa- pillosis, 1-1.6 mm longis. Fructus baccatus pericarpio carnosulo 8 pyrenibus instructus. JOURNAL OF THE ARNOLD ARBORETUM Ficure 2. Meryta malietoa: a, leaf, b, infructescence; c, fruit. [VOL. 66 1985] COX, MERYTA 119 Ficure 3. Meryta mauluulu: a, leaf; b, infructescence; c, apex of fruit. Few-branched tree 8 m tall, with leaves inserted near ends of branches, apparent phyllotaxis 10/3. Leaves with petiole 9-11 cm long; lamina oblan- ceolate, 37-40 by 10-11 cm, apex short acuminate, base short decurrent, mar- gin very slightly undulate, glabrous, chartaceous, with lateral nerves 24 to 28 on each side, prominent. Infructescence racemose, bracteate, unbranched, with 120 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 fruits borne in heads; heads sessile, globose, 2.5—3 cm in diameter, with 12 to 16 fruits. Fruits sessile, united along lower half, free along upper half, slightly conical, 5-7 mm long, baccate, green, the calyx persistent, calyx members usually 8, the stigmas persistent, usually 8, sessile, 1-1.6 mm long, papillose; pericarp fleshy; pyrenes 8, asymmetrically oblong, 8 by 3 by | mm. Ovule solitary, pendulous, anatropous, oblong, 2.2 by | mm, smooth; endosperm copious. Type. Western Samoa, Savaii Island, on road between Letui and Aopo in young forest, 24 June 1979, Cox 252 (holotype, Uc; isotypes, BISH, GH). The specific epithet comes from the Samoan name given this plant by bo- tanically adept Samoans resident in the type area. It is a cognate of “kulukulu,” the Tongan name for this species as noted on several sheets from Tonga ( Yunck- er 16050, Yuncker 16181, Setchell 15652, Parks 16231), and “lutulutu,” the Fijian name noted by Smith (1971) for the type specimen of Meryta tenuifolia (M. J. Berry 97). The leaves are used to wrap food for baking in stone ovens (“umu’’) SPECIMENS EXAMINED. Western Samoa. Upo.u: Malolelei above Apia, 1600 ft alt., Setch- ell 15667 (BisH); Mt. Vaea, 150 m alt., Bryan 99 (BisH); Lefaga-Salamumu, Bristol 2118 (Bis); Afiamalu, 600 m alt., Whistler 806 (us); Mt. Mariota, 600 m alt., Whistler 1269 (us); Tiavi, 700 m alt., Whistler 715 (us), Cox 5 (Gu); Malolelei, 550 ftalt., Christophersen 304 (BisH); Lepupupue, Cox 166 (Gu), Teraoka & Kennedy 87 (us); Teraoka : Whitaker 340 (us). Sava: Avao, Vaupel 135 (Bis); between Letui and Aopo, Cox 236 (GH, uc); So ed 262 (Gu); Asau, Teraoka 342 (us), 300 m alt., Whistler pres American LA: ridge above Pagopago, Garber 929 (n1sH): Alava ridge, 400 m alt., ie 1130 (sis, us); Papatele ridge, 300 m alt., Christophersen 1006 (ais, us); Pagopago ridge west, Setchell 1253 (isn). ies Noor trail, 600 ft alt., Garber 622 (A); central mountain, Cox 312 (BIsH, GH, US). Tonga. VAvAU: Setchell 15652 (uc); 150 m alt., Yuncker 16181] (Gu). Eva: Parks 16231] res! Anovai Lake, 20 m alt., Yuncker 16050 (GH). ACKNOWLEDGMENTS I thank Aumalosi, H. G. Baker, L. Constance, L. Dempster, F. R. Fosberg, L. Heckard, Samu, A. C. Smith, P. F. Stevens, F. Tauiliili, and A. Whistler for helpful advice at various stages; D. Betham and B. Cox for logistical support: and C. Hannan for artwork. I also thank the curators of the Gray Herbarium (Gu), the Arnold Arboretum (a), the Bishop Museum (isu), the U. S. National Herbarium (us), and the University of California Herbarium (uc) for work- space, loans, and numerous courtesies. During this study, I was funded by fellowships from the Danforth Foundation, the National Science Foundation, and the Miller Institute for Basic Research in Science, and grants from the National Science Foundation and the Fernald Fund of Harvard University. LITERATURE CITED Baker, H. G., & P. A. Cox. 1984. Further thoughts on islands and dioecism. Ann. Missouri Bot. Gard. 71: 230-239. 1985] COX, MERYTA 121 CHRISTOPHERSEN, E. 1935. Flowering plants of Samoa. Bernice P. Bishop Mus. Bull. 128: 1-221. Forster, J. R., & G. Forster. 1775. Characteres generum plantarum, quas in itinere ad insulas Maris Australis, collegerunt, eee ae runt, annis MDCCLXXII-MDCCLXXY. White, Cadell, and Elmsly, L Gray, A. 1854. Botany. Phanerogamia. /n: C. WILKES, U. S. Tae Expedition. Vol. 15, Part 2. Putnam, New York. HALLE, F., R. A. A. OLDEMAN, & P. B. TOMLINSON. 1978. Tropical trees and forests. Springer- Verlag, New Yor Harms, H. 1938. Zur Kenntnis von Meryta sonchifolia Linden et André und einigen anderen Arten der Gattung. Notizbl. Bot. Gart. Berlin-Dahlem 14: 315-321. SEEMANN, B.C. 1862. Botryodendrum Endl. = Meryta Forst. Bonplandia 10: 294, 295. SmitH, A.C. 1971. Studies of Pacific island plants, XXII. New flowering plants from Fiji. Pacific Sci. 25: 491-501. & B.C. Stone. 1968. Studies of Pacific island plants, XIX. The Araliaceae of the New Hebrides, Fiji, Samoa, and Tonga. J. Arnold Arbor. 49: 431-501. WiLuis, A. J. 1973. A dictionary of the flowering plants and ferns. ed. 8 (revised by H. K. Airy SHAW). Cambridge University Press, Cambridge, England. DEPARTMENT OF BOTANY AND RANGE SCIENCE BRIGHAM YOUNG UNIVERSITY Provo, UTAH 8460 JOURNAL OF THE ARNOLD ARBORETUM INSTRUCTIONS FOR AUTHORS General policy The Journal of the Arnold Arboretum is primarily a staff journal, and staff papers have priority. Other papers are accepted, as space permits, from former staff or former students, and from other botanists who have worked on our collections or who have done research on a plant group or in a geographic area of interest to the Arboretum. Submission of manuscripts Manuscripts should be submitted in triplicate to Ms E. B. Schmidt, Managing Editor, Journal of the Arnold Arboretum, 22 Divinity Avenue, Cambridge, Massachusetts 02138. 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GEORGE Tc ROGERS ci oa tics Sehr R489 bib bbs $a uheLed Mhokn as | Journal of the Arnold Arboretum Index to Authors and Titles, Vol- umes 51-65 (1970-1984), ELIZABETH By SCHMIDT J visi dod do0 4 ooo 58s bce ara eka RS em 39 Perspectives on the Origin of the Floristic Similarity between Eastern Asia and Eastern North America. DRUCE Ti IPN Y a 6-4-Fixgia ae Bp nied 04 ed beak andeaienss 73 The Genera of Thelypodieae (Cruciferae; Brassicaceae) in the South- eastern United States. IHSAN A. AL-SHEHBAZ ... 0000000 cece cee e cece. 95 The Genus Meryta (Araliaceae) in Samoa. PAG AUAMICOM 525 wovdcide bien cael Ghdwaaw edn eveiack: 113 Volume 65, Number 4, including pages 429-592, was issued October 12, 1984. JOURNAL oF te ARNOLD ARBORETUM HARVARD UNIVERSITY VOLUME 66 NUMBER 2 ISSN 0004-2625 Journal of the Arnold Arboretum The Journal of the Arnold Arboretum (ISSN 0004-2625) is published quarterly in January, April, July, and October for $50.00 per year, plus $5.00 postage for addresses outside of the United States, by the Arnold Arboretum of Harvard University. It is printed and distributed by the Allen Press, Inc., 1041 New Hampshire Street, Law- rence, Kansas 66044. Second-class postage paid at Lawrence, Kansas. POSTMAS- TER: send address changes to Journal of the Arnold Arboretum, % Allen Press, Inc., P. O. Box 368, Lawrence, Kansas 66044. Subscriptions and remittances should be sent to Journal of the Arnold Arboretum, 1041 New Hampshire Street, Lawrence, Kansas 66044, U.S. A. Claims will not be accepted after six months from the date of issue. Volumes |!—51, reprinted, and some back numbers of volumes 52-56 are available from the Kraus Reprint Corporation, Route 100, Millwood, New York 10546, U.S.A. EDITORIAL COMMITTEE S. A. Spongberg, Editor E. B. Schmidt, Managing Editor P.S. Ashton K. S. Bawa P. F. Stevens C. E. Wood, Jr. Printed at Allen Press, Inc., Lawrence, Kansas COVER: The stylized design appearing on the Journal and the offprints was drawn by Karen Stoutsenberger. JOURNAL OF THE ARNOLD ARBORETUM VOLUME 66 APRIL 1985 NUMBER 2 THE SUBFAMILIES AND TRIBES OF GRAMINEAE (POACEAE) IN THE SOUTHEASTERN UNITED STATES! CHRISTOPHER S. CAMPBELL THE FAMILY GRAMINEAE (POACEAE), the fourth largest family of flowering plants, is represented in the southeastern United States by about 575 species, 130 genera, and 21 tribes assigned to five subfamilies. In number of genera it matches the Compositae (Asteraceae) almost exactly and exceeds both the Leguminosae (Fabaceae) (ca. 72 genera) and the Orchidaceae (ca. 50 genera) in this area of some 444,000 square miles (1.15 million square kilometers). The present account contains a comprehensive family description; general I ic Fl fthe Southeastern United States, a long-term project made possible 'Prepared for by grants from the National Science Foundation and at this nny, supported be BSR-8111520 (C. E. Wood, Jr., principal investigator), under which a part of this research nd BSR-8303100 (N iller, principal investigator). This account, the 107th in the series, follows 3 in general the format established in the first paper (Jour. Arnold Arb. 39: 296-346. 1958) and continued to the present. It departs from this format in some respects, most notably in the AppeNprx (a data matrix) and in the single bibliography placed at the end of the paper, instead of a separate one under the family and each subfamily and tribe. Only references cited are included in the bibliography. In the interest of readability, dates of papers referred to in the text usually are given, as in other papers of zs isiana. The descriptions are based primarily on the plants of ine area, watt information about extraregional members of the family in brackets [ ]. I thank Carroll Wood for his support and guidance, his critical review of the manuscript, and his work on the nomenclature of the taxa in this paper. Mary E. Barkworth, sy W. Hall, Walter S. Judd, Elizabeth A. Kellogg, John R. Reeder, Thomas R. Soderstrom, and John W. Thieret provided many helpful comments. I am grateful to Elizabeth B. Schmidt and to Stephen A. Spongberg for their editorial expertise. Ficure | was drawn by Donna Marino, and Ficure 2 is by Scott E. Bergquist. Figures 3-11 were drawn a Karen Stoutsenberger in 1975, 1976, and 1977, salsa under NSF Grant BMS-21469 (C. E. WOO: Jr., principal inves tieeto!); Carel Wood or Kenneth R. Robertson and the author uRE 4 was based on living plants collected by No rton Miller near Chapel Hill, North Carolina, or grown by Carroll Wood in Cambridge, Massachusetts. © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 123-199. April, 1985. 124 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 comments on the systematics, phylogeny, origin and distribution, reproductive biology, and economic importance of the family; a general diagnosis of the family followed by a key to the subfamilies and tribes; and brief diagnoses and discussions of the subfamilies and tribes. Fuller descriptions of these taxa are given in the APPENDIX (a data matrix based on 84 characters) at the end of the paper. Two pages of figures illustrate variations in leaf epidermis and internal leaf anatomy; four genera are illustrated as in other papers in the Generic Flora series; and five pages of drawings show details of spikelets, florets, and various other parts of representatives of 17 of the 21 tribes. GRAMINEAE A. L. de Jussieu, Gen. Pl. 28. 1789. Nom. alt. POACEAE Barnhart, Bull. Torrey Bot. Club 22: 7. 1925. (GRASS FAMILY) Annual or perennial herbs or shrubs with stems to 7.6 m high [trees to over 40 m in height and 30 cm in diameter], occasionally aquatic [or climbing]; hardness of woody stems not from secondary growth but from caps of fibers on both sides of the vascular bundles, lignified ground tissue, and to a lesser extent, silicified epidermis. Cyanogenic glycosides and various fructosans often present; major flavonoids flavone C-glycoside and tricin. Nucleoli disintegrat- ing before or after metaphase, either enclosed within a lumen during interphase or not. Vessel members with mostly simple perforation plates. Primary roots usually ephemeral, the mature root system adventitious and fibrous (FIGURES 4a, 6a, 10a); prop roots sometimes adventive from lower stem nodes; epidermal cells all equal in size or alternating long and short; root hairs perpendicular to or obliquely angled from the surface of the root; roots sometimes forming mycorrhizae. Corms and bulbs sometimes present. Shoot apex with | or 2 tunica layers. Stems jointed, terete to somewhat flattened, rarely quadrangular, erect, ascending, or prostrate; in some biennials and perennials forming sterile tufts of leaves (innovations) that later grow into fertile stems; branching absent or at the upper nodes, sometimes from dormant buds, and near the ground by tillering intravaginally, the plants then often caespitose (FiGURE 10a), or ex- travaginally and then often stoloniferous or rhizomatous (FIGURE 4a); all veg- etative branches bearing 2-keeled prophylls proximal on the adaxial surface of the branch and perpendicular to the plane of distichy of succeeding leaves; internodes growing by basal intercalary meristems, hollow or solidly filled with parenchyma; vascular bundles scattered to more or less concentrated toward the periphery; nodes transversely septate [armed with spines or thorns]. Leaves distichous [phyllotaxis 3/8 in the Australian endemic Micraira F. Mueller], green or glaucous from 2-3-diketone-containing waxes, and usually consisting of sheath, ligule, and blade, the sheaths and blades growing by basal intercalary meristems. Sheaths tightly encircling and supporting the stem (FIGURE 4b), the margins overlapping or, less commonly, united to form a tube. Ligules consisting of a membranaceous flange or a fringe of hairs at adaxial apex of sheath (Figures 4b, 6b, 8b, 10d), rarely absent. Blades simple, 1-150 cm [5 m] long, entire, usually linear, less often lanceolate to ovate [sagittate or cor- 1985] CAMPBELL, GRAMINEAE 125 date], flat, involute, convolute, or terete, sometimes deciduous from the sheath, continuous with the sheath or petiolate [the petiole twisting], sometimes di- morphic (much reduced on the main stem and normal on the branches), usually absent from leaves on rhizomes; venation parallel, rarely pinnate, cross-veins absent to prominent; small basal auricles often present (FiGuRE 6b). Leaf epi- dermis (FIGURE 1) composed predominantly of files of long (length considerably greater than width) and short (more or less isodiametric) cells; walls of long cells sinuous or straight, with or without small epidermal protrusions (papillae); short cells usually occurring over veins, often absent from between veins, arranged in files of 5 or more, mainly paired or solitary, in short rows, or in mixtures of 1’s, 2’s, and short rows, often containing cork bodies or silica bodies, sometimes modified into usually apically pointing hooks or prickles (the latter larger than the former) or microhairs; silica bodies sinuous or crenate, cross to dumbbell shaped or nodular, tall and narrow, saddle shaped, crescentic, or oryzoid; microhairs usually in or between stomatal rows, usually bicellular, rarely unicellular [3- or 4-celled], the apical cell spherical to linear; stomata paracytic, biperigynous (i.e., the subsidiary and guard cells not derived from the same meristematic cell), raised above or at the same level as surrounding epidermal cells, with parallel-sided to triangular subsidiary cells; macrohairs unicellular, rarely multicellular, intergrading with prickles; 2-celled salt glands found in some halophytes and their relatives. Transverse-sectional anatomy of leaves (FiGuRE 2) either C, or C,—see discussion below; midrib bundle(s) 1 or more than | and either arranged in an arc or not, conspicuous or incon- spicuous; vascular-bundle sheaths usually 2, an inner, thick-walled, endodermal mestome sheath and an outer parenchyma sheath, less often only | sheath present, rarely 3; sclerenchyma associated with all or nearly all vascular bundles, or only with larger bundles, as girders connecting the bundle and epidermis or as strands not reaching the epidermis; ‘‘arm” or “ratchet” cells with invaginated walls and large, elongated ‘“‘fusoid” cells present or absent; simple, fan-shaped groups of bulliform cells present or absent in the adaxial epidermis; colorless cells sometimes traversing the mesophyll or forming deeply penetrating fans, narrow groups penetrating into the mesophyll, or arches over small bundles; palisade parenchyma rarely present. Primary inflorescence a spikelet (FiGuREs 3-11) composed of an axis, the rachilla (FicuRES 3F2, G2; 4g; 5A2, B2, C2; 6), k; 7D2, 12), bearing distichously [spirally] arranged and closely overlapping basal bracts (glumes) and florets; disarticulating above the glumes or as a unit and with or without other spikelets; dorsally compressed (perpendicular to the plane of distichy; FiGure 10n) or laterally (parallel to the plane of distichy; FiGure 4c); the base sometimes formed into a hard, often pointed and/or hairy callus (FiGuRE 3A3); sometimes viviparous (containing bulbils or bearing germinating seeds while still attached to the plant) or proliferating (1.e., converted into a leafless shoot, usually by growth of the lemmas); rarely subterranean. Spikelets borne in terminal or terminal and lateral secondary inflorescences of various kinds: panicles (FIGURES 4a: 10b, c), false panicles, cymes, racemes, rames (FIGURE 8a, k), and spikes (FiGuRE 6c) that mature either basipetally or acropetally and basipetally from the middle and that may or may not be associated with leaves or bladeless 126 JOURNAL OF THE ARNOLD ARBORETUM [voL. 66 sheaths. Glumes proximal on the rachilla (FiGuRE 4c), usually 2, equal (FIGURE 4d) or unequal (Ficures 5A1, 10f) in size and appearance, sometimes | (FIGURE 5D2) (then usually the upper) or absent, awned or unawned, O- to several- nerved, and subtending no axillary structures. Florets (Figures 3-11) maturing acropetally within a spikelet, made up of a bract (the lemma) subtending a flower and a bract (the palea) lying between the flower and the rachilla, 1-30 (-50) per spikelet; uppermost floret terminal or subterminal (with the rachilla therefore prolonged above it); base of florets sometimes formed into a hard, often hairy or pointed callus (FiGures 4e, k; 5J3; 7C2). Lemmas similar or dissimilar to the glumes in texture or appearance, indurate or membranaceous, Q- to several-nerved; awn(s) 0, 1, or more, apical or abaxial, straight or hy- groscopically sensitive and basally twisted and geniculate. Paleas with 2, in- frequently 0, 1, or more than 2, nerves, often hyaline, sometimes absent, rarely awned, usually smaller than and more or less enclosed by the lemma. Flowers (FiGures 41, 6h, 8h, 10h) small, perfect or imperfect (the plants then variously monoecious or dioecious), anemophilous, rarely entomophilous, mostly protandrous, greatly reduced relative to most other monocotyledons in the size and number of floral parts. Lodicules (the outermost floral parts) 2 and located adjacent to the lemma and opposite the palea, less often 3, rarely 1 [or more than 3], translucent, veined or veinless, glabrous or hairy, apically thick or thin, toothed, pointed or truncate, rarely adnate to palea. Stamens hypogynous, 6 in 2 whorls of 3 or, more commonly, only the 3 outer present, less often 1, 2, or 4 [to 30]; filaments slender, free or connate; anthers (FIGURES 4h, 6f, 81) 4-sporangiate, 2-locular at anthesis, appearing versatile, dehiscing extrorsely (or in the stamen between the lodicules, introrsely) by longitudinal slits or terminal pores; anther wall formation of the monocotyledonous type; [staminodes present]. Pollen (FiGurEs 6g, 8j) trinucleate when shed, mono- porate, operculate, more or less spheroidal-ovoid, (14—)20-55(—130) um in diameter, very ephemeral, the sexine granular. Gynoecium tricarpellate, syn- carpous. Styles 2, less often 1 or 3, terminal or rarely subterminal, free or connate; stigmas (FiGuREs 3C3; 4f, g, 1, l; 6e, h, i, k; 7A2, A3: 8a, c, h; 9A], AS, BS; 10e, h) dry, plumose, white or colored, free or connate. Ovary superior, unilocular, uniovular, smooth or hairy. Ovule anatropous, hemianatropous, campylotropous, or orthotropous, bitegmic, rarely the integuments | or none, pseudocrassinucellate or sometimes tenuinucellate; micropyle formed by the inner integument; megasporogenesis of the Polygonum (rarely Adoxa) type; antipodals proliferate (3). Fruit (FiGuRres 6n, 8m, 10) a single-seeded caryopsis (grain), in which the pericarp is adnate to the seed, or when the pericarp is free, an achene or utricle [or berry], often associated with parts of the floret or spikelet for dispersal; hilum punctiform to linear and more than '2 the length of the fruit; endosperm (FiGures 4m, 6m, 10k) present or absent, hard or milky, with or without lipids, its development nuclear; starch grains simple or compound. Embryogeny of the asterad type; embryo achlorophyllous, basal and lateral (Figures 4m, 6m, 10k), from 4, of the length of the seed to equal to it; radicle ensheathed by the coleorhiza; plumule ensheathed by the coleoptile; scutellum large, flat, adjacent to the endosperm, haustorial, its base free from (FiGuREs 8n, 101) or adnate to 1985] CAMPBELL, GRAMINEAE ey, (FiGuRE 4n) the coleorhiza; epiblast (a small, uonvascularized outgrowth op- posite the scutellum; FiGURE 4n) present or absent; vascular bundles to scu- tellum and coleoptile separated by an internode (the embryo mesocotyl; FiGURES 8n, 101) or not separated (FiGurRE 4n); plumule leaves with many to few vascular bundles, margins either overlapping (FiGuREsS 80, 10m) or not (FIGURE 40). Seedlings (FIGURE 8p—r) with adventitious roots present or absent at scutellar and coleoptilar nodes; first several leaves above coleoptilar node with or without a well-developed blade; first well-developed blades either broad and horizontal to ascending or more or less narrow and erect. Chromosomes mostly with median to submedian centromeres, the base numbers primarily 7,9, 10, and 12. (Including Agrostidaceae Burnett, Andropogonaceae Herter, Anomochloa- ceae Nakai, Arundinellaceae Herter, Avenaceae Burnett, Bambusaceae Burnett, Chloridaceae Herter, Eragrostidaceae Herter, Festucaceae Herter, Graminaceae Lindley, Hordeaceae Burnett, Lepturaceae Herter, Miliaceae Burnett, Oryza- ceae Burnett, Panicaceae Herter, Parianaceae Nakai, Phalaridaceae Burnett, Saccharaceae Burnett, Spartinaceae Burnett, Sporobolaceae Herter, Stipaceae Burnett, and Streptochaetaceae Nakai.) Type GeNus: Poa L References used in family description: Anton & Astegiano; Arber (1925, 1934); Avdulov; Barnard; Beetle (1980); Bor; W. V. Brown (1958a, 1977); W. V. Brown, Harris, & Graham; W. V. Brown & Johnson; Burns; Calderén & Soderstrom (1973); Cheadle (1955); Clayton (1970, 1978); Clifford & Watson; Cronquist; Davis; Ellis (1976, 1979); Evans; Gibbs; Gould & Shaw; Hackel (1890); Harborne & Williams; Hitchcock; Hubbard (1973a); Jacques-Félix (1962): Lipschitz & Waisel; McClure (1973); Metcalfe (1960); Monod de Froideville; J. S. Page; Pohl; Reeder (1957); Roshevits,; Row & Reeder; So- derstrom (1981la); Stapf; Stebbins (1982); Tulloch & Hoffman; Wagner; and Yakovlev & Zhukova A very natural family, the fourth largest in the flowering plants (about 600 genera and 10,000 species) and the foremost in ecological and economic im- portance. Species occur on all continents, in desert to freshwater and marine habitats, and at all but the highest elevations. Communities dominated by grasses (e.g., the North American prairie and plains, the South American pam- pas, the Eurasian steppes, and the African veld) account for about 24 percent of the earth’s vegetation (Schantz). The grassland communities of the south- eastern United States (e.g., the Pennyroyal area of Tennessee and the Black Belt of Alabama) occupy small areas, but grasses are major components of the flora, with 130 genera—about ten percent of the total number of angiosperm genera. A division of the family into two major groups (the pooids and the panicoids) based on the structure of the spikelet, the basic unit of the inflorescence, and dating from Robert Brown (1810, 1814), was used in most floras through the first half of this century. Evidence from leaf and embryo anatomy, from chro- mosome number and size, and from a remarkably broad series of morpholog- ical, anatomical, physiological, chemical, cytological, and phenological studies has subsequently led to the recognition by most workers of from five to eight subfamilies and as many as 60 tribes. All five of the subfamilies recognized 128 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 here (Bambusoideae, Arundinoideae, Pooideae, Chloridoideae, and Panicoi- deae) have indigenous members in the southeastern United States, and the 21 tribes that occur there include most of the major ones in the family. Difficulties with grass taxonomy at all levels stem from a number of features. First, the great reduction in size and complexity of reproductive parts has limited the use of characters that are taxonomically useful in many other families (Stebbins, 1982). Second, parallelism is believed to be frequent in the family (Arber, 1934; Hubbard, 1948; Prat, 1960; Stebbins & Crampton; Decker: Phipps; Guédés & Dupuy; Renvoize, 1981; Estes & Tyrl). Third, two common aspects of the breeding system of grasses—hybridization, with the attendant phenomena of polyploidy and apomixis, and inbreeding—have obscured taxo- nomic boundaries and made the biological species concept difficult to apply to many grasses. SYSTEMATICS, PAST AND PRESENT In his sexual system of classification, Linnaeus recognized 38 genera of grasses in six groups. His knowledge of the morphology of grasses was as limited as his sytematic treatment, for he was not clear about the nature of the “‘spicula”’ (his term for the spikelet; see Jacques-Félix (1972) for a multilingual etymology of the parts of grass spikelets and flowers). Robert Brown (1814) interpreted the spikelet as a modified inflorescence consisting of an “outer envelope or gluma’” (the latter term taken from Jussieu) and an “‘inner envelope” (the calyx of Jussieu, 1.e., the lemma and palea). He considered the “inner valve” (the palea) to be homologous with two fused members of the “‘proper envelope”’ (outer perianth whorl) and the “squamae”’ (lodicules) to be derived from the inner perianth whorl. He defined (1810, 1814) the Paniceae (the Panicoideae of modern authors), a mostly tropical group bearing spikelets with two florets, of which the lower is imperfect, and the Poaceae (the Pooideae), a group mostly of temperate climates, the spikelets of which contain one to many florets, with the imperfect florets, if present, not basal. This remarkably perceptive taxo- nomic insight is supported by a wealth of data (see below), and it orders suprageneric studies in the family even to the present. The gradual accumu- lation of taxonomic knowledge of the tribes and genera of the family through the efforts of Palisot de Beauvois, Trinius (1820, 1824), Dumortier, Kunth, and others culminated in the cosmopolitan treatments of Bentham, Bentham & Hooker, and Hackel (1887). These classifications include a dozen or more tribes in two subfamilies corresponding to Brown’s subdivisions. The classifications of Bentham & Hooker and of Hackel rely almost exclu- sively on gross morphology, especially that of the inflorescences. At about the same time many workers were uncovering systematically useful variation in leaf anatomy (Duval-Jouve, T. Holm, Pée-Laby), in embryology (Van Tie- ghem), and in the nature of starch grains in the endosperm (Harz). In spite of the patent taxonomic value of these works, they were largely ignored, perhaps because of major incongruities with morphological classifications. The work of Avdulov (1931) on the size and base numbers of chromosomes and that of Prat (1932, 1936) on the leaf epidermis emphasized the synthesis of morpho- logical and nonmorphological data in grass systematics. They initiated redef- 1985] CAMPBELL, GRAMINEAE 129 inition of the Pooideae by removing the chloridoid grasses. These had tradi- tionally been grouped with the pooids because of spikelet characters, but new characters clearly showed them to be much closer to panicoids. Each also established an additional major subdivision, Avdulov’s series Phragmitiformes and Prat’s Bambusoideae The subsequent search for new taxonomic data and the use of these in establishing subfamilial relationships have been highly productive. While vari- ation in some characters (e.g., pollen morphology (J. S. Page) and flavonoid chemistry (Harborne & Williams)) is small throughout the family, a diverse series of morphological, anatomical, physiological, chemical, cytological, and phenological features provides useful taxonomic information (see Reeder, 1957; Bor; Metcalfe, 1960; Prat, 1960; Tateoka, 1960; Stebbins & Crampton; Jacques- Félix, 1962; Auquier; Clifford & Watson; and Gould & Shaw for additional discussions of taxonomically useful variation). As a rule, this array of characters distinguishes not only the two extremes of the family, the panicoid and pooid groups, but also one or more of the other subfamilies recognized here. The contrasts given in the paragraphs that follow are intended to show the breadth of characters separating the panicoids and pooids in the restricted, modern sense. The wider taxonomic use of each of these characters, if one exists, will be detailed later. The pooids accumulate fructosans as the predominant reserve polysaccha- ride; panicoids accumulate starch (De Cugnac, D. Smith, 1968). Pooid cary- opses contain consistently higher levels of alanine, methionine, and phenyl- alanine than do those of panicoids (Yeoh & Watson). Taira also pointed out differences in amino-acid composition of the two groups. Fairbrothers & John- son and P. Smith demonstrated a clear serological distinction between pooid and panicoid grasses. In pooids the nucleoli do not persist beyond metaphase and do not appear to lie within a lumen during interphase, but in panicoids they do persist and are surrounded by a lumen (Avdulov; Brown & Emery, 1957). Vessels tend to be more specialized in pooids than in panicoids (Cheadle, 1960). Pooid shoot apices mostly have two tunica layers, and panicoids one layer (Brown, Heimsch, & Emery). Goller established differences between pooid and panicoid anatomy of the cortex and stele of the root. Pooid root hairs are directed toward the root apex and come from relatively small epidermal cells alternating with larger cells, while panicoid root hairs tend to emerge at right angles from uniformly sized cells (Row & Reeder). Hitch & Sharman noted several differences in the vascular patterns of pooid and panicoid axes. Pooids tend to have a definite sheath pulvinus and no culm pulvinus; panicoids usually bear a culm pulvinus but a poorly developed sheath pulvinus (Brown, Pratt, & Mobley; Ebinger & Carlen). Brown, Harris, & Graham found that pooid stem internodes are mostly hollow, panicoid internodes mostly solid. On the basis of the nature of the vascular-bundle sheaths, De Wet (1960a) and Auquier & Somers set up groups that correspond well to those based on leaf transverse-sectional anatomy es- tablished by Brown (1958a, 1977) and Carolin and colleagues (see below). The second and third leaves of seedlings are less differentiated in pooids than in panicoids when the shoot breaks through the coleoptile (Stebbins & Crampton). The absence of bicellular microhairs from the leaf epidermis of pooid grasses 130 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 separates them nom panicoids (Tateoka et al., Johnston & Watson, 1977). Pooids g d or crenate silica bodies and sunken stomata bordered by parallel- sided subsidiary cells, while in panicoids the epidermis bears cross- or dumbbell-shaped or nodular silica bodies, and the stomata are flush with the rest of the epidermal cells and have triangular subsidiary cells (Prat, 1936; Clifford & Watson; Watson & Johnston). Pooid guard cells tend to be semicircular in cross-sectional outline, and the mem- brane is absent or rudimentary, while panicoid guard cells are angular and have a well-developed membrane (Brown & Johnson). In addition to the spikelet differences upon which Robert Brown founded his two subdivisions, pooid spikelets tend to be compressed laterally, to dis- articulate above the glumes, and to have the rachilla extending above the uppermost floret. In contrast, panicoid spikelets tend to be compressed dorsally, to disarticulate below the glumes, and to have the rachilla ending at the up- ermost floret. They also tend to be viviparous less often than pooid spikelets (Beetle, 1980). Vasculature of the spikelets of the two groups differs (N. Chan- dra, 1962). In pooids the three or four nodes below the inflorescence do not bear branches, while in panicoids all but the uppermost node below the inflo- rescence bear branches or buds (Latting). The lemmas of pooids do not have germination flaps, while all panicoid lemmas studied so far have them (John- ston & Watson, 1981). Lodicules are thin, nonvascularized, and truncate in pooids and thick, heavily vascularized, and acute in panicoids (Decker; Ta- teoka, 1967; Jirasek & Jozifova). The diffusible pollen-wall antigens of pooids and panicoids are immunolog- ically distinguishable from each other (Wright & Clifford, Watson & Knox). Pooid ovules often have short outer integuments, no periclinal divisions in the nucellar epidermis, and laterally positioned antipodals. Long outer integu- ments, periclinal divisions, and chalazally positioned antipodals characterize panicoid ovules (N. Chandra, 1963). Numerous studies have shown that ga- metophytic apomixis in pooids is mostly (three out of four genera) diplosporous, and that the mature apomictic megagametophyte has the usual complement of nuclei. Apomictic panicoids are usually (18 out of 19 genera) aposporous, and their asexually derived megagametophytes contain only four nuclei (Brown & Emery, 1958; Reddy; Connor, 1979). Reeder (1957, 1962) used four characteristics of the mature embryo to sort grasses into six groups (see below), including a pooid and a panicoid group. Genera with liquid or soft endosperm are found only among pooid grasses (Terrell). Starch grains are mostly smooth walled and either simple or com- pound in the pooids, and angular walled and usually simple in the panicoids (Harz; Tateoka, 1962). The germination of pooid seeds is inhibited more by isopropyl carbamate and low oxygen tensions than is that of panicoid seeds (Al-Aish & Brown). Pooid seedlings have narrow and erect or ascending leaves and often produce transitionary node roots. Panicoid seedling leaves are broad and horizontal and do not have transitionary node roots (Avdulov, Kuwabara, Hoshikawa). Large chromosomes with a base number of seven characterize pooids, while small ones in multiples of nine or ten are found in panicoids (Avdulov; Tateoka, 1985] CAMPBELL, GRAMINEAE 131 1960). Different viruses and fungi attack pooid and panicoid hosts (Watson; Watson & Gibbs; Savile). Finally, Robert Brown’s early observation about the different geographic distributions in pooid and panicoid grasses has been sup- ported by more recent studies (Hartley, 1950; Clayton, 1975, 1981a; Cross). There are numerous exceptions to these differences between pooid and pan- icoid grasses. In addition, many characters define groups distinct from the pooids and panicoids and corresponding to other suprageneric taxa. Further- more, there is a strong congruence between the various groups established on the basis of these diverse characters. The most striking congruences come from leaf anatomy, embryo anatomy, and karyotypes. Some of the best evidence for relationships at the subfamilial and tribal levels in grasses is from leaf anatomy. The abaxial epidermis of the blade provides two excellent diagnostic features. First, bicellular microhairs are generally found in all subfamilies except the Pooideae (FiGure 1a), from which they are uni- formly absent (Tateoka et a/.; Johnston & Watson, 1977). Variation in the shape and wall thickness of the distal cell is useful in distinguishing the Chlo- ridoideae (FiGure 1d) from the Panicoideae (FiGure Ic). Second, the shape and distribution of silica bodies often characterize tribes or subfamilies (Prat, 1932, 1936; Metcalfe, 1960; Clifford & Watson; see APPENDIX, characters 52- 58). The shape of stomatal subsidiary cells is of secondary value. Light- and electron-microscope studies of the transverse-sectional anatomy of leaves (Duval-Jouve; Brown, 1958a, 1975, 1977; Carolin et al.; Johnson & Brown) have established two extremes in grasses. At one extreme 1s the presence of a well-developed mestome sheath (presumably with endodermal functions) around the vascular bundles; a parenchyma sheath (outside the mestome sheath) with chloroplasts similar to those of the surrounding mesophyll cells; and irregularly arranged chlorenchyma cells in the mesophyll. At the other extreme the mestome sheath is either present or absent, and there are specialized, thick- walled photosynthetic cells located in bundle sheaths or rarely in the mesophyll. The chloroplasts of these specialized sheath cells are radially or tangentially arranged and are larger and more numerous than the chloroplasts in the me- sophyll; there are many plasmodesmatal connections between the specialized cells and mesophyll; and the mesophyll cells are more or less radially arranged around the vascular bundles. The first extreme reflects the C, photosynthetic pathway and characterizes the Pooideae (FiGuRE 2b), the Bambusoideae (FIGURE 2a), most of the Arundinoideae, and 20 percent of the Panicoideae. The other extreme, known as the “‘kranz syndrome,” is associated with the C, pathway. It occurs uniformly in the Chloridoideae (FiGuRE 2c), in most Panicoideae (FiGurRE 2d), and in about 10 percent of the genera of the Arundinoideae. The best histological predictor of the photosynthetic pathway is the “one cell distant criterion” (Hattersley & Watson, 1975, 1976): in C, plants no chlorenchyma mesophyll cell is more than one cell away from the parenchyma sheath, while Kranz” is a German noun, meaning ring or wreath (W. V. Brown, 1977), and hence ec in German. In accounts in English, capitalization has been retained, as vouen of some i agneee ce. Since kranz is not a proper noun, lower case is used here to avoid possibl fi h the name of a per 132 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 SZ ac aS Nee. O,° ° 290 00g aes Sa Sena eee SERA: > — = Ss << 2 er, ——) Tee VR A ENCORE Cee eres SS = —— Oo ¢ =) O eWrees = ek —> a. S> S SH 3 cz Roy sO. oO SS = a oo rd ‘Can nds sae Ax Q@Leos Ficure |. Camera-lucida drawings of abaxial leaf epidermises (leaf apex toward top) prepared according to hot-acids method of Steward and observed with phase-contrast microscopy, all x 130. a, Elymus Hystrix (Hystrix patula; Pooideae, Triticeae): note straight cell walls of long cells, parallel-sided stomatal subsidiary cells, and prickle hair. b, Arundinaria gigantea (Bambusoideae, Arundinarieae): note narrow distal cell of bi- more or less saddle-shaped silica bodies, dome-shaped stomatal subsidiary cells, and large macrohair. c, Andropogon virginicus (Panicoideae, Andropogoneae): not distal cell of bicellular microhairs, sinuous cell walls of long cells, dumbbell-shaped to nodular silica bodies, more or less triangular stomatal subsidiary cells, and prickle hairs. d, Tridens flavus (Chloridoideae, Cynodonteae): note inflated distal cell of bicellular microhair, sinuous cell walls of long cells, dumbbell-shaped to nodular silica bodies alternating with cork cells, and more or less triangular stomatal subsidiary cells. 1985] CAMPBELL, GRAMINEAE 133 in C, plants some mesophyll cells are. All subfamilies, tribes, and genera (as circumscribed here) are uniformly either C, (non-kranz) or C, (kranz), except the Arundinoideae and Panicoideae (B. N. Smith & Brown; Brown, 1977; Renvoize, 1981), in which both pathways occur. The kranz pune: sheath | of some Cs grasses is derived from a mestome sheath (MS), and hl lly positioned and contain either no grana or only small ones 25 (Brown, 1977). “In species with this MS subtype of kranz anatomy, the four-carbon compound transported into kranz cells is decarboxylated by NADP-malic enzyme (NADP-me). The kranz sheath of other C, grasses is derived from the parenchyma sheath (PS), and the four- carbon compound in this PS subtype of kranz anatomy is decarboxylated by one of two enzymes: PEP-carboxykinase (PCK or PEP-ck) is associated with a centrifugal position of the kranz bundle-sheath chloroplasts, NAD-malic enzyme (NAD-me) witha centripetal position. The significance of the difference between the PCK and NAD-me kinds of the PS subtype of kranz anatomy is not understood. There is, however, a clear association between systematics and variation in kranz anatomy (see discussion under the C, taxa and character 67 of the APPENDIX). Plants with the C, pathway and those with the C, differ in numerous phys- iological ways: in the first intermediate into which atmospheric CO, is fixed, in carbon-isotope ratios, in light-saturation levels of photosynthesis, in tem- perature optima of photosynthesis, in photosynthetic translocation efficiency, and in CO, compensation point (Bj6rkman & Berry; Brown, 1977; Ehleringer; Waller & Lewis). The C, pathway provides a high concentration of CO, in the parenchyma sheath and thereby allows higher photosynthetic rates in habitats with high light intensities and temperatures and low soil moisture (McWilliam & Mison). Low temperatures during growth offset the advantages of the C, pathway. Finally, the physiological differences between C, and C, grasses are associated with different geographic distributions. In North America the great- est relative abundance of C, species is found where the minimum temperature during the growing season is highest (Teeri & Stowe). Other characters pertaining to transverse-sectional anatomy of the leaf have more or less unique states in certain subfamilies or tribes (Brown, 1958a; Clifford & Watson; also see below). Reeder’s (1957, 1962) embryological studies revealed four important char- acters, for each of which he determined two states, one found in the Panicoideae (designated ‘‘P”’) and the other in the Pooideae (designated “‘F”’ for Festucoi- deae, now a synonym of the Pooideae): presence (P) or absence (F) of an internode between the scutellar and coleoptilar nodes; presence (designated by a “+” and characteristic of the Pooideae) or absence (designated by a - the panicoid state) of a small flap, the epiblast, opposite the scutellar node; presence (P) or absence (F) of a cleft between the scutellum and the coleorhiza; and transverse section of the first embryonic leaf showing few vascular bundles and nonoverlapping margins (F) or many vascular bundles and overlapping margins (P). Hence the Pooideae are F + F F (Ficure 4n, 0) and the Pani- coideae P — P P (Ficures 8n, 0; 101, m). The five subfamilies in this paper have unique combinations of these four characters (see characters 38-41 in 134 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the APPENDIX). Five of the six embryological groups established by Reeder are the same as five of the six groups based on transverse leaf anatomy (Brown, 1958a; Carolin et al.). The distribution of Avdulov’s character states of chromosome size and base number divides the Gramineae into his three major subfamilial groups. His Sacchariferae have small chromosomes with base numbers of nine or ten. This group is basically the kranz subfamilies Panicoideae and Chloridoideae. His Poatae contain two “series”: Festuciformes, with large chromosomes and base number usually seven, equivalent to the Pooideae; and Phragmitiformes, with small chromosomes in multiples of twelve, including the balance of the family. While the works of Avdulov and Prat released grass systematics from the two-subfamily system, those of Reeder (1957, 1962) and Brown (1958a, 1977) have tended to stabilize formal classifications at five to eight subfamilies (Ta- teoka, 1957a; Prat, 1960; Parodi; Stebbins & Crampton; Clayton, 1978; Ren- voize, 1981; Hilu & Wright; Gould & Shaw). Some agrostologists (Jacques- Félix, 1962; Clifford & Goodall; Hubbard, 1973b; Clifford & Watson), however, appreciating the taxonomic uncertainties at the highest subfamily levels, em- ploy many more informal groupings. The subfamilial classification used here consists of the Bambusoideae, Arun- dinoideae, Pooideae, Chloridoideae, and Panicoideae. Subfamily Bambusoi- deae is broadly conceived as encompassing the woody bamboos, the so-called herbaceous bambusoid grasses (e.g., the Phareae) (Tateoka, 1957a; Parodi; Clayton, 1978; Soderstrom & Calderon, 1979a; Renvoize, 1981; Hilu & Wright), and the oryzoid grasses (Jacques-Félix, 1955, 1962; Tateoka, 1957a; Clayton, 198la; Renvoize, 1981). Since its conception as Avdulov’s Phragmitiformes, subfam. Arundinoideae has encompassed a diverse assemblage of grasses united, not by the presence of specialized features, but by a general lack of specializa- tion. As such, it presents both the greatest subfamilial taxonomic problem and the greatest potential source of insights regarding relationships at this level. Renvoize’s (1981) concept of this subfamily, followed here, includes the Cen- totheceae (the Centothecoideae of Soderstrom (1981b)), the Aristideae, and the core tribe Arundineae, as well as other tribes not occurring in the southeastern United States. Subfamily Pooideae, a heterogeneous group even after the trans- fer of C, grasses to the Chloridoideae, has become more sharply defined by the removal of three traditionally pooid tribes, the Brachyelytreae, Diarrheneae, and Stipeae, by Macfarlane & Watson (1980, 1982). These three tribes do not fit well into any of the five subfamilies and are therefore treated here as un- placed. The composition of the Chloridoideae is similar to that of most systems of the past 30 years, but the tribal limits are broader here. The only major systematic question is the placement of tribe Aristideae. Some (Pilger; Parodi; Clayton, 1978; Hilu & Wright; Gould & Shaw) consider it to be chloridoid, but its closeness to Danthonia DC. and its relatives (Brown, 1977) argues for including it in the Arundinoideae, as Reeder (1957), Tateoka (1957a), Prat (1960), Stebbins & Crampton, Jacques-Félix (1962), and Renvoize (1981) did. Robert Brown’s (1810, 1814) delimitation of the Panicoideae (as the Paniceae) persists with minor changes to the present. The works of Butzin and of Clayton (1981c; in prep.) are important sources for answers to nomenclatural questions at the suprageneric level. oR OSA: SS @ at PRe ees ; S Qiee’s 2 @@ mean hear 4 Oy Ad SRR IO tt Sa a @' : isbearstnseiis €OOa Cd; FiGure 2. Drawings of portions of transverse sections of leaves. a, Arundinaria variegata (Bambusoideae, Arundinarieae; after Metcalfe (1960), fig. XVIII, no. 3): note numerous cells separating veins, indicating C, photosynthesis; large, elongated fusoid cells and arm or ratchet cells with invaginated cell walls; and sclerenchyma associated with vascular bundles. b, Phalaris tuberosa (Pooideae, Agrostideae; after Barnard, fig. 4.22): note numerous cells separating veins, indicating C, photosynthesis; 2 bundle sheaths; bulliform cells in upper epidermis; and stomata in both upper and lower epidermis. c, Tragus racemosus (Chloridoideae, Zoysieae; after Jacques-Félix (1962), fig. 153B): note short interveinal distance indicative of C, photosynthesis, large parenchyma sheath cells, bulliform cells, and thickened cuticle. d, 4 ndropogon Gerardii (Pani- coideae, Andropogoneae; after Barnard, fig. 4.2/): note short interveinal distance indicative of C, photosynthesis, 2 bundle sheaths, sclerenchyma associated with vascular bundles, bulliform cells in upper epidermis, and stomata confined to lower epidermis. oh} as i; r- A Oa te ss AVANINVUYD “TIAddNVO [S861 Sel 136 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 PHYLOGENETIC RELATIONSHIPS The presence of numerous unique features makes the family Gramineae readily distinguishable from all other monocotyledons. Only two of its genera, Anomochloa Brongn. and Ochlandra Thw., are questionably graminaceous (Arber, 1934; Hubbard, 1948; Clifford, 1961). The distinctive bicellular mi- crohairs of grasses may be derived from the multicellular hairs found in many monocotyledons (Stebbins, 1982). The complex development of the inflores- cence characteristic of many grasses is not known outside the family (Stebbins, 1972), nor are structures strictly equivalent to the grass spikelet and its glumes, lemmas, and paleas. The anatomy of the grass stigma is unique (Y. Heslop- Harrison & Shivanna). Grasses are exceptional in having both gametophytic self-incompatibility and tricellular pollen (J. Heslop-Harrison). Finally, the coleoptile, epiblast, coleorhiza, and scutellar and coleoptilar nodes are peculiar to the grass embryo. Questions about the homologies of these unique features are still not fully answered. Most agrostologists agree that grass perianths are derived from a trimerous, biseriate state but disagree about what has happened to the perianth in the evolution of the grass flower. Hackel (1881) thought that the palea was a modified prophyll because of its position and two nerves. Holttum, Bor, Hub- bard (1973a), Clifford & Watson, Clayton (1978), Soderstrom (1981la), and many others also take this view, but Bourreill (1969) regarded the palea as homologous with a leaf sheath. A sepaloid origin of the palea was first hy- pothesized by Robert Brown (1814) and was supported by Bentham, Schuster, Stebbins (1972, 1982), and Cronquist. Virginia Page studied the unusual spike- lets of the bambusoid genus Streptochaeta Schrader, which has two large, basally fused “‘palea bracts” (her term designating the position of the structures and not necessarily their equivalence to the palea of other grasses). Although she confirmed earlier reports of the separateness of the two palea bracts and the presence of a primordium of a third bract in the same whorl, she neither verified nor falsified the sepaloid homology of the palea. She suggested that the palea bracts of Streptochaeta might instead be sterile bracts or lemmas, a view also taken by Soderstrom (1981la). Hackel (1881) apparently thought the perianth to be totally absent from grass flowers, for he saw the position of the lodicules (between the lemma and the androecium in grasses with two lodicules) as evidence of their being two halves of a bract that continues the distichy of the spikelet. Arber (1934) pointed out that lodicules surely must be modified perianth parts because intermediates between stamens and lodicules can be found. According to Guédés & Dupuy, the fundamentally peltate nature of the lodicules confirms their petaloid origin. With respect to the embryo, the nature of the scutellum is involved in interpretations of other parts. Brown (1960a), who also reviewed the extensive literature on homologies of the parts of the grass embryo, postulated that neither the scutellum nor the coleoptile is foliar because they do not arise from the shoot apex. He considered them to be parts of the cotyledon separated by an intercalated meristem, the mesocotyl. Cocucci & Astegiano suggested that the scutellum, coleoptile, and epiblast are lamina, ligule, and sheath, respectively, 1985] CAMPBELL, GRAMINEAE 137 of the foliar cotyledon. Shah & Sreekumari proposed that the scutellum, the coleoptile, and even the coleorhiza are parts of the cotyledon. The prevailing view holds that the scutellum and coleoptile are homologous with the cotyledon and first leaf of the shoot, respectively (Reeder, 1953, 1956; Guignard; Negbi & Koller; Guignard & Maestre). The formation of typical leaf hairs and chlo- rophyll in these structures supports this interpretation (Norstog). Because of the position of the epiblast opposite the scutellum, some (e.g., Negbi & Koller; see also Brown, 1960a) have seen it as a much-reduced second cotyledon. However, that the epiblast is actually an outgrowth of the coleorhiza is widely supported by observation (Brown, 1960a; Guignard; Soderstrom, 1981a) and experimentation (Foard & Haber). Apparently it 1s never vascularized (Reeder, pers. comm.). The predominant view of the coleorhiza is that it is homologous with the primary root or at least with the outer covering of the primary root (Guignard; Negbi & Koller; Guignard & Maestre). In view of these specialized features, it is not surprising that the Gramineae are separated from other families by a large gap and that, as a result, their systematic relationships are poorly understood. The families most frequently considered as close relatives are the Cyperaceae, the Flagellariaceae, and the Palmae (Clifford, 1970; Dahlgren & Clifford). The resemblance in overall ap- pearance and spikelet morphology of the Gramineae and the Cyperaceae has led to their union in various suprafamilial taxa. The two also have silica bodies in the leaf epidermis (Metcalfe, 1960, 1971), similar flavonoid patterns (Har- borne & Williams), similar micropyles and ovules (Maze et a/.), and nuclear endosperm formation (Dahlgren & Rasmussen). They are the only monocot- yledonous families with C, species (Waller & Lewis). These similarities are, however, only superficial and may well represent parallel evolution (Metcalfe, 1971; Clayton, 1978). Many fundamental differences separate the two families. The bracts of the sedge spikelet are more often spirally than distichously ar- ranged, and the similarity between sedge and grass spikelets is not close (Steb- bins, 1982). Sedges also have differently shaped silica bodies (Metcalfe, 1971), pollen grains with more than one aperture (S. Chandra & Ghosh), simultaneous rather than successive microsporogenesis (Dahlgren & Rasmussen), embryos embedded in endosperm, several embryological features unlike those of grasses (Guignard; Clifford, 1970; Maze et al; Maze & Bohm, 1973), lateral rather than terminal flowers, and diffuse centromeres. The Cyperaceae appear actually to lie closer to the Juncaceae (Takhtajan; Soo; Metcalfe, 1971; Stebbins, 1982; Dahlgren & Rasmussen), and the grasses share more features with the Flagel- lariaceae or the Joinvilleaceae, a segregate of the Flagellariaceae (Tomlinson & Smith). The Gramineae and Joinvilleaceae have both long and short epi- dermal cells that often have sinuous walls, similar stomata (Smithson), ulcerate pollen (S. Chandra & Ghosh), and some similar vegetative character states (Dahlgren & Clifford). Nevertheless, beyond its ties with this monogeneric family of Southeast Asia and the South Pacific, the Gramineae remain isolated. By using the Joinvilleaceae (sensu stricto) or the monocotyledons in general as outgroups, it is possible to establish some evolutionary trends within char- acters of grasses and thereby some notions of evolution within the family. Stebbins (1982) used this outgroup criterion and four others to polarize the 138 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 states of 36 anatomical and morphological characters and two karyotype char- acters. Some of these characters—for example, habit (perennial vs. annual), ligule morphology, presence or absence of rhizomes, and several inflorescence characters—are not very useful taxonomically at the subfamilial and tribal levels and hence cannot help in phylogenetic hypothesis formation. The lack of knowledge about homologous structures for an outgroup makes polarization uncertain in seedling morphology (but see Hoshikawa’s postulated trends), several inflorescence characters, and embryo anatomy. The use of starch grains (Stebbins, 1982) and karyotypes (Avdulov; Tsvelev; Brown & Smith, 1972; Mehra et al.; Sharma; Stebbins, 1982) is limited by lack of information about the outgroup character state. These qualifications leave leaf anatomy and floral morphology as useful. The contention that the presence of microhairs in the leaf epidermis 1s prim- itive rests on their homology with the multicellular hairs of Joinvillea Gau- dichaud and other monocots (see also Prat, 1936). There seems to be little doubt that the anatomical and physiological adaptations of the kranz syndrome are derived from the non-kranz conditions; Brown (1977) pointed out that there is no good evidence for reversals from C, to C;. Among kranz grasses, long parenchyma-sheath cells are considered primitive and short ones derived (Brown, 1974). If it is assumed that grasses arose from ancestors with char- acteristically trimerous monocotyledonous flowers, it is safe to define as prim- itive in grasses perfect flowers with three highly vascularized lodicules, six stamens, and three styles. Hubbard (1948), Dedecca, Auquier, Sharma, and Ghorai & Sharma also called these floral states ancestral. On the basis of these assertions about character-state evolution, the subfamily Bambusoideae, which has the greatest number of primitive floral character states among the subfamilies, is usually thought of as containing the most primitive extant grasses (Bews; Prat, 1936; Beetle, 1955; Stebbins, 1956b; Tateoka, 1957a; De Wet, 1958; Clayton, 1975, 1981a; Soderstrom & Calderén, 1979a). Floral evolution involves reduction in the number of each of these floral parts. The prominence of these floral reductions perhaps prompted Brown and colleagues (1957) to generalize that specialization in grasses means reduc- tion. The absence of microhairs from the Pooideae and the kranz syndrome of the Chloridoideae and Panicoideae mark them as more advanced than the remaining subfamilies. ORIGIN AND GEOGRAPHIC DISTRIBUTIONS There is really no clear evidence for a place of origin of grasses. Some specialists (Bews; Stebbins, 1972; Clayton, 1975, 198la) have suggested that they originated in tropical forests or at their margins. From these forest dwellers, an early offshoot similar to the Arundinoideae (Brown & Smith, 1972; Clayton, 1975, 1981la; Renvoize, 1981) extended into savannas and gave rise to—and was partially replaced by—the photosynthetically more efficient kranz subfam- ilies in the tropics and the pooids in a Nore Temperate Zone. The pooids migrated successfully along th America following the joining of North and South America in the Pliocene. An alternate hypothesis (Tsvelev) 1985] CAMPBELL, GRAMINEAE 139 calls for pooid-like prototypes bearing bambusoid flowers and originating in high mountains, with later movement to plains and temperate regions. This view finds some supporting evidence in the primitive nature of leaf and stem anatomy of pooids (Brown, 1958a; Auquier & Somers). The meager fossil remains of grasses do little to resolve questions of the geologic age of the family, its relationships with other monocots, and evolution within the family. The oldest records of grass pollen are from the Paleocene (doubtful records from the Cretaceous) and, in North America, the uppermost Eocene (Muller). The first abundant grass pollen comes from Miocene deposits in Kansas and Nebraska. Caryopses of four species from England and oryzoid leaves from Germany, all from the Eocene, are among the first megafossil remains (Daghlian; Stebbins, 1981). Isolated florets (in which the flowers are not preserved) of the Stipeae and Paniceae from the Miocene in Kansas, and of the Oryzeae from the Miocene in Nebraska, provide the first extensive grass megafossils (Thomasson). The Miocene upsurge in grasses likely stems from their symbiotic relationship with the then newly evolved groups of grass-eating ungulates (Clayton, 1981la; Stebbins, 1981; De Wet, 1981). Present distribution, in conjunction with past continental plate movement, can be used to infer the age of suprageneric grass taxa. Clayton (1975, 198 1a) and Brown & Smith (1972) postulated that the subfamilies, tribes, and even some subtribes evolved by the end of the Cretaceous or the first half of the Tertiary before the continents were sufficiently separated to prevent dispersal between them. As a consequence, the continents now contain a full array of suprageneric taxa. The differentiation of many modern genera, however, fol- lowed the movement of continental plates beyond the dispersal range of most grasses, so that two-thirds of modern grass genera occur on single continents (Clayton, 1975, 198 1a). The subfamilies and larger tribes occupy all the world’s tropical to temperate regions. Only the subfamily Pooideae has taken extensively to colder climates. Clayton (1975) recognized seven basic centers of distribution of grass genera (excluding those with worldwide ranges): Eurasia, North America, temperate South America, tropical America, Africa, India—-Southeast Asia, and Australia. North America shares genera with only Eurasia (24 genera), temperate South America (ten), and Australia (one). Several disjunct distributions involve grass genera of the southeastern United States. Five genera—Arundinaria, Brachy- elytrum, Diarrhena, Schizachne, and Torreyochloa (Puccinellia)—are found there, elsewhere in North America, and also in China or Japan (Koyama & Kawano). Gymnopogon, Muhlenbergia, and Zizania show a New World-In- dian disjunction (Clayton, 1975). Temperature and rainfall strongly influence geographic distribution (Hartley, 1950, 1958a, 1958b, 1964, 1973; Hartley & Slater; Cross). These factors are discussed under the individual subfamilies and tribes. Native grasslands develop where there are periodic droughts, level to gently rolling topography, frequent fires, and in some instances grazing and certain soil conditions (R. C. Anderson). Drought, fire, and grazing prevent invasion by woody plants, and the latter two may actually stimulate grassland produc- tivity. Several factors may account for the competitive advantage of grasses in 140 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the presence of fire and grazing: basal tillering; intercalary meristems at the base of the internodes, sheaths, and blades; short internodes of nonflowering stems; and caespitose habit. The general success of grasses may be further attributed to the protection of flower and fruit within the spikelet and to the great diversity of habit, photosynthetic pathways, breeding systems, and dis- persal mechanisms. REPRODUCTIVE BIOLOGY The vagility of the fruits has promoted the ubiquity and ecological hegemony of grasses. Caryopses rarely leave the parent plant free from the spikelet or one or more of its parts, for these parts are multifariously adapted for dispersal by animals, wind, or water (Roshevits; Monod de Froideville; Hubbard, 1973a; Van der Pijl). Spiny involucres (as in Cenchrus), barbs, bristles, teeth, gluelike glandular secretions, hairs, awns, and awnlike glumes and lemmas catch on animal hair or even, in the case of the awns of some Triticeae, penetrate the skin around the mouth of herbivores (Stebbins, 1972). Many grasses bear fruits specially adapted to attract herbivores, which can then disperse the seeds. Some species have elaiosomes, encouraging ant dispersal (Monod de Froideville). Some bamboos produce fleshy berries, and the hard lemmas of some oryzoids are thought to have evolved as a protection from digestive enzymes (Stebbins, 1972). Wind dispersal depends upon winglike developments on spikelet parts or, more commonly, plumes on various spikelet or secondary-inflorescence parts. All or part of the inflorescence may break free from the plant and disperse by tumbling (Roshevits; Rabinowitz & Rapp). Grasses have at least two pre- sumed adaptations for self-sowing of the dispersal unit. Hygroscopically sen- sitive awns may force the dispersal unit into the soil (Clayton, 1969; Stebbins, 1972; Clifford & Watson). Spikelet and floret calluses may serve the same purpose, sometimes operating together with awns (Hackel, 1890; Jain & Pal). Grass flowers have obvious characteristics for wind pollination: reduced perianth (the lodicules), small and smooth pollen grains, high pollen-ovule ratio, and feathery stigmas. Pollination by pollen-collecting insects is infre- quently of secondary importance (see Adams ef a/. and references therein), and itis primary only in certain herbaceous bambusoid grasses of relatively windless forests (Soderstrom & Calderén, 1971). Adaptations associated with animal pollination—large pollen (Adams ef a/.), numerous closely placed, bright-yel- low anthers (Soderstrom & Calderon, 1971), and perhaps the striking sexine pattern of the insect-pollinated Pariana Aublet (J. S. Page)—are found in these partially or entirely entomophilous grasses. Anthesis in grasses 1s of short duration (usually minutes), and in many species it regularly occurs at a certain time of day or night (Jones & Brown, Evans). The critical events of grass anthesis are the rapid swelling of the lodicules, which forces open the florets, the rapid extension growth of the staminal fila- ments, and the spreading of the stigmatic branches. Grass pollen is viable for less than five minutes in some species, and for up to 24 hours in others. Gregarious flowering of numerous genera of woody bamboos at sometimes very long intervals is an astounding phenomenon that 1s very rare in angio- 1985] CAMPBELL, GRAMINEAE 14] sperms (Soderstrom & Calderén, 1979a). Frequent protandry and rare pro- togyny (Hackel, 1890; Stapf; Monod de Froideville) promote outcrossing. A two-locus, multi-allelic control of self-incompatibility has been demonstrated in numerous grasses (J. Heslop-Harrison). On the other hand, self-compatibility and self-fertilization through cleistogamy mmon in grasses (East; Connor, 1979, 1981). In the majority of cases of cleistogamy in grasses, two conditions prevail: leaf sheaths or bracts confine the spikelets so that the lodicules cannot open the spikelet for chasmogamy, and the pollen-ovule ratio of cleistogamous flowers is lower than that of chasmogamous flowers of the same individual or species (Hackel, 1906; Campbell et a/., 1983). Knobloch listed over 2400 hybrids in grasses. Hybridization is often asso- ciated with polyploidy, the doubling of chromosomes in a sterile hybrid re- storing chromosome pairing and fertility. Of the 4000 grass species for which chromosome counts have been made, 2200 show a multiple of the base number of the genus (Goldblatt). If the uncounted species of obviously polyploid genera are included, this estimate jumps from 55 to 64 percent. Hybridization and polyploidy have undoubtedly played significant roles in grass evolution (for examples, see Myers; Stebbins, 1956b, 1975; McWilliam; Dewey; Waines et al.). Apomixis, usually arising following hybridization or polyploidization or both, has been demonstrated in 33 grass genera (Connor, 1979). Most apomictic grasses are pseudogamous. The genus Poa contains aposporous, diplosporous, pseudogamous, and nonpseudogamous biotypes (Nygren). As judged by the frequency of cleistogamy (reported from 82 genera from a broad tribal spectrum by Campbell et a/., 1983) and the more extensive oc- currence of self-compatibility (East), inbreeding is common in grasses. Like apomixis, inbreeding generates populational phenomena that pose major sys- tematic problems. Inbreeding has also apparently been an important factor in the colonizing success of many weeds (Allard). ECONOMIC IMPORTANCE The economic importance of grasses lies in their paramount role as food: 70 percent of the world’s farmland is planted in crop grasses, and over 50 percent of the world’s calories come from grasses (Heiser). Man has cultivated the cereals for 10,000 years (De Wet, 1981). From the beginning of their domes- tication, wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), and oats (Avena sativa L.) in the Near East, sorghum (Sorghum bicolor (L.) Moench) and pearl millet (Pennisetum americanum (L.) K. Schum.) in Africa, rice (Oryza sativa L.) in southeastern Asia, and maize (Zea Mays L.) in Meso-America have made possible the rise of civilizations. In terms of world production today, the first four crops are grasses: sugar cane (Saccharum officinarum L.), wheat, rice, and maize. Barley is seventh and sorghum eleventh. For an extensive review of the cultivation, breeding, and history of major grass crops, the reader is referred to volumes on sugar cane (Artschwager & Brandes), wheat (Quis- enberry), rice (Grist), maize (Sprague), barley (Briggs), and sorghum (Hulse e¢ aL). 142 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Grasses are also used for livestock feed, erosion control, and turf production and as a sugar source for the fermentation of many alcoholic beverages. Bam- boos are an integral part of the economies of many tropical areas since they contribute young shoots for food, fiber for paper, pulp for rayon, strong stems for construction, and various items for numerous other uses (Soderstrom & Calderon, 1979a). In the southeastern United States the forage crop—ruminant livestock industry yields 40 percent as much in total sales as all row crops and close-grown field crops (Mays). Sugar cane, rice, maize, and sorghum are also grown commercially in this area. The spread of civilization, commercial trade between the continents, and man’s great nutritional dependence upon grasses have produced important often weedy, adventive grass floras throughout the world (Hartley, 1964; De Wet, 1981). Species belonging to some 80 genera are cultivated as ornamentals in the United States (Bailey ef a/.). KEY TO THE SUBFAMILIES AND TRIBES OF GRASSES IN THE SOUTHEASTERN UNITED STATES General characters: Annual or perennial herbs, rarely shrubs, roots fibrous; leaves dis- tichous, made up of sheath, ligule, and usually linear blade; leaf epidermis dominated by long cells and short cells, the latter often modified into hooks, prickles, or bicellular microhairs, or containing cork or variously shaped silica bodies; transverse-sectional anatomy of leaves either kranz and characterized by specialized bundle sheaths with large chloroplasts or non-kranz,; primary inflorescence a spikelet consisting of an axis (the rachilla) and 3 kinds of distichously arranged bracts—glumes (basal, usually 2), lemmas, and paleas; secondary inflorescence paniculate, cymose, racemose, or spicate; florets 1- 30 per spikelet and comprising a lemma subtending a flower and a the lower and the rachilla; flowers perfect or imperfect, “anemophilous; the outermost floral parts, the lodicules, 2 (rarely 3), fleshy; stamens 3, someti) ee : or 6; ovary superior, unilocular and uniovular, stigmas 2 or 3 (1); fruit a caryops 258 Often achene or utricle; ae basal and lateral, with a large cotyledon, the eee series usually abundar A. Plants with C, photosynthesis and non-kranz leaf anatomy (2 or more mesophyll cells separating adjacent vascular bundles, chloroplasts uniform and all starch form- ing); hilum usually linear; embryos small, less than '4 the length of the caryopsis; Ape subsidiary cells mostly pareilel sided or dome shaped and fusoid cells usually present cary 2a) (fusoid cells absent in some ae); stamens often more than 3; s eae usually 3 (2 in Oryzeae); first ere leaf without a blade, except in Phareae. .......................00.. ea ipa Gale Agee Go bine ts anal wae ee ea ” subfamn. 1. BAMBUSOIDEAE. C. Stems woody; leaf blades disarticulating; fertile florets 6-12 per spikelet; glumes usually 2 per spikelet; flowers perfect; scutellar tail present Veep Fark deie pare oe oh Gt A ee ee es ribe la. ApucINARIERS C. Stems herbaceous; leaf blades not disarticulating; fertile floret 1 per spikelet: glumes usually absent (rarely | or 2 and vestigial); flowers often imperfect (plants monoecious); scutellar tail rarely present. D. Transverse veins absent in leaf blades; spikelets solitary; stigmas 2; first seedling leaf without a blade; microhairs aa silica bodies oryzoid; vascular bundles in stem internodes in | or 2 rings. biatch steht mgt dreaeies edge ttaa tok jodedtemt tora gets ape vos Bese Tribe 1b. OrRYZEAE. . Transverse veins present in leaf blades; spikelets paired; stigmas 3; first e) 1985] CAMPBELL, GRAMINEAE 143 seedling leaf with a blade; microhairs absent; silica bodies cross to dumb- bell shaped to nodular; vascular bundles in stem internodes scattered. . eee epee ae ee Shea ae eee Tribe Ic. PHAREAE. B. Arm and fusoid cells absent (FiGuRE 2b-d) (arm cells present in some Arundi- neae); stamens 3 or fewer; sti igmas 2; first seedling leaf with a blade. E. Scutellar tail absent (present in reece embryo mesocotyl short; mi- Sa =i (present i in some Stip . Rachilla no permost floret; lodicules 2 or 3; microhairs sometimes oe “silica ce saddle shaped and crescentic. ......... deradiraict le toes inentecels Beis detach ota yeh ie este wae tare tian eee tem Tribe 6c. STIPEAE. F. Rachilla prolonged above uppermost floret; lodicules generally 2; micro- hairs absent; silica bodies elongated, sinuous or crenate (absent from Brachyelytreae). G. Embryonic leaf margins overlapping; silica bodies cross to dumbbell shaped to nodular. H. Floret 1 per spikelet; lemmas awned, equally as firm as the glumes; lodicules eabrous, ey apex hairy; pericarp adnate to seed; aaa dosperm soft, th bodies not elongated, sinuous or crenate: sclerenchyma accom- panying the smallest vascular bundles absent; base chromosome number 11. .................00.. Tribe 6a, BRACHYELYTREAE. H. Florets 2-5 (rarely 1) per spikelet; lemmas awnless, firmer than the glumes; lodicules hairy; ovary apex glabrous; pericarp free from the seed; endosperm hard, at least some of the starch grains com- pound; epidermis not papillate; silica bodies elongated, sinuous or crenate; sclerenchyma accompanying at least some of the smallest vascular bundles present; base chromoso pe number 10. ....... Be Pas a oes ep ne aoe ribe 6b. DIARRHENEAE. G. Embryonic leaf margins not overlapping; cross- to ae silica bodies absent, tall and narrow silica bodies present. ......... satan haondatNtien iis ce AB alee hah nd ea neal et Subfam. 3. POOIDE EAE, I. Leafauricles often present; ovary apex hairy; epiblast absent (present in some Triticeae); starch grains eae seedling transitionary node roots present (supertribe Triticana J. Inflorescence a panicle (rarely a es lodicules glabrous; ovary appendage present; caryopsis compressed laterally. .......... Sigetae sie tare Gee aioe Coane ig es eee Ges ribe 3e. BROMEAE. J. Inflorescence a solitary spike (rarely with spiciform branches); lodicules hairy (rarely glabrous); ovary appendage absent; cary- opsis usually compressed dorsiventrally. .................... I. Leaf auricles absent; apex glabrous (hairy in some Aveneae); epiblast present; at least some starch grains compound (rarely all simple in some Agrostideae); seedling transitionary node roots ab- sent (supertribe Poanae). K. Lodicules often truncate, connate, distally fleshy and palpably vascularized; base chromosome number 9 or 10. ........... Stasis CM ae ote ee tas Baste ee eas Tribe 3c. MELICEAE. K. Lodicules acute, free, distally seine nace and without ev- ident veins; base chromosome number mostly L. Crescentic silica bodies present; nance folded (rarely cnet ain hee nese eee co Se esse te ribe 3d. PoEAE. L. Crescentic silica bodies absent; vernation rolled (rarely fold- ed). 144 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 M. Florets usually | per spikelet; ovary sae glabrous (rarely hairy); hilum punctiform (rarely linear). ............. Pe ed hate ak oe eee eee Tribe ns AGROSTIDEAE. M. Florets usually more than | per spikelet; ovary apex mostly hairy (rarely glabrous); hilum linear. ......... Uh eaten Gade ats enacts pane ees Tr me a AVENEAE. E. Scutellar tail present; embryo mesocotyl long; microhairs pres N. Spikelets usually dorsally compressed, disarticulating below the glumes, with | caryopsis-l gins overlapping (rarely not); base chromosome number Benerally. 9 Ord, x: 20ticteraeccaagyn fila ea en aaa eae ed ee Tribe 5b. PANICEAE. N. eas laterally Bai ty or not compressed, disarticulating above e glumes, with more than | caryopsis-bearing aie embryonic leaf ae not Ne ee base chromosome number 12. .............. getig Hssih toaesh as ean Satneehe dete deed cet eh pee pees Subfam. 2. ee O. Rachilla prolonged above uppermost floret; hilum punctiform (rarely linear); epiblast absent; first seedling leaf curved; bulliform cell groups absent. 20.0.0... 00 eee ribe 2b. ARUNDINEAE. O. Rachilla not prolonged above uppermost floret; hilum linear; epiblast present; first seedling leaf supine; bulliform cell uae present. .... See ieee ative we oat eal ass Moe ae ae Tribe 2c, CENTOTHECEAE. A. Plants with C, photosynthesis and kranz leaf anatomy (no more ae | mesophyll cell separating adjacent vascular bundles, bundle sheaths starch forming); hilum mostly punctiform; embryos mostly large, more than '4 the length of the caryopsis; stomatal subsidiary cells dome shaped or triangular. P. Stomatal subsidiary cells dome shaped. ..... Subfam. 2. ARUNDINOIDEAE. Q. Floret 1 per spikelet; lemmas firmer than glumes; kranz bundle-sheaths 2; base chromos osome nun mer Vole ag eee Peas eae ae ibe 2a. ARISTIDEAE. 1; base chromosome aie 12. 000., Tribe 2b. unDTNEKE (Neyraudia). P. Stomatal subsidiary cells triangular. R. Spikelets compressed dorsally; staminate or neuter floret proximal to the lowermost carpel-bearing floret; epiblast absent; embryonic leaf margins over- lapping; microhair distal cell narrow; tall and narrow silica bodies and saddle- shaped silica bodies absent (rarely present); parenchyma sheath cells elongate, their chloroplasts centrifugally positioned and containing either small grana or none; sclerenchyma accompanying the smallest vascular bundles absent. EAeo ahaa culate ated Ga eture: os dg ees Subfam. 5. PANICOIDEAE. S. Glumes firmer than lemmas, the first glume longer than the spikelet; lemma Tr nerves usually 3 or fewer. ................ ibe 5a. ANDROPOGONEAE. S. Glumes softer than lemmas, the first glume usually much shorter than the spikelet; lemma nerves usually 3 or more. ......... Tribe 5b. PANICEAE. R. Spikelets eouieiescct cane (rarely dorsally) or not compressed; staminate or neuter florets usually distal to the lowermost carpel-bearing floret; epiblast present (rarely absent); embryonic leaf margins rarely overlapping; microhair distal cell inflated; tall and narrow silica bodies and saddle-shaped silica bodies present (rarely absent); parenchyma sheath cells short, their chloroplasts cen- tripetally positioned and saa ci grana; sclerenchyma accompanying the smallest hbo bundles pres .... Subfa 1 4. CHLORIDOIDEAE. T. Lemma nerves 7-11; silica aie cross to d Il shaped; colorless cells oe the leaf absent ee de nase eh eg eee ees Tribe 4c. UNIOLEAE. Lemma nerves 7 or (wel, silica bodies saddle shaped; colorless cells traversing the leaf usually present. U. Leaf blade disarticulation present; flowers — plants dioecious. as fat do giclee eaaGNie 6 ade GE tech eae ieee tae aims eal tat e 4a. AELUROPODEAE. a 1985] CAMPBELL, GRAMINEAE 145 U. Leaf blade disarticulation usually absent; flowers usually perfect. V. Rachilla usually prolonged above uppermost floret; lodicules usu- ally distally fleshy; combined adaxial and abaxial girders with an “anchor,” “I,” or “T” shape usually absent. .................. Sst toh ae atten ete ela eee Meee Tribe 4b. CyYNODONTEAE. . Rachilla not prolonged above uppermost floret; lodicules distally membranaceous; combined adaxial and abaxial girders with an “anchor,” “I,” or “T” shape present. ...... Tribe 4d. ZoySIEAE. < Subfamily 1. BAMBUSOIDEAE Ascherson & Graebner, Synop. Mitteleurop. Fl. 2: 769. 1902. Aquatic to terrestrial, often rhizomatous annuals, perennial herbs, or woody plants. Lodicules 2 or 3; stamens 6, sometimes fewer; stigmas 2 or more often 3. Hilum linear, embryo small, with an epiblast but without a mesocotyl. Seedling mesocotyl usually short; first seedling leaf blade generally absent. Papillae and microhairs with narrow distal cells present in the leaf epidermis (FiGure 1b). Arm and fusoid cells often present in the mesophyll; midrib with 2 or more vascular bundles that are usually superposed; photosynthesis of the C, type (FicuRrE 2a). Base chromosome number usually 12. (Including Ory- zoideae Parodi ex Caro, Dominguezia 4: 10. 1982.) Type Genus: Bambusa Schreber. FiGures 1b, 2a, 3A—D. A widely distributed, almost cosmopolitan subfamily, especially in the trop- ics. Each of the three groups making up the subfamily is represented by an indigenous tribe in the southeastern United States: the bamboos by the Arun- dinarieae, the herbaceous bambusoid grasses by the Phareae, and the oryzoids by the Oryzeae. There are about ten genera and 13 species in our area. The concept of the Bambusoideae has been expanded from comprising only the woody bamboos to include a group of tribes called (Soderstrom & Calderon, 1979a) the herbaceous bambusoid grasses (Jacques-Félix, 1955; Tateoka, 1957a; De Wet, 1958; Parodi; Clayton, 1978; Renvoize, 1981; Soderstrom, 198 la, Soderstrom & Calderon, 1974, 1979a, 1979b; Hilu & Wright; Gould & Shaw). Important similarities between the bambusoids in general and the oryzoids (Brown, 1950; De Winter, 1951; Tateoka, 1957a; Reeder, 1962; Clifford, 1965; Christopher & Abraham, 1971; Clayton, 1978, 1981a; Renvoize, 1981) warrant inclusion of rice and its relatives in this subfamily as well. The bamboos, herbaceous bambusoids, and oryzoids share character states in the flowers, bundle-sheath anatomy (Brown, 1958a; Auquier & Somers), and amino-acid composition of the caryopses (Yech & Watson). Two mesophyll cell types, arm and fusoid cells (FiGuRE 2a), are almost unique to this subfamily (arm cells occur in Phragmites and some other arundinoids). Although these cells differ somewhat in bambusoids and oryzoids (Calderon & Soderstrom, 1973), their presence supports a monophyletic origin of this subfamily. Terrell & Robinson and Soderstrom (1981a) suggest that these cells may be adaptations for life in moist forests or aquatic habitats. Because of the number of lodicules, stamens, and stigmas of many members of the Bambusoideae, the subfamily is generally considered to contain the most primitive extant grasses. On the other hand, woodiness, complex vegetative 146 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 growth and inflorescence branching, various spikelet reductions, and perhaps the presence of arm and fusoid cells are presumably derived. Tribe la. Arundinarieae Ascherson & Graebner, Synop. Mitteleurop. FI. 2: 770. 1902 Stems woody. Leaf blades with transverse veins, disarticulating. Spikelets (FiGurE 3D) solitary, with 6-12 fertile florets and 2 glumes. Lemmas | 1-17- nerved. Flowers perfect, with 3 lodicules, stamens, and stigmas. Embryos with a scutellar tail. Initial or first few seedling leaves without blades. Leaf epidermis (FiGuRE 1b) with microhairs, cross- to dumbbell-shaped silica bodies, and saddle-shaped silica bodies, but without oryzoid silica bodies. TyPE GENUS: Arundinaria Michaux. FiGures 1b, 2a, 3D A tribe of 61 genera extending from a center of distribution in tropical forests to 46°N and 47°S latitudes, to 4000 m elevation, and to regions with snowy winters (Soderstrom, 198 1a). The major center of diversity of the group appears to be southeastern Asia. In the New World there are 17 genera. The one native bamboo in the southeastern United States, Arundinaria gigantea (Walter) Muhl., is the only New World member of this genus of over 100 species (McClure, 1973). This species, commonly called giant or switch cane, consists of three subspecies that grow in moist ground from southern Maryland and Ohio to Florida and Texas. Its rhizomatous growth produces extensive populations, sometimes called canebrakes, which are sought for cattle forage and as a source of materials for fishing rods, baskets, and other purposes (Hitchcock). Hall reported that various species of Bambusa, Pseudosasa Makino ex Nakai, and Phyllostachys Sieb. & Zucc. persist after cultivation in Florida. Holttum’s study of ovary anatomy and Grosser & Liese’s study of rhizome and leaf anatomy generated four concordant groups. Nevertheless, tribal limits and interrelationships are not clear (McClure, 1966; Calderon & Soderstrom, 1980; Soderstrom & Calderon, 1979b), at least in part because bamboos grow primarily in the tropics where the flora is relatively poorly known, and more importantly, because it is difficult to make good herbarium specimens of the bulky stems and branches, the growth patterns of which are taxonomically important. Moreover, because the plants flower infrequently, they are often avoided by collectors and are not well represented in herbaria. The infrequency of flowering is associated with flowering cycles of up to 120 years in many (perhaps the majority) of bamboos (Soderstrom & Calderén, 1979a). What makes the cyclical flowering all the more fascinating is that populations of a taxon tend to flower gregariously and, after fruiting, die. The functioning of the biological clock governing this rare phenomenon is unknown. Janzen hypothesized that this mast flowering oversaturates the food supply of fruit predators. The fruits of some bamboos may be as large as an avocado, and being poorly dispersed (at least by the wind), may accumulate in large numbers under the plants following a gregarious flowering (Soderstrom & Cald- eron, 1979a). Although Arundinaria may flower annually or remain sterile for many years, its aerial stems are monocarpic like those of most bamboos. Bamboos rely predominantly on vegetative reproduction by thick, extensively branched rhizomes (McClure, 1966, 1973). Reduced selection pressures for floral evolution may explain the primitiveness of bamboo flowers. 1985] CAMPBELL, GRAMINEAE 147 The bamboos are unique among grasses for their long-persistent aerial stems. Their woodiness comes not from cambial activity but from caps of fibers on both sides of the vascular bundles, thick-walled and lignified ground tissue, and to some extent, silicification of the epidermis (Soderstrom, 1981a). The two-stage growth pattern of bamboo stems is also unique. It consists of a relatively short period of apical dominance characterized by rapid internode elongation and suppression of lateral appendages, and then extensive lateral branching (Calderon & Soderstrom, 1980). Soderstrom (1981a) argued that competition with tropical trees for light brought about woodiness in bamboos, and that this woodiness and the polyploidy of bamboos are evidence for their derivation from the diploid herbaceous bambusoid grasses. Clayton (198 la, fig. 1) presented the same phylogeny. nother unusual feature of bamboos, which is also found in herbaceous bambusoids, is leaf torsion or “sleep movement.” Leaf-pulvinus activity serves either to orient all leaves of a branching system in one plane or to move leaves from a horizontal position during the day to a reflexed one at night (Calderon & Soderstrom, 1973). In addition to their unusual flowering cycles, growth pattern, and leaf torsion, the bamboos are parasitized by fungi generally distinct from those on other grasses (Savile). Tribe 1b. Oryzeae Dumortier, Obs. Gram. Belg. 83. 1824. Annual or perennial herbs. Stems and leaves more or less aerenchymatous. Leaf blades without transverse veins, not disarticulating. Spikelets (FiGURE 3A, B) solitary, with 1 fertile floret and glumes either small or absent. Lemmas 3- 5(-7)-nerved. Flowers perfect, or more often plants monoecious; lodicules 2, stamens 6 (rarely as few as 1), stigmas 2. Embryos without a scutellar tail (except in Zizania). First seedling leaf without a blade. Leaf epidermis with microhairs and oryzoid silica bodies, but without cross- to dumbbell-shaped silica bodies or saddle-shaped silica bodies. TyPE GENUS: Oryza L. FIGURE 3 A tribe containing about ten genera (Hubbard, 1973a) and 100 species. It is best known for rice, both the Asian species, Oryza sativa, which occasionally escapes from cultivation in the southeastern United States, and the wild rice of North America, Zizania aquatica L. Oryza, and the four native genera that represent the tribe in our area, fall into three subtribes (Terrell & Robinson). The Oryzinae include the perfect-flowered Oryza and Leersia Sw. The mono- generic Zizaniinae Hitchc. are characterized by monoecy, the presence of a scutellar tail, the fusion of pericarp and seed coat, and a karyotype of relatively large chromosomes and base numbers of 15 or 17. Luziola Juss. (including Hydrochloa caroliniensis Beauv., of our area) and Zizaniopsis Doell & Asch- erson, of the Luziolinae Terrell & Robinson, are also monoecious, but they lack a scutellar tail, the pericarp is free from the seed coat, and the chromosomes are small with a base number of | The tribe Oryzeae has been regard eddie an tic offshoot of the bambusoids (Ghorai & Sharma). The presence of stem and leaf aerenchyma, arm and fusoid cells (Terrell & Robinson), and the least specialized vessels of the family (Chea- dle, 1960) may be associated with the predominently moist or aquatic habitats — _ CO JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Awa SS Se FIGURE 3. Spikelets or their parts, Bambusoideae and Arundinoideae. A, Zizania aquatica (Oryzeae): Al, 2 staminate spikelets slightly after anthesis, all anthers shed but | (note longitudinal dehiscence), no glumes, each spikelet 1-flowered, x 3; A2, carpellate spikelet at anthesis (note styles), with pedicel and portion of rachis (palea clasped by lemma), x 3; A3, base of carpellate spikelet disarticulated from pedicel to show callus, 1985] CAMPBELL, GRAMINEAE 149 of this tribe. The tribe is characterized by the oryzoid type of silica body, which is found elsewhere only sparingly in the genus Aristida (Watson & Dallwitz, 1981). The oryzoid silica body is basically dumbbell shaped, but unlike those of similarly shaped silica bodies of other grasses, its long axis is perpendicular to the long axis of the leaf. It seems best to recognize the affinities of this tribe by including it in the Bambusoideae rather than giving it subfamilial rank (Pilger; Parodi; Stebbins & Crampton; Hilu & Wright; Gould & Shaw) or treating it as a “‘series” (Jacques-Félix, 1962) or a “group” (Clifford & Watson). Difficulty in assessing homology has beset the interpretation of the parts of the spikelets and florets of the Oryzeae. Hitchcock described the spikelet as one-flowered with reduced glumes, but most agrostologists consider Hitch- cock’s glumes to be actually the lemmas of sterile florets below the terminal, fertile floret (De Winter, 1951). The glumes form an inconspicuous cupular structure. In his review of the numerous ideas about the fertile floret, De Winter (1951) supported Pilger’s concept of fusion of two florets, with the loss of paleas from both and of lodicules, androecium, and gynoecium from one. If this view is correct, then the three-or-more-nerved “‘palea’”’ is actually a lemma and is the only remaining part of the terminal floret. Tribe lc. Phareae Stapf in Thiselton-Dyer, Fl. Capensis 7: 319. 1898. Perennial herbs. Leaf blades with obliquely oriented main veins connected by transverse veins, not disarticulating. Spikelets paired (1 carpellate and | staminate), with 1 fertile floret and no glumes. Lemmas few nerved. Stamens 6: stigmas 3. Embryos mostly without a scutellar tail. First seedling leaf with a blade. Leaf epidermis with cross- to dumbbell-shaped silica bodies, but without microhairs, saddle-shaped silica bodies, or oryzoid silica bodies. TyPE GENUS: Pharus P. Br. Ficure 3C. The Phareae are made up of the African genus Leptaspis R. Br. and Pharus, a New World genus of eight species. Pharus has survived where other herba- ceous bambusoids presumably have not because it is successful in disturbed sites and disperses well (Soderstrom, 1981a). The sole member of the tribe in our area, P. parvifolius Nash, is rare in northern and central Florida (Hall). lemma (to right) and palea partly separated, styles protruding (spikelet rotated 90° from position in A2), x 6. B, Leersia oryzoides (Oryzeae), spikelet (lemma and palea separated, glumes absent), x 6. C, Pharus parvifolius (Phareae): C1, stamiinate (pedicellate) and carpellate spikelets (sessile; note dense pubescence [individual uncinate hairs not visible at this scale), x 4; C2, staminate siete eee 4 of 6 stamens, x 6; C3, lemma of 3 protruding styles), x 4. D, Arundinaria gigantea Gina ices) D1, spikelet, x 2; D2, floret (lemma clasping palea), x 3. E, Danthonia spicata (Arundineae): E1, spikelet, x 3; E2, floret (lemma awned; note rachilla segment), x 5. F, Chasmanthium latifolium (Centotheceae): Fl, spikelet, x 1.5; F2, floret, x 3; F3, caryopsis, x 5. G, Phragmites australis (Arundineae): G1, spikelet (parts spread out and hairs omitted for clarity), x 4; ie floret with villous rachilla segment, x 5. H, Arundo Donax (Arundineae): H1, spikelet, x 3; H2, yee (from adaxial side; note hairs along edge of lemma and glabrous rachilla segment), x 150 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 The herbaceous bambusoid grasses as a group consist of eight tribes and 24 genera (Soderstrom, 1981a). Only five genera are native to the Old World, while 21 occur from Mexico to Argentina, especially between 10°N and 9°S latitudes, mostly below 850 m, and in forest shade or more open places (So- derstrom & Calderén, 1979b). In addition to the characters of the APPENDIX that separate them from the more evolutionarily advanced bamboos, the her- baceous bambusoids differ in being mostly diploid, rather than mostly tetra- ploid or hexaploid (Hunziker et a/.), and in their much simpler stem branching. Otherwise the boundary between the two groups is not well marked. Animal pollination has developed in herbaceous bambusoids in response to the relative lack of wind in their habitats (Soderstrom & Calderén, 1971). In Eremitis Doell cleistogamy in subterranean spikelets (Soderstrom & Calderén, 1974) may also be a compensation for lack of wind. The strongly twisted awns of Streptochaeta (Soderstrom, 1981a) and the short, hooked hairs of the per- sistent lemma of Leptaspis (Bor) and perhaps those of Pharus are evidently adaptations for catching on animal fur. The regularly produced spikelets of herbaceous bamboos may be inconspic- uously situated within leaf sheaths, behind broad leaves, or even under leaf litter (Calder6n & Soderstrom, 1980). Hence these plants may be as neglected by collectors as the bamboos are. The herbaceous bamboos are, however, better understood taxonomically. The flower of Streptochaeta is solitary and sub- tended by numerous spirally arranged bracts (V. M. Page; Soderstrom, 198 la). These specialized structures, called pseudospikelets (McClure, 1966, 1973), are also found in some bamboos (Soderstrom, 198 1a). Leaf torsion is also common to both groups. Subfamily 2. ARUNDINOIDEAE Tateoka, Jour. Jap. Bot. 32: 377. 1957, **Arundoideae.”’ Perennial (rarely annual) herbs (in Phragmites somewhat woody). Ligules fringed or of hairs. Embryo with a scutellar tail and a long mesocotyl. First seedling leaf blade curved or supine. Microhairs with a narrow distal cell. Photosynthesis mostly C, (C, in about 7 genera, including Aristida and probably Neyraudia of our area). Base chromosome number (11) 12. (Centothecoideae Soderstrom, Taxon 30: 614. 1981, as ‘““Centostecoideae.”” Phragmitoideae Par- odi ex Caro, Dominguezia 4: 13. 1982. Aristidoideae Caro, ibid. 16.) TyPE GENUS: Arundo L. FiGures 3E-H, 7B. A subfamily treated by Renvoize (1981) as comprising eight tribes and 72 genera. It is represented in the southeastern United States by three tribes, four genera, and about 30 species. Subfamily Arundinoideae is the least sharply defined and the most undoubt- edly polyphyletic of the subfamilies. The AppeNpIx shows the variability in numerous characters that are taxonomically discriminating for other subfam- ilies— for example, hilum shape (character 35), embryo size (36), seedling mor- phology (43, 45), and some leaf-epidermal (59-62) and transverse-sectional characters (63, 67, 75, and 82). Internal diversity in leaf ultrastructure (Carolin et al.) and in amino-acid profiles (Taira) surpasses that of other subfamilies. 1985] CAMPBELL, GRAMINEAE 151 It is not surprising, then, that discussions of the subfamily focus on phrases such as ‘miscellaneous group” (De Wet, 1958), “less homogeneous” (Stebbins & Crampton), “unspecialised subfamily” (Clayton, 1978), and “loosely related genera” (Renvoize, 1981), or that Clayton’s fig. J (198 1a) shows this subfamily, as defined by Renvoize, to be paraphyletic. The taxonomic concept of this group varies from one considerably broader than Renvoize’s to one separating one to all three of the tribes of our area into different subfamilies (Pilger; Parodi; Clayton, 1978), “series” (Jacques-Félix, 1962), or groups (Clifford & Watson). Prat (1960) and Stebbins & Crampton agreed with Renvoize at least in including the Aristideae, Arundineae, Cen- totheceae, and Danthonieae in the subfamily. The results of Renvoize’s multi- variate analysis illustrate arundinoid taxonomic complexity well. Of the 72 genera he included, only 43 formed an “‘arundinoid nucleus,” and 29 were peripheral. This nucleus, except for Lygeum L. and a few peripheral genera, makes up his Arundineae. The taxonomic relationships of Lygeum, Danthonia, and Neyraudia of Renvoize’s Arundineae, as well as of four of Renvoize’s peripheral tribes (Aristideae, Centotheceae, Ehrharteae Link, and Micraireae Pilger) need further study. This diverse assemblage holds together because its members have slightly more similarity to each other than to other grasses. That only four genera of arundinoids are native to the southeastern United States reflects the Old World, Southern Hemisphere, subtropical, and Gon- dwanaland distribution of the subfamily (Clayton, 1975; Cross). The wide geographic distribution hints at considerable age. Tribe 2a. Aristideae C. E. Hubbard in Bor, Grasses Burma, Ceylon, India, Pakistan, 685. 1960. Annuals or perennials. Spikelets 1-flowered, with a 3-awned lemma. Embryo without an epiblast. Two kranz bundle-sheaths present. Base chromosome number 11. Type Genus: Aristida L. Figure 7B A tribe considered by De Winter (1965) to comprise the large, cosmopolitan, often xerophytic Aristida (330 species) and two primarily African genera, Sti- pagrostis L. and Sartidia De Winter. In our area there are about 20 species of Aristida (Hitchcock). Depending upon what aspect of the plant one considers, the Aristideae re- semble several other groups. The overall similarity of spikelets, caryopses, and base chromosome number to those of the Stipeae are countered by a wealth of differences in ligules (character 7 of the AppENDIx), lemma-awn and nerve numbers (20, 22), lodicule number (24), embryos (38-40), silica bodies (52), and leaf anatomy (66, 67, and 78). The Aristideae have often been associated with chloridoids on the bases of leaf-mesophyll anatomy (characters 67, 78) (Brown, 1958a; De Winter, 1965; Carolin ef al.; Sutton) and amino-acid pat- terns of the caryopses (Yeoh & Watson). But again, there are more differences: lemma-awn number (20), lodicule texture (25), epiblasts (38), microhair distal- cell shape (49), silica-body type (52), and base chromosome number (84). The presence of microhairs with narrow distal cells and cross- to dumbbell-shaped silica bodies in the leaf epidermis unites the Aristideae and the Panicoideae. 152 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Furthermore, in longitudinal sections of leaves, the parenchyma-sheath cells are longer than wide in both the Aristideae and the Paniceae (Brown, 1974, 1975). These cells are usually isodiametric in chloridoids. Nevertheless, there are important differences between the Aristideae and the Paniceae in lodicule texture (25), embryonic leaf margins (41), silica-body types (52, 56, 57), col- orless cells traversing the leaf (78), and base chromosome number (84). In a consideration of the systematic position of the Aristideae, an important character is the unique double kranz sheath of Aristida. In all other C, grasses, the kranz bundle-sheath has evolved either from the parenchyma sheath (most chloridoids, danthonioids, and some panicoids) or the mestome sheath (some panicoids) (Brown, 1977). In Aristida both sheaths are kranz, giving the cross- sectional anatomy of the leaves a distinctive double sheath (Lommasson; Brown, 58a). Brown (1977) viewed the Aristideae as specialized, single-floreted Dantho- nieae and argued that the Aristideae arose from some danthonioid ancestor, possibly in southern Africa. Bourreill (1969) claimed that the wide distribution of Aristida indicates a Cretaceous beginning for the genus. His hypothesis (1968) about intratribal phylogeny disagrees with Brown’s (1977) and does not give enough weight to the probably derived double sheath of Aristida. Tribe 2b, Arundineae Dumortier, Obs. Gram. Belg. 82. 1824, ““Arundinaceae.”’ Perennials. Spikelets 2- to many-flowered (except in axillary cleistogamous spikelets of Danthonia). Rachilla prolonged above uppermost floret. Stamens 3. Embryo without an epiblast. Parenchyma sheaths with large vacuoles and no chloroplasts. Bulliform cell groups absent from leaves. Base chromosome number 12. (Elytrophoreae Jacques-Félix, Jour. Agr. Trop. Bot. Appl. 5: 304. 1958. Cortaderieae Zotov, New Zealand Jour. Bot. 1: 83. 1963. Danthonieae Zotov, ibid. 86. Molineae Jirasek, Preslia 38: 33. 1966.) Type GeNus: Arundo L. Figure 3E, G, H. According to Renvoize’s (1981) circumscription, a tribe of 57 genera. Five genera, all posing taxonomic problems, grow in the southeastern United States. Both Arundo, with one Old World species (A. Donax L., the reed, FiGure 3H), and Phragmites Adanson, whose single species in our area (P. australis (Cav.) Steudel (P. communis Trin.), FIGURE 3G) has the widest geographic distribution of any angiosperm (L. G. Holm et a/.), are peripheral in the tribe. Their stomata are narrower than the intervening epidermal cells and dominate the intercostal zones. Phragmites is unusual in the invaginated walls of the mesophyll cells (see Decker’s fig. 3), which resemble bambusoid arm cells. Cortaderia Stapf, pampas grass, a genus of the Southern Hemisphere rep- resented in our area by the frequently planted ornamental C. Sel/loana (Schultes) Ascherson & Graebner, 1s unique in the subfamily in that its vascular bundles are linked by sclerenchyma to the adaxial leaf surface only. It was one of the ungrouped genera of Renvoize’s Arundineae. Zotov put it in its own tribe, the Cortaderieae. Neyraudia Hooker f. is a small Old World genus of the Southern Hemisphere, represented by N. Reynaudiana (Kunth) King & Hitchc., an es- cape in Florida (Hall). It was placed in the Eragrostideae (the Cynodonteae in 1985] CAMPBELL, GRAMINEAE 153 this paper) because of its embryo anatomy (Decker) and its radially arranged mesophyll. Brown (1977) put it in the Tristegineae (Melinideae) of the Pani- coideae because of its PS subtype of kranz leaf anatomy, but there is no bio- chemical evidence to verify its C, photosynthesis. Phillips suggested that the genus lies on the boundary between the Arundinoideae and the Chloridoideae. On the whole, morphological and anatomical data support placement of Ney- raudia in the Arundinoideae (Tateoka, 1957a; Stebbins & Crampton; Jacques- Félix, 1962; Clifford & Watson; Renvoize, 1981). Finally, Danthonia DC. in Lam. & DC. (FiGureE 3E), represented by only three species in the Southeast, is the largest genus of a primarily Southern Hemisphere group often recognized as the Danthonieae. Traditionally, it was grouped with the Aveneae because of its many-flowered, laterally compressed spikelets. However, Hubbard (1948), De Wet (1954, 1956), and Reeder (1957) pointed out numerous differences in spikelets, karyotypes, embryo anatomy, and leaf anatomy. Its intermediacy between the pooid and panicoid extremes of the family makes it a taxonomic problem. Since it fits quite well into Ren- voize’s arundinoid nucleus, he sank the Danthonieae into the older Arundineae. Nevertheless, the danthonioids remain a diverse group containing both C, genera, such as Danthonia, and C, genera, such as Allochaete Hubb., Asthen- atherum Nevski, and Pheidochloa S. T. Blake. Further study of the group may elucidate some aspects of evolution in the family as a whole. Many genera of the Arundineae are small and not dominant floristic ele- ments—a situation that suggested to Renvoize (1979) that they are competi- tively inferior relative to the mainstream of grass evolution. Tribe 2c. Centotheceae Ridley, Mater. Fl. Malay. Penin. 3: 122. 1907. Perennials. Spikelets awnless, few- to many-flowered (FiGuRE 3F); rachilla not prolonged above uppermost floret. Stamen[s] | [generally 3 in other cento- thecoids]. Embryo without an epiblast. Parenchyma-sheath vacuoles not as large as those of the Arundineae. Bulliform cell groups prominent in leaves. Base chromosome number 12. Type GENUS: Centotheca? Desv. FIGURE 3F. A group of nine genera and 26 species, represented in the southeastern United States by Chasmanthium Link. This endemic genus of five woodland species has its center of distribution in our area (Yates). Many-flowered, laterally flattened spikelets made Chasmanthium an un- questioned member of the pooid alliance until Reeder (1957, 1962) demon- strated a unique embryo anatomy for this and related genera. Jacques-Félix (1962), Reeder (1962), and Decker established a centothecoid group on the basis of the transversely veined (tessellate) and pseudopetiolate leaves, truncate and heavily vascularized lodicules, distinctive embryo, narrow distal cell of the microhairs, dumbbell-shaped silica bodies, prominent bulliform cell groups in the leaves, and base chromosome number of 12. In addition, the plants of 3Reeder (Taxon 30: 348, 349. 1981) has proposed th nservation of this spelling over Centosteca, an orthographic error. 154 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 this group grow in moist, often tropical forests, in contrast to the various habitats of the largely temperate pooids. Jacques-Félix (1962) put his centothecoid series on an evolutionary line defined by embryo type between bamboos and chloridoids, but not far from the arundinoid series (see his figs. 32 and 33). Brown (1958a), Brown & Smith (1974), Clayton (1978), Ghorai & Sharma, and Renvoize (1981) mentioned ill-defined relationships with the bamboos. Soderstrom & Decker (1973), how- ever, outlined numerous differences between the groups in leaf anatomy, lod- icule morphology, caryopsis compression, and hilum shape. There are simi- larities to panicoids in amino-acid patterns (Taira) and smut pathogens (Watson), and to oryzoids in seedlings (Hoshikawa) and karyotypes (De Wet, 1960b). Tribe Centotheceae or its genera have either been placed in the Arundinoideae or its equivalent (Tateoka, 1957a; Prat, 1960; Parodi; Stebbins & Crampton; Yates; Renvoize, 1981) or been given the status of subfamily (Clayton, 1978; Soderstrom, 1981b; Gould & Shaw) or an informal, high-level group (Clifford & Watson). Whatever the rank, there is now a consensus about the composition of the group (Clayton, 1978; Renvoize, 1981; Soderstrom, 1981b). It fits into Renvoize’s broad definition of the Arundinoideae, and differences from arun- dinoids in the palisade layer of the mesophyll, in nucleolus persistence (Brown & Emery, 1957), and in seedlings (Hoshikawa) do not warrant separation of the two groups at the level of subfamily. The inclusion of Chasmanthium in Uniola L. by most authors prior to Yates’s work reflects a striking example of convergent evolution in spikelet morphol- ogy. The Unioleae are a monogeneric tribe of the Chloridoideae (q.v.). Chas- manthium differs from other centothecoids in not having transversely veined and strongly pseudopetiolate leaves and in some aspects of leaf anatomy (Deck- er). In leaf cross-section it resembles some members of the Arundineae. In general, however, it 1s unquestionably centothecoid. Subfamily 3. POOIDEAE [A. Braun in Ascherson, Fl. Prov. Brandenb. 32, 1864, “‘Poéideae’’]. Ligules membranaceous. Spikelet disarticulation usually above the glumes; rachilla prolonged above the uppermost floret. Staminate or neuter florets usually distal to lowermost carpel-bearing floret; lemmas usually with 3 or more nerves. Lodicules distally membranaceous, weakly vascularized. Hilum generally linear. Embryos small; epiblast present or absent, scutellar tail absent, Ficure 4. Poa (Pooideae, Poeae). a—o, P. pratensis: a, flowering plant with lateral stolons at base, =x '4; b, apex of leaf sheath, ligule, and base of blade, x 3; c, spikelet, x 12; d, glumes, first glume to left, x 20; e, floret before anthesis, the lemma long- pubescent below, x 12; f, spikelet * ith lower flower open and stigmas receptive, the second floret open, anthers dehisced, x 12; g, floret at anthesis, lemma to left, palea and rachilla to right, x 12; h, dehisced anther with 2 locules, x 12; i, turgid lodicules and gynoecium with receptive stigmas, removed from open floret, x 15; j, portion of inflo- rescence with mature fruits, 2 sings falling from spikelets, disarticulation occurring above glumes and between florets, x 6; k, floret in ds (note pubescent lemma), x 12; l, caryopsis, lemma removed, a to left, x 12; caryopsis in diagrammatic longi- tudinal ON lemma to left, palea to right, sae stippled, embryo unshaded, CAMPBELL, GRAMINEAE n, embryo in diagrammatic se eae section (scutellum to left, égicoptile and parece to right, vascular tissue in black), showing no internode between scutellar and coleoptilar nodes, epiblast (small flaplike structure opposite scutellum), and no cleft between base of scutellum and coleorhiza; 0, diagrammatic transverse section of embryo through scutellum, coleoptile, and first embryonic leaf at level of arrow in ‘‘n,” showing few vascular bundles in leaf, ae oa of which meet but do not overlap (‘‘n” and “‘o” redrawn after Reeder, 1957, fig. 2 156 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 mesocotyl short, embryonic leaf margins not overlapping. First seedling leaf usually narrow and erect. Microhairs absent; elongated, sinuous or crenate silica bodies present; subsidiary cells parallel sided. Photosynthesis exclusively of the C, type. Base chromosome number most commonly 7. (Festucoideae Rouy, Fl. France 14: 28. 1913.) Type GeNus: Poa L. Ficures la; 2b; 4; SA- C, E-I; 6. A subfamily of about 155 genera in eight tribes and two subtribes (Macfarlane & Watson, 1982). Six tribes are represented in the southeastern United States by about 40 genera and 132 species. The center of distribution of the Pooideae is the Mediterranean area (Cross). The not-nearly-as-diverse North American pooid component may represent immigrants from Europe before the separation of North America and Europe in the Eocene (Clayton, 1975). Today members of the Pooideae characteris- tically grow at high latitudes, especially in the Northern Hemisphere (Hartley, 1950, 1973; Cross). Past dispersal along tropical mountains presumably took members of the subfamily to the Southern Hemisphere. Robert Brown’s (1814) perceptions of spikelet morphology clearly defined the panicoids but left other grasses in one heterogeneous group, the pooids. The use of other character suites by Avdulov, Prat (1932, 1936), Reeder (1957, 1962), and Brown (1958a) led to the removal of major groups such as the bambusoids, arundinoids, and chloridoids from the Brownian Poeae. Decker and Macfarlane & Watson (1980, 1982) sharpened the limits of the subfamily even further and produced a reasonably homogeneous taxon, although there is nO unique character state holding all pooids together. As a result of Mac- farlane & Watson’s thorough studies, three traditionally pooid tribes (Brachy- elytreae, Diarrheneae, and Stipeae) have been removed from the subfamily. Until more is known about these tribes 1t seems best to leave them unplaced (see tribes 6a-). In supertribe Poanae there are five tribes: the Agrostideae, Aveneae, Meli- ceae, and Poeae, in our area; and the Seslerieae, a small tribe in the Mediter- ranean region. Supertribe Triticanae Macfarlane & Watson contains tribes Bromeae and Triticeae, which occur in our area, and the monogeneric Brachy- podieae of tropical mountains. The two supertribes differ in numerous ways: presence or absence of auricles, number of nerves in the lemma awns, spikelet and caryopsis length (Macfarlane & Watson, 1982), lodicule and ovary-apex hairiness (characters 26 and 29 of the APPENDIX), presence of an epiblast (38), seedling mesocotyls (43; Harberd), and transitionary node roots (Hoshikawa). For most of these characters, considerable variability in one or more of the tribes produces overlap between the two supertribes. In addition, chemical differences exist in chain length of the starch fructosan (D. Smith, 1973), re- dundant DNA sequences (Bendich & McCarthy), enzyme kinetics of RuBP carboxylase (Yeoh ef a/.), pollen antigens (Watson & Knox), and the kinds of caryopsis glycosides (De Cugnac), globulins (P. Smith), and amino acids (Yeoh & Watson). Starch grains (character 42 of the APPENDIX) are simple or com- pound in the Poanae and always simple in the Triticanae. With the exception 1985] CAMPBELL, GRAMINEAE 17 of this difference in starch grains, these chemical features are like the morpho- logical characters in not being entirely definitive. The great number of these divergent tendencies, however, supports recognition of the two groups. Tribe 3a. Agrostideae Dumortier, Obs. Gram. Belg. 83. 1824. Spikelets usually 1-flowered. Ovary apex usually glabrous. Hilum usually punctiform. Embryo with an epiblast. At least some starch grains compound. (Phalarideae Dumort. Anal. Fam. Pl. 64. 1829. Milieae Endl. Fl. Posoniensis, 109. 1830. Anthoxantheae Endl. ibid. 113.) Type GENus: Agrostis L. FIGURES 2b, 5G. The Agrostideae, as delimited by Macfarlane & Watson (1982), are the largest tribe in the Pooideae. Its 55 genera are most abundant relative to other grasses north of a line between 52° and 62°N latitude, with southern extensions in eastern and western North America (Hartley, 1973). Nineteen genera and about 50 species occur in the southeastern United States. Thirteen of the genera (Agrostis, Alopecurus L., Ammophila Host, Calamagrostis Adanson, Cinna L., Deschampsia Beauv., Hierochloé R. Br., Koeleria Pers., Limnodea L. H. Dewey, Milium L., Phalaris L., Sphenopholis Scribner, and Trisetum Pers.) have in- digenous species. Six genera (Aira L., Anthoxanthum L., Holcus L., Lagurus L., Phieum L., and Polypogon Desv.) indigenous mostly to Europe are repre- sented in our area by one or more adventive species. The Agrostideae are most closely related to the Aveneae; the relationship between the two tribes is discussed under the latter. Both tribes also appear to be close to the Poeae serologically (P. Smith), in enzyme kinetics of RuBP carboxylase (Yeoh et a/.), and in being the only tribes of grasses in which the endosperm is liquid in some species (Terrell; Macfarlane & Watson, 1982). These three tribes may form a “reticulate biological unit” (Hilu & Wright). The tribe Phalarideae has been recognized on the basis of the presence of reduced structures between the glumes and the single, perfect terminal floret of spikelets in its three genera (Anthoxanthum, Hierochloé, and Phalaris). These reduced structures, often thought to be sterile lemmas (Hitchcock), are not necessarily homologous between genera. Barnard considered the spikelet of Anthoxanthum to consist of four sterile glumes and two lemmas, each of which subtends a single stamen. The gynoecium forms directly from the apex of the spikelet axis. Since nothing else sets these genera off from agrostoid or avenoid grasses, the Phalarideae have been lumped either with the Agrostideae (Mac- farlane & Watson, 1982) or the Aveneae (Clayton, 1978), or with the combined Agrostideae and Aveneae (Tateoka, 1957a; Stebbins & Crampton; Hilu & Wright). Tribe 3b. Aveneae Dumortier, Obs. Gram. Belg. 82. 1824, ““Avenaceae.” Spikelets usually 2—7-flowered. Ovary apex usually hairy. Hilum linear. Em- bryo with an epiblast. At least some starch grains compound. TyPE GENUS: Avena L. 158 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Macfarlane & Watson (1982) included eight genera in the Aveneae. Four are confined to the Old World, one to the New, with three occurring in both. In our area the tribe is represented by three adventive species in three genera, Avena (A. fatua L.), Amphibromus Nees (A. scabrivalvis (Trin.) Swallen), and Arrhenatherum Beauv. (A. elatius (L.) Mert. & Koch) This tribe is so similar to the Agrostideae that many workers (Pilger; Tateoka, 1957a; Stebbins & Crampton; Watson; Hilu & Wright) have united the two. On the basis of rather small samples, it seems that the two tribes are not distinct serologically (P. Smith), embryologically (Maze & Bohm, 1974), or in terms of enzyme kinetics of RuBP carboxylase (Yeoh ef al.). In contrast, immu- nology (Watson & Knox) and amino-acid complements (Yeoh & Watson) appear to separate the two tribes, but sample sizes here were also small. Mac- farlane & Watson (1982), who have made the most recent and thorough study of the two groups, maintain them as tribes. In addition to noting differences in the number of florets per spikelet, hairiness of the ovary apex, and hilum shape (see characters 15, 29, and 35 in the ApPpENDIx), they pointed out ten- dencies for the Aveneae to bear longer spikelets, awns from terminal notches (rather than abaxially), and lower glumes with more than one vein (rather than usually a single vein). Tribe 3c. Meliceae Reichenbach, Consp. Reg. Veg. 53. 1828, ‘‘Melicaceae.” Lodicules usually connate, truncate, and distally fleshy. Ovary apex glabrous. Leaf-sheath margins more or less connate. Embryo with an epiblast. Base chromosome number 9 or 10. Type GeNus: Melica L. Figure SA- A tribe of nine genera that do not form a closely interrelated group (Hilu & Wright; Macfarlane & Watson, 1982). Three genera, G/yceria R. Br., Melica, and Schizachne Hackel, with about 12 species, occur in our area. The Meliceae are distinguished from other pooids by unusual lodicules and relatively small chromosomes with base numbers atypical for the subfamily. Figure 5. Spikelets and their parts, Pooideae, Stipeae, and Brachyelytreae. A, Gly- rachilla extending upward as bristle against palea, segment of rachis to right of spikelet, x 5. E, Lolium perenne (Poeae): El, spikelet with portion of rachis, x 3; E2, second floret from base of spikelet, lemma without awn, palea toward viewer, < 5; E3, awned lemma of fertile floret, palea hidden from view, x 5. F, Briza minor (Poeae): F1, spikelet, x 6; F2, floret with rachilla Ue ae palea not visible, x 12; F3, same, seen from axis, palea visible within lemma, x 12. G, Agrostis hiemalis (Agrostideae), x 12: G1, spikelet, showing glumes and single ane G2, floret (lemma) enclosing caryopsis, palea absent. H, Elymus repens (Agropyron repens) (Triticeae), x 3: H1, spikelet with part of rachis behind it (contrast with El); H2, floret from near base of Spice showing back of awned lemma; H3, same, showing palea. I, E/ymus canadensis (Triticeae), x 2: I1, section of rachis with a pair of spikelets, each with 2 glumes and | floret; 12, upper florets of a CAMPBELL, GRAMINEAE spikelet, lateral view showing awned lemma. J, Piptochaetium avenaceum (Stipa aven- acea) (Stipeae): J1, spikelet with single floret (only base of lemma awn shown), x 2; J2, floret, to show relative length of hygroscopic lemma awn, x '; J3, floret, note hairy base of lemma and rachilla forming bearded, sharp-pointed callus, lemma clasping pointed palea (only base of lemma awn shown), x 5; J4, palea, x 5S. 160 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 The tribe is also serologically distinct (on the basis of Melica alone—Fair- brothers & Johnson, P. Smith) and is unusual among pooids for its sometimes abundantly papillose leaf epidermis, uniformly thickened walls of the inner bundle sheath (Decker), and scarcity of silica bodies in the leaf epidermis (Stebbins & Crampton). Although in most characters the tribe certainly belongs in the supertribe Poanae, its similarity to the supertribe Triticanae in disac- charides and oligosaccharides in the seeds (MacLeod & McCorquodale), amino- acid patterns of the caryopses (Yeoh & Watson), and enzyme kinetics of RuBP carboxylase (Yeoh ef a/.) hints that it may be intermediate between the two supertribes. Tribe 3d. Poeae [R. Brown in Flinders, Voy. Terra Austral. 2: 583. 1814]. Leaf vernation often folded. Ovary apex glabrous. (Festuceae Dumortier, Obs. Gram. Belg. 82. 1824. Including Monermeae C. E. Hubb. in Hutchinson, Brit. Fl. Pl. 332. 1948.) Type GeNus: Poa L. FiGures 4; SE, F. A tribe of 50 genera (Macfarlane & Watson, 1982), primarily north-temperate in distribution. According to Hartley (1950), they are most abundant relative to other grasses north of the 50°F isotherm for mean temperature of the mid- winter month. Four (Festuca L., Poa, Puccinellia Parl., and Vulpia K. C. Gmelin) of the ten genera found in the southeastern United States are repre- sented by native species. The other genera, Briza L., Catapodium Link, Cy- nosurus L., Dactylis L., Lolium L., and Parapholis C. E. Hubb., are mostly natives of Europe. In all, there are approximately 37 species of this tribe in our area. The Monermeae, containing the genus Parapholis of our area, have been included in the Poeae by Macfarlane & Watson (1982). The group 1s rather heterogeneous morphologically, serologically (P. Smith), and in the composition of seed carbohydrates (MacLeod & McCorquodale) and fructosans (D. Smith, 1968, 1973). The only pooid tribe with more mul- tistate characters in the APPENDIX Is also the only larger tribe, the Agrostideae. The Poeae are morphologically very close to both the Agrostideae and the Aveneae (see discussion under Agrostideae). The Poeae differ from the other two tribes in having folded, rather than rolled, vernation (character 6 of the APPENDIX) and in the presence of crescentic silica bodies in the leaf epidermis (56). They differ further from the Agrostideae in the number of florets per spikelet (15), and from the Aveneae in the lodicule apex (27) and ovary apex (29). Tribe 3e. Bromeae Dumortier, Obs. Gram. Belg. 82. 1824, “‘Bromaceae.” Stem leaf sheaths united into a tube. Lemma awns abaxial or from a terminal notch. Ovary appendage hairy, terminal; styles laterally positioned. Embryo without an epiblast. Starch grains all simple. Type GENUs: Bromus L. The genus Bromus (about 50 species) is distributed in cooler regions through- out the world. It is usually either isolated as a monogeneric tribe (Clayton, 1978; Hilu & Wright; Macfarlane & Watson, 1982) or grouped with Boissiera Hochst. & Steudel (Bor). About 15 species of Bromus, two-thirds of them adventive, occur in the southeastern United States. 1985] CAMPBELL, GRAMINEAE 161 Inflorescence and spikelet morphology alone dictate placement of Bromus in the Poeae, and it has often been placed there (e.g., Hitchcock; Pilger; Prat, 1960; Parodi; Jacques-Félix, 1962; Decker; Hubbard, 1973a; Gould & Shaw). Hubbard (1948) and Stebbins & Crampton, while maintaining Bromus in the Poeae, pointed out that its starch grains are all simple (first noted Py Harz) and never compound like those of members of the Poeae. Both Avdulov and Hubbard (1948) noted the similarity of Bromus and the Triticeae in their starch grains and hairy ovary apices. In addition, the Bromeae and Triticeae share numerous morphological, anatomical, and other character states (see discussion of subfam. Pooideae). The two tribes are clearly distinct from one another, however, in secondary-inflorescence form (character 10 of the ApPpENDIX), lemma-awn position (21), lodicule hairiness (26), and ovary appendage (30). The Bromeae also differ from the Triticeae in amino-acid composition of the caryopses (Yeoh & Watson). The Bromeae have been con- sidered to be a linking group between the Triticeae and other pooids (P. Smith; Clayton, 1978). Tribe 3f. Triticeae Dumortier, Obs. Gram. Belg. 82. 1824. Inflorescence a solitary spike. Lemma awns apical. Lodicules hairy. Ovary apex hairy. Embryo with or without an epiblast. Starch grains all simple. (Hordeae Spenner, FI. Friburg. 1: 155. 1825. Secaleae Reichenb. Consp. Reg. Veg. 48. 1828. Brachypodieae Harz, Linnaea 43: 15. 1880. Frumenteae Krause, Verh. Nat. Ver. Preuss. Rheinl. 59: 172. 1903.) Type GENus: Triticum L. FIGURES la; 5H, I; 6 The Triticeae are not a prominent tribe in our area, for there are only about nine indigenous species in three genera (Agropyron Gaertner, Elymus L. [in- cluding Hystrix Moench], and Hordeum L.). About seven species in five genera (Aegilops L., Agropyron, Hordeum, Secale L., and Triticum) are adventive, mostly from Eurasia. In North America the tribe is more common at latitudes north of 35°N (Dewey). Worldwide, it is most frequent relative to other grasses in low-lying areas in and near Asia Minor, Iraq, the Caspian Sea, and to a lesser extent, the western United States (Hartley, 1973). The Triticeae, easily recognized by the spicate inflorescences, form a close- knit group (Macfarlane & Watson, 1982) most closely related to the Bromeae (see discussion under the latter tribe). Within the tribe, however, there have been widely differing opinions about generic limits, ranging from a monogeneric concept (Stebbins, 1956a) to the most generally accepted circumscription of 15 to 30 genera (Baum, 1982a, 1982b, 1983; Dewey). Taxonomic problems persist in the group, although the economic importance of some of 1ts members as cereals (wheat, barley, and rye [Secale cereale L.]) and as forage and range grasses (Agropyron and Elymus) has motivated extensive research The Triticeae are remarkable for the great extent of intergeneric hybridiza- tion. For the 28 genera Baum (1982a) recognizes, he records 65 intergeneric crosses or about 17 percent of all possible intergeneric hybrids. Only five genera do not hybridize with others, while Agropyron and Hordeum each cross with 14 other triticoid genera. It is therefore not surprising that the taxonomy of this tribe at both generic and specific levels is difficult and that polyploidy 162 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 FiGureE 6. Elymus (#ystrix) (Pooideae, Triticeae). a-n, E. Hystrix (H. patula): a, base of plant, x 12; b, junction of leaf sheath and leaf blade (note ligule), x 6; c, inflorescence, x 1: d, paired spikelets from near base of inflorescence (note 2 glumes subtending each spikelet), x 1; e, spikelet with | floret at anthesis (lemma awn not shown), x 4; f, longitudinally dehiscent basifixed anther, x 6; g, pollen with single germination pore, x 750; h, gynoecium and turgid lodicules, x 6; 1, tip of stigmatic branch, x 500; j, floret in fruit, x 2; k, base of same to show palea and rachilla, x 5; 1, tip of lemma awn, x 25; , base of floret in fruit, vertical section (rotated 90° from floret in “k’’), endosperm stippled, embryo unshaded, x 5; n, adaxial side of caryopsis, x 6. 1985] CAMPBELL, GRAMINEAE 163 predominates: only two of the approximately 50 species occurring in North America are diploid. Hybridization has been important in the development of agriculturally desirable taxa such as triticale (Triticum x Secale) and the bread wheats Subfamily 4. CHLORIDOIDEAE Rouy, FI. France 14: 2. 1913, “Chloridi- neae.”” Ligules often fringed. Spikelets often laterally flattened; staminate or neuter florets usually distal to the lowermost carpel-bearing floret; lemma nerves often 3 or fewer. Lodicules usually fleshy distally. Hilum punctiform. Embryo with an epiblast and a long mesocotyl, usually with a scutellar tail; embryonic leaf margins not overlapping. First seedling leaf usually broad. Microhair distal cell usually inflated; both tall and narrow silica bodies and saddle-shaped silica bodies usually present; subsidiary cells generally triangular. Photosynthesis of the C, type; mesophyll cells radially arranged. Sclerenchyma accompanying the smallest vascular bundles usually present. Base chromosome number usually 10. (Eragrostoideae Pilger, Nat. Pflanzenfam. ed. 2. 14d: 167. 1956.) TyPE GENUs: Chloris Sw. Figures 1d; 2c; 7A, C-I. A subfamily of about five tribes, 90 genera, and 900 species. In the south- eastern United States, the 26 genera, six of which are represented only by adventive species, are divided into four tribes. The boundaries between some of the traditionally recognized tribes (e.g., Eragrostideae and Cynodonteae (Chlorideae); Eragrostideae and Sporoboleae) are arbitrary (Hubbard, 1973a, Christopher & Abraham, 1974; Clayton, 1978; Hilu & Wright; Phillips). A broad tribal concept is therefore used here. The Chloridoideae, perhaps the most homogeneous grass subfamily, are clearly defined by leaf anatomy. The distal cell of the microhairs is inflated (character 49 of the APPENDIX); the parenchyma sheath is kranz, and its chlo- roplasts are in most cases centripetally positioned (Brown, 1960b, 1975, 1977; Sutton); and salt glands are known in 17 chloridoid genera but in none outside this subfamily (Lipschitz & Waisel). The subfamily is apparently most closely related to the Arundinoideae (Clif- ford et al., Clayton, 1981a; Phillips) and may be evolutionarily derived from ancestral stock of that subfamily. Some affinities with the Paniceae have also been suggested (Watson), and the two groups do share a center of distribution in Africa (Clayton, 1981a). They differ, however, in numerous ways (see dis- cussion under the Panicoideae). The abundance (in terms of number of taxa and endemics) of chloridoids in tropical Africa led Hartley & Slater to propose an African origin for the group. Their association of high speciation with arid climates was challenged by Cross, who characterized chloridoids as savanna grasses primarily of Africa and Aus- tralia. Clayton (1981a), noting the conspicuously large number of chloridoids in North America, suggested that they are filling a gap created by the “‘evo- lutionary lethargy” of the pooids there. Tribe 4a. Aeluropodeae Nevski ex Bor, Oesterr. Bot. Zeitschr. 112: 184. 1965. 164 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Fic . Spikelets and their parts, Chloridoideae and Aristideae. A, seal eae ake ae nae 5: Al, staminate spikelet at anthesis, 3 stamens visible; A carpellate spikelet at tip of ae with 4 leaves; A3, carpellate floret (glumes en B, Aristida longispica (Aristideae): B1, spikelet with glumes spread apart, x 6; B2, floret with mature caryopsis, 3-awned lemma completely enclosing palea and caryopsis, x 6; B3, caryopsis, x 6; B4, palea, x 12 (note palea drawn twice as large as lemma in B2). ~— 1985] CAMPBELL, GRAMINEAE 165 Rhizomatous or stoloniferous. Leaf blades disarticulating. Plants usually dioecious. Lemma nerves 7 or more. Embryo without a scutellar tail. Starch grains all simple. Short cells over the veins solitary or in short rows. TyPE GENUS: Aeluropus Trin. FIGURE A small tribe of about seven genera including 25-30 species. They are rhi- omatous or stoloniferous, often dioecious halophytes, mostly with narrow distributions in the New World. The largest genus, Distichlis Raf., is represented by D. spicata (L.) Greene in the southeastern United States. The only other species in our area comes from the monotypic genus Monanthochloé Engelm. (M. littoralis Engelm.), which is found elsewhere only in the West Indies. The Aeluropodeae are close to the Cynodonteae but are distinguished by several features uncommon in the subfamily: short, pungent leaves; abundant epidermal papillae; small, rounded, often sunken microhairs; and many-nerved lemmas (Stebbins & Crampton; Decker; Soderstrom & Decker, 1964). Tribe 4b. Cynodonteae Dumortier, Obs. Gram. Belg. 83. 1824, “Cynodoneae.” Inflorescence usually paniculate or of spiciform branches. Spikelets disarticu- lating above the glumes. Cross- to dumbbell-shaped silica bodies present. (Chlo- rideae Reichenb. Consp. Reg. Veg. 48. 1848. Spartineae Gren. & Godron, FI. France 3: 434. 1855. Sporoboleae Stapf in Thiselton-Dyer, Fl. Capensis 7: 315. 1898. Eragrostideae Stapf, ibid. 316. Perotideae C. E. Hubb. in Bor, Grasses Burma, Ceylon, India, Pakistan, 686. 1960.) TyPE GENUS: Cynodon Rich. Ficures 1d; 7C-E, G-I. A broadly defined tribe, here including four traditionally recognized tribes: Cynodonteae (Chlorideae), Eragrostideae, Spartineae, and Sporoboleae. The first two contain many genera; the third, only Spartina Schreber; and the last, only Calamovilfa (A. Gray) Scribner, Muhlenbergia Schreber and Sporobolus R. Br. Twenty-one genera of this enlarged tribe occur in the southeastern United States: Bouteloua Lag., Buchloé Engelm., Calamovilfa, Chloris, Crypsis Aiton, C, Ctenium aromaticum (Cynodonteae), x 6: Cl, transverse section of rachis (unshaded) with 2 spikelets (spikelets in 2 rows), the first spikelet shaded (note small first glume, stoutly awned second glume; first 2 florets sterile and with long awns, third ae fertile); C2, fertile (third) floret, showing hairy lemma, palea, and hairy callus. D, Cynodon dactylon (Cynodonteae): D1, portion of rachis, showing sessile spikelets in rows, each spikelet 1-flowered, x 6; D2, floret, lemma to left, rachilla prolonged behind palea, x 12. E, Eustachys (Chloris) petraea (Cynodonteae): El, portion of rachis, showing spikelets n 2 rows, x 10; E2, spikelet, x 12; E3, spikelet with glumes removed, fertile floret to a rudimentary floret to right (stippled), x 12; E4, fertile floret, turned to show part of palea within lemma, x 12. F, Uniola paniculata (Unioleae): Fl, spikelet, lower ors sterile, x 1.5; F2, fertile floret, palea to left, x 12. G, Muhlenbergia Schreberi (Cyno- 2 thesis, stigmas protruding, | anther visible, x 6; H2, spikelet, showing long pedicel of this species, x 3. I, Eragrostis Elliottii (Cynodonteae): I1, spikelet, x 5; 12, floret with segment of rachilla, x 12; 13, caryopsis, palea persistent on rachilla, and mature floret, x 12. 166 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Ctenium Panzer, Cynodon, Dactyloctenium Willd., Diplachne Beauv., Eleusine Gaertner, Eragrostis Wolf, Eustachys Desv., Gymnopogon Beauv., Leptochloa Beauv., Muhlenbergia, Opizia Raf., Schedonnardus Steudel, Spartina, Spo- robolus, Tridens Roemer & Schultes, and Triplasis Beauv. Clayton (1967), D. E. Anderson, and Phillips have discussed numerous problems in defining ge- neric limits in the Cynodonteae. The four tribes combined here are based upon inconsistent inflorescence characters: the Cynodonteae and Spartineae bear one-sided, spiciform second- ary inflorescences of one-flowered spikelets; the Eragrostideae, panicles of sev- eral-flowered spikelets; and the Sporoboleae, panicles of one-flowered spikelets. Hilu & Wright pointed out that certain genera (e.g., Dactyloctenium, Eleusine, and Leptochloa) bear the spiciform inflorescences of the Cynodonteae, but their spikelets are eragrostoid in having several florets. The Eragrostideae may rarely have one-flowered spikelets like the Sporoboleae (Phillips). Furthermore, at least for the Cynodonteae and Eragrostideae, there are no other significant distinguishing characters, and the two groups should either be given subtribal status (Hilu & Wright) or merged entirely. The Sporoboleae, on the other hand, differ from eragrostoids in lacking a culm pulvinus (Brown ef al., 1959b) and in the centrifugal position of the parenchyma-sheath plastids of some of the species of Muhlenbergia and Sporobolus (Brown, 1960b). That these differences do not hold all the time, however, underscores the artificiality of the Sporo- boleae. Phillips considered the tribe to be “clearly no more than an offshoot of the Eragrostideae,” and Stebbins & Crampton, Sutton, and Gould & Shaw lumped it with the Eragrostideae. Spartina does not differ from the Cynodon- teae sufficiently to warrant tribal status (Mobberley; Hitchcock; Reeder & Singh; Hubbard, 1973a). The broadly circumscribed Cynodonteae make up most of the Chloridoi- deae, and hence the discussion of the distribution of the subfamily applies well to this dominant tribe. Tribe 4c. Unioleae (Clayton) Roshevits ex C. S. Campbell, stat. nov. Lemma nerves 7-11. Microhair distal cell narrowly dome shaped; cross- to dumbbell-shaped silica bodies absent; cork-silica pairs absent; short cells over the veins in rows of 5 or more. Midrib bundles more than | and arranged in an arc. (Subtribe Uniolinae Clayton, Kew Bull. 37: 417. 1982. Tribe Unioleae Roshevits, Zlaki, 244. 1937, nomen invalidum sine descriptione latine.) TyPE GENUS: Uniola L. FiGure 7F. The tribe contains only Uniola, comprising two species of sea beach grasses. Uniola Pittieri Hackel ranges from Mexico to Ecuador, and U. paniculata L., commonly called sea oats, occurs from Virginia to Texas and in the Caribbean and Mexico. Spikelets of Uniola strongly resemble the many-flowered, laterally compressed spikelets of many non-chloridoid grasses, but Yates clearly dem- onstrated that leafand embryo anatomy and chromosome number show Uniola to be chloridoid. It differs from other chloridoids in the lemma nerves and in several characters of the leaf epidermis (see diagnosis above). 1985] CAMPBELL, GRAMINEAE 167 Tribe 4d. Zoysieae Bentham, Jour. Linn. Soc. Bot. 19: 29. 1881. Floret 1 per spikelet; disarticulation below the glumes; rachillas not prolonged above the floret. Tall and narrow silica bodies absent. (Nazieae Hitchc. Gen. Grasses U. S. 15. 1920. Trageae Hitche. Contr. U. S. Natl. Herb. 24: 599. 1927.) Type Genus: Zoysia Willd. FiGure 2c. Clayton & Richardson considered this tribe of 12 genera to be entirely Old World in distribution and closely related to the Cynodonteae. One species of Tragus Haller, T. racemosus (L.) All., is occasionally adventive in our area, and a few species of Zoysia used in lawns escape from cultivation (Hitchcock). Subfamily 5. PANICOIDEAE A. Braun in Ascherson, Fl. Prov. Brandenb. 32, 799. 1864. Spikelets (FicGures 8-11) compressed dorsally, with 1 carpel-bearing floret per spikelet, the staminate or neuter florets proximal to the carpel-bearing one. Lodicules distally fleshy (Ficures 8h, 10h). Embryo witha scutellar tail, without an epiblast, the mesocotyl long (FiGures 8n, 101), embryonic leaf margins overlapping (FIGURES 80, 10m). First seedling leaf blade broad. Microhair distal cell narrow; cross- to dumbbell-shaped silica bodies present (FiGuRE Ic); guard cells overlapped by interstomatals. C,- or C,-type photosynthesis (FiGuRE 2d); sclerenchyma not accompanying the smallest vascular bundles. Base chro- mosome number mostly 9 and 10. (Saccharoideae Reichenb. Repert. Herb. 37. 1841. Andropogonoideae Ridley, Mat. Fl. Malay. Penin. 3: 120. 1907.) Type GENUS: Panicum L. Ficures Ic, 2d, 8-11. Because of its distinctive spikelets, the subfamily Panicoideae was circum- scribed early (R. Brown, 1810, 1814). This is the largest subfamily in terms of genera (about 200) and species (about 2800), most of which fall into two large tribes, the Andropogoneae and Paniceae. Up to ten other tribes, all with fewer than seven genera, are recognized by some agrostologists, but the three small panicoid tribes represented in the southeastern United States— Anthephoreae, Maydeae, and Tristegineae (Melinideae)—are here included in the two large tribes. In our area there are about 46 genera and 275 species. Clayton (1981a) considered subfamily Arundinoideae to have provided the ancestral stock for the Panicoideae. Of the other subfamilies it resembles the Chloridoideae in C, photosynthesis, chromosome base number (mostly 10), and broadly tropical distribution. These two subfamilies differ in numerous ways, however: spikelets (APPENDIX, characters 12, 15, and 18), embryos (38, 41), microhair distal-cell shape (49), and silica bodies (53-55). In photosyn- thetic pathway (67), 20 percent of the genera of Panicoideae are non-kranz; of the kranz genera, 89 percent are of the mestome-sheath (MS) subtype of kranz anatomy (Brown, 1977). Chloridoids, on the other hand, uniformly have the parenchyma-sheath (PS) subtype. The caryopses of the Panicoideae contain — lower levels of glutamine and methionine and higher levels of proline, alanine, and leucine than the Chloridoideae (Yeoh & Watson). The levels of proline and glycine in the Paniceae are intermediate between the levels in subfam. Chloridoideae and in tribe Andropogoneae. 168 JOURNAL OF THE ARNOLD ARBORETUM Gf ae ie 3 = Hf {. f. Pa CH Nef ir Ty Z \ FiGure 8. Schizachyrium (Panicoideae, Andropogoneae). a-r, S. scoparium (Andro- pogon scoparius): a, solitary inflorescence with | spikelet at anthesis, x 2: b, apex of leaf sheath, ligule, and base of blade, x 3; c, spikelet pair, sterile spikelet to upper left and behind, fertile spikelet at anthesis, =x 6; d, first glume (abaxial side), x 6; e, second glume (abaxial side), x 6; f, sterile lemma, x 6; g, fertile lemma with long awn (palea absent), 1985] CAMPBELL, GRAMINEAE 169 More chromosome base numbers have been reported in the Panicoideae than in any other subfamily (character 84 of the APPENDIX). Base numbers are mostly nine or ten, but five (Christopher & Abraham, 1976) and four (Celarier & Paliwal) have also been reported. Tribe 5a. Andropogoneae Dumortier, Obs. Gram. Belg. 84. 1824, “Andro- pogineae.”” Spikelets often paired, with | sessile, perfect or carpellate, and 1 pedicellate, staminate or neuter (FIGURES 8, 9); glumes usually firmer than the lemmas and with 3 or fewer nerves; lemmas of fertile floret awned (FIGURE 8g) or unawned. Photosynthesis type kranz, subtype MS. (Saccharineae Dumortier, op. cit. 83, 141. Maydeae Dumortier, op. cit. 84, 142. Zeae Reichenb. Consp. Reg. Veg. 55. 1828. Ophiureae Dumortier, Anal. Fam. 64. 1829. Imperateae Gren. & Godron, Fl. France 3: 471. 1855. Coiceae Nakai, Ord. Fam. etc. Append. 223. 1943. Euchlaeneae Nakai, ibid. Tripsaceae Nakai, ibid.) Type GENUS: Andro- pogon L. Ficures lc, 2d, 8, 9. The approximately 85 genera of the Andropogoneae form one of the most easily recognized and clearly monophyletic large taxa in the family. Clayton (1972, 1973, 1981b, and in prep.) recognized about 12 subtribes, eight of which occur in our area: Andropogoninae Presl (Andropogon and Schizachyrium Nees); Anthistirriinae Presl (Heteropogon Pers., Hyparrhenia Fourn., and The- meda Forskal); Coicinae Reichenb. (Coix L.); Dimertinae Hackel es Beauv.); Rottboelliinae Pres] (Coe/orachis Brongn. [Manisuris L., in part Elionurus Willd., Eremochloa Buese, Hackelochloa Kuntze, and He see R. Br. [Manisuris, in part]); Saccharinae Griseb. (Erianthus Michaux, /mperata Cyr., and Microstegium Nees); Sorghinae Stapf (Bothriochloa Kuntze, Chry- sopogon Trin., Sorghastrum Nash, Sorghum Moench, and Vetiveria Bory); and Tripsacinae Dumort. (Tripsacum L.). The last was long recognized as the tribe Maydeae, but this group is closely tied to the Andropogoneae through the Rottboelliinae. These 21 genera contain about 57 species in our area All species studied so far are C, and have the MS subtype of kranz anatomy (Carolin et al.; Johnson & Brown; Brown, 1977). Epidermal and transverse- sectional anatomy of leaves (Renvoize, 1982), base chromosome number (Ce- larier), host distribution of smuts aso), Overall morpnolosy (Hackel, 1889; Keng), and perhaps the nature of th i a the unifor mity of the tribe and its distinctness from other tribes. x 6;h, floret (Iemma removed), showing turgid lodicules tive stigmas, and staminal filaments (anthers fallen), < 12; i, dehisced anther with apical slits, x 6; j, pollen with 1 germination pore, x 500; . _ solitary inflorescence, x 2; 1, spikelet pair in fruit, vestigial sterile spikelet recurved to right, x 6; m, caryopsis, x 6; n, embryo in diagrammatic longitudinal section ete to left, coleoptile and coleorhiza to right, vascular tissue in black), showing internode between scutellar and coleoptilar nodes, no epiblast, and cleft between base of scutellum and coleorhiza; 0, diagrammatic transverse section of embryo through scutellum, coleoptile, and first embryonic leaf at level of arrow in “n,’ showing numerous vascular bundles and overlapping margins of leaf (“‘n’”’ and “‘o’ > after Reeder, 1957, fig. 16) 170 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 h HS i ce! iy Pm se — 2S FIGURE 9. Inflorescences, spikelets, and their parts, Andropogoneae (Panicoideae). A, Coix Lacryma- -Jobi: Al, inflorescence, staminate spikelets above, carpellate spikelet enclosed in bony invonicre ee style of fertile spikelet and tips of 2 sterile spikelets protruding, x 2; A2, glumes of staminate spikelet, x 3; A3, fertile staminate floret, palea facing viewer, lemma behind, x 3: A4, sterile staminate floret, x 3; A5, carpellate spikelet removed from involucre, glumes separated to show fertile floret, sterile florets removed from both sides of central ridge on fertile floret, x 2; A6, fertile floret seen from side opposite that in AS, delicate lemma overlapping thin palea, x 3; A7, sterile carpellate floret, x 2. B, Tripsacum dactyloides: B1, portion of inflorescence with staminate spike- lets, x 2; B2, staminate spikelet seen from side, showing glumes, x 3; B3, nae x 3. C, Coelorachis rugosa (Manisuris rugosa): Cl, portion of inflorescence, showing 2 fertile spikelets (outer ee rugose) and their pedicellate sterile spikelets, x 3; C2, joint 1985] CAMPBELL, GRAMINEAE Lyi The andropogonoid spikelet pairs are often grouped into a linear structure (Ficures 8a, k; 9B1, B4) traditionally called a raceme but perhaps deserving a separate term such as rame (Pohl). At maturity this linear structure breaks up into dispersal units (FiGuReEs 81, 9D1) consisting of an internode, a sessile spikelet, a pedicel, and the pedicelled spikelet if it has not already senesced and fallen The Andropogoneae presumably arose in the Old World (Hartley, 1950, 1958a; but see Cross) from a kranz panicoid ancestor (Brown & Smith, 1972; Johnson & Brown) probably resembling members of the small tribe Arundi- nelleae (Clayton, 1981a). The andropogonoids reached North America by way of southern Europe before the separation of the continents beyond dispersal range in the Tertiary (Brown & Smith, 1972). Now they range broadly in the tropics and subtropics, with centers of diversity in savannas of Indochina and southwestern Africa (Hartley, 1950, 1958; Cross) In addition to the differences between the Andropogoneae and Paniceae given in the diagnoses, the Andropogoneae have higher levels of proline and glycine in their caryopses (Yeoh & Watson) and more numerous and longer mesocotylar roots in their seedlings (Hoshikawa). They may also be a younger group (Brown, 1958b) Tribe 5b. Paniceae R. Brown in Flinders, Voy. Terra Austral. 2: 582. 1814. Spikelets usually solitary; glumes usually less firm than lemmas and with 3 or more nerves; lemmas usually awned. Photosynthesis types non-kranz and kranz, subtypes MS and PS (both NAD-me and PCK). (Tristegineae Link ex Nees in Hooker & Arnott, Bot. Voy. Beechey, 237. 1836. Melinideae Link, Hort. Bot. Berol. 1: 270. 1827, nomen invalidum; see Clayton, 1981c. Anthe- phoreae Pilger ex Potztal, Willdenowia 1: 771. 1957.) TyPE GENUs: Panicum. Ficures 10, 11 A large, widely distributed tribe represented in the southeastern United States by about 26 genera and 230 species. Cross documented the wide distribution of the Paniceae in the tropics and their prominence in the grass flora of the East African savanna. Hartley (1950, 1958b) pointed out the prominence of the tribe in the moist New World tropics, especially northeastern South Amer- ica. The tribe does appear to be better developed in the New World than the andropogonoids. Brown (1958b) recorded a geographic distribution of panicoid apomictic taxa more widespread and uniform than that of andropogonoid apomicts. If, as he assumed, apomicts are more poorly dispersed than sexually reproducing taxa, then the distributional difference between panicoid and an- dropogonoid apomicts might indicate a greater age for the former group. The relatively frequent occurrence of apomicts in the Paniceae may be linked to of rachis, with fertile ene to right ae pedicellate ae spikelet above and behind fertile spikelet, x 5; C3, joint of rachis, x 5; C4, sterile spikelet and pedicel, x 5; C5, fertile floret, lemma to left x 5. D, An dr ropogon Gerardi. x 4: D1, spikelet pair, joint of rachis to right behind fertile spikelet, pedicellate spikelet above and behind awn, with slight notch at left marking limit of spikelet (sterile); D2, fertile floret. Li2 JOURNAL OF THE ARNOLD ARBORETUM Mile al \) la SK — Ze Ficure 10. Panicum (Panicoideae, Paniceae). a—m, P. clandestinum oe clandestinum): a, part of winter rosette of leaves, x '; b, inflorescence of chasmogam spikelets, x ‘2: , c, upper part of nae chasmogamous spikelets in fruit or a cae inflorescence, inflorescence of cleistogamous spikelets below, = 1; d, detail of upper part of leaf sheath, base of blade, and ligule, x 6; e, chasmogamous spikelet at anthesis, pollen already shed from anthers, | stamen not visible, x 6; f, small first and larger second glume, x 10; g, sterile lemma (pubescent) and sterile palea, x 10; h, flower of cleistogamous spikelet (note shriveled staminal filaments, pollen on stigmas, and Sanne x 20; 1, fertile lemma (behind) and palea enclosing mature caryopsis, x 10; j, mature caryopsis, adaxial surface (note shriveled styles and hilum), x 12; k, diagrammatic longitudinal 1985] CAMPBELL, GRAMINEAE 173 the high frequency (77 percent) of polyploidy estimated by Christopher & Abraham (1976) for this tribe. Unlike the Andropogoneae, the Paniceae are not sharply defined in leaf anatomy (Carolin et a/.) or photosynthetic pathway (Brown, 1977). Thirty-one genera are characterized by C, photosynthesis; 44 have the MS subtype of kranz anatomy, 13 the PS subtype; and two (Panicum and Alloteropsis Pres) contain both C, and C, taxa. Both PCK and NAD-me types have been reported among the PS taxa. Brown (1975) postulated two origins of kranz anatomy in the Paniceae, one involving the mestome sheath for most of the kranz taxa, and the other the parenchyma sheath. Up to about eight small tribes are more or less closely related to the Paniceae. Two of these, the Anthephoreae and the Tristegineae (Melinideae), are rep- resented in our area by adventive taxa. They are close enough to the Paniceae to be included (Stebbins & Crampton), although they are also a bly separable (Pilger; Brown, 1977). The Anthephoreae include Anthephora "Schreber (about 20 species), which resembles the Paniceae in all respects except two. First, while the genus as a whole shows the MS subtype of kranz anatomy, some species also have “distinctive cells” —kranz cells not associated with a vascular bundle. That these unusual cells uniquely characterize the Anthephoreae and three other small panicoid tribes (Arthropogoneae Pilger, Garnotieae Tateoka, Arun- dinelleae Stapf) has suggested to some (Johnson & Brown; Brown, 1977) that these taxa should be amalgamated. Second, the spikelets of Anthephora are partially fused into groups of four. The Tristegineae are mostly African, with two species from two genera, Melinis (M. minutiflora Beauv.) and Rhynche- lytrum Nees (R. repens (Willd.) Hubb.), adventive in the southeastern United States. This tribe is characterized by the PS subtype of kranz anatomy, known elsewhere in the Paniceae only in the subtribe Brachiariinae Butzin (see below) and in Panicum subgenus Panicum. The small panicoid tribes are important to an understanding of phylogeny within the subfamily. The Anthephoreae may share a common ancestor with the Andropogoneae, since both have MS anatomy, delicate and often awned fertile lemmas, and a base chromosome number of 10. Clayton (1981a) considered the Arundinelleae to be ancestral to the Andropogoneae; both he and Brown (1977) considered another small tribe, the Isachneae Bentham, to have been ancestral to the Paniceae. Brown (1977) divided the Paniceae (sensu stricto) into four groups. All genera with the MS subtype of kranz anatomy fall into his informal group, subtribe 1. Thirteen of these genera occur in our area: Athaenantia Beauv., Axonopus section of caryopsis, embryo to left, adaxial side to right, hilum to right of embryo, section ofembryo yea scutellum, coleoptile, and first embryonic leaf at level of arrow in “‘],” ular bundles and overlapping margins of leaf. n, P. anceps: spikelet in fruit, rst aac ic lower right, second glume to left, sterile lemma and tip of fertile lemma visible, x 10. (Diagrammatic sections ‘‘l’’ and ‘““m” after Reeder, 1957, 174 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 \ a See = Sy > oe oe a ip My “aii. y hyve a Figure !1. Inflorescences, spikelets, and their parts, Paniceae (Panicoideae). A, Cen- chrus gracillimus: involucre with spikelets, x 5. B, Cenchrus echinata: B1, involucre with spikelets, x 5; B2, tip of spine from involucre, x 25; B3, spikelet, x 5; B4, floret, (slightly rugose), x 10; C3, spikelet, showing second glume and slightly rugose indurated lemma of fertile floret, x 10; C4, fertile floret, lemma clasping palea, x 10. D, Sacciolepis striata, x 10: D1, spikelet, showing 2 glumes and lemma of sterile floret; D2, same, turned 90° to show i of sterile lemma and glumes; D3, fertile floret, showing lemma 1985] CAMPBELL, GRAMINEAE 175 Beauv., Cenchrus L., Digitaria Heister, Echinochloa Beauv., , Leptoloma Chase, the non-kranz genera, which both his (1977) and Hsu’s data support as the most primitive in the tribe. Seven genera are found in our area: Amphicarpum Kunth, Hymenachne Beauv., Lasiacis (Griseb.) Hitchc., Panicum subgenus Dichanthelium Hitchc. & Chase, Oplismenus Beauv., Sacciolepis Nash, and Steinchisma Raf. Brown’s third group, the Brachiariinae, has the PS, PCK subtype of kranz anatomy. It contains three genera in the Southeast: Brachiaria Griseb., Coridochloa Nees, and Eriochloa Kunth. The last group, the Panicinae southeastern United States are P. capillare L., P. flexile (Gatt.) Scribner, and P. virgatum L. UNPLACED TRIBES Three small tribes, all with C, photosynthesis and mostly temperate in dis- tribution and therefore traditionally assigned to the Pooideae, are not well accommodated in that subfamily (Macfarlane & Watson, 1980). All three share several character states with the Bambusoideae as defined here, but none of them fits well in either that subfamily or any other. Hence they are left unplaced pending further study. Tribe 6a. Brachyelytreae Ohwi, Bot. Mag. Tokyo 55: 361. 1941. Stem internodes solid. Transverse veins sometimes present in the leaves. Rachillas prolonged; spikelets (FIGURE 6D) 1-flowered; glumes very small; ovary with a short-hairy apex below the styles, forming a persistent beak on the caryopsis. Embryo with or without a scutellar tail; embryonic leaf margins overlapping. Microhairs absent; papillae present; dumbbell-shaped silica bod- ies present but elongated, sinuous or crenate silica bodies and tall and narrow silica bodies absent. Sclerenchyma not accompanying the smallest vascular bundles; vascular bundles without both adaxial and abaxial girders. Base chro- mosome number 11. Type GeNus: Brachyelytrum Beauv. FiGure 5D. A monogeneric tribe; B contains one species (B. erectum (Schre- ber) Beauv.) found in noise woodlands of eastern Canada, the United States, Japan, Korea, and China. The Asian populations have been considered distinct at the varietal or specific level. The genus has most often been placed in the Pooideae, either in the Agrostideae (Bentham; Hitchcock; Prat, 1960; Stebbins clasping palea. E, Stenotaphrum secundatum: El, section of flattened, thickened rachis, SE of 2 ‘lowest pairs aborted, x 5; F3, fertile floret, lemma behind, inrolled margins clasping palea, x 5. 176 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 & Crampton), the Poeae (Pilger), or the Stipeae (Hackel, 1887; Brown, 1950; Clifford, 1965) or in its own tribe and near the Stipeae (Tateoka, 1957b) or the Bromeae (Ohwi). Reeder (1957) and Macfarlane & Watson (1980) noted the similarity of the embryos of Brachyelytrum to those of Oryza and Leersia. There are other character states shared by Brachyelytrum and the Bambusoideae. Brown (1958a) put Brachyelytrum and the bambusoids together because of their somewhat specialized, thick-walled parenchyma sheath cells, and because transverse veins (character 4 of the ApPpENDIXx), papillae (51), and cross- to dumbbell-shaped to nodular silica bodies (53) are found in both taxa. Among C, grasses, a base chromosome number of 11 is known in the Stipeae and some herbaceous bambusoids (Calder6én & Soderstrom, 1980). Campbell and colleagues (in prep- aration) present evidence for bambusoid affinities of Brachyelytrum in seedling morphology and leaf ultrastructure. Like the seedlings of herbaceous and woody bamboos (Hoshikawa; Soderstrom, 1981a), that of Brachyelytrum has a very short mesocotyl and no adventitious roots at the first two seedling nodes or in the internode connecting them. In terms of leaf ultrastructure, Brachyelytrum and the few bamboos studied by Carolin and co-workers, unlike pooids, have few or no osmophilic granules in the mestome sheath and numerous thylakoids and large grana in the mesophyll plastids. There are, however, numerous fundamental differences between Brachy- elytrum and the Bambusoideae in number of floral parts (characters 24, 28, and 31 of the APPENDIX), ovary apex (29, 30), first seedling leaf blade (44), microhairs (47), stomatal subsidiary-cell shape (60), and leaf anatomy (69, 70). The inclusion of Brachye/ytrum in the Bambusoideae would greatly loosen the circumscription of the subfamily. Tribe 6b. Diarrheneae (Ohwi) Tateoka ex C. S. Campbell, stat. nov.” Rachis prolonged above uppermost floret; spikelets with 2-5 florets. Lodi- cules hairy; ovary appendage yellowish or whitish, hard and glossy. Pericarp free from the seed coat. Embryo with a scutellar tail; embryonic leaf margins overlapping. Microhairs absent; elongated, sinuous or crenate silica bodies and cross- to dumbbell-shaped to nodular silica bodies present; tall and narrow silica bodies absent. Some vascular bundles with both adaxial and abaxial girders. Base chromosome number 11. Type Genus: Diarrhena Beauv. Like Brachyelytrum, Diarrhena is a small genus of broad-leaved, rhizoma- tous, woodland herbs with appendaged ovaries and a distributional disjunction between the eastern United States (D. americana Beauv.) and eastern Asia (several species). None of the subfamily positions suggested in the past— Pooi- deae (Stebbins & Aalees Deeks Soe & eel eno grae ae 1957a, 1957c), an wab)—is d M & Wat- son, 1980). Hilu : Wright recommended a possible new subfamily, the Nar- doideae, composed of Diarrhena, Nardus L., and Lygeum and intermediate between oryzoids and pooids. From embryo anatomy, Macfarlane & Watson (1980) concluded that this odd genus might have some connection with oryzoids or bambusoids. *See note on page 188. 1985] CAMPBELL, GRAMINEAE Lee Tribe 6c. Stipeae Dumortier, Obs. Gram. Belg. 83. 1824, “‘Stipaceae.” Rachillas not prolonged above uppermost floret; spikelets with 1 floret; lem- ma awns terminal, often basally twisted. Lodicules 2 or 3 per flower. Microhairs present or absent; epidermal papilla | per cell; elongated, sinuous or crenate silica bodies absent, saddle-shaped silica bodies and crescentic silica bodies present. Some vascular bundles with both adaxial and abaxial girders. Base chromosome numbers 9, 10, 11, 12. Type GeNus: Stipa L. FiGure 5J. The Stipeae comprise about nine genera and 380 species, most of which belong to the genus Stipa. The tribe occurs primarily in dry grasslands of temperate latitudes and especially in the Caspian Sea region, Australia, and the Andes (Hartley, 1973). It is noteworthy for its rather extensive fossil record (Thomasson, Muller). In the southeastern United States the tribe is represented only by Stipa leucotricha Trin. & Rupr. and two species of Piptochaetium Presl: P. avenaceum (L.) Parodi (Stipa avenacea L.) and P. avenacioides (Nash) Va- lencia & Costas (S. avenacioides Nash) There is abundant and eclectic evidence that the Stipeae are not closely related to pooid grasses (Macfarlane & Watson; Barkworth). Rachillas are not prolonged and lodicules are two or three in stipoids. Pooids and stipoids also differ in silica-body complements (APPENDIX, characters 52, 53, 55, 56). John- ston & Watson (1977) reported microhairs from the adaxial leaf surface of several species of Stipa. The two groups differ serologically (P. Smith), in terms of amino-acid complements (Semikhov; Yeoh & Watson), in the rusts and smuts parasitizing them (Watson, Savile), and in their germination response to IPC (Al-Aish & Brown). The stipoid embryo bears a distinctively long epiblast and a sharply bent primary root (Reeder, 1957). Finally, the extensive aneuploid series of chromosome numbers based on 11 and 12 (Reeder & Reeder) is quite unlike pooid karyotypes. 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Bot. 38: 963. 1960) suggested that the establishment of a separate tribe might be ‘the best way to arrange Diarrhena into the grass system.” However, because further studies seemed desirable, Tateoka confined himself to pointing out the peculiarities of the genus. It seems appropriate at this point to raise the subtribe formally to the rank of Diarrheninae Ohwi (Acta Phytotax. Geobot. 10: 134. 1941), with the type genus Diarrhena Beauv APPENDIX. Data matrix of grass subfamilies and tribes. CHARACTER TAXON l 2 3 4 5 6 7 8 9 10 ll BAMBUSOIDEAE a(b) var var pr(ab) (pr)ab (a) a(b) a/b b d/e a(b) ARUNDINARIEAE b b var pr pr NC var a b d/e RYZEAE a (a)b var ab ab (a) a (a)b b d/e a PHAREAE a a pr pr ab NC a b b e b ARUNDINOIDEAE a(b) var ab ab (pr) ab var b a(c) b (a/b)e a ARISTIDEAE a ar ab ab b a b a b a/e a ARUNDINEAE a(b) var ab ab var var b a(c) b e a CENTOTHECEAE a b ab ab ab NC b a b b a POO E a (a)b ab (pr) ab ab a(b) a a b (a/b/d)e a(c) AGROSTIDEAE a b ab b a(b) a a b e a JENEAE a b ab b a a a b e a MELICEAE a b ab (pr)ab ab ar a a b (d)e a E a (a)b ab (a)b a a b (a)e a BROMEAE a ab ab ab a a a b (d)e a TRITICEAE a (a)b ab ab ab a a a b a(b) a(c) CHLORIDOIDEAE a var (pr) ab ab var a(b) (a)b a(b/c) (a)b a a AELUROPODEAE a a ab pr a b (a/b)c b a CYNODONT a var (pr)ab ab (pr) ab var (a)b a(b/c) (a)b G)b(e/ADe a UNIOLEAE a b ab ab N NC b? a b a ZOYSIEAE a a ab ab ab a b a b yeh a PANICOIDEAE a(b) var (pr) ab (pr)ab (pr)ab var va a(b) a (a)b(c)e(f) ar ANDROPOGONEAE a(b) a(b) (pr)ab a a var (a)b a(b) var (a)b/e(f) a/b(c) PANICEAE a(b) var (pr)ab (pr)ab (pr)ab a(b) va a (a) b(c)e UNPLAC BRACHYELYTREAE a a ab var ab a a a b e a DIARRHENEAE a NC ab ab ab NC a(b) a b e a STIPEAE a(b) var ab ab ab var a(b) a b e a AVANINVYUD “Tadd N VO [S86I 681 APPENDIX (continued ). CHARACTER TAXON 12 13 14 15 16 17 18 19 20 BAMBUSOIDEAE a/c var b 1 (6-12) 0(1/2/3) ab/NA b/NA b/NA a/b ARUNDINARIEAE a a b 6-12 (1)2(3) ab b b a/b ORYZEAE a/c var b 1 0(2) NA NA NA a/b PHAREAE c NA b 1 NA NA b a ARUNDINOIDEAE a(b/c) a a(b) 1-20 2 (pr) ab a(b)NA (a/b)e var a(b) a a 1 2 var NA b b/c ARUNDINEAE a/c a a 2-20 Q ab var a/c var CENTOTHECEAE a a b 3-12 2 ab a c a POOLDEAE a(b)ec a(b) a(b) 1-30 (0/1)2 (pr)ab (a)b/NA var a/b(c) AGROSTIDEAE a(b)c a(b) a(b) ~-12 2 (pr) ab a/b/NA var a/b(c) AVENEAE a/c a a (1)2-7(10) 2 ab a/b/NA b(c) b MELICEAE a/c a(b) a (1)3-7(16) 2 ab b b a/b POEAE a/c a a )2-10(22 2 var b var a/b BROMEAE a/e a a (1/2) 3-30 2 ab b c a/b TRITICEAE a/c a/b a (1)2-7(12) (0/1)2 var b/NA var (a)b(c) CHLORIDOIDEAE a(b)/c a(b)NA var 1-45 (0)2 (pr)ab (a)b(c) var a(b/c) AELUROPODEAE a/e a/NA a (2)3-12(20) 0/2 ab b NC a CYNODONTEAE a(b)/c a(b)NA a(b) -5( (0)2 var b/NA (var) a(b/c) a a -13 2 ab a/c a/c a ZOYSIEAE var b/NA b 1 2 ab NA a a PANICOIDEAE (a)b(c) (a)b/NA (a)b 1 (0/1)2 (pr) ab a/NA a/b(c) a/b ANDROPOGONEAE (a) b(c) b b l 2 (pr) ab a/NA a a/b (a)b(c) (a)b/NA (a)b l (0/1)2 (pr) ab a (a)b(c) a UNPLACED BRACHYELYTREAE b/c a a 1 1/2 ab NA é b DIARRHENEAE a/c a a (1)2-5 2 ab b b a STIPEAE a/c a b l 2 ab NA b/c b WOLAYOUAV ATIONYV AHL JO TVNANOL 061 99 ‘10A] CHARACTER TAXON 21 22 23 24 25 26 27 28 29 30 BAMBUSOLDEAE a/NA 3-17 2 or more 2/3 (b) var var (1-)3/6 b ab ARUNDINARIEAE a 11-17 3 NC var b b ab ORYZEAE a/NA 3-5(7) (2)3 or more 2 b b var (1-)6 b ab PHAREAE NA NC NC NC NC NC NC 6 NC NC ARUNDINOIDEAE a(b)NA 1-15 0-2 (0)2 var (a)b (a)b 1(2)3 b ab ARIST IDEAE a 1-3 0-2 0/2 b b b 1-3 b ab ARUNDINEAE a/b 1-15 2(var) 2 a(b) var NC 3 b ab CENTOTHECEAE NA 5-15 2 2 a b var 1 b ab POOIDEAE (a)b/c (1) 3-15 (0/1)2(4) 2 (a)b (a)b var (1/2)3 var (pr)ab AGROSTIDEAE b/c (1)3-5(7) (0/1) 2(4) 2 b (a)b var (1-)3 (a)b ab AVENEAE c 3-15 2 2 b b (a)b 3 a(b) ab MELICEAE b/c 5-15 2 2 a b (var) 3 b ab POEAE var 3-15 2 2 b b a(b) (1-)3 (a)b ab BROMEAE b/e 5-15 2 2 var b b 2/3 a pr TRITICEAE a(b) (3)5-7(11) 2 2 b a(b) var 3 a ab CHLORIDOLIDEAE var/NA 1-11 (0/1)2 (0)2 a(b) b (a/b) (1-)3 b ab ELUROPODEAE NA 3-7 2 2 var b a 3 b ab CYNODONTEAE a/b 1-7 2 2 a(b) b (var) 3 b ab UNLOLEAE NA 7-11 2 2 a NC NC 1/3 b ab ZOYSIEAE NA 1/3 0/1/2 2 b b a 2/3 b ab PANICOLDEAE a/b(c)NA (0)1-6(11) 0/2/NA (O/1)2— a(b) (a)b b (1-)3 b ab ANDROPOGONEAE (0) 1-3(5) 0/2/NA (0)2 a(b) (a)b b (1-)3 b ab PANICEAE (0) 3-6(11) 2 (O/1)2.— a(b) b b 3 b ab UNPLACED BRACHYELYTREAE a 5 2 2 b b b 3 a pr DIARRHENEAE NA 3-5 2 2. b a var (1)2/3 b ab STIPEAE a/b 3-7 1/2 2/3 var b b (1)3 b ab AVANINVYD ‘TIddNVvo [S86 Tol APPENDIX (continued ). CHARACTER TAXON 31 32 33 34 35 36 37 38 39 40 41 BAMBUSOIDEAE 2) (a/b) pr(ab) b/e a b b pr var b a(b) ARUNDINARIEAE 3 NC pr c a b b pr i b a ORYZEAE 2 a/b (ab) b/e a b b pr (pr)ab b a/b PHAREAE 3 NC NC NC NC NC NC pr (pr)ab b a err 2 b (pr)ab var var var b (pr)ab pr a b DEAE 2 b ab b a/b a b ab pr a b ian NEAE 2 b var a/b (a)b var b (pr)ab pr a b eee 2 b ab b b b b pr pr a b POOIDEAE 2 b var var a(b) (a)b (a)b pr(ab) ab b b AGROSTIDEAE 2 b var var (a)b (a)b var pr ab b b AVEN EAE 2 b var var a b (a)b pr ab b b MELICEAE Z b pr a/c a b b pr ab b b POEAE 2 b var a(b) var b Gay pr ab b b BROMEAE 2 b pr b a b b ab ab b b TRITICEAE 3 i pr a(b/c) a b b var ab b b CHLORIDOIDEAE 2 (a)b ab var b a(b) b pr(ab) pr(ab) a(b) (a)b AELUROPODEAE 2 NC NC NC b NC b pr b a b CYNODONTEAE 2 (a)b ab var b a(b) b pr var a(b) (a)b UNIOLEA 2 b NC NC b a NC pr pr a b ZOYSIEAE 2 b ab var b a b pr pr a b PANICOIDEAE 2 b ab var (a)b a(b) b ab pr a a(b) ANDROPOGONEAE 2 b ab var b a(b) b ab pr a a(b) PANICEAE 2 b ab a(b/c) (a)b ab) b ab pr a a UNPLACED eo 2 b pr a/e a b b pr pr/ab b a DIARR EAE 2 a NC c var b b pr is b a ST ee 2 b ab a/c a b b pr ab b b WOLAYOIUV GIONUV AHL AO TYNANOfL C6 99 “10a] CHARACTER TAXON 42 43 44 45 46 47 48 49 50 51 52 53 BAMBUSOLDEAE (b) b ab(pr) a(b) (a)c pr (ab) 2 a/NA a pr ab pr (ab) ARUNDINARIEAE NC b ab NA NA pr 2 a a pr ab pr ORYZEAE b var ab NA NA pr 2 a a pr ab ab PH NC b pr a c ab NA NA a NC ab pr ARUNDINOIDEAE b var pr var b(c) pr(ab) 2 a a ab (pr) ab pr ARISTIDEAE b b pr b b pr 2 a a ab pr pr ARUNDINEAE b var pr var b pr (ab) 2 a a ab ab pr CENTOTHECEAE NC a pr a c pr 2 a a NC ab pr POOIDEAE (a)b var pr var a ab NA NA var (pr)ab pr (pr)ab AGROSTIDEAE (a)b a(b) pr (a)b a ab NA NA var ab pr (pr) AVENEAE b a (var) (a) ab NA NA (a)b a MELICEAE b a (pr) (var) (a) ab NA NA var pr/ab pr (pr) POEAE b a(b) pr (a)b a ab NA NA var (pr)ab pr ab BROMEAE a var pr b a ab NA NA b ab pr ab TRITICEAE a (a)b pr b a ab NA NA var ab pr ab CHLORIDOIDEAE (a)b a(b) pr a(b) (var) pr(ab) 1/2 (a)b a(b) var (pr) ab var AELUROPODEAE a NC NC NC va 1/2 b a var ab CYNODONTEAE b (a) (pr) (a/b) (a/b) pr 1/2 (a)b a(b) var (pr) (pr/ab) UNIOLEAE NC NC NC NC pr 2 a a ab ab pr ZOYSIEAE b a/b pr a a/c pr(ab) 2 b a var ab ab PANICOIDEAE var a(b) pr a var pr (1)2 a(b) a(b) var ab pr ANDROPOGONEAE var a (pr) (a) var pr 2 a(b) a(b var ab pr ANICEAE a(b) a(b) pr a (a)b(c) pr (1)2 a(b) a(b) (pr)ab ab pr UNPLACED BRACHYELYTREAE a b pr b var ab NA NA a pr ab pr DIARRHENEAE b NC NC NC NC ab NA NA a ab pr pr STIPEAE var var pr b a var 2 a a var ab pr AVANINVUD “T1dddWVO [S86 c6l APPENDIX (continued ). CHARACTER TAXON 54 55 56 57 58 59 60 61 62 63 BAMBUSOIDEAE ab (pr) ab (pr) ab (pr) ab ab (b) (a)e (var) var b ARUNDINARIEAE ab pr ab a ab NC c NC b(a) b ORYZEAE ab ab (pr) pr ab b a var var b PHAREAE ab ab ab ab ab NC c NC a b ARUNDINOIDEAE pr(ab) pr(ab) pr (ab) (pr) ab ab var var var var (a)b ARISTIDEAE pr pr var ab var a(b) var a/c a ARUNDINEAE (pr) (pr) (pr) ab ab var var var var (a)b CENTOTHECEAE ab ab ab ab ab NC a pr var b POOIDEAE pr(ab) (pr)ab (pr) ab ab (pr)ab a(b) b var (a)b/c b AGROSTIDEAE (pr) (pr) ab ab (pr) a(b) b var (a/b)c b AVENEAE ab ab ab ab ab a(b) b b b/c b MELICEAE ab ab ab ab ab NC b var (a/b)c b (pr) ab pr ab ab a(b) b var (a/b)c b BROMEAE pr ab pr ab ab a b ab var b TRITICEAE pr (pr) pr ab ab a b var b/e b CHLORIDOIDEAE pr(ab) pr(ab) var b ab (a)b a(b/c) pr (ab) var a AELUROPODEAL pr r ab ab var a pr c a CYNODONTEAE (pr) pr(ab) (pr/ab) ab ab var a(b/c) var a(b/c) a UNIOLEAE ab ab ab ab NC a ab a a ZOYSTEAE ab pr pr ab ab var a pr var a PANICOIDEAE (pr)ab (pr)ab ab ab (pr)ab (a)b a var a(b/c) a(b) ANDROPOGONEAE ab ab ab ab ab b a var a(b/c) a PANICEAE (pr) (pr) ab ab (pr) (a)b a var a(b/c) a(b) UNPLACED BRACHYELYTREAE ab ab ab ab ab var b ab a b DIARRHENEAE ab ab ab ab ab a var ab a/c b STIPEAE pr pr pr ab ab var var ab var b WOLAYOPIAV CTIONAYV AHL AO TYNUNOL v6 99 “10a] CHARACTER TAXON 64 65 66 67 68 69 70 ral 72 73 74 BAMBUSOIDEAE ab (ab) ab a (a)b pr pr(ab) (a)b pr var (var) ARUNDINARIEAE ab NC ab a b pr r b NC pr NC ae ab ab ab a b pr var (a)b (pr) var var B NC NC ab NC a pr pr b pr NC NC ARUNDINOIDEAE (ab) ab var a(b) b (pr)ab ab a(c) (pr) ab var var EAE ab ab pr b b ab ab a ab var var ARUND INEAE NC ab var a b (pr)ab ab a/c ab var ab CENTOTHECEAE NC NC ab a b ab ab NC pr NC NC POOIDEAE (ab) ab (pr)ab a b ab ab a(c) (pr var var AGROSTIDEAE (ab) ab (pr)ab a b ab ab a(c) (pr) va (pr)ab AVENEAE NC ab ab a NC ab ab a NC (pr) ab var MELICEAE ab ab ab a NC ab ab a (pr) (pr)ab (pr)ab OEAE NC ab ab a b ab ab a NC ar (pr) ab BROMEAE NC ab ab a b ab ab a NC var ab TRITICEAE NC ab ab a b ab ab a(c) NC var (pr)ab CHLORIDOIDEAE (ab) ab pr (ab) a (a)b ab ab a/c (pr) var var AELUROPODEAE NC ab pr a b ab ab a NC ab ab CYNODONTEAE (ab) ab pr (ab) a (b) ab ab a(c) (pr) (pr)ab pr(ab) UNIOLEAE ab ab pr a NC ab ab Cc P pr NC ZOYSLTEAE NC ab pr a var ab ab a NC var var PAN ICOIDEAE (pr) ab (pr)ab pr (ab) var var ab ab a/c (var) var var ANDROPOGONEAE (ab ab r (ab) b a(b) ab ab (ajc NC vat var PANICEAE (pr) ab (pr)ab pr (ab) var var ab ab a/c (var) var var UNPLACE BRACHYELYTREAE ab ab ab a ab ab a pr pr ab DIARRHENEAE ab ab ab a NC ab ab a pr pr ab TIPEAE NC ab ab a ab ab a/c pr pr ab AVANINVUD “TIddWNVO [S86 c6l APPENDIX (continued ). CHARACTER TAXON 75 76 dd 78 79 80 81 82 83 84 BAMBUSOLDEAE (ab) (ab) (var) (var) (pr) pr pr (ab) a/ 12 ARUNDINARIEAE NC NC NC NC NC pr pr NC NC 12 ORYZEAE ab ab var var pr pr (pr) ab a 12(15/17) PH NC NC NC NC NC pr NC NC c 12 ARUNDINOIDEAE var ab ab var pr pr var var a/b(c) (11)12 RISTIDEAE ab ab ab pr pr pr ab pr b/e 1. ARUNDINEAE var ab ab ab pr pr var var a/b 12 CENTOTHECEAE NC NC NC NC NC pr NC NC a/b 12 POOLDEAE ab ab ab (pr) ab pr(ab) var var (pr) ab a/b (var) AGROSTIDEAE ab ab ab ab pr(ab) pr (ab) (pr) ab (pr)ab a(b) (4/5)7(9/13) AVENEAE ab ab ab (pr)ab pr pr (ab) ab (pr) ab a 7 MELICEAE ab ab ab ab pr pr(ab) var ab (a) 9/10 POEAE ab ab ab ab pr(ab) var (pr) ab (pr) ab (a) (5)7(13/19) BROMEAE ab ab ab ab var pr var ab a 7 TRITICEAE ab ab ab ab pr(ab) pr(ab) (pr)ab ab a 7 CHLORIDOIDEAE ab ab (pr) ab var pr(ab) pr (ab) var ab a(b) (7/9)10(12) AELUROPODEAE ab ab ab pr r pr pr ab NC CYNODON ab ab (pr)ab pr (ab) pr(ab) pr (ab) (pr)ab ab var (7)10(9/12) UNIOLEAE ab ab NC ab pr NC NC ab a 10 ZOYSIEAE ab ab ab var pr pr pr ab a 10 PANICOIDEAE ab (pr) ab var (pr)ab (pr) ab pr(ab) var (pr)ab var 5/9/10(var) ANDROPOGONEAE ab (pr) ab var (pr) ab (pr)ab pr(ab) var (pr) ab var 5/10(var) PANICEAE ab (pr) ab var (pr)ab (pr)ab ~ pr(ab) (pr) ab ab var 9/10(var) UNPLACED BRACHYELYTREAE ab ab ab ab ab ab ab ab NC ll DIARRHENEAE ab ab ab ab pr pr var ab NC 10 ab ab ab ab pr pr pr var a 9-12 961 WOLAYOUAV ATIONAV AHL JO TVNANOfL 99 10a] for this table are based on the character states found in the genera of the h from the literature Reape aa on, 1977; arlane & W ny ce 982; Soderstrom, living ram or es i aotelbee (A, GH, NY, e are defined below Two or more charact i e 'var,'' mea os “aniaplie: th make up the tribes and subfamilies Data come bot McClure, 1973; Reeder, 1 , 1962; Metcalfe, 3; Yates, 1966 98la; Watson & Dallwitz, 1981, and from examination o and US). he characters and t r states i is t roughly equal frequency are separated by a slash, wh fe) tribe une indicates nee cae and ean no data available. r ‘ab,'' respectively. nclosed in parentheses are rare, oc The presence or ace of a character is indicated by "pr ip maee oe United States Terrell; Mac nies are available s are also enclose CHARACTERS AND THEIR STATES AS USED ABOVE (b) woody (b) hollow (a) herbaceous, (a) solid, Stems: Stem internodes: Pseudopetioles: pr/ab pr/ab Leaf blade disarticulation: pr/ab (b) folded (a) rolled, 1 2 3 4, Transverse veins: 5 6 Vernation: 7 Ligules: (a) membranaceous, (b) of hairs fe) ringed 8. Sex distribution: (a) some perfect flowers c present, (b) plants monoecious, plants dioecious 9. Inflorescences: (a) leafy, (b) not leafy 10. paar form: (a) solit ike, (b) s iform branches, (c) glonerule, (d) raceme, ee panicle, (f) o ll. Spikelets: (a ) solitary, (b) paired, (c) in 3's 12. Spikelet compression: (a) lateral, (b) absent dorsal, (c) 13% Spikelet disarticulation: (a) above glumes, (b) below glumes (NA indicates disarticulation of axis at some point below the spikelet (a) prolonged above cern eae ve uppermost flo Rachilla: (b) not prolonged abov / +1 noe spiketect Carpellate and/or perfect florets Glumes/spikelet Glume awns: pr/ab (a) savas to rmos loret, (b) distal o lowermost ia ee floret, (c) t aaa and distal to lowermost carpel-bearing flo Staminate or neuter Seana Relative glume/lemma firmness: (a) glumes firmer, emmas firmer, (c) equal (a) 0, (c) more than 1 Lemma-awn number: (b) 1, Lemma-awn position: (a) apical, (c) dorsal Lemma-nerve number Palea-nerve number (b) apical notch, FTVANINVAUD “TIAddNVO [Sg6I L6l 24. Lodicules/flower Lodicules: (a) distally membranaceous fleshy, (b) distally Lodicules: (a) hairy, (b) glabrous Lodicules: (a) toothed, Stamens/flower Ovary apex: (a) hairy, Ovary appendage: pr/ab Stigmas/gynoecium Pericarp: (a) free, (b) Caryopsis groove: pr/ab Caryopsis compression: (b) lateral, (c) none (b) entire (b) glabrous adnate to seed (a) dorsiventral, Hilum: (a) linear, (b) punctiform Embryo length: (a) more than one third of rd caryopsis, (b) less than one thi of caryopsis Endosperm: (a) liquid or soft, (b) hard Epiblast: pr/ab Scutellar tail: pr/ab Embryo mesocotyl: (a) long, (b) short Embryonic leaf margins: (b) not overlapping (a) overlapping, aa ho Starch hs ns: (a) all simple east some compound Seedling mesocotyl: (a) long, First seedling leaf blade: pr First seedling leaf blade; (a narrow First Sake leaf ie (a curved, (c) s Microhairs: ae Microhair cell number Microhair distal cell: (a) na Long cell wall: (a) sinuous, straight Papillae: pr/ab Elongated, sinuous or crenate Cross-— to dumbbell-shaped to bodies: pr/ab Tall and narrow silica bodies: Saddle-shaped silica bodies: Crescentic silica bodies: pr/ Oryzoid silica bodies: pr/ab Acutely angled silica bodies: > (b) at (b) short Jab ) broad, (b) ) erect, (b) rrow, (b) inflat (b) more or less silica bodies: nodular silica pr/ab pr/ab ab pr/ab ed pr/ab 861 WOLAYOUUV CWIONAV AHL JO TVNUNOFL 99 “10A] Ne} je) bo Wo a — Guard cells: (a) overlapped by interstomatal ells, (b) not overlapped by interstomatal s Subsidiary cells: (a) triangular, (b) parallel sided, (c) dome shaped Cork-silica cell pairs: pr/ab — Baa over the veins mostly: (a) in or more, (b) nadned: (c) ewes or in short rows Maximum cell interveinal distance count: (a) one (indicates C ee 2 two 4 or more (indicates C, photosynthesi Isachne-type mesophyll: pr/ab Circular cells in mesophyll: pr/ab Radially arranged mesophyll: ia ate Whether XyMS_ or ae : (a) XyMs (indicates C, photosynthes or C, type PCK or NAD-me), 4 @) xy me ee C) photosynthesis type Bundle sheath number: (a) one, (b) at least so veins with two or three Arm cells: pr/ab Fusoid cells: pr/ab Midrib bundle number: (a) one, a more ad one and not arranged in an arc, (c than one and arranged in an arc 78. 79. lee) i) 84. Bulliform cell groups: pr/ab Simple fans of bulliform cells without colorless cells: pr/a caer: erage pes fans of bulliform and rless cells: pr/ab Narrow, penetrating groups of bulliform and colorless cells: pr/ab Arches of bulliform and colorless cells over small bundles: pr/a Colorless cells comprising adaxial half of sophyll over midrib or of middle part of oon ab Colorless cells traversing leaf: pr/ab Sclerenchyma accompanying smallest vascular ndles: pr/ab Some vascular bundles with both adaxial and abaxial girders: pr/ab pon ries adaxial and abaxial girders with an "anchor," "I," or "T" shape: pr/ab Nonbundle leaf sclerenchyma: pr/ab Vascular bundles in stem internodes: (a) in one or two 8 (b) in three or more rin (c) scatte Base chromosome number [S861 AVANINVUD “TIAddNVO . 661 KELLOGG, POA SECUNDA COMPLEX 201 A BIOSYSTEMATIC STUDY OF THE POA SECUNDA COMPLEX ELIZABETH ANNE KELLOGG THE GENUS Poa L. comprises taxa with extraordinary ecological diversity and highly varied reproductive biology, yet with equally unusual morphological uniformity. It has a worldwide distribution, occurring mostly in temperate areas in both hemispheres and on all continents except Antarctica. It probably includes more than 200 species, about a quarter of which occur in the Pamirs and Himalayas; other centers of diversity are Alaska, Iceland, and Kamchatka (Hartley, 1961). Habitats range from moist meadows to warm deserts, from sea level to nearly 4000 m, and from the arctic to equatorial regions. Some species are fully sexual, whereas others are partial or obligate apomicts; both inbreeding and fully outbreeding and dioecious species also occur (Clausen, 1961 Most workers have attempted to divide the genus into subgenera and/or sections, but the resulting classifications have not been similar (Bentham & Hooker, 1883; Hackel, 1887; A. S. Hitchcock, 1950; Marsh, 1952; Edmondson, 1978). Some of these classifications are compared in TABLE |. In general there are few reliable characters on which to base such classifications; the ones that have been used most often are habit, size and pubescence of various plant parts, and sex of flowers. Habit is a reflection of mode of branching (extra- or intravaginal), and this character can also be used to delimit large groups of species. However, size and pubescence characters are quite unreliable in some groups, often varying widely with environment or even within a single plant. Mode of apomictic embryo-sac formation, whether aposporous or diplospo- rous, may be useful for creating a subgeneric classification; however, this char- acter has not been studied for most species and would in any case only be applicable to those that are apomictic. There seem to be fertility barriers among some groups of species (see Hiesey & Nobs, 1982). The Poa secunda Pres] complex (also known as the P. sandbergii Vasey complex; see next section) is a widespread, difficult group; it is distributed over most of western North America, with disjunct populations in the Gaspé Pen- insula of Quebec and others in Chile (Map 1). The plants occur in a wide range of habitats, from low deserts to high alpine areas in the Sierra Nevada and the Rocky Mountains; most grow in relatively dry sites, but some occur in wet meadows or in damp gorges. There are currently 45 epithets in the group, and these have historically been included in from one to 11 species. The results of Heidel and colleagues (1982) and Gilmartin and coworkers (unpubl. MS) illustrate the nature of the taxonomic problem. Both groups © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 201-242. April, 1985. 202 JOURNAL OF THE ARNOLD ARBORETUM [voL. 66 Map |. Distribution of Poa secunda complex in North America. Cross shows dis- tribution of P. curtifolia, Within shaded area collections too numerous to show individ- ually. looked at sets of vegetative and floral characters, comparing variation within and between several populations of Poa secunda in eastern Washington. They found that for the vegetative characters the ratio of inter- to intra-populational variance was similar to that of other unrelated grass species; for the floral characters, however, variance within populations was unusually low compared to that between populations. With respect to floral characters, in other words, populations of Poa secunda are more differentiated than those of other grasses, although my own data show that this differentiation never leads to complete discontinuity. Faced with this low but perceptible differentiation, some tax- onomists have recognized the “units” taxonomically. he complex is commonly distinguished from the rest of the genus by the lack of a prominent keel on the lemma. I have examined lemma cross sections of 15 different species of Poa to determine the anatomical basis of this character, TABLE |. A comparison of five classifications of the genus Poa.* Hacke (1887) BENTHAM AND Hooker (1883) EDMONDSON (1978) Hitcucock (1950) MarsH (1952) Subg. Dioicopoa Subg. Eupoa Subg. Poidium Subg. Pseudopoa Subg. Dioicopoa Subg. Eupoa Subg. Poidium Subg. Pseudopoa Subg. Leucopoa Subg. Dioicopoa . Poa ect. Ochi Sect. Coenopoa Sect. Stenopoa Sect. Bolbophorum Sect. Tichopoa Sect. Homalopoa t. Cenisia t. Macropoa Sect. Leptophyllae Sect. Oreinos Sect. Abbreviatae Sect. Nanopo Epiles . Scabrellae ct. Nevadenses Subg. Dioecia Subg. Pistillata Annuae Palustres Alpi Pratenses Homalopoae Subg. Secundae *The first two classifications include the entire genus, the third only attempts to classify the European species, species. Corresponding sections in Edmondson’s and Hitchcock’s classifications overlap only in part. and the fourth and fifth include only North American XATMIWOD VAONNOAS VOd ‘DOOTIAN [S86I £0C 204 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 and I have found no appreciable difference in cross section between the P. secunda complex and other members of the genus. All species examined have two or three layers of sclerenchyma on the abaxial side of the middle vascular bundle, and these layers taper evenly to a single layer on both sides of the vein. Because the keel has no anatomical basis, and because specimens cannot easily be determined as keeled or nonkeeled, it may be an unreliable taxonomic character. More consistently useful distinguishing characters are the lengths of the ra- chilla internodes (0.6-1.9 mm, vs. < 0.5 mm for most other members of the genus) and the spikelets. Anthers are long (1-4.2 mm), whereas those of many other bluegrasses are less than 1 mm. The plants are perennial and caespitose, with intravaginal branching; the panicles are mostly narrow, and the flowers are perfect, although frequently pollen sterile. Although there 1s often a tuft of hairs on the callus, the long, tangled, cobwebby hairs characteristic of many other species of Poa are lacking. Spikelet shape and rachilla-internode length are the most distinctive char- acters of the Poa secunda group in comparison to the rest of the genus; most other bluegrasses have more or less ovoid spikelets with a very short internode between the first two florets. Intravaginal branching distinguishes all the caes- pitose bluegrasses from A. S. Hitchcock’s sections Homalopoae, Palustres, and Pratenses. The lack of a prominent cobweb at the base of the lemma also distinguishes the P. secunda group from most members of the latter two sec- tions. The perennial habit distinguishes it from section Annuae, which is made up entirely of annuals. The Poa secunda complex is defined more by exclusion than by inclusion; there is thus no evidence that the group is strictly monophyletic (1.e., including only and all the descendants of a single ancestor). The long rachilla internodes and elongate spikelets might be considered apomorphies (unique, derived fea- tures) characterizing the group, but then such imperfect-flowered species as P. cusickti Vasey and P. epilis Scribner would have to be included as well. These latter two species may, in fact, prove to be obligately apomictic descendants of P. secunda, but this is only speculation at the moment. The whole notion of apomorphy, however, is difficult to apply in a genus in which there is probable hybridization. In such a group cladistic analysis 1s not appropriate, since it 1s based entirely on an assumption of branching evolution (but see Fink, 1982, for discussion of cladistic treatment of hybrids). Sister groups might be sought in Hitchcock’s (1950) sects. A/pinae or Epiles, as was suggested by Clausen and Hiesey (1958). The taxa in these sections are, like Poa secunda, mostly caespitose; they are alpine or arctic in distribution. They all lack a cobweb on the lemma. Such evidence does not allow inference of phylogeny but at least permits elimination of some possible sister groups. Because there are fertility barriers and differences in branching, embryo-sac formation, and spikelet size and shape, P. secunda is probably not closely allied to P. nemoralis L., P. sylvestris Gray, P. autumnalis Muhl., or P. palustris L. or other members of sect. Pal/ustres (Kellogg, 1983; see also Hiesey & Nobs, 1982). This study had three major goals: to analyze the pattern of morphological variation in the Poa secunda complex (and to assess the level at which taxo- nomic characters varied, whether within the individual, within a population, 1985] KELLOGG, POA SECUNDA COMPLEX 205 or between populations); to decide how many taxa the complex represented; and to investigate the reproductive biology of the group and its role in producing the pattern of morphological variation. HISTORY OF SYSTEMATIC TREATMENTS The type specimen of Poa secunda was collected by Thaddeus Haenke “in cordilleris Chilensibus”’ probably sometime between 1790 and 1794 and was described by Presl in Reliquiae Haenkeanae in 1830, making this the oldest valid name in the group. Later in the century, collectors in the western United States, particularly Vasey, Piper, Scribner, and Rydberg, found and described many of the other species included in the P. secunda complex, beginning with Sandberg’s collection near Lewiston, Idaho, in 1892 of the plant that bears his name. Names proliferated, often without much justification. A case in point is Scribner’s (1883, p. 66) description of P. nevadensis, in which he stated “The characters of the grass agree in many points with those of Atropis scabrella, Thurber, in Bot. Calif. 1, p. 310, but whether it be the same I am unable to say, having never seen any authentic specimens of that species.” He then went on to publish the name Poa nevadensis as a new species. By 1935 more than 40 names had been published. Jones (1912) had proposed an extensive synonymy, but it had not been accepted. In 1935 A. S. Hitchcock finally resolved some of the chaos by dividing the group into two sections, Scabrellae and Nevadenses, each with four species. Most other works since Hitchcock’s Manual of the Grasses of the United States have followed his classification, recognizing similar—if not identical—groups of species. Hitchcock’s (1935) keys and descriptions were soon seen to be a poor re- flection of the variation observed in nature. C. L. Hitchcock and colleagues (1969) stated that the range of variation in the complex is so continuous that were the populations freely interbreeding, the group should be regarded as a single polymorphic taxon. Cronquist and co-workers (1977) concluded that the distinction between sects. Scabrellae and Nevadenses is quite artificial — useful for keying purposes but tending to belie the close relationship among all the species. Marsh (1952) simply synonymized all the members of the group, recognizing only the single species Poa secunda; his treatment, however, has not been followed. Authors have also disagreed on the relationship between the South American Poa secunda and the North American P. sandbergii, for a detailed review of the literature on the question, see Arnow (1981). Arnow compared North and South American populations both morphologically and ecologically, conclud- ing that there is no reason to separate them and therefore that P. secunda is the appropriate name for the species. My observations support her conclusion. METHODS As noted below, taxa in Poa are recognized primarily on the bases of the size of parts and the presence or absence of trichomes and scabrosities on various parts of the plant. The core of any taxonomic revision within the genus must therefore involve a detailed analysis of variation in these characters. 206 JOURNAL OF THE ARNOLD ARBORETUM [vVOL. 66 PLANTS AND CHARACTERS: PRODUCTION OF THE DATA MATRIX The analysis of character variation was done on two separate sets of plants. The first set consisted of 95 plants chosen to represent the full range of geo- graphic and morphological variation (see APPENDIX |). At least one plant was chosen from each of the states or provinces in which the species occurs, with additional plants taken from some states to include the extremes of morpho- logical variation. The second set was chosen to evaluate variation within pop- ulations (““‘population” is defined here as plants growing in close proximity to each other, with no implication about the extent of interbreeding). Such an evaluation was necessarily limited by the collections available. Most of these populations were my own collections and included groups of plants that had been growing within a few meters of each other. For some of the “‘populations,”’ however, I had to use herbarium collections with the same or sequential col- lection numbers from the same locality. All plants are listed in APPENDIX 2. Each of the populations could be placed in one of four broad morphological groups: large plants with short ligules, those with open panicles, those char- acteristic of Poa curtifolia, and ‘“‘ordinary” P. secunda. Plants were scored for the following 60 characters: Nonvarying or nearly so Varying as much within a population as l 1. habit of plant within the complex 2. scabrousness of ligules 21. scabrousness of culms 3. decurrence of ligules 4. ciliate nature of ligule margins 5. scabrousness of leaf margins 6. scabrousness of panicle branches 10. shape of glume apexes 11. shape of lemma apexes 12. ciliate nature of lemma margins 13. no. of lemma nerves Environmentally controlled 14. color of culms 15. involution of leaves 16. glaucousness of leaves Varying as much within a clone as within the complex 17. no. of nerves in Ist ee 18. no. of nerves in 2nd glum 19. aba of glumes He to keel 20. scabrousness of leaf midveins 22. width of culms 23. scabrousness of sheaths 24. scabrousness of abaxial side of leaves 25. scabrousness of adaxial side of leaves 32. length of pubescence on Ist lemmas 33. distribution of apicaaat on lemmas 34. length of hairs on lemm 35. length of pubescence on ec paleas 36. hairs or teeth on palea keels 37. pubescence of paleas 38. shape of lodicules Ranges of variation overlapping among populations 39. height of plant 40. height of flag leaves 41. length of flag leaves 42. length of basal leaves 1985] KELLOGG, POA SECUNDA COMPLEX 207 43. shape of panicles 52. length of spikelets 44. length of panicles 53. length of Ist glumes 45. distance from Ist to 2nd panicle nodes 54. length of 2nd glumes 46. distance ae oie to 3rd panicle nodes 55. width of Ist glumes 47. width of leav 56. width of 2nd glumes 48. shape of fievles 57. length of lemmas 49. length of ligules 58. length of paleas 50. no. of florets per spikelet 59. length of anthers 51. length of Ist rachilla internodes 60. length of lodicules This list includes all characters used in earlier keys, as well as many others suggested by close inspection of the specimens. For all quantitative characters five measurements were taken from each specimen and averaged. The mean was used in the final data matrices unless only integral values were possible (e.g., number of branches per panicle node), in which case the mode was used. After scoring and recording character values for each plant, I could remove from the analysis those characters that were invariant, those that varied as much within as between individuals, those that varied as much within as between populations, and those that were clearly under environmental control (character weighting; see also Davis, 1983) For assessment of variation among the offspring of self-pollinated plants, seeds from plants that I had self-pollinated in 1981 were stratified and planted in the greenhouse in early autumn. Percentage of germination was compara- tively low in all cases, but two plants (Kellogg 29, from Nez Perce Co., Idaho, and Kellogg 122 from Morrow Co., Oregon, both corresponding to Poa canbyi) produced a large number of surviving offspring; I will refer to these as families 29 and 122, respectively. Fourteen plants in family 29 and 17 in family 122 bloomed in the spring of 1983. The plants of each family were measured for height of plant, length of panicles, length of basal leaves, height and length of flag leaves, width of leaves, length of ligules, distances from the first to the second and from the second to the third panicle nodes, number of florets per spikelet, length of spikelets, length of first and second glumes, length of lemmas, paleas, and anthers, length of first-rachilla internodes, and extent of lemma pubescence (all from the fifth section of the character list). NUMERICAL TAXONOMY: ANALYSIS OF THE DATA MATRIX The analysis of the data matrix in taxonomy is simply a search for pattern, where pattern 1s defined as sets of correlated characters (see, for example, Sneath & Sokal, 1973). This correlation is not linear, however, but rather what Farris (1969) has called hierarchical. Because Farris’s term uses neither the word a “saps” in the distribution of points. The distinction between concordant and JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 208 a) |. © ig b) . ° e? ee ~ ° ° * g e e e ee ; . . ° c) wee d) on *ee (| . ° - ‘ a baa e ee 4 *. qq e bs . went ‘ ee oe doe _ ry © e Ge ‘< ql . ° SAT ]b a P Of] GAhaal FIGURE ior belay correlated and concordant characters: a, characters linearly correlated (r = 0.83) and concordant, b, characters linearly correlated but not concordant (r = 0.82); c¢, ies less well correlated but concordant (r = 0.65); set as a, but with histograms for each character displayed on axes, characters same data . Axes = values of a continuously almost continuously distributed but still concordant varying morphological character, points = organism linearly correlated characters is shown by comparison of FiGure la-d. In FiGure la the overall linear correlation coefficient (r) is 0.83; here the two characters are both linearly correlated and concordant in that they define two nonoverlapping sets of organisms. FIGURE 1b, on the other hand, shows two characters that have a similar linear correlation (r = 0.82) but no possibility of hierarchy since the characters do not define discrete sets of points. Finally, in FiGure lc, the characters are concordant but linear correlation is reduced (r = 0.65). FiGure Id shows histograms projected onto the axes of the same graph as la, showing that the univariate distribution of points is not dramat- ically bimodal; clearly, though, the lack of points in the lower right and upper left corners creates both the high correlation coefficient and the gaps that allow us to partition the points into two groups. 1985] KELLOGG, POA SECUNDA COMPLEX 209 I began my search for pattern by using univariate, bivariate, and multivariate statistical techniques to examine various combinations of characters; I looked for concordance among the characters and for nonoverlapping sets of organ- isms. Multivariate techniques have been applied to many groups of grasses in the past (Morishima & Oka, 1960; Goodman, 1968; Phipps, 1970; Clayton, 1971; Baum, 1974; Barkworth, 1978; Williamson & Killick, 1978; Doebley & IlItis, 1980). I chose to begin with principal-component analysis, a multivariate meth- od that considers each plant as a point in multidimensional space, where each dimension is a taxonomic character. It is possible to visualize the relative positions of the plants on axes that are combinations of characters by math- ematically reducing the dimensionality of the hyperspace. Plotting of the OTUs (operational taxonomic units—individual plants in this case) against pairwise combinations of the factors may make discontinuities between the clusters detectable (see, for example, McNeill, 1975). Each axis (factor) is a linear combination of several taxonomic characters; these characters are said to be “‘loaded”’ on that axis. By examining the factor loadings, one can determine which characters are responsible for explaining most of the variance in the data matrix. I performed a variety of principal-component analyses on different sets of plants and characters (see TABLE 2). There are three major problems with the use of principal-component analysis. First, because it assumes multivariate normality, binary or multistate characters may be weighted disproportionately by the algorithm. I therefore ran one analysis with only the quantitative characters. Second, this type of analysis is strongly affected by outliers. I therefore did another analysis excluding all the representatives of Poa curtifolia. Third, principal-component analysis will pick out only the most distinct groups in a set of OTUs, partly because it is designed to find linear correlations among characters that, as shown earlier, may or ma not be taxonomically concordant. The results thus have one-sided implications: if a group is found to be discrete, then it probably really is quite distinct, but the converse does not hold. Discriminant analysis is useful for comparison with principal-component analysis in that it allows one to compare variation within populations to overall variation in the data matrix. Although discriminant analysis could be used to test the validity of previously described taxa, there is an element of circularity in using it in this way. Because such analyses attempt to minimize variance within groups relative to that between them, they effectively assume that the groups to which the OTUsare assigned are somehow real entities. Furthermore, by assigning plants to groups a priori, the taxonomist can only test whether those particular groups are nonrandom—very different from testing whether they in fact represent sets of concordant characters. If there are discrete groups in the complex that are quite different from the ones being tested, they may easily go undetected in a discriminant analysis. To minimize prejudice in the analysis, I therefore used populations as the groups. Cluster analysis is also commonly utilized in studies of this sort, but because this imposes a hierarchical structure on the data (Gower, 1967), it would be circular to use it to test for 210 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the presence of such structure (and inappropriate to use it in a hybridizing group). Because of the difficulty of obtaining adequate population samples, I had to restrict the discriminant analyses to two populations of Poa curtifolia, five populations of large plants with short ligules, and three populations of open- panicled plants, with the rest being plants from southern California and the Gaspé Peninsula. Such a sample is clearly highly biased toward recognizing discrete groups; it thus has one-sided implications opposite those of principal- component analysis. Nondiscrimination of groups convincingly shows their morphological indistinctness, but discrimination does not prove that groups are discrete. RESULTS CHARACTERS STUDIED All members of the complex have a caespitose habit (1).! The only exception is Poa curtifolia, which sometimes produces short rhizomes, although it main- tains the intravaginal branching characteristic of the rest of the group. Many plants, particularly those on dry sites, become red with age (14). As Arnow (pers. comm.) has also observed, this character varies within a site. Plants that are red in their native habitat are often green when grown the next season in the garden, and all plants are green when grown in the greenhouse. This character is thus environmentally controlled. Members of the complex are frequently glaucous (16), with a waxy coating on the leaves, but this also depends on the environment in which the plants are grown. The one exception to this is Poa curtifolia, which is glaucous in any environment, although the extent to which the culms become red varies among individual plants. In general, larger plants are more likely to be strikingly glaucous, whereas smaller ones are more likely to become red during development. Because these char- acters are not consistently expressed, however, they cannot be used as reliable taxonomic characters, except to distinguish P. curtifolia. Such characters can be used to reinforce an existing classification but not to establish it. Height of plants (39) (greater vs. less than 3 dm) has been used as a specific character in previous classifications. This character varies apie. with environment, among members of a population, and within a clone. Some relative differences in size persist in the garden, so this er may still help distinguish groups within the complex. The range of variation is great within populations, however, and there is considerable overlap between them (FIGURE All members of the complex have a conspicuous tuft of more or less erect basal leaves; these sometimes become more lax when the plants occur on very wet sites (such as the open-panicled plants growing near Multnomah Falls, Oregon, in wet canyons). The length of the basal leaves (42) varies within and among populations (see FiGure 3). The flag leaf (the uppermost leaf on the ‘Numbers in parentheses refer to character numbers in the list of characters. TABLE 2. Summary of multivariate analyses. CUMULATIVE AXES ILLus- PERCENT OF CANONICAL bina Tea VARIANCE CORRELATIONS BIGEN® (figuri VALUES ANALYSIS PLANTS INCLUDED CHARACTERS USED no 1 A2 A3 Al A2 A3 > 1 Principal- All in Appendix |! 15, 22, 23, 32, 40, 42,43, — 39 44 68 3 component : All in Appendix | except 15, 22, 23, 32, 40, 42, 43, 16 38 56 69 3 Poa curtifolia 47, 48 All in Appendix 1 1-60 17, 18 17 29 38 16 All in Appendix 1 2-8, 16, 19, 21-37, 39-60 — 20 32 43 13 All in Appendix | 17, 18, 26-28, 32, 34, 35, _ 28 48 56 7 39-42, 44-47, 49-60 All in Appendix | except 1-60 19 24 36 44 11 Poa curtifolia Discriminant Allin Appendix 2 23, 32, 39-44, 47-50, 20 58 71 81 98 95 95 7 52-54, 57, 59 All in Appendix 2 except 23, 32, 39-44, 47-50, 21 52 66 79 98 95 95 7 population 52-54, 57, 59 All in Appendix 2 23, 32, 39-41, 43, 44 — 48 64 77 .98 95 .94 7 47-50, 52-54, 57, 59 All in Appendix 2 except 23, 32, 39-41, 43, 44 _ 45 62 77 97 .94 94 6 population AG-50. $954. 57:59 XATAWOOD VANNOAS VOd ‘DOOTIAN [S861 ELe pA JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 @ PLANT HEIGHT (cm) @ BASAL LEAF LENGTH (cm) 16 —_—m- 8 | 8 =n 3 a 18 2 i] 19 ones i 7 = 5 = 4 wee n _ 15 a 6 =: 3 = 7 me 2 a 18 * 5 = 3 (ae 7 ce 1 = 13 a 6 J 14 Se ——_—_— n Ll 19 a. 12 = 1 nea 9 _— 7 ies 1 = 10 = 6 a 2 = 10 mp 4 os 21 a 21 = 26 =_— 25 F 20 ee 24 24 EEE 2 ah 22 a 22 a] 25 ee 20 Sey 23 - 23 Beso aaa] 4 1 n n 4 L j ee | 30 50 70 90 106 3 10 30 50 70 80 or URES 2, 3. Range of variation compared within and among populations: 2, plant height; 3, pe aia length. Each bar = separate population. Only | population of Poa curtifolia (26) shown. Numbers refer to population numbers as listed in APPENDIX 2. Narrow 2. | line = range of values for that population, broad horizontal bar ex- tends | standard deviation on both sides of mean, narrow vertical line = mean. Hori- zontal scale = full range of variation in complex. culm) is rarely borne much above midpoint on the culm (40) and varies con- siderably in length (41). The margins of the leaves are scabrous (5). The midvein is frequently scabrous (20) as well, particularly near the tip on the abaxial side of the leaf, but this character varies within an individual, some leaves being scabrous and others not. On some plants leaves are scabrous on either the abaxial (24) or the adaxial (25) side or both, but I have never founda population that was not polymorphic for this character. Leaf width varies from 0.4 to 4 mm (47; Ficure 4). Although some basal leaves tend to be somewhat wider than culm leaves, the difference is neither consistent nor, when present, significant. I therefore did not separate leaf width into basal and culm leaf components. Among herbarium specimens there is considerable variation as to whether the leaves are rolled or flat (15), and this has been widely used as a specific character to distinguish Poa juncifolia Scribner from P. ampla Merr., and P. sandbergii from P. incurva Scribner & Williams. However, all plants, if given enough water, have flat leaves. Furthermore, few plants can be found with truly involute leaves. If the leaves are 1.5 mm or less in width, they will tend to appear involute on drying but are actually merely folded. 1985] KELLOGG, POA SECUNDA COMPLEX 213 The ligule of all members of the complex is nonciliate (4), decurrent (3), and more or less scabrous (2), but almost never glabrous. Variation in length (49; Ficure 5) and shape (48) is almost continuous from short (0.5 mm) and truncate to long (6 mm) and acuminate. Plants with scabrous sheaths (23) are not found in pure populations; they are always mixed with glabrous-sheathed plants. This character has been used in the past to distinguish Poa scabrella (Thurber) Bentham from the rest of the complex, but the pattern of variation suggests that it is simply a population-level polymorphism. Inflorescences are either contracted or open panicles (43); plants with open panicles are usually referred to Poa gracillima Vasey. However, panicles of all plants become open for about a week at anthesis, contracting again afterward in most. Those plants with persistently open panicles occur mainly in montane habitats in the Rocky and Cascade mountains and the Sierra Nevada, and a few are known from Chile (Arnow, 1981). They frequently grow in cracks in granite outcrops but are not restricted to such sites. The open panicle of these plants persists in the garden. The panicle branches and rachis are scabrous (6, 7) on nearly all specimens. There is considerable variation in culm width (22) just below the inflorescence, in distance between the first and second (45) and the second and third panicle nodes (46), and in number of branches at each of the first three nodes (26-28). Panicle length (44) also varies widely within populations, and the ranges of variation overlap (FIGURE 6). Spikelets have from two (rarely one) to eight florets (50) and vary greatly in length (52; Figure 7). As noted above, the first rachilla internode (51) is relatively long for Poa species, varying from 0.6 to 1.9 mm, but variation is continuous among populations. The rachilla may be pubescent, scabrous, or glabrous (29), but this too varies within populations. Glume and lemma apices are similar in shape (10, 11), mostly acute to nearly obtuse; there is no striking variation within the complex. The upper parts of the margins of both glumes and lemmas are finely ciliate (9, 12), and glume keels are consistently scabrous, at least toward the apex (8). The glumes of most plants each have three nerves (17, 18), although within a clone occasional glumes with one or five nerves can be found. Lemmas are consistently 5-nerved (13). Some glumes within a clone may also be scabrous next to the keel (19), but this character is rarely consistent within a population. Glume width (55, 56) varies almost as much within populations as within the entire complex, and the range of variation in length of the first (53; FiGure 8) and second (54) glumes overlaps considerably among populations. Lemma pubescence (32) is a major character in all classifications of Poa and has been heavily relied on in the P. secunda complex. Poa ampla, P. juncifolia, P. nevadensis, and P. curtifolia have been distinguished from other members of the complex on the basis of their scabrous to glabrous lemmas, and A. S. Hitchcock (1950) put them in a separate section, Nevadenses, on this basis. I have found, however, that this character commonly varies within populations, in some cases nearly as much as in the complex as a whole (FiGuRE 9). Pu- bescence can extend up to nearly three-quarters the length of the lemma, but 214 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 @ LEAF WIDTH (mm) ©) LIGULE LENGTH (mm) 6 a 24 n r 25 J 17 ] 26 4 18 = 23 a 16 aa 20 7 19 it 22 7 7 a 2 i] 8 a 15 i 10 ae 17 - 12 ] 19 ] 9 = 16 a] 4 Boa 6 7 2 ape 13 a 15 a 14 a 5 - 18 a 13 -_ 12 a 3 = nN =e 21 oe 2 == — 1 - 9 — = —— 14 - 5 ee 22 —_—— 4 oe 24 i 3 = 26 - 1 = 20 ] 7 ede 25 ere 10 = 23 r 8 eee of 20. a0 of 1030 : 50. 65 Ficures 4, 5. Ranges of variation compared within and among populations: 4, leaf width; 5, “ligule length. Format same as in FiGures 2, 3. the character varies continuously. In this group lemma pubescence is thus of doubtful taxonomic utility. The lemma may or may not be scabrous above the area where there is pubescence (31); there may also be a small tuft of hairs on the callus (30). The pubescence may be distributed evenly, it may extend somewhat higher on the marginal nerves and keel (33), or it may rarely be confined only to the keel and margins, not occurring between; the trichomes may be as much as 0.3 mm long (34). All these characters vary at the population level. Lemma length (57) is relatively less variable within populations, but the ranges of variation overlap between populations (FicurE 10 Palea pubescence (37) has been useful in separating other species of Poa (e.g., P. reflexa Vasey & Scribner and P. /eptocoma Trin.; Soreng & Hatch, 1983), but it is too variable to be of help in P. secunda. Paleas may be pubescent, scabrous, or glabrous, but all character states occur in almost every population studied. The palea keels may have either hairs or teeth (36), but this too varies 1985] KELLOGG, POA SECUNDA COMPLEX 215 © PANICLE LENGTH (cm) @ SPIKELET LENGTH (mm) 15 # 8 co 16 - 15 t 17 - 13 == 18 a 4 a 9 ‘ n ee 13 som I 4 al 19 ee] 8 = 5 - ET 9 a 4 — 14 =—_—_ 7 = 2 ae 6 Eee 5 + 7 De 1 = 18 od 3 5 3 ae 6 —- 16 Se ee! nN + 21 = 10 | 2 = 12 = 26 * 21 * 24 a 7 a 10 as 26 = 1 Rape - 20 _ 25 Po ei 22 a 22 aS 24 Se 9 2 25 —_— 20 fe 23 23 * y 10 15 20 Hh i | io aan) Ficures6,7. Ranges of variati length; 7, spikelet length. Format same as in FiGures 2, 3. 6, panicle within populations. The length of the hairs (35) is variable: long hairs near the bottom of the palea nerves frequently grade into stiff teeth nearer the top. Again, the only remaining Sona is palea length (58), which shows consid- erable overlap among popu Lodicule shape (38), like nieces length (60), varies as much within as between populations. Anther length (59) also varies within and between pop- ulations (FIGURE 11). VARIATION AMONG OFFSPRING OF SELF-POLLINATED PLANTS The offspring of plants I self-pollinated showed substantial variation within each family. I gave a set of the offspring and a traditional key (C. L. Hitchcock & Cronquist, 1973) to taxonomists not familiar with the group; they identified the offspring of each family as a mixture of Poa scabrella, P. nevadensis, and P. gracillima. Individual plants were generally identified differently by different taxonomists. Histograms for some of the quantitative characters measured are shown in Ficure 12. Comparison of these with Figures 2-11 shows that the range of 216 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 FIRST GLUME LENGTH (mm) Onnare OF LEMMA PUBESCENCE (mm) 12 6 * . a 25 aa ul SES - 21 a] : See el 0 8 ae 24 ome 's * 2 ——_ a — 3 —__ 23 nbn 3 Ln 12 EE 19 aT 10 2 a " a 4 ae 5 a ——§ 8 =i 26 4 7 Peat — 7 ae 10 Baoan 8 5] 16 SR - 16 ee 9 a 5 a 2 a 17 Ls] aS a 18 —— #6 # 19 7 4 as 1 * : = 15 *- 7 = 2 : 20 = 3 = 22 Le 4 = 25 * _ oe _ NO f) Nn wn we }° w va b fe) > wn Ww G ° ° La) ° Ld we) Ficures 8,9. Ranges of variation compared within and among populations: 8, first- glume length; 9, extent of lemma pubescence. Format same as in Ficures 2, 3. variation within each family is very high relative to the range of variation in the complex as a whole. For plant height the range within family 29 is 78 percent of that in the entire complex. The range for distance between the second and third panicle nodes 1s actually greater than that observed in the rest of the complex (1.5-6 cm vs. 0.6-3.6 cm). For many of the other characters, the range is between 38 and 62 percent of that of the whole complex. More important than the range of variation, though, is the distribution of values. Comparison of the ranges of values in the histograms of FiGure 12 with those in the appropriate bar graphs of FiGureEs 2-11 shows that the range of values in either family 29 or family 122 crosses most of the apparent breaks in distribution in the bar graphs. This is particularly true with such characters as extent of lemma pubescence (Ficures 9, 12g), often considered to be of high taxonomic value in the genus. Variation in each family could be entirely phenotypic, entirely genotypic, or some combination of the two. If all the plants were apomictically produced, they would be genetically identical, assuming no autosegregation or mitotic crossing-over. Although all the plants were greenhouse grown, the experiment was not controlled for small differences in environment. At the other extreme 1985] KELLOGG, POA SECUNDA COMPLEX 217 FIRST LEMMA LENGTH (mm) wD) ANTHER LENGTH (mm) 12 eal 15 —_—_ 19 on el 7 a | 6 = 12 co] 5 = 19 Ss 17 apes 5 . im Races 13 = 15 ' 18 =. 8 eee] 7 ie 18 to] 14 ae 21 aa 2 Teaco — 4 Pan) 24 ee 24 Ts 10 ES 13 a 6 =e 26 ada 8 4 3 ro n te] 10 oe 4 | 16 Drea at] 3 cee 9 ET 22 as 14 Bastay 25 Se 1 lina 16 = 2 Se 21 = 7 me 26 eS 20 aad —_- 22 os 9 a 25 eae 23 a 23 ' 20 Pe 25 35. 40. 45°~«<50 SS lo 15.20.25 30. 3's Ficures 10, 11. Ranges of variation compared within and among populations: 10, first-lemma length; 11, anther length. Format same as in FiGures 2, 3. the variation could be all genetic. If all the seeds were sexually produced, then they could all be genetically different. To sort out the phenotypic plasticity of these characters would require careful factorial experiments like those done by Davis (1983) in his study of Puccinellia. No matter how the variation is ex- plained, however, it is still high enough to suggest that the characters are of minimal taxonomic value. Could it be that, quite by accident, I happened on two unusually variable plants? Although possible, this seems unlikely. Plant 29 was collected from a crumbling basalt outcrop in northern Idaho, and plant 122 in a grassy meadow in north-central Oregon, both common habitats for Poa secunda; neither was part of an unusually variable population. Both plants were collected in 1978 and grown in a common garden for three years before being moved into the greenhouse early in 1981. The patterns of variation for many of the characters are strikingly similar for the two plants. Neither is consistently more variable from stem to stem than the other for all characters, and for such characters as spikelet and glume lengths, the ranges are virtually identical. It seems unlikely, therefore, that these results are simply accidental. The numerical analyses in the next section amplify and further support this conclusion. 218 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 66 jo) NO > RE 12. Histograms for 8 quantitative ah ree measured on 31 offspring of 2 eae plants: a, plant height (bar width = 0 cm); b, panicle length (bar width = Black bars = offspring - menor 29, white bars = offspring of Kellogg 122, are scale = number of plan 1985] KELLOGG, POA SECUNDA COMPLEX 219 NUMERICAL TAXONOMY Removal of all characters except those in which the range of variation is greater among than within populations leaves only 21 characters, the ranges of which still overlap among populations. The data described in the previous section suggest that many of these characters themselves are of questionable taxonomic value. Most of the key characters have been eliminated. Ligule decurrence is constant throughout the group. Sheath scabrousness and lemma pubescence vary as much within as between populations. Date of blooming (see next section), culm color, leaf involution and glaucousness, and—to a certain extent—plant height are all under environmental control. Of Hitch- cock’s eight original key characters, only panicle shape, ligule length and shape, and gross differences in height remain. There are 17 additional, non-key char- acters that are not automatically filtered out because of their variation pattern. This suggests three possible ways to describe and classify the complex: 1) four entities corresponding roughly to open-panicled plants, large plants, Poa cur- tifolia, and everything else, distinguished on the basis of combinations of the four characters mentioned above; 2) more than four entities, distinguished on the basis of characters other than those used in the past; or 3) one or more entities, none of which corresponds to previously recognized taxa. UNIVARIATE STATISTICS. Both histograms and bar graphs show that no single character can be used to divide the complex. Histograms of the quantitative variables are mostly unimodal and approach normality, although a few are highly skewed; none is strongly bimodal. Four representative histograms, for all plants listed in AppENDIxES | and 2, are shown in Ficur_e 13. Plants with extreme values for one character do not necessarily have extreme values for others. On the other hand, occasional aberrant individuals appear in which many of the parts are unusually large. When compared with many of the other plants, these stand out as strikingly different. This pattern of variation also appears in the population samples illustrated in Figures 2-11. The order of populations, from lowest to highest mean values for each character, is not always the same. Furthermore, populations that are highly variable for one character are not highly variable in others, again sug- gesting noncorrelation of characters. The only exception 1s population 23, collected by C. V. Piper in the Grand Coulee, Washington, in 1900. This population is represented by three herbarium specimens that are all extremely large for most of the characters measured. However, because this “population” is a group of herbarium specimens with the same number, and because the range of variation in most characters is quite narrow, it may represent a single clump divided into three parts. Hence its extreme position should be treated cautiously (see also below). BIVARIATE STATISTICS. Bivariate plots (see Figures 14, 15) show similar con- tinua. Lemma pubescence and ligule length are two characters that have often been used in the taxonomy of the complex; they show, however, no perceptible groups. Other combinations of characters are similar. Although some characters such as plant height and panicle length are linearly correlated (r = 0.8), they 220 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ¢) 40 85 FiGure 13. Histograms for 4 representative morphological characters measured on all plants in AppENDIxEs | and 2: a, plant height (bar width = 5 cm); b, extent of lemma pubescence (bar width = 0.2 mm); c, basal-leaf length (bar width = 5 cm); d, lemma length (bar width = 0.4 mm). Vertical scale = number of plants. 1985] KELLOGG, POA SECUNDA COMPLEX 22] ° 10 ° 2,80 e . . e a 2.45 T e e e e ‘a ° » . . o e ry ° 2.10 ee ma ms e sa) . :° = Zi ks e e £ oo t e & ane . ey is . aaa ° 5 Let " eee «s . = oe nA wD cp oe E 1.40 ° . ee os . 6 = is Pas a? ia ef z= . ° a 50 * ° e 4 1.05 oe ° ° ee val e ee e e oo e oe. % ; & 0,70 ee ° e : *s * s w o**; o cee = 7 4 on es ee e 0.35 ° s en oo . bd oo ts te 2% © . : an a Z 4 5 7.25 10.5 14 7.5 21 24.5 14 Licute LENGTH (Ma) 15 PANICLE LENGTH (cr) Ficures 14,15. Bivariate plots for plants listed in APPENDIX 1: 14, lemma pubescence vs. ligule length (r = 0.087); 15, plant height vs. panicle length (r = 0.806). are not concordant and do not suggest any infrastructure for the group. It is more likely that the high linear correlation represents genetic linkage or similar developmental trajectories for the two characters. PRINCIPAL-COMPONENT ANALYSES. A principal-component analysis on only the characters used by A. S. Hitchcock (FiGurE 16) shows that his taxa intergrade and that the single characters he used to define his species do not correlate with any other characters. The analysis using all 60 characters produced four notable results. > +) t ° ee a a a an e » o : r eu 2 se e F e es a e e oN CN oJ oe ee a a: a et P+ cee «ee, ° g Q ge ee 3 ee e a ae ue 2 6s e e e e e ee e° e ee e e 16 Factor 1 17 Factor 1 Ficures 16,17. Principal-component analyses: 16, A. S. Hitchcock’s characters only (solid squares = Poa scabrella, open squares = P. nevadensis, solid circles = P. sandber- gii, open circles = P. gracillima, open diamonds = P. canbyi, crosses = P. juncifolia, triangles = P. ampla), 17, all 60 characters (diamonds = Poa curtifolia, open circles = open-panicled plants, triangles = large plants with short ligules, solid circles = all other plants). Each axis = 6 standard deviations. Zoe JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Factor 2 FAcToR 3 es e * Factor | 18 Factor 1 19 Ficures 18,19. Principal-component analyses: 18, all 60 characters (open triangles = separate culms of Kellogg 56 scored as if separate plants, solid circles = all other plants), 19, all 60 characters, eliminating Poa curtifolia (triangles = large plants with short ligules, open squares = large plants with long ligules, solid circles = all other plants). Each axis = 6 standard deviations. First, Poa curtifolia formed a more or less distinct cluster in the Factor 1 x 2 plot, separate from the other plants (Figure 17). This result is particularly interesting in that the characters most distinctive of this species—leaf succu- lence and a white leaf margin—were not included in the data set. (See the following section for a discussion of leaf anatomy). Second, the first three factors mainly represent size of vegetative features (characters 22, 39-42, 44-47), size of spikelet parts (characters 20, 52-59), and amount and distribution of trichomes (characters 14, 32, 33, 35). The first factor in particular thus probably includes a large environmental component. This is borne out by the fact that garden-grown plants tend not to cluster with field-grown plants from the same population. Third, the individuals marked by open triangles in FiGure 18 are actually separate culms of the same plant (Kellogg 56) scored as if they were separate individuals. They are scattered over about one and a half standard deviations in character space in most factor combinations, suggesting that variation within a single clone is large relative to that in the whole group. Fourth, sixteen factors have eigenvalues greater than one, and the first three factors together explain only 39 percent of the variance. This is what one would expect if there were no definite groups and the OTUs all formed a nearly hyperspherical constellation in multidimensional space. Examination of the first three principal-component axes on the three-dimensional visual display created by Huber and his graduate students (see Kolata, 1982) shows that the constellation of points is actually more or less L- or T-shaped. Most of the plants form a dense cloud that is the bar of the T; individuals classified as Poa curtifolia plus the plants with extremely large values in several characters form a more diffuse “tail.” Some of the large plants fall as far from the dense part of the cloud as do members of P. curtifolia. 1985] KELLOGG, POA SECUNDA COMPLEX 223 I examined plots of all possible two-way combinations of the first ten factors and found no pattern any more interpretable than those shown. The open- panicled plants are closest acne in the plot of factor | vs. factor 5, but even so they do not form a discrete gro Eliminating the characters that vary rath the plant and those that are clearly under environmental control reduces the total number of characters to 48 —29 quantitative and 19 qualitative. This changes the results only slightly. The first three factors now explain 43 percent of the variance. The relationships of most plants to each other remains similar, although Poa curtifolia is somewhat more distinct. The results of the analysis with quantitative characters only are also similar to those in the other analyses When Poa curtifolia is eliminated Goin the analysis, the first three factors explain 45 percent of the variance and some weak groups appear in the plot of Factor | x 3 (FiGure 19). The group in the lower right corner of the graph includes mostly large plants with relatively short ligules. Factor loadings remain similar to those in the other analyses. The two plants in the upper right corner, shown by open squares, appear together in all analyses and are always distant from the rest of the group. These plants both have extremely large panicles on Vv long culms. Reference to the bivariate plot of plant height vs. panicle length (FiGuRE 15) shows that the two plants (the rightmost points) are indeed extreme and may have slightly unusual proportions of those parts. Although the two plants are morphologically quite similar, they were collected nearly 600 miles apart and on very different sites, one near Reno, Nevada, the other in the Wasatch Mountains of Utah. Again, this suggests that the very largest plants are simply isolated extreme forms. DISCRIMINANT ANALYSES. In the first of these analyses (shown in FiGure 20), plants of population 23 (from eastern Washington—far left) appear radically different from the large plants in populations 21, 22, 24, and 25 (center), which are in turn distinct from the rest of the group. Poa curtifolia (populations 29 and 30) is less well separated than by the principal-component analysis. The open-panicled populations, the Gaspé populations, and the California group all cluster together. The greatest discrimination is provided by the first canonical variable, which is primarily a function of basal-leaf length, flag-leaf length and height, leaf width, and ligule shape. Characters loading on axis II are length of the flag leaves, the panicles, the first glumes, the lemmas, and the anthers, width of the leaves, and extent of pubescence on the lemmas. As noted earlier, population 23 is an outlier in terms of most characters; furthermore, it may represent not a population but a single clump (clone). Removing it from the analysis produces the picture shown in FiGuRE 21. Again the large plants of populations 21, 22, 24, and 25 are distinct, although not as dramatically so as in the first analysis. Poa curtifolia is now clearly separate. The other populations in the right-hand group overlap; the jackknife procedure? A procedure whereby an OTU is removed from the data matrix and the discriminant functions are recalculated. The OTU is then entered into the new discriminant functions and is classified accordingly. This is done for each OTU in turn. If the group to which the OTU was initially assigned is discrete from the other groups, then the OTU will be reassigned to the group from which it came. 224 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 produces frequent misclassifications, SUBEESEDS ute vegunuawee: among them. Thus, ina procedure designed to maximize distances pulations there are only three clear groups formed: P. curtifolia, large a per every- thing else. The cloud of points in Figure 21 is roughly T-shaped, with the large plants forming a more or less diffuse tail. Virtually all discrimination is on the first canonical axis, which—like the first principal-component axis—represents size of vegetative parts. The variables with the highest F-values are the lengths of both basal and flag leaves. Removal of these from the analysis produces es- sentially the same picture, with the large plants now being distinguished on the basis of the short ligule. Because of the bias in the sample, these results are good evidence for the conclusions that panicle shape is not concordant with any other character, and that plants with open panicles do not form a discrete group. The same bias, however, means that this analysis does not provide good evidence for formal recognition of large plants with short ligules; large plants with long ligules were not included in the analysis. Thus, principal-component analyses give a weak argument for lumping these large plants with the rest of the complex, while discriminant analyses provide an equally weak argument for maintaining them as distinct. Other data on population structure and dis- tribution give no rationale for recognizing them as a separate taxon. OTHER CHARACTERS Extensive analyses of gross morphology have shown that the Poa secunda complex is made up of only two taxa. This conclusion is supported by data on phenology, leaf anatomy, and ecology. PHENOLOGY Both C. L. Hitchcock and co-workers (1969) and Cronquist and colleagues (1977) have used phenology as a taxonomic character, separating species into those that bloom in April, May, or June vs. those that bloom in July or August. Date of blooming in the wild, however, appears to correlate more with altitude and habitat than with morphology: plants consistently bloom in the early part of the growing season and then become dormant. I followed marked plants in two natural populations near Moscow, Idaho, and observed two apparent peaks of blooming time, about three to five days apart, with each totaling about ten days. The early-blooming plants seemed to be somewhat smaller and to have smaller, narrower leaves than the later ones. Unfortunately, the numbers of plants observed were too small for any statistical tests of these observations. Plants from a variety of provenances, when grown in the experimental garden, bloom within a period of 17 days; plants forced in the greenhouse bloom within four weeks of being brought indoors. Blooming time is thus not a good diag- nostic character. In general, in both garden and greenhouse, specimens of Poa curtifolia are some of the earliest plants to reach anthesis, and the large plants that traditionally would have been assigned to P. amp/a are among the latest. 1985] KELLOGG, POA SECUNDA COMPLEX 225 5 ° eo 6 a a . ere e 7 . 2.5 + ‘< —_ rn eo ee, B 0 | a aoe - - ‘ a oe oe < a a . = = K Py S25 1 4 “s. ° S ry S-5 T ee° ,* ee e e -/,5 ° 20 -21 -18 -15 -12 -9 -6 -3 0 3 6 CANONICAL VaRIABLE 1 ¢ o eS te , o N oe° Ww ¢ pa 25] =; e a = a = 4 a 4 3 25 . — a eee — a a A eee. rat a aa ope ee 20 7, ed ..% S a aa oe > e@ Ceseee 9 © a a as oe al e @oo0e . Y + + + t t * 21 -2 -9 -6 -3 0 3 6 CANONICAL VARIABLE 1 FiGures 20, 21. Discriminant analyses: 20, 18 characters and all plants listed in APPENDIX 2; 21, 18 characters and all plants listed in APPENDIX 2 except population 23 (diamonds = Poa curtifolia, open circles = open-panicled plants, triangles = large plants with short ligules, solid circles = all other plants). If plants are assigned to Hitchcock’s taxa and time to anthesis 1s compared among all taxa by analysis of variance, the earliest species is found to be sig- nificantly earlier than the latest. Because this represents the average time to anthesis, however, and because there is still considerable overlap among all the ranges, statistical significance may not indicate biological significance. The weak tendency for time of anthesis to correlate with plant size is shown in FIGURE 22 ANATOMY Cross sections of leaves show that members of the complex are anatomically variable (FiGureE 23). All plants have double bundle sheaths and a row of 226 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 g 6/294 3 6/194 . ° ole = = i: ee © e ee ° e e eee «ae eweee e w 6/8 + e as e e eo 8 6& cf More ree eee 5/294 eo oe Sew» e ee ©» e080 e J eo CC @ 4 i is i L 1 L - > T T tT + T T T tT? 10 20 30 40 50 60 70 80 90 PLANT HEIGHT (cM) FiGure 22. Bivariate plot of date of anthesis vs. plant height (7 = 0.45). bulliform cells on both sides of the midrib. Plants differ primarily in the amount of sclerenchyma and in the shape of the epidermal cells. Although many plants have the major vascular bundles fully embedded in sclerenchyma, others have sclerenchyma not connected to the vascular bundles, and some have the scler- enchymatous region reduced to only a few cells. The amount of sclerenchyma seems to correlate with the moisture level of the site, being much greater in plants grown on drier sites. Relative amount also varies when plants are moved from field to experimental garden, which also suggests environmental influence. The epidermal cells may be somewhat flattened in cross section, in which case there is generally a thick cuticle, or they may be more rounded and irregular with a thinner cuticle. In some plants the adaxial surface has rounded epidermal cells and the abaxial epidermis has flattened ones. Epidermal peels from a sample of 20 plants were all similar, with sinuous-sided silica bodies and parallel-sided subsidiary cells. Leafanatomy thus conforms to the standard festucoid pattern (as described in Gould & Shaw, 1983), and the variation that occurs does not correlate with other characters. SUBSTRATE Members of the complex grow on a variety of substrates, generally on neutral to strongly alkaline soils, sometimes with high amounts of soluble salts. Plants Ficure 23. Cross sections of leaves showing range of variation in complex: a, Kellogg 154 (Oregon; large plant with short ligules and nearly glabrous lemmas, greenhouse grown); b, Ke/logg 226 (central Idaho, open-panicled plant with long ligules, greenhouse grown); c, Kellogg 227 (Poa curtifolia, central Washington); d, Kellogg 263 (Oregon, 1985] KELLOGG, POA SECUNDA COMPLEX 221 ine od & a sy COVED rage NZ SCOOT a, see ‘4 Ga : 4 : x open-panicled plant with short ligules); e, Kellogg 210 (Idaho, alpine plant with long ligules and pubescent lemmas). Scale = 0.1 mm; s = sclerenchyma; vb = vascular bundle; os = outer bundle sheath; is = inner (mestome) sheath; bu = bulliform cells; ec = epi- dermal cells; p = prickle hair. 228 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 with open panicles and short ligules occur only on the walls of wet, mossy gorges near Multnomah Falls above the Columbia River in Oregon; those with open panicles and long ligules are montane and usually grow in crevices in granite. Large, glaucous plants are often but not always found in apparently saline basins. These generalizations about ecology do not hold up to close inspection, however. To see if any edaphic characters correlated with mor- hology, I ran three multiple regressions of seven soil characteristics against basal-leaf length, ligule length, and lemma length (three characters shown by numerical taxonomy to be important in describing the total variation in the group). R* values are 0.092, 0.296, and 0.127, respectively, for all combinations of soil characters with the three morphological characters. Edaphic factors are thus taxonomically uninformative. Poa curtifolia is the one exception, being restricted to serpentine soils in the Wenatchee Mountains of central Washington. Other members of the P. secunda complex are also found on serpentine soils, but they are not morphologically distinct. REPRODUCTIVE BIOLOGY The Poa secunda complex has long been known to be apomictic (Nygren, 1951), and apomixis has been widely used to explain morphological variability in the group. Early in my studies of the reproductive biology of the group, | developed a hypothesis, based on some sketchy preliminary data, that some of the more distinctive morphs (like the large, short-liguled plants) were more highly apomictic than the other members of the complex. This hypothesis not only proved to be wrong but also was based on a logical flaw that I will discuss briefly below. Bagging experiments showed that pollen is necessary for seed set; apomixis, when it occurs, must be pseudogamous. All plants set seed when self-pollinated. From 2721 attempted crosses I produced 4 apparent hybrids; other offspring were morphologically indistinguishable from the maternal parent and so were presumed to be apomictic. The parents of the hybrids were very different morphologically. This suggests that if there are fertility barriers, they are not between forms that are highly morphologically differentiated. These results are confirmed by the much larger studies of Hiesey and Nobs (1982). Thus, sexual reproduction can and presumably does occur even between very different morphs. To determine the extent of apomixis in individual plants, I cleared ovules in Herr’s solution and observed them with Nomarski optics (see Kellogg, 1983; Greene, 1984). In each of 25 plants, I scored up to 50 ovules as being sexual or potentially apomictic. The percentage of apomictic ovules varied from 25 to 100. It varied as much as 40 percent among plants collected from the same locality, and percentages from the same plant in subsequent years are also quite different. Percent apomixis in parent plants did not correlate with that in the offspring. This variation in percent apomixis does not reflect variation in pollen stainability; although highly apomictic plants are usually mostly pollen sterile, 1985] KELLOGG, POA SECUNDA COMPLEX 229 pollen-fertile plants may exhibit any amount of apomixis. Like percent apo- mixis, percent pollen stainability varies widely with the environment. It is not correlated with regularity of meiosis. Chromosome number is likewise variable. Poa curtifolia has 2n = 42. Other members of the complex have numbers varying from 2” = 44 to 2n = 106 (Hartung, 1946). Many of the largest plants are 9-ploid, but some have higher or lower numbers, and not all 9-ploids are large. Thus, chromosome number is not associated with morphological variants. Were they morphological characters, the aspects of reproductive biology that I have investigated would be ruled out as taxonomically unimportant. Some, such as interfertility, do not vary within the group. Others, such as percent apomixis and percent pollen stainability, are highly variable depending on the environment, but even if they were stable, they would be of no use in explaining the morphological variation since they do not correlate with any aspect of morphology. Because of this lack of correlation, there is no way in which I can conclude that the morphological complexities exist because of apomixis. My initial hypothesis of the unusual morphs being more highly apomictic than the more widespread ones has thus proved to be wrong, but even had it been correct, it would have been an inadequate explanation for the morphological variation. The only way apomixis can maintain a particular form is if it is obligate. If there is any recombination at all (and the production of a small number of hybrids suggests that there is), then the plants are effectively sexual in terms of their ability to generate variation. In the case of facultative apomixis, the process of recombination is slowed but by no means stopped (see discussions by Marshall & Weir, 1979, and Lynch & Gabriel, 1983). DISCUSSION AND CONCLUSIONS In general, my work suggests that much of the presently accepted taxonomy of the genus Poa is suspect. The amount of population-level variability in the P. secunda complex is not unique in the genus. The genus contains several widespread polymorphic taxa, including P. pratensis, P. alpina, P. arctica, and P. glauca, in which one to many species are commonly recognized. All include numerous entities that have been given specific status at some time in the past, and all are circumboreal, apomictic, and with aneuploid chromosome numbers suggesting some ancestral hybridization. Although characters that are variable in one part of the genus may still be taxonomically useful in another, such characters, once shown to be unreliable, should not be used blindly. Overre- liance on one or a few gross morphological characters may have caused un- necessary splitting, producing artificial morphological entities rather than bi- ological ones. Studies of other bluegrasses must consider the possibility that many traditionally used characters are unreliable. Lemma pubescence is heavily relied upon to separate species or sections throughout the genus. However, the amount of lemma pubescence often varies greatly within populations in P. secunda and among the offspring of a single self-pollinated plant; it also varies in populations of P. curtifolia, a narrowly endemic species. This character must 230 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 thus be used carefully. Similarly, I have shown leaf folding to be controlled by soil moisture, yet a number of bluegrass species are distinguished by such features as folded or involute leaves. In other groups the value of this character can only be verified by common garden studies. Included in the first multivariate analyses were several plants from species outside of the complex. On the basis of the characters used in the analyses, however, they did not appear distinct from other members of the group. This suggests that other taxa in the genus may prove, on closer examination, to be poorly delimited and, like the members of the Poa secunda complex, part of a continuum of variation. Panicle shape has no taxonomic value in this complex. Plants with panicles that remain open after anthesis were formerly known as Poa gracillima. They often occur in granite Hea frequently at high altitude, in the northern Rocky Mountains and the Sierra Nevada, as well as in Chile (Arnow, 1981). The character state persists even in garden-grown plants. The preceding anal- yses have shown, however, that this character state does not correlate with any others. Open-panicled plants are shown by triangles in the scatter diagrams; it is obvious that they intergrade completely with other members of the complex on the basis of all characters but this one. Several hybrids were produced in crosses of open-panicled plants with nar- row-panicled ones. The F,s had panicles that were narrow at the top, but the bottom two branches remained at an angle of about 30° to the rachis after anthesis. Such a plant would be classed by most taxonomists as having a narrow panicle, and its morphological intermediacy would probably go undetected. Thus, populations comprising plants with genes for both open and narrow panicles may not be recognized. Poa curtifolia is morphologically distinct, based on the characters used in the numerical analyses. Not included, however, were the facts that it has thick, almost succulent leaves often with a prominently white margin, it is restricted to serpentine soils in the Wenatchee Mountains of Washington, and its chro- mosome number is 27 = 42, with good pairing at meiosis. It should therefore continue to be recognized as a species distinct from the rest of the complex. Many of the very largest plants are separated from the rest of the complex because of gaps in relative sizes of parts. These unusually large plants are geographically isolated from each other, with neither distinct ecological re- quirements nor a discrete range. I have never found them growing in pure stands. Either they grow with smaller members of the complex, or they occur as isolated plants in ditches or on cut-banks. What these forms represent bio- logically is still an unanswered question. Because sexual reproduction can and presumably does occur in the group (Kellogg, 1983), they may be simply un- usual segregants that happen to be particularly vigorous on extreme sites. This contention is supported by the data presented under Results: among the off- spring of a single self-pollinated plant, some had extreme values for certain characters. Unusually large plants may thus be produced fairly commonly. In their most striking form these large plants, most of which would tradi- tionally be put into Poa ampla, have short ligules, little lemma pubescence, 1985] KELLOGG, POA SECUNDA COMPLEX Zo and very glaucous foliage, but their most distinctive character is their long leaves. In Ficure 3, which represents a univariate display of basal-leaf length, there is a break at about 20 cm separating the large plants. The histogram for this character (FIGURE 13C), however, shows little reason to define groups in this way. Also, the histogram in Ficure 12C shows that the offspring of a single self-pollinated plant vary across the apparent break. Increasing the sample size obscures even the univariate pattern. Some taxonomists might still prefer formal recognition of these plants at the varietal level at least. Such plants are most valuable as forage grasses, which sets them apart from the other members of the complex that are largely ignored by cattle. Cattle graze by wrapping their tongues around the leaves of the plants they eat and so prefer plants with ong basal leaves. Cows can therefore “‘rec- ognize” Poa ampla as distinct from the rest of P. secunda because of the leaf length, a character with a nearly continuous distribution. Formal recognition of P. ampla would thus be arbitrarily dividing the continuum of basal-leaf length so as to create a special-purpose classification reflecting the mouthparts of cattle. Continuity of variation makes it unjustifiable to recognize these forms taxonomically. e Poa secunda complex is made up of many fewer taxa than previously described. In this study I have defined a species as a group of plants with similar morphology and with no obvious morphological gaps in sets of concordant characters. Only P. secunda and P. curtifolia adequately fit this definition. Such taxa as P. sandbergti, P. canbyi, P. scabrella, and P. incurva can be confidently placed in synonymy. The characters on which they were based either vary at the level of the clone or population or are almost completely under environ- mental control. Furthermore, no other characters were found that distinguish groups within this part of the complex. The search for taxonomically useful patterns in P. secunda has shown that no characters are concordant—i.e., that no characters define nonoverlapping sets of plants. In other words, a species is a cluster of points in taxonomic hyperspace, where the dimensions of the space are broadly defined to be any set of characters; in this case the characters are predominantly morphological ones. Poa secunda can be described as a sort of minimal species; at the very least we can make generalizations of the form “plants with character X will also have character Y.” This is the rationale for not considering P. gracillima as a separate species even though it can be dis- criminated on the single axis representing open vs. closed panicles. Knowing that the plants have open panicles still does not allow even very trivial gen- eralizations. Such a conclusion also means that, at our current level of knowledge, we can make no claims about evolution within Poa secunda. Because there are no characters that can serve as evolutionary “‘markers,” we cannot evaluate the various processes that might have generated the pattern. Hypotheses of fusion of disparate lineages by hybridization, although appealing, are merely plausible suggestions, not subject to test. The roles of polyploidy and apomixis cannot be evaluated. The pattern of variation, in other words, does not illuminate the historical pattern of microevolutionary processes. 232 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Ficure 24. Poa curtifoliaand P. secunda. a, P. curtifolia, habit (Kellogg 227), x 0.35. b—m, Poa secunda. b, habit (Kellogg 56), x 0.35. c-f, variation in lemma size and pu- bescence, all x 3.5: c, Stevens 1208 (pao); d, Hitchcock 11301 (us); e, Ward 488 (us); f, Maguire 13874 (DAO). g, open panicle (Kellogg 226), x 0.35. h-m, variation in ligule size and shape, all x 3.5: h, Kellogg 214; i, Kellogg 114; j, Kellogg 222; k, Kellogg 36, 1, Kellogg 274; m, Kellogg 10]. Complete specimen citation in APPENDIX 1. Poa secunda has been delimited on phenetic, not cladistic, grounds. Although it can be distinguished from other members of the genus by a combination of characters, there is no reason to believe that any of these characters is uniquely derived. As noted at the outset, the only possible apomorphies for the group 1985] KELLOGG, POA SECUNDA COMPLEX 233 are shape of the spikelet and length of the first rachilla internode, and even these are not unique to P. secunda. Other characters, such as caespitose habit and perfect flowers, may be plesiomorphic and therefore not indicative of phylogenetic relationship. Still others, such as lack of a lemma web, may be either plesiomorphic or convergent. The group is thus not demonstrably mono- phyletic sensu Hennig; monophyly could only be determined in the context of a phylogeny for the entire genus. Quite possibly other species should be included in a group united by long spikelets and rachilla internodes; P. secunda may thus be paraphyletic. To try to define a species within the complex as the smallest strictly monophyletic unit (see Mishler & Donoghue, 1982) seems unworkable, given the distribution of characters. The basic model of cladistics does not apply to hybridizing groups; the apomorphies of the parental lines become hopelessly blended, lineages cannot be identified, and the application of concepts of strict monophyly seems inappropriate. The definition I have used for a species, therefore, not only prevents analysis of evolution within P. secunda, but also analysis of evolution between P. secunda and other parts of the genus. I have thus chosen to recognize formally only morphological units within which all characters vary and covary continuously. There are no gaps in the distribution of the characters, and most are uncorrelated. Such units do not reflect anything about phylogeny. Given the current state of classification and knowledge of characters in Poa, such a species concept may be the only one that can be applied with any consistency. The foregoing points all lead to the conclusion that there is only one defensible taxonomic treatment for the group: to recognize Poa curtifolia and to include everything else in P. secunda. Variation in many characters is indeed complex, both at the level of the species (P. secunda) and also apparently at other levels. To impose any taxonomic structure would obscure, rather than illuminate, the pattern. TAXONOMIC TREATMENT Poa curtifolia Scribner, Circ. U.S. Div. Agrost. 16: 3. 1899. Type: Washington, Kittitas Co., Cascades, Mt. Stuart, Aug. 1878, E/mer 1148 (holotype, us!). FIGURE 24a. Plants 2-5 dm, caespitose to short-rhizomatous, glaucous; branching intra- vaginal; culms 0.5—0.8 mm thick below inflorescences, sometimes becoming red with age. Basal leaves 3-8 cm x 0.5—2.5 mm, the blades extending almost at right angles from sheath, flat, more or less fleshy, with prominent white marginal vein, scabrous on margin only. Flag leaves 0.5-2 cm x 0.2-2.6 mm, borne well below midpoints of culms. Sheaths open, glabrous. Ligules 2-6 mm, acute to acuminate, strongly decurrent, entire, sparsely scabrous abaxially. Panicles narrow, 5-10 cm, spreading at anthesis, branches 2 to 4 per node; spikelets 2- to 5-flowered, 7-10.5 mm, generally at least 4 times as long as wide except at anthesis, more or less terete; glumes somewhat unequal (first 3.8-5.5 x 1.4-1.9 mm, second 4.5-6.7 x 1.8-2.3 mm), acute, 3-nerved, sca- 234 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 brous on upper '4-' of keel; lemmas 4.6-6.6 mm, rounded, acute, with erose upper margin, 5-nerved, glabrous to pubescent along lower 13 of keel and marginal nerves, hairs to 0.3 mm, paleas 4-5.8 mm, slightly shorter than lemmas, glabrous; rachilla internodes 0.9-1.9 mm, glabrous; anthers 2.5—4.2 mm, yellow; lodicules 0.6-1.1 mm. Chromosome number 2” = 42. DIsTRIBUTION. Wenatchee Mountains, central Washington; serpentine soils. REPRESENTATIVE SPECIMENS. See APPENDIXES | and 2. Poa secunda Presl, Reliq. Haenk. 1: 271. 1830; not Roemer & Schultes, Syst. Veg. 2: 697. 1817, nomen nudum. Tyre: ex Cordille[r]ja de “Chili,” 1790, Haenke (holotype, pr!; isotypes, GH!, MO). FiGure 24b-—m. Aira brevifolia Pursh, Fl. Amer. Sept. 1: 76. 1814. Airopsis brevifolia (Pursh) Roemer ltes, Syst. Veg. 2: 578. 1817; not Poa brevifolia DC. 1806. Type: in the plains of Missouri, ©. Lewis s.n. (pH). The specimen in the Lewis and Clark herbarium at PH bears the label: ‘The most common grass through the plains of Columbia R. 10 u ” It is probably therefore not the holotype. Sclerochloa californica Munro ex Bentham, Pl. Hartweg. 342. 1857, nomen nudum. Atropis californica Munro ex Thurber in S. Watson, Bot. Calif. 2: 309. 1880; Era- grostis fendleri Steudel and Poa andina Nutt. as synonyms. Poa californica (Munro ex Thurber) J. M. Coulter, Manual Bot. Rocky Mtn. Region, 420. 1885; not Steudel, 1854. Syntypes: California, San Francisco, Bolander s.n.,; California, [“in valle Sacremento,”] Hartweg 2035 (Gu!). Poa tenuifolia Buckley, Proc. Acad. Nat. Sci. Philadelphia, 1862: 96. 1863; not A. ich. 1851. Poa buckleyana Nash, Bull. Torrey Bot. Club 22: 465, nomen novum. per tenuifolia (Buckley) Thurber in S. Watson, Bot. Calif. 2: 310. 1880. Pani- cularia nuttaliana Kuntze, Rev. Gen. Pl. 2: 783. 1891. Type: Columbia R., Nuttall s.n. (holotype, PH!; isotypes, GH!, ny), Poa tenuifolia Nutt. ex S. Watson in King, Rep. Geol. Expl. 40th Parallel 5: 387. 1871; neither A. Rich. 1851, nor Buckley, 1863. SyNrypes: Nevada, E. Humboldt Mtns., alt. 8000 ft, Aug. 1868, and Diamond Mtns., alt. 6500 ft, July 1868, Watson 1318 (Gu!, Ny!, us!; specimens mounted together, lectotypification not attempted here). Also numbered /3/8: Nevada, Virginia Mtns., alt. 6000 ft, Aug. 1867 (GH!, us!); Nevada, Pah-Ute Mtns., alt. 5000 ft, June 1868 (GuH!, us!). Poa tenuifolia Nutt. ex S. Watson var. elongata Vasey in Rothrock im Wheeler, Rep. Geogr. Survey W. 100th Meridian 6: 290. 1878. Poa buckleyana Nash var. elongata (Vasey) M. E. Jones, Contr. W. Bot. 14: 14. 1912. Type: Colorado, Twin Lakes, 1873, Wolf 1141 — us). Poa tenuifolia Nutt. ex S. on var. rigida Vasey in Rothrock in Wheeler, Rep. . Geogr. Survey W. ier Meridian 6: 290. 1878, nomen nudum. Poa andina Nutt. ex S. Watson in King, Rep. Geol. Expl. 40th Parallel 5: 387. 1897; not Trin. 1835-36. Type: Colorado, Trinity Mtns., alt. 5000 ft, May 1868, tectaia 1319 (holotype, us!; cee hs ny!). Also numbered /3/9: Colorado, E & W. Hum- boldt Mtns. (Nv!); N a, Clover Mtns. (Ny!, us! Poa andina Nutt. ex S. ae var. spicata Vasey in Rothrock in Wheeler, Rep. eogr. Survey W. 100th Meridian 6: 290. 1878. Synrypes: Colorado, 1873, Wolf 1135. 1136, 1137 (us, not seen). Poa andina Nutt. ex S. Watson var. major Vasey in Rothrock in Wheeler, Rep. U. S. Geogr. Survey W. 100th Meridian 6: 290. 1878. Syntypes: Arizona, 1872, Wolf 1133 (us, not seen); Colorado, 1873, Wolf 1134 (us, not seen). 1985] KELLOGG, POA SECUNDA COMPLEX pip) Atropis pauciflora Thurber in S. Watson, Bot. Calif. 2: 310. 1880. Poa pauciflora (Thurber) Bentham ex Vasey, Grasses U.S. 42. 1883; not Roemer & Schultes, 1817. Panicularia thurberiana Kuntze, Rev. Gen. Pl. 2: 783. 1891, nomen illegit. Poa thur- beriana (Kuntze) Vasey, U.S. D. A. Div. Bot. Bull. 13: p/. 84. 1893, nomen illegit. Type: California, Sierra Valley, 1871, Lemmon s.n. (holotype, Ny!). Atropis scabrella Thurber in S. Watson, Bot. Calif. 2: 310. 1880. Poa scabrella (Thurber) tham ex Vasey, Grasses U. S. 42. 1883. Panicularia scabrella (Thurber) Kuntze, Rev. Gen. Pl. 2: 783. 1891. Puccinellia scabrella (Thurber) Ponert, oo Repert. 84: 740. 1974. Type: California, Oakland, Bolander s.n. (holotype, NY Poa nevadensis Vasey ex Scribner, Bull. Torrey Bot. Club 10: 66. oe Atropis ne- vadensis (Vasey ex Scribner) Beal, Grasses N. Amer. 2: 577. 1896. Puccinellia ne- vadensis (Vasey ex Scribner) Ponert, Feddes Repert. 84: 740. 1974. Type: S. Utah, N. Arizona, etc., 1877, Palmer 474 (ny!). The label data on the specimen at Ny eae with those eer cited, and this is an isotype. However, the specimen at s, ““Austin, Nevada, M. E. Jones 1882,” is sometimes cited as the type. It bears the sepia note a “AC [Agnes Chase] Aug. 1951”: “Specimen in Nat. Herb. named ‘Poa nevadensis Vasey’ in Vasey script is ‘Austin Nevada ME Jones 1882.’ Since Vasey is given as author by Scribner his specimen was taken as type by ASH.” Poa tenuifolia Nutt. ex S. Watson var. scabra Vasey ex Scribner, Bull. Torrey Bot. Club 10: 66. 1883, nomen nudum. Glyceria canbyi Scribner, Bull. Torrey Bot. Club 10: 77. figs. 1-4. 1883. Atropis canbyi (Scribner) Beal, Grasses N. Amer. 2: 580. 1896. Poa canbyi (Scribner) Howell, Fl. W. Amer. 1: 764. 1903. Puccinellia canbyi (Scribner) Ponert, Feddes Repert. 84: 739. 1974, Type: Cascade Mtns., Washington Terr., Aug. 1882, Tweedy & Brandegee s.n. (holotype, US?, not seen). Poa orcuttiana Vasey, W. Amer. Sci. 3: 165. 1887. Type: California, near San Diego, Chollas Valley, 26 May 1884, Orcutt 1070 (holotype, us!). Poa a Vasey, Contr. U.S. Natl. Herb. 1: 271. 1893. Type: Idaho, Nez Perce Co., ocky soueee te Tatwet Creek, 1892, Sandberg 138 (holotype, Us?, not seen; a GH!, N Poa gracillima a sae U.S. Natl. Herb. 1: 272. oe not Rendle, 1904. Poa gracillima Vasey, Grasses U. S. 42. 1883, nomen ea E: Washington Terr., — Mt. Paddo, Suksdorf s.n. (holotype, us!; isotypes, N Festuca spaniantha Philippi, Anal. Univ. Chile 94: 174. 1896. Type: sine loco, Anon- mous S$.n. (SGO, not seen, fide Arnow, Syst. Bot. 6: 418. 1981 Festuca patagonica Philippi, Anal. Univ. Chile 94: 174. 1896. Tyee: {Chile,] ad lacuna Pinto in ae australi, bar s.n. (SGo, not seen, fide Piper, Proc. Biol. Soc. Wash 18: 147. — Mee ae Contr. U. 8. Natl. Herb. 1: 273. 1893; neither Borbas, 1877, nor R. 10. Atropis laevis (Vasey) Beal, Grasses N. Amer . 2: 577. 1896. Puccinellia es (Vasey) Ponert, Feddes Repert. 84: 739. 1974. Type: Montana, North Fork Smith R., 19 July 1883, Scribner s.n. (holotype, us!; isotype, NY!). Poa laevigata Scribner, a U. S. Div. Agrost. 5: 31, 1897. Poa nevadensis var. laevigata (Scribner) M. E. Jones, Contr. W. Bot. 14: 14. 1912. Type: Wyoming, Green R., 25 June 1896, Scribner 2039 (holotype, Us?, not seen). oe laevis (Vasey) Beal var. rigida Beal, Grasses N. Amer. vs 578. 1896. Tyre: h, Lake Point, 19 July 1879, M. Jones 1021 eae Msc!). a hie Vasey, Contr. U.S. Natl. Herb. 1: 274. 1893. Type: Colorado, on mountain i near Georgetown, [Clear Creek Co.,] 3 July 1885, Patterson 73 (holotype, a At PH are two specimens bearing the same number collected at Georgetown, Col- seas 18 July 1892. Poa sandbergii Vasey, Contr. U. S. Natl. Herb. 1: 276. 1893. Poa buckleyana var. sandbergii (Vasey) M. E. Jones, Contr. W. Bot. 14: 14. 1912. Paneion sandbergii 236 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 (Vasey) Lunell, Amer. Midl. Naturalist 4: 223. 1915. Type: Idaho, near Lewiston, 1892, Sandberg 164 (holotype, us!; isotypes, GH!, NY!). Atropis tenuifolia (Buckley) Thurber var. stenophylla Vasey ex Beal, Grasses N. Amer. 2: 580. 1896 (as stenophyla). Poa buckleyana var. stenophylla (Vasey) M. E. Jones, Contr. W. Bot. 14: 14. 1912. Type: Oregon, 1887, Howell s.n. (not seen). Poa capillaris Scribner, Bull. U. S. Div. Agrost. 11: 51. fig. 77. 1898; not L. 1753. Poa sae Scribner, Circ. U.S. Div. Agrost. 9: 1. 1898, nomen novum. Type: California, ero, 9 April 1892, Anonymous s.n. (holotype, Us!). Eee a Scribner, Bull. U. S. Div. Agrost. 11: $2. pl. VITT. 1898. tea edie var. juncifolia (Scribner) M. E. Jones, Contr. W. Bot. 14: 14. 1912. Type: Wyomin weetwater Co., Black Rock Springs, Point of Rocks, 13 July 1897, Nelson 3721 eciotise us!; isotypes, GH!, NY!). Poa wyomingensis Scribner ex Pammel, Proc. Davenport Acad. Nat. Sci. 7: 242. 1899. Type: Wyoming, Sheridan Co., Big Horn, July 1897, Pammel 192 (holotype, us). Poa saxatilis Scribner & Williams, Circ. U.S. Div. Agrost. 9: 1. 1899. Poa gracillima Vasey var. saxatilis (Scribner & Williams) Hackel, Allg. Bot. Zeitschr. 21: 79. 1915. Type: Washington, Mt. Rainier, on rock cliffs, alt. 7000 ft, Aug. 1895, Piper 1964 (holotype, us!). Poa leckenbyi Scribner, Circ. U. 8. Div. Agrost. 9: 2. 1899. Poa nevadensis Vasey ex Scribner var. /eckenbyi (Scribner) M. E. Jones, Contr. W. Bot. 14: 14. 1912. Type: Washington, Klickitat Co., Scott, 5 June 1898, Leckenby s.n. (holotype, us!). Poa mee eee Scribner, Cire. U. S. Div. Agrost. 9: 4. nee Type: Oregon, Grave , 21 May 1884, Howell s.n. (holotype, Us!; isotype, Gu!). ae nas Scribner, Circ. U. S. Div. Agrost. 9: 4. 1899. Type: ex Calif. Acad. Sci. Herb. 26, sine loco, Anonymous s.n. (holotype, us!). Poa limosa Scribner & Williams, Circ. U.S. Div. Agrost. 9: 5. 1899. Type: California, Mono Lake, 1866, Bolander s.n. (holotype, us!). Poa invaginata Scribner & Williams, Circ. U. S. Div. Agrost. 9: 6. 1899. Type: [Cal- ifornia,] Sierra Nevada, Summit Camp, 10 July 1870, Scribner 20 (holotype, us). Poa incurva Scribner & Williams, Circ. U.S. Div. Agrost. 9: 6. 1899. Tyre: Washington, Olympic Natl. Park, moraine of Duckaboose Glacier, alt. 7000 ft, Aug. 1895, Piper Poa ampla Merr. Rhodora 4: 145. 1902. Type: Washington, Steptoe, 3 July 1901, Vasey 3009 (holotype, us!). Poa laeviculmis Williams, Bot. Gaz. (Crawfordsville) 36: 55. 1903. Type: Washington, Steptoe, 25 June 1900, Vasey 3026 (holotype, us!; isotype, NY Poa ae Rydb. Bull. Torrey Bot. Club 32: 607. 1905. TYPE: ‘Woming Albany Co., Medicine Bow Mtns., 28 July 1900, Ne/son 7787 (holotype, Ny!; isotype, us!). — truncata Rydb. Bull. Torrey Bot. Club 32: 607. 1905. Type: Colorado, Summit Dillon, 26 Aug. 1896, Clements 373 (holotype, Ny!; isotype, Gu!). Sporabols ene Vasey, Bot. Gaz. (Crawfordsville) 11: 337. 1886; not Poa bo- landeri 882. Type: Oregon, Multnomah Falls, Bolander s.n. (holotype, US?, t see — GH!). Poa pees Piper, Bull. Torrey Bot. Club 32: 435. 1905. Poa gracillima var. multnomae (Piper) C. Hitchce. Vasc. Pls. Pacific Northw. 1: 661. 1969. ae Oregon, Multnomah Falls, 25 June 1904, Piper Ae ge i isotype, NY!). Poa alcea Piper, Bull. Torrey Bot. Club 32: 436. 1905. Oregon, on Elk Rock near Portland, 3 June 1904, — 6463 (holotype, us!; raiegs Poa brachyglossa Piper, Proc. Biol. Soc. Wash. 18: 145. 1905. ue Washingto Do uglas ee alt. 1300 ft, oy a 1893, Sandberg & Leiberg 267 (holotype, - =) ° sotype, Poa helleri oe Bull. Torrey Bot. Club 36: 534. 1909. Type: Idaho, Nez Perce Co. Lake Waha, alt. 2000-3500 ft, 20 June 1896, Heller & Heller 3274 (holotype, us! isotypes, Ds!, NyY!). 1985] KELLOGG, POA SECUNDA COMPLEX 237 Poa englishii St. John & Hardin, Mazama 11: 64. 1929. Type: Washington, Whatcom Co., Mt. Baker Natl. Forest, Bagley Lake, 14 Aug. 1928, Hardin & English 1391 (holotype, wsu!; isotype, us!). Poa juncifolia Scribner subsp. porteri Keck ex Porter, Fl. Wyoming 3: 24. 1964. Type: Wyoming, Albany Co., Pole Mtn. region, 6 July 1943, Porter 3249 (holotype, Ny!; isotypes, CI, RM). Plants caespitose, 1.5—11 dm, sometimes glaucous, frequently becoming red later in season; branching intravaginal; culms 0.3-1.4 mm thick just below inflorescence. Basal leaves 3-80 cm x 0.4-3(—4) mm, usually much shorter than culms, sometimes so narrow as to appear involute, flat or becoming folded on drying, tip often drying early, scabrous on abaxial midvein and usually on margin (especially near tip), occasionally scabrous throughout. Flag leaves 0.2- 22 cm x 0.4—4 mm, borne near midpoints of culms. Sheaths open, or closed only ca. % of length, glabrous or scabrous on margin or throughout. Ligules 0.5-6.5 mm, occasionally obtuse to truncate to more often acuminate, decur- rent, entire, becoming erose or laciniate with age, generally sparsely scabrous abaxially. Panicles narrow, 2-27 cm, spreading at anthesis (and remaining open in some plants), the branches 2 to 8 per node, most commonly 3 or 4, some floriferous only near tip, others nearly to base; spikelets 1- to 6-flowered, 3.5- 12 mm, generally 4 times as long as wide except at anthesis, more or less terete; glumes somewhat unequal (first 2-5 x 0.7-1.8 mm, second 2.5-6 x 1-2.3 mm), acute, more or less erose at margins, 3- (to 5-)nerved, scabrous on upper "3—'o of keel, sometimes also scabrous next to keel; lemmas 2.9-6.1 mm, not conspicuously keeled, acute at apex, with erose upper margin, 5-nerved, sca- rous throughout, entirely glabrous, or pubescent up to % of lower part of lemma, with hairs evenly distributed or extending higher on keel and marginal nerves, to 0.3 mm long, then scabrous above; calluses often with tuft of hairs; paleas 2.5-5.6 mm, equaling or slightly shorter than lemmas, scabrous to pubescent the length of marginal nerves, glabrous to scabrous or pubescent between nerves; rachilla internodes 0.6-1.9 mm, often remaining attached to floret below, glabrous to scabrous or pubescent; anthers 1-3.8 mm, yellow or purple or both; lodicules 0.3-1 mm. Chromosome number 2n = 44, 56, 61- 66, 68, 70-72, 78, 81-106. DIsTRIBUTION AND ECOLOGY. Poa secunda is distributed throughout western North America from the Yukon to northern Mexico, and it extends eastward across the northern Great Plains to a few isolated populations north of the Great Lakes and on the Gaspé Peninsula (Map 1). In addition, there are several disjunct populations in Chile; these are described in detail by Arnow (1981). The Gaspé representatives of P. secunda occur in isolated populations on limestone outcrops and seem not to colonize all available habitats. These populations are small (generally fewer than 50 plants), and seed set and plant vigor appear to be low. The members of the complex grow on a variety of substrates—generally neutral to strongly alkaline soils, which sometimes contain high amounts of soluble salts. Plants with open panicles and short ligules occur only on the walls 238 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 of wet, mossy gorges near Multnomah Falls above the Columbia River in Oregon. Those with open panicles but long, acuminate ligules are montane and are found most frequently in crevices in granite. Large, glaucous plants are often found in saline basins, although they are by no means restricted to such areas. The remaining forms in the complex are widespread from sea level to alpine areas up to 4000 m, growing on sites that dry out early in the season. Blooming time is early in the growing season, varying from April to July depending on latitude and altitude. REPRESENTATIVE SPECIMENS. See APPENDIXES | and 2. A full list of specimens examined is on file in the library of the Arnold Arboretum and Gray Herbarium. NOMINA EXCLUDENDA These names have been included in the Poa secunda complex by some previous workers, but the affinities of the plants to which they refer appear to lie elsewhere for the reasons cited. Poa cottonil Piper, Proc. Biol. Soc. Wash. 18: 146. 1905, as cottoni. Type: Washington, Yakima Co., Rattlesnake Mtns., 7 May 1902, Cotton 557 (holotype, us!; isotype, Nv!). Excluded because the spikelets are large relative to the size of the plant, making 11 look more similar to P. cusickii (for a discussion of which, see introduction Poa macroclada Rydb. Bull. Torrey Bot. Club 32: 604. 1905. Type: Colorado, Gunnison Watershed, Resets, elev. 9000 ft, 14 Aug. 1901, Baker 802 (holotype, Ny!). Excluded because of the small spikelets and the diffuse panicle that suggest affinities with P. interior. Poa fibrata Swallen, J. Wash. Acad. Sci. 30: 210. 1940. Type: California, Siskiyou Co. 3 m1 S of Grenada, Shasta Valley, alt. 2600 ft, 30 June mae Wheeler 3629 (holotype, us!; isotype, Ny!). Excluded because of extravaginal branch Poa napensis Beetle, Leafl. West. Bot. 4: 289. 1946. Type: California, Napa Co., 2 mi N of Calistoga at Myrtledale Hot Springs, 7 May 1946, Beetle 4256 (holotype, uch; isotype, Ny!). Excluded because of the unusually short rachilla internodes and the more nearly ovate glumes. ACKNOWLEDGMENTS For direction and criticism of this work, I thank M. J. Donoghue, C. W. Greene, D. M. Henderson, P. F. Stevens, E. L. Taylor, and C. E. Wood. For help with illustrations, many thanks are due to A. C. Kellogg. This study formed part of a doctoral dissertation submitted to the Department of Organismic and Evolutionary Biology, Harvard University, and was supported in part by a ational Science Foundation Dissertation Improvement Grant. Specimens were kindly loaned by CAs, DAO, KANU, and us. Thanks are also extended to A. J. Gilmartin and J. Davis for their detailed comments on the manuscript, and to C. 8. Campbell and L. Wagner for their critical reviews. LITERATURE CITED Arnow, L. A. 1981. Poa secunda Presl versus P. sandbergii Vasey (Poaceae). Syst. Bot. 6: 412-42]. 1985] KELLOGG, POA SECUNDA COMPLEX Pee BARKWorTH, M. E. 1978. A taxonomic study of the large-glumed species of Stipa (Gramineae) occurring in Canada. Canad. J. Bot. 56: 606-625. Baum, B. 1974. Avena, numerical taxonomy. Canad. J. Bot. 52: 2241-2262. BENTHAM, G., & J. D. Hooker. 1883. Poa. Gen. Pl. 3: 1196. CLAUSEN, J. 1961. Introgression facilitated by apomixis in polyploid poas. Euphytica 10: 87-94. & W.M. Hiesey. 1958. Experimental studies on the nature of species. IV. Genetic studies of ecological races. Publ. Carnegie Inst. Wash. 615: 232-235. CLayTon, W. D. 1971. Studies in the Gramineae: XX VI. Numerical taxonomy of the Arundinelleae. Kew Bull. 26: 111-123. Cronaulist, A., A. H. HotmGren, N. H. HoLtmaren, J. L. REVEAL, & P. K. HOLMGREN. 977. Intermountain flora: vascular plants of the cea West, U.S. A. Vol. 6. The monocotyledons. Columbia Univ. Press, New Davis, J. I. 1983. Phenotypic eet ay and the selection of iene characters in Puccinellia (Poaceae). Syst. Bot. 8: 341-353. DoeBLey, J. F., & H. H. Ivtis. 1980. Taxonomy of Zea (Gramineae). I. A subgeneric classification with key to taxa. Amer. J. Bot. 67: 982-993. Epmonpson, J. R. 1978. Infrageneric taxa in European Poa L. In; V. H. HEywoop, ed., Flora Europaea, notulae systematicae no. 20. J. Linn. Soc., Bot. 76: 329-334. Farris, J. S. 1969. A successive pin corer approach to character weighting. Syst. Zool. 18: 374-385. Fink, 8. V. 1982. Report on the second annual meeting of the Willi Hennig Society. Syst. Zool. 31: 180-197. Gitmartin, A. J., E. KeLLoccG, J. Doprowo sk, D. Sortis, & G. Harris. Variability within among populations of four grass species. Unpubl. MS, submitted to Evolut GOODMAN, M. M. 1968. The races of maize. II. Use of multivariate analysis of variance to measure morphological similarity. Crop Sci. 8: 693-698. GouLp, F. W., & R. B. SHAw. ns Grass systematics. ed. 2. Texas A. & M. Univ. Press, College Station, Tex Gower, J.C. 1967. Ac ee of some methods of cluster analysis. Biometrics 23: 623. 637. Greene, C. W. 1984. Sexual and apomictic reproduction in Ca/amagrostis (Gramineae) from eastern North America. Amer. J. Bot. 71: 285-293. HackEL, E. 1887. Gramineae. Jn: A. ENGLER & K. PRANTL, eds., Nat. Pflanzenfam. II. 2: 73 Hart ey, W. 1961. Studies on the origin, evolution, and distribution of the Gramineae. IV. The genus Poa L. Austral. J. Bot. 9: 152-161. Hartunc, M. E. 1946. Chromosome numbers in Poa, Agropyron, and Elymus. Amer. J. Bot. 33: 516-531. Herpet, B., J. Curisty, & A. J. GitMARTIN. 1982. Numerical phenetic analysis of variation in populations of Poa secunda Presl and Bromus japonicus Thunb. (Po- aceae). Northwest Sci. 56: 108-120. Hiesey, W., & M. A. Noss. 1982. Experimental studies on the nature of species: VI. Interspecific hybrid derivatives between facultatively apomictic species of blue- grasses and their responses to contrasting environments. Publ. Carnegie Inst. Wash. 636: 1-119. Hitcucock, A. S. 1935. Manual of the grasses of the United States. U. S. D. A. Misc. Publ. 200: 1-1040. 1950. Manual of the ae of the United States. ed. 2 (revised by AGNEs CH ASE). Dover Publ., Inc., ork. Hircucock, C. L., & A. Ce 1973. Flora of the Pacific Northwest. Univ. Washington Press, Seattle. M. Ownpsey, & J. W. THompson. 1969. Vascular plants of the Pacific 5) 5) 240 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Northwest. Part I: Vascular cryptogams, g I and tyled Univ. Washington Press, Seattle. Jones, M. E. 1912. Poa. Contr. W. Bot. 14: 13-15. KeLtoce, E. A. 1983. A biosystematic study of the Poa secunda complex. Unpubl. D. thesis, Harvard Univ., Cambridge, Massachusetts. Kotata, G. 1982. Computer graphics comes to statistics. Science 217: 919, 920. Lyncu, M., & W. GABRIEL. 1983. Phenotypic evolution and parthenogenesis. Amer. Naturalist 122: 745-764. Mars, V. L. 1952. A taxonomic revision of the ne Poa of United States and southern Canada. Amer. Midl. Naturalist 47: 202-256. MarsHa tL, D. R., & B.S. Wetr. 1979. Maintenance of genetic variation in apomictic plant populations. I. Single locus models. Heredity 42: 159-172. McNEILL, J. 1975. A generic revision of Portulacaceae tribe Montieae using techniques of numerical taxonomy. Canad. J. Bot. 53: 789-809 MISHLER, B., & M. J. DoNoGHuE. 1982. Species concepts: an argument for pluralism. Syst. Zool. 31: 491-503. MorisHima, H., & H. OKA. 1960. The pattern of interspecific variation in the genus Oryza; its quantitative representation by statistical methods. Evolution 14: 153- 65. ac) x l NyaGren, A. 1951. Embryology of Poa. Carnegie Inst. Wash. Year Book 50: 113-115. Puipps, J. B. 1970. Studies in the Arundinelleae (Gramineae). X. Preliminary taxi- metrics. Canad. J. Bot. 48: 2333-2356. Pres_, J. S. 1830. Reliquiae Haenkeanae. J. G. Calve, Pragu ScRIBNER, F. L. 1883. A list of grasses from Washington To ae Bull. Torrey Bot. Club 10: 63-66. SNeEATH, P.H.A., & R.R.SOKAL. 1973. Numerical taxonomy. Freeman, San Francisco. SorEnG, R. J., & S. L. HAtcu. 1983. A comparison of Poa tracyi and Poa occidentalis (Poaceae: ee Ree 10: 123-141. — C.J.,& R.J. Kiviick. 1978. Multivariate methods as an aid in identifying ampla x pi pratensis hybrids from maternal-type offspring. Heredity 41: 215- APPENDIX |, Specimens measured for evaluation of eee variation using principal-component analyse Canada. YUKON TERRITORY: vic. of Mackintosh (mi 1022, Alaska Hwy.), Schofield & Crum 7475 (ps); Canol Rd., mi 95, Upper Rose R. valley, elev. 3600 ft, Porsild & Breitung 10345 (Gu). British CoLtumBiA: Allies Mine, Tranquille, 4000 ft, Dominion Range Exp. Sta. 86 (us); on ridges between Baldy Mtn. and Dunn Peak ca. 7 mi ENE of Littlefort, ca. 51°27’N, 120°03’W, ca. 7000 ft, Calder, Parmelee, & Taylor 19911B (DAO); apres Is., Esquimault, Macoun 71 (us). NoRTHWEST TERRITORIES: Mackenzie Distr., N. of Brintnell L. Camp, alt. 3500 ft, Raup & Soper 9668 (A), Mackenzie Distr., Slave R. lowlands on E side of Slave R., NE Ann’s prairie, 60°46'N, 112°44’W, Reynolds 27 (DAO). ALBERTA: Waterton Lakes Nall. Park, Mt. Crandell, elev. 7500 ft, Breitung 17405 (us), Webster Twp., Manyberries, Campbell 85.B (pAo); Beaverlodge, Truax Farm, E of town, Barkworth 1460 (pao). MANITOBA: Medora, Dore 11067 (DAO); Brandon, Stevenson F121] (DAO). SASKATCHEWAN: Regina, Shevkenek 15 (DAO); Watman, Groh s.n. (DAO). ONTARIO: Flowerpot Is., Barkworth 2001 (DAO). QUEBEC: Gaspé Co., stony summit of Mt. Ste. Anne, Percé, Pease 36592 (GH); Rimouski Co., Pointe aux Corbeaux to Cap Caribou, Bic, Fernald & Collins 899 (GH). United States. ALASKA: Juneau, Hitchcock 4072 (us);* Skagway, Hitchcock 4206 (us). WASHINGTON: Chelan Co., alpine crest of Three Brothers Peak, 7000 ft, Thompson 12625 *Not a member of the Poa secunda complex. Eliminated from most analyses. +Poa curtifolia. 1985] KELLOGG, POA SECUNDA COMPLEX 241 (us);t Cowlitz Co., wet cliffs near Smelt Landing, Thompson 12729 (Gu); Kittitas Co., ¥4 mi above Teanaway R. (N Fork) on trail to Ingalls Lake, Kruckeberg 5037 (cas);t Kittitas Co., Mt. Stuart region, 5000 ft, Thompson 7813 (us),t Thompson 7820 (us);t Kittitas Co., open talus slopes at head of Beverly Creek, 5000 ft, Thompson 9511 (ps);t Kittitas Co., on Beverly Turnpike Trail, Wenatchee Mtns. at 5200 ft, Kellogg 232* (field- and garden-grown specimens);f Yakima Co., Rattlesnake Mtn., Cotton 556 (us); Pull- man, Piper 3973D (us). OREGON: banks of Willamette R., Howell 33 (us); Gilliam Co., W-facing slope on E side of Phillippi Canyon Rd., 3 mi S off Hwy. 80, and W of Blalock, Kellogg 22 (field-, greenhouse-, and garden-grown specimens); Grant Co., on steep sandy cut-bank next to rd. along E side of S Fork John Day R., 11 mi S of John Day, Kellogg 154 (field-, garden-, and greenhouse-grown specimens); Multnomah Co., on Oneonta Pringle s.n., 6 April 1882 (cas); El Dorado Co., between Shingle Springs and El Dorado, Heller 12297 (Gu); San Bernardino Co., Mojave Desert, 15 mi NE of Barstow on Garlic Springs Rd., %) mi N of 2nd summit, alt. 2800 ft, Wolf 6516 (Gu); San Bernardino Mtns., flats near ihoet Creek, alt. 6800 ft, Munz 17080 (Gu); Siskiyou Co., Yreka, Butler 1294 (GH); mtns. S Dixey Valley, Davy s.n., 5 July 1894 (us). IpAHo: Clark Co., at U. S. Sheep Exp. Sta. between Spencer and Dubois, E of Rte. 15, 50 yd E of RR tracks, Kellogg 56 (field- and garden-grown collections; 8 separate culms of field-grown clump scored as separate plants); Elmore Co., 13 mi NE of Mountain Home, on N slopes near headwaters of Rattlesnake Creek, Christ & Christ 16655 (us); Bitterroot Natl. Forest, Salmon Mtn., Kellogg 226 (garden- and greenhouse-grown collections); Lemhi Co., on rock outcrop at 9400 ft, | aa E of Doublesprings Pass and SW of Buck Creek, Kellogg 196 (field-, garden-, and ); Lemhi Co., just below microwave relay station near rd. run ning N from Bannock Pass (3 mi from pass), Kellogg 22]. Nevapa: vic. of Reno, Hunter Creek Canyon, Hitchcock 10554 (us); Washoe Co., Dins- more Camp, Hunter Creek Canyon, 6000 ft, Kennedy 1639 (cas). UTAH: slope of Aquar- ius Plateau, alt. 9000 ft, Ward 488 ba side of Bald Mtn., elev. 11,500 ft, ee 4004 (us); Cache Co., meadows 3 m of Logan, Maguire 13874 (DAO). ARIZON Mojave Co., Mokiak Springs, 19 mi S Saint George, Utah, alt. 3000 ft, Gould 1643 (GH); Pipe Spring, alt. 5000 ft, A¢. Jones 5266 (ps). MONTANA: Glacier Natl. Park, on large nearly bare rock above McDermott, Hitchcock 11301 (us); Glacier Natl. Park, Greenwood’s Camp, 4500 ft alt., . Jones s.n., 15 Aug. 1910 (us); Glacier Natl. Park, near E entrance, Swallen 6458d (us). Wyomina: Jacksons Hole, above Leighs Lake, alt. 9000 ft, Merrill & Wilcox 341 Pee Natl. Park, S of Mt. Washburn, Hifch- cock 2036 (us). COLORADO: Gunnison Co., NW Castle Peak, Gothic Basin, ca. 12,000 ft, Ewan 11752 (us); Rabbit Ear Pass, Swallen 1379 (us); Moffat Co., W ri pee Canyon, elev. 7500 ft, Porter 3670 (GH). NEw Mexico: Fitzgerald Cienaga, Wooton (us). NortH Daxora: Billings Co., edge of Moody Plateau, Swallen 5787 (DAO); Wells (GH); Dawes Co., Tolstead 7 (us). MICHIGAN: Isle Royale, Monument Rock, Tobin Harbor, McFarlin 2175 (us). MINNESOTA: Ottertail Co., Perham, Chandonnet 2562 (GH). Maine: North Berwick, Parlin 1233 (us). APPENDIX 2. Specimens measured for discriminant analyses and evaluations of population variation.£ United States. CALIFORNIA. San Diego Co.: Cleveland Natl. Forest, T15S RSE, on road from Cibbett’s Flat, Kellogg & Taylor 295 (1; 4 sheets); on W side of hwy. N of Mt. Laguna ca. | mi, Kellogg & Taylor 298 (2; 4 sheets); N end of Cuyamaca Reservoir, Kellogg & Taylor 300 (3; 3 sheets); on rocky outcrops at N end of Cuyamaca Reservoir, Kellogg & Taylor 302 (4; 3 sheets). Riverside Co.: on N side of Hwy. 74, T7S R4E S16, *One specimen of each Kellogg collection is at A tNumbers in boldface refer to population aiber on bar graphs. 242 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Kellogg & Taylor 304 (5; 4 sheets); next to Hwy. 79 E of Rancho eee sa ache on river banks, Kellogg & Taylor 307 (6; 4 sheets). San Bernardino Co.: Fort Irwin Rd. ca. 14 mi NE of Barstow, 0.9 mi beyond 2nd summit in side canyon 300 yd from rd., Kellogg & Taylor 314 (7; 4 sheets). Kern Co.: in Red Rock Canyon, ca. 20 mi N of Mojave on steep slopes W of Hwy. 14, Kellogg & Taylor 315 (8; 3 sheets). Los Angeles Co.: T7N R16W S13, in canyon ca. 100 yd below Upper Shake Campground, Kellogg & Taylor 316 (9; 8 sheets); T8N R17W S29, on cut-bank above County rd. N2, Kellogg & Taylor 321 (10; 4 sheets). Santa Barbara Co.: ca. 4 mi W of LaCumbre Peak, Santa Ynez Mtns., ca. 3800 ft, Kellogg & Taylor 322 (11; 3 sheets); on steep N-facing road- cut on N side of Gato Ridge on oil co. property, ca. 900 ft, Kellogg & Taylor 323 (12; 4 sheets). Mono Co.: just below Carnegie Inst. Transplant Garden, Timberline Exp. Sta., Kellogg & Kiest 370 (16; 5 sheets); Minarets Wilderness, on River Trail between Garnet Lake and Shadow Lake turnoffs, Kellogg & Kiest 377 (17; 4 sheets). Inyo Co.: Big Pine Lakes, head of Big Pine Creek between First and Second lakes, elev. 10,000 ft, T9S R32E S33 NW'4, Kellogg & Kiest 379 (18; 4 — Fresno Co.: just W of Swede Lake, W of Three Sisters, Dinkey Lakes area, ca. 40 mi NE of Fresno, T9S R26E $12 SE'4, Kellogg & Kiest 382 (19; 4 sheets), WASHINGTON. ee Co.: sandy W shore of Columbia R. at Inchelium, below 1290 ft level, Rogers 537] (20; CAs, DS, GH). Haak ae border of alkaline pond in Grand Coulee 7 mi above Dry Falls, Rogers 589 (21; Cas, Ds, GH, US). Kittitas Co.: canyon of Bushy Creek, alt. 1000 ft, Cotton 1620 (22; Gu, Ba "1621 (22; us), 162112 (22; us); Wawawai, on banks of Snake R., Piper 2567 (23: GH, US—2 sheets); Rese City, Piper 3912—2 sheets, 39/6, 39/8, 3920— 2 sheets (24; GH, Us). Whitman Co.: Albion, 8 mi NW of Pullman in RR right-of-way, Keck & Hiesey 5340, 5341, 5342 (25; ps). Chelan Co.: alpine slopes of Chumstick Lookout, 6000 ft, Thompson 14979 (26, CAS, DS, GH). Kittitas Co.: open alpine ridges at head of Beverly Creek, 5000 ft, Thompson 95] ] (27; CAs, DS, GH, US—2 sheets); on Teanaway Divide, Beverly Turnpike Trail, 5700 ft, Kellogg 233 (28; 5 ae Canada. Quésec. Rimouski Co.: on shale outcrop below calcareous cliffs above St. Fabien sur Mer, Kellogg & Kiest 351 (13; 8 sheets). Gaspé Co.: Grand Coupe ca. 1 mi NW of Percé, ca. 550 ft alt., Kellogg & Kiest 358 (14; 7 sheets). Bonaventure Co.: on S- facing cliffs just below summit of Mt. St. Joseph, Kellogg & Kiest 363 (15; 3 sheets). HARVARD oo nee 22 Divinity AVEN CAMBRIDGE, Tene HUSETTS 02138 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 243 THE EOCENE NORTH ATLANTIC LAND BRIDGE: ITS IMPORTANCE IN TERTIARY AND MODERN PHYTOGEOGRAPHY OF THE NORTHERN HEMISPHERE! Bruce H. TIFFNEY THE TRANSITION from the Cretaceous to the Tertiary marks a time of sig- nificant modernization in the history of flowering plants. During this interval, a wide range of extant families and genera first appeared, as recorded in the fossil record of pollen (Muller, 1970, 1981) and fruits and seeds (Tiffney, unpubl. data). This modernization was probably spurred by coevolution with pollinators (Crepet, in press) and dispersal agents (Tiffney, in press) and resulted in a major change in the floristic and vegetational composition of the world’s plant communities. Concomitant with this modernization, the newly evolved taxa spread rapidly over the Northern Hemisphere (Wolfe, 1975) during a period of equable climate (Kennett, 1977; Savin, 1977; Buchardt, 1978; Wolfe, 1978) to form a hemi- spheric flora. This flora seems unusual by modern standards since it consisted of a mixture of taxa, the modern counterparts of which are found in habitats ranging from deciduous northern hardwood forests (e.g., Juglans L., Carpinus L., Betula L.) to tropical and paratropical rain forests, particularly of south- eastern Asia and Malaysia (e.g., Nypa Steck, Mastixia Blume, Tetrastigma Planchon, and members of the Icacinaceae). In recognition of its northern geography and the thermophilic affinities of many of its component taxa, Wolfe (1975, 1977) referred to this assemblage as the ““boreotropical flora.” The classic example of this flora is the Early Eocene London Clay assemblage of south- eastern England (Reid & Chandler, 1933; Chandler, 1961, 1962, 1963, 1964, 1978). Although the boreotropical flora was apparently not a homogeneous unit, its composition was strikingly similar throughout its range. Reid and Chandler (1933) saw the modern Indomalaysian affinities of the London Clay assemblage as suggestive of a tropical flora that had moved along the coasts of the Tethys Seaway. This conclusion was subsequently supported by discov- ery of London Clay taxa in the Eocene of eastern Europe (Palamarev, 1973) and the Eocene (Chandler, 1954) and Oligocene (Bown et al., 1982) of Egypt. The Middle Eocene Clarno Formation of Oregon represents an extension of this flora to the west (Scott, 1954; Chandler, 1964; Manchester, 1981, 1983), as do some small, unreported floras in the Rocky Mountains (pers. obs.). 'This is the mee of two related papers. The first, entitled “‘Perspectives on the Origin of the Floristic Similarity between Eastern Asia and Eastern North America,” appeared in the January, 1985, issue of cf jan of the Arnold Arboretum © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 243-273. April, 1985. 244 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Although the Clarno assemblage has not been fully investigated, it is clear that the fruit and seed portion of the flora includes several genera and perhaps some species in common with that of the London Clay. The geographic links between the Clarno and London Clay floras are conjectural; they could lie across the northern Pacific and East Asia (see data of Zaklinskaya, 1980), they could reflect the influence of the Tethys Seaway—North Atlantic route, or they could result from a combination of the two. Once the early Tertiary boreotropical flora had spread, it was influenced and altered by subsequent geographic and climatic events, giving rise to the modern flora and vegetation of Eurasia and North America. Two geographic changes were of particular importance. In the Old World the closing of the Turgai Straits during the Oligocene (Vinogradov, 1967-1968; McKenna, 1975; see Map 5) permitted biotic exchange between central Asia and Europe. The dis- appearance of this sea also introduced a more continental climate to western Siberia. This led to the evolution of increasingly drought-tolerant, continental communities of a modern aspect, which ultimately invaded Europe from the east (see Friis, 1975). The second geographic modification involved the west- ward movement of North America. On its trailing edge this movement was powered by expansion along the Mid-Atlantic Ridge, which caused the wid- ening of the North Atlantic and the sundering of early Tertiary ties between Europe and North America (McKenna, 1975, 1983a; Hoch, 1983). On its leading edge the westward movement contributed to the Tertiary orogenies of western North America. This mountain building provided direct topographic barriers to plant movement and resulted in a lengthening shadow of drier climates across central North America. Consequently, a new and more drought- tolerant flora and vegetation evolved in the western mountains and eastward, while the remnants of the earlier, moisture-adapted boreotropical flora were largely confined to the western slopes or retreated southward (Leopold & MacGinitie, 1972). The effects of these geographic alterations were further modified by climatic changes through the Tertiary (Friis, 1975; Kennett, 1977; Buchardt, 1978: Wolfe, 1978; Hickey, 198la). The temperate global climates of the earliest Tertiary gave way to increasingly warmer climates in the Early Eocene. During the latter time, much of the Northern Hemisphere supported a warm-temperate to subtropical vegetation, and thermophilic vegetation grew at fairly high lat- itudes (Wolfe, 1975, 1977). A climatic deterioration involving a decrease in world temperature and an increase in seasonality occurred during the later Eocene (Collinson et a/., 1981; Keller, 1983) or at the Eocene-Oligocene bound- ary (Kennett, 1977; Buchardt, 1978; Wolfe, 1978) and extended into the Oli- gocene (Keller, 1983). This resulted in the contraction of the boreotropical flora and the geographic expansion of a species-poor deciduous vegetation of north- ern latitudes (Wolfe, 1969, 1977, 1978, 1980; Hickey, 1981la, 1981b, pers. comm.; Hickey et a/., 1983). In the later Oligocene and the Miocene the climate fluctuated between warm and cool, leading to selection of cool-adapted taxa from the boreotropical flora and their addition to the developing deciduous vegetation, which diversified and is now recognized as the mixed mesophytic forest (Wolfe, 1969; see also Mai, 1964, 1981). Later Miocene and Pliocene 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 245 climates became increasingly cooler, leading to the extreme cold of the Pleis- tocene. This cooling resulted in a thermal segregation of the products of the boreotropical flora. The evergreen and cold-intolerant elements of the wide- spread Paleogene forests were restricted to protected southerly refugia; where these were not available, or where climatic change occurred more rapidly than dispersal and regeneration, local extinction occurred. The more recently seg- regated warm-temperate elements of the mixed mesophytic forests were like- wise restricted to protected sites or became extinct, although the effects of glaciation were less disruptive on this group of plants than on the tropical members of the boreotropical flora. To the north a northern hardwood forest of low diversity developed, and north of it taiga and tundra communities evolved. As a result of these geographic and climatic changes during the Tertiary, the evergreen and mixed mesophytic remnants of the boreotropical flora now oc- cupy widely separated ‘“‘Tertiary refugia.” Classically, these include the Balkans, the Caucasus, Southeast Asia, Japan, western and eastern North America, and portions of the eastern highlands of Mexico (especially Veracruz) and northern Central America (see Szafer, 1964; Wood, 1972). Although these localities share common elements, they preserve different diversities and often different subsets of the boreotropical flora. Southeast Asia harbors the greatest representation of the early Tertiary flora, particularly in Japan and in the zone from the mixed mesophytic forests of China south through the tropical evergreen forests of Malaysia. The fossil record suggests that both western North America (Wolfe, 1975, 1977, 1978) and Europe (Chandler, 1964; Mai, 1964, 1970, 1981) had a rich sample of the boreotropical flora and the succeeding mixed mesophytic forest in the early and mid-Tertiary. However, the interaction of global climate and local topography caused the extinction of many of these thermophilic elements in the late Tertiary and Quaternary. This elimination was particularly pronounced in Europe, where advancing Pleistocene glaciers trapped the floras against the east-west oriented mountains, leaving only scraps of the original flora in Europe and more developed remnants in the diverse topography of the Balkans and the Caucasus. In western North America, boreotropical elements were first restricted to moister west-facing sites by the rising Rocky Mountains and were subsequently influenced by the cooling climates of the later Tertiary and Quaternary (Wolfe, 1969, 1977, Leopold & MacGinitie, 1972). Again, depauperization of the flora occurred, but with less drastic effects than in Europe. Southeastern North America presently has a diverse representation of ev- ergreen and deciduous woody elements of the boreotropical flora. The similarity of this flora to that of eastern Asia has been given as an example of disjunction since the time of Linnaeus (Graham, 1972) and Gray (1840, 1859; Boufford & Spongberg, 1983). However, the New World floras are generally considered to have a lower diversity of boreotropical elements than the modern floras of Japan, China, and Indomalaysia. The contention that the modern descendant of the boreotropical flora in southeastern North America is less diverse than its counterpart in Southeast Asia is central to the discussion to follow. However, I do not believe this 246 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 statement has ever been supported in a quantitative manner, and I therefore present a numerical summary (TABLE). Hu (1935) estimated that there were 969 genera of woody spermatophytes and approximately 2000 species of trees in China. The second edition of the first five volumes of the /conographia Cormophytorum Sinicorum (Anonymous, 1980) suggests a woody flora of ap- proximately 950 genera and 3400 species. The /conographia is acknowledged to be incomplete and is being superseded by the Flora Reipublicae Popularis Sinicae. This multi-volume flora is still being published and thus cannot be used to obtain a direct count of diversity. However, comparison of reports for 19 woody families in the /conographia and the Flora suggests increases of roughly 15 percent in generic diversity and 100 percent in specific diversity in the latter publication. If this is correct, the woody flora of China would involve about 1030 genera and 6800 species. Ohwi’s (1965) Flora of Japan records 278 genera and 858 species of woody spermatophytes from the much smaller area of Japan. By contrast, Gray’s Manual of Botany (Fernald, 1950) lists 161 genera and 665 species of woody spermatophytes (including trees, shrubs, and vines) in northeastern North America. The Manual of the Vascular Flora of the Caro- linas (Radford et al/., 1964) lists 211 genera and 554 species of woody sper- matophytes in the flora of North and South Carolina. Small’s (1933) Manual of the Southeastern Flora lists 412 genera and 1202 species of woody sperm- atophytes in the southeastern United States. Biases exist in all these tabulations, and the final figures must be taken as approximate. The /conographia Cor- mophytorum Sinicorum embraces slightly more tropical areas than occur in the southeastern United States. The three North American sources cover sep- arate portions of the flora of eastern North America rather than the entire flora (TABLE). Nonetheless, it is clear that the extant woody flora of eastern North America has approximately one-third to one-half the specific diversity of the woody flora of East Asia. While many of the East Asian genera are rare or monotypic, this is not the sole cause of the difference in diversity; comparison of vegetational surveys of China (Wang, 1961) and eastern North America (Braun, 1950) reveals 119 genera and 563 species of ecologically important trees in the former flora, and 46 genera and 112 species in the latter. Again, biases exist in the use of these data for the estimation of diversity, but the general picture 1s clear. Herbs have not been mentioned in the above discussion inasmuch as a significant proportion of herbaceous taxa appear to have evolved locally in the middle and late Tertiary (Tiffney, 1981a, 1985) rather than spreading with the boreotropical flora. If they were included, it would only accentuate the observed pattern (see TABLE). The cause of the lower diversity of boreotropical taxa in the modern flora of eastern North America is not immediately clear. Wolfe (1977) suggested four contributing factors: eastern North America was isolated from western North America and Europe in the Tertiary;? the Eocene-Oligocene climatic Wolfe (1977, p. 49) suggested, after MacGinitie (1969), that the isolation of eastern North America is ancient, and that the original Paleogene boreotropical flora of the area was less diverse than that of Europe or western North America. Generic and Specific Diversities of Selected Eastern Asian and Eastern North American Floras.* PERCENT OF FLORA TOTAL FLORA Woopy PLANTS HERBACEOUS PLANTS THAT IS WOODY TOTAL AREA LocATION (sq. km) Genera Species Genera Species Genera Species Genera Species China a. 3:550,071 2389 7702 949 3397 1440 4305 40 44 b. 2840 15,400 1030 6790 1810 8610 36 44 Jap 369,698 364 278 85 710 2790 28 235 N. E. ‘North America 2,515,885 815 4227 161 665 654 3562 20 16 Carolinas 216,628 826 3157 211 554 615 2603 25.5 7S S.E. North America 1,700,374 1510 5563 412 1202 1098 4361 27 21.5 *All figures should be regarded as approximations. Introduced cultivated plants were excluded when identifiable as such. If a genus included more than one physiognomic type (e.g., tree, vine), placement of the genus and its included species in a physiognomic class was dictated by the prevalent physiognomy. In some cases this resulted in arbitrary decisions. The total number of taxa in a ones area ee both biological reality and the systematic concepts of the reporting author(s). For oe Small (1933) is generally regarded as a “‘splitter,”’ and th y reported in his flora is presumably inflated relative to the diversity reported by othe ee rces: China “‘a,”’ after Anonymous (1980); China “‘b,”’ eenied from Anonymous (1959-present); Japan, Ohwi (1965); northeastern United States, hee as 50); the Carolinas, Radford et a/. (1964); southeastern United States, Small (1933). Data for areas taken from Bartholomew ef al. (1980); those for China exclude the floristically poor highlands of Tibet, Mongolia, and Sinkiang. FOCI GNVT OLLNVILV HLYON ‘AFNASATL [S861 Lve 248 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 deterioration further depauperized the flora of eastern North America; this same event separated the incipient mixed-mesophytic flora of the area from more tropical floras isolated to the south, preventing enrichment of the former by the latter in the mid-Tertiary; and the area had little topographic diversity. Although the last point may be taken as given, the first three raise three se- quential questions. First, was the Eocene boreotropical flora of eastern North America significantly less diverse than that of contemporaneous Europe or western North America? This involves both a consideration of the fossil record of eastern North America and an examination of the degree of geographic isolation of this area in the early Tertiary. Second, if this flora was as rich as that of Europe and western North America, did it give rise to an equally rich mixed-mesophytic flora, or as Wolfe has suggested, was its diversity curtailed by the Eocene-Oligocene climatic deterioration? Third, if diversity was not restricted by this deterioration, at what subsequent time was it reduced? I believe that the original Paleogene boreotropical forest of eastern North America was nearly as rich as those of western North America and Asia, and that the reduced diversity of the present southeastern North American flora 1s a function of the subsequent Eocene-Oligocene and/or Pleistocene climatic fluctuations. Demonstration of this supposition is circumstantial and requires evidence from the fossil record and paleogeography. First, the Tertiary fossil record of eastern North America must be shown to contain a significant number of boreotropical taxa. The stratigraphic distribution of these taxa might aid in distinguishing between an Eocene-Oligocene and a Pleistocene depauperization of the flora. Second, examination of the paleozoogeography, paleogeography, and paleoclimatology of the early Tertiary must demonstrate that eastern North America was not isolated from the rest of the Northern Hemisphere during the spread of the boreotropical flora. I will examine these two lines of evidence and suggest that the data, although equivocal, support the contention of a diverse early Tertiary flora in eastern North America that was reduced by subsequent, primarily climatic changes. THE PALEOBOTANICAL RECORD OF EASTERN NORTH AMERICA Our present understanding of the Tertiary paleobotanical history of eastern North America is poor. Paleogene and Neogene plant-bearing deposits are rare on the Atlantic Coastal Plain. The tectonic setting of this area in the Tertia did not favor the formation of deep depositional basins. The few fossiliferous deposits that accumulated have been severely eroded by ice sheets in glaciated terrain and deeply weathered to the south of the limit of glaciation. The low angle of repose of the present terrain does not favor natural exposure of the coastal plain sediments, and extant vegetation hampers exploration efforts. Finally, few workers are investigating this time and area In spite of these difficulties, evidence for the presence of boreotropical genera may be found in both the micro- and the macrofossil records. Among micro- fossils, Elsik (1974) has recorded pollen of Engelhardtia Leschen. ex Blume, Pterocarya Kunth, Platycarya Sieb. & Zucc., Alangium Lam., Ficus L., and the Icacinaceae, and Frederiksen (1980b) reported pollen of the palm Nypa 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 249 from Middle and Upper Eocene sediments of the Mississippi Embayment. The pollen of Platycarya is of particular note since 1t peaks both in the Early Eocene floras of the Atlantic Coastal Plain and the Mississippi Embayment (Freder- iksen, 1980c) and in the Early Eocene Willwood Flora of Wyoming (Wing, 1981). Although circumstantial, this implies a degree of Early Eocene floristic exchange between the southeast and the eastern slope of the Rocky Mountains. Traverse (1955) recorded pollen of Engelhardtia, Pterocarya, Alangium, and Glyptostrobus Endl. from the Brandon Lignite of Vermont. This deposit has been dated as Oligocene (Wolfe & Barghoorn, 1960) or perhaps Early Miocene (D. Mai, pers. comm.; N. Frederiksen, pers. comm.) in age. Frederiksen (1984) has found pollen of Sciadopitys Sieb. & Zucc., Pterocarya, and the Engelhardtia “sroup” (Engelhardtia, Alfaroa Standley, Oreomunnea Oersted) in the Miocene of Massachusetts, and Rachele (1976) has recorded pollen of Pterocarya and Engelhardtia in the Miocene of New Jersey. All of these genera are members of the boreotropical flora and currently exist in the flora of East Asia. However, although present in the Tertiary pollen floras of eastern North America, these taxa formed a small percentage of the total flora; in most cases the pollen floras of this area appear to be dominated by New World taxa or by pollen taxa that lack specific biogeographic affinities. The macrofossil record of the Gulf Coastal Plain is poor for the late Tertiary but far better for the Paleogene. Revisions of Berry’s (1916, 1924, 1930) early studies on the leaves of the Mississippi Embayment deposits have only recently been initiated (Dilcher, 1971; Crepet, 1979, and references therein), and com- parison of these leaf floras with others in the Northern Hemisphere is difficult. The existing data suggest some similarity between the floras of the Embayment and those of the early Tertiary of western North America (Wing, 1981). How- ever, the degree of this similarity is not fully understood, and the timing of its onset or decline is unclear. Climatic reconstructions using leaves (Dilcher, 1973) and pollen (Frederiksen, 1980a) suggest that the warm climates of the earlier Eocene in the Northern Hemisphere were distinguished in the southeast by a pronounced dry season. If this is correct, such a seasonal drought may have promoted the evolution of a flora and vegetation distinct to some degree from that of western and northeastern North America. The one megafossil from the Mississippi Embayment with a clear boreotropical affinity is the fruit of the palm Nypa from the Middle Eocene of Texas (Arnold, 1952; Tralau, 1964), which is also known from pollen (Frederiksen, 1980b). Nypa was widely dis- tributed in the early Tertiary of Europe (Tralau, 1964) but is presently restricted to estuarine sites in Indomalaysia and northern Australia. Outside of the Mississippi Embayment, macrofossils have been studied less frequently than microfossils, yet they often provide more specific biogeographic information. The fossil distribution of Nypa is paralleled by that of two species of ?Euphorbiaceae from the Early Eocene of Maryland and Virginia, Wether- ellia Reid & Chandler and Pa/laeowetherellia Chandler (Mazer & Tiffney, 1982). Wetherellia is known from Eocene sediments in England (Reid & Chandler, 1933: Chandler, 1964) and is one of the most common elements of the London Clay; Palaeowetherellia is known from early Tertiary deposits in northern Egypt (Chandler, 1954). Although specimens of the latter genus from Egypt and the 250 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 New World are clearly different from one another, those of Wetherellia from England and the Atlantic Coastal Plain are virtually indistinguishable, and their depositional context suggests that they were produced by a coastal plant. The distributions of these two taxa, and of Nypa, appear to reflect the westerly extension of coastal elements of the London Clay Flora along the northern shore of the Tethys. The one exception to the dearth of macrofossil deposits in northeastern North America is the Brandon Lignite of west-central Vermont. This deposit is rich in pollen, wood, fruits, and seeds; its age is uncertain but probably falls between Oligocene (Wolfe & Barghoorn, 1960) and Miocene (Frederiksen, pers. comm.). The flora is pertinent to the present discussion because it provides an instructive comparison between the biogeographic information inherent in micro- and macrofossil floras, and because it demonstrates the presence of several boreo- tropical genera in the Tertiary of eastern North America that are not found in the extant flora of this area. The only boreotropical genera recorded in the microflora (Traverse, 1955) are Alangium, Engelhardtia, Glyptostrobus, and Pterocarya; the remainder of the palynoflora appears to have New World or cosmopolitan affinities. By contrast, the macroflora includes both some taxa with close relationships to modern genera restricted to East Asia, and a smaller number of taxa related to boreotropical forms found in the Tertiary floras of Europe. Nyssa brandoniana Eyde & Barghoorn (Eyde & Barghoorn, 1963) is very similar to N. javanica (Blume) Wangerin of Burma. Phellodendron Rupr. and Euodia J. R. & G. Forster (Rutaceae; Tiffney, 1980a) are presently restricted to East Asia but were common in Europe during the Tertiary. Turpinia Vent. (Staphyleaceae; Tiffney, 1979) is found in both the Old and New World tropics. The Brandon specimen shows closer affinity with existing New World species; a second species is found in the European Miocene (Mai, 1964). Similarly, Cleyera Thunb. (Theaceae; Tiffney, in manuscript) 1s largely a New World genus but is closely related to the Old World Eurya Thunb. Cleyera/Eurya- like fossils are common in the European Tertiary, and the two genera are probably sister groups of Tertiary origin. Magnolia waltonii Tiffmey (Magno- liaceae; Tiffney, 1977) and Microdiptera parva Chandler (Lythraceae, Tiffney, 1981b) are both Brandon taxa that are closest to extinct forms of the European Tertiary. Undescribed fossils now under investigation include achenes similar to those of Caldesia Parl. (Alismataceae), a genus of the Old World tropics and known from the European Tertiary, and at least three species of Symplocos Jacq., only one of which appears to have New World affinities. In addition, endocarps of A/angium (Alangiaceae; Eyde et a/., 1969), paralleling the pollen record, are known from the deposit. Although the fruit and seed flora of the Brandon Lignite has not been fully described, it does include several clearly boreotropical taxa and is far more closely related to the boreotropical flora than would have been judged from the associated microflora. Further, this flora 1s later than Eocene in age and emanates from a very small deposit (only a few cubic yards of fossiliferous sediment are available for study). These last two factors suggest that the Bran- don Flora is probably a limited subset of the boreotropical flora that was originally in eastern North America. 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE Zl In summary, palynological evidence suggests that a few boreotropical taxa now restricted to eastern Asia were present in the earlier Tertiary of eastern North America. However, compared to western North America (e.g., Leopold & MacGinitie, 1972), eastern North America appears to lack several common boreotropical pollen taxa in the early Tertiary. By contrast, macrofossil evi- dence from two isolated occurrences of fruits and seeds, and from the Oligocene or Miocene Brandon Lignite, demonstrates the presence of boreotropical ele- ments in eastern North America. The assemblage of boreotropical taxa in the Brandon Lignite indicates that eastern North America had a greater initial diversity of boreotropical taxa—and perhaps of derived mixed mesophytic taxa—than has previously been suspected. The paleofloristic affinities of the Paleogene floras of the Mississippi Embayment are presently unclear, although limited evidence suggests some floristic interchange with western North Amer- ica in the early Tertiary. The fossil record is too scanty to resolve the timing of the depauperization of the eastern North American flora. PALEOGEOGRAPHIC EVIDENCE ON THE DEVELOPMENT OF THE EASTERN NORTH AMERICAN FLORA AND VEGETATION If eastern North America was separated from other northern continents in the early Tertiary, this would reinforce Wolfe’s (1977) suggestion that the lower current diversity of the southeastern North American flora stemmed from its early isolation from the general boreotropical flora. However, if early Tertiary connections with other portions of the Northern Hemisphere can be demon- strated, this would support the contention that the lower current diversity is a function of later Tertiary events and would parallel the fossil data enumerated above. The connection of eastern North America to other boreal landmasses 1s bidirectional. The classic perception (e.g., H. L. Li, 1972), perhaps influenced by the present proximity of Siberia and Alaska, suggests a linkage through western North America. This route involves two subunits: the connection of eastern Asia to western North America across the Bering Straits, and that of western to eastern North America through the mid-continental area. The al- ternative route involves linkage of eastern North America to Europe across the early Tertiary North Atlantic. Although accepted by paleozoologists (e.g., Lehmann, 1973; McKenna, 1975, 1983a; Russell, 1975), the latter route is rarely considered by paleobotanists; only Tiffney (1980b) and Wolfe (manu- script submitted) have discussed its significance in early Tertiary phytogeog- raphy. This route is also bipartite, involving the linking of North America to Europe, and of Europe to East Asia. Each of these routes of connection will be considered. THE BERING CONNECTION The Bering land bridge has been recognized in biogeographic discussions for nearly a century (e.g., Matthew, 1915; Hopkins, 1967). The vertebrate paleontological record of Beringia suggests a barrier to faunistic exchange in 22 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the Paleocene (Chow & Zheng, 1979), an Early Eocene period of connection between Alaska and Siberia, a Middle Eocene period of isolation, and a limited Late Eocene resumption of exchange (Kurtén, 1966; Novodvorskaja & Ja- novskaja, 1975). The nature of the barrier to exchange 1s not certain; 1t could involve climate and/or land position. Kurtén noted that the Early Eocene exchange between eastern Asia and western North America involved elements different than those found in Europe and North America at the same time. During the Eocene, world climates (Kennett, 1977; Buchardt, 1978; Wolfe, 1978: Collinson et al., 1981; G. Keller, 1983) were warm enough to support thermophilic vegetation and vertebrates (e.g., Estes & Hutchison, 1980; McKenna, 1980) at far northern latitudes. The primary limitation to the north- erly extent of evergreen boreotropical taxa at this time was light (Allard, 1948; Hickey, pers. comm In earlier papers Wolfe (1972, 1977) suggested the presence of evergreen forms in Alaska north of their modern latitudinal limit of tolerance to low light levels. On this basis he postulated (Wolfe, 1975) that the angle of incli- nation of the earth’s axis of rotation was lower during the Eocene. This sug- gestion has drawn much criticism (e.g., Donn, 1982; McKenna, 1983b), and theoretical models of climate (Eric Barron, pers. comm.) suggest that such a change would actually lead to polar paleotemperatures much colder than those inferred. More recently, Wolfe (manuscript submitted) has reevaluated the distribution of floras in northwestern North America and has concluded that the Eocene Bering land bridge was primarily occupied by a broad-leaved, deciduous forest, perhaps with a thin southern fringe of evergreen, megathermal communities. As a result, Wolfe suggests that the Bering bridge is of limited importance in explaining the spread of megathermal elements of the Eocene boreotropical flora. Estimation of the degree of floristic movement of evergreen taxa across the Bering bridge is complicated by the complex tectonic history of this area. Alaska lay somewhat north and east of its present position in the early Tertiary (Smith & Briden, 1977), but its southern margin was in flux. Much of Pacific North America is now considered to be formed of an aggregation of “‘microplates”’ that have drifted against North America. Many of Wolfe’s Paleogene floras are located on these terranes (see Map 1). The exact paths of movement and times of collision of these plates with western North America are the subject of debate and active research. The literature (e.g., Coney ef a/l., 1980; Ben-Avraham ef al., 1981) generally suggests that accretion was over by the early Tertiary, but recent evidence (Cowan, 1982; Bruns, 1983) demonstrates that some terranes may have moved considerable distances as recently as the mid-Tertiary. It appears that most of these plates collided with North America at about the latitude of British Columbia and then slid northwestward toward Alaska. If so, these terranes had little impact on the phytogeography of the Bering bridge. However, it is not clear at this time that this is true for all these terranes. For the present, phytogeographers should continue to consider the possibility that some of these terranes may have formed island “‘stepping stones” south of Alaska in the early Tertiary, perhaps connecting to Asia via islands associated with the ancestral Aleutian arc (DeLong ef a/., 1978). However, this geographic 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 253 AP |. Alaska, aa margins of presently identified allochthonous terranes (after Ben-Avraham et a/., 1981, fig. 7) with Tertiary floras reported by Wolfe (1972) from this area. Light oe = — margins, closed circles = Paleocene and Eocene floras, open circles = Oligocene or later floras. All Paleogene floras except Sagavanirktok on north slope lie on recently accreted terranes. arrangement is highly tentative, and the limited available habitat of such an island chain would curtail its biogeographic significance (McKenna, 1983b). I conclude that the Bering land bridge was a viable route for the exchange of deciduous boreotropical taxa in the early Tertiary. Evergreen elements of this flora were probably restricted in their use of the Bering bridge by day length. Alternative, more southerly routes were limited in area, if they existed. The climatic deterioration of the later Tertiary (Kennett, 1977; Buchardt, 1978; G. Keller, 1983) increasingly restricted this route to cool-temperate taxa. THE CENTRAL NORTH AMERICAN PROBLEM Floristic exchange between western and eastern North America involves the central portion of the continent, but evidence is inferential about the degree to which this could or did occur. The terrestrial plant record of this area is limited to a few primarily Neogene localities (e.g., MacGinitie, 1962; Segal, 1966a, 1966b; Thomasson, 1977, 1980a, 1980b), with the exception of the 254 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 U PALEOCENE EOCENE Te MAAS Sern Map 2. Sequential generalized en ecg Late Cretaceous to early Tertiary, showing regression of North American Mid-Continental Seaway (shaded area). Data after Schuchert (1955), Reeside (1957), Gill and Cobban (1966), McDonald (1972), McGookey ef al. (1972), and Williams and Stelck (1975 — Late Paleocene—Early Eocene Golden Valley Flora of North Dakota (Hickey, 1977) Central North America was occupied by an epicontinental seaway in the Late Cretaceous. This formed a relatively successful phytogeographic barrier, separating the largely western North American Aquilapollenites floristic prov- ince from the largely eastern North American—European normapolles province (Muller, 1970). This seaway retreated to the north and south in the latest Cretaceous and Paleocene (Map 2), eliminating its moderating climatic influ- ence and giving way to an increasingly continental climate. This regression occurred concomitantly with the uplift of the Rocky Mountains, which as they rose, cast an increasingly long rain shadow to their east (Leopold & MacGinitie, 1972). The temporal relationship between the spread of the boreotropical flora, the retreat of the seaway, and the development of these drier climates is unclear. In particular, the exact geographic borders of the Late Cretaceous Mid-Con- 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 295 tinental Seaway and of the Paleocene Cannonball Sea have not been rigorously demonstrated in the geologic literature. Late Paleocene-Early Eocene floras from the eastern face of the present Rocky Mountains (e.g., Hickey, 1977: Wing, 1981) contain a few boreotropical elements, as well as some elements 1m common an ne Eocene of the Mississippi Embayment (Wing, 1981). Wolfe ts that Wing’s and Hickey’s floras may have been dominated by floodplain vegetation, and that the interfluvial areas may have supported a paratropical rainforest. Leopold and MacGinitie (1972) noted that the Early Eocene floras of the Rocky Mountain region have East Asian affinities, while those of the Middle Eocene are dominated by taxa with relatives in the New World tropics. They associated this change with increasing seasonality of rainfall from the Early to Middle Eocene, presumably related to the uplift of the Rocky Mountains. This suggests that a moisture-based filter-barrier came into existence between eastern and western North America by the Middle Eocene. However, the barrier may not have been continuous; corridors of migration may have existed along rivers flowing eastward from the mountains to the plains. Perhaps the most tantalizing evidence for the later Paleogene plant communities of central North America comes from Retallack’s (1983a, 1983b) investigations of fossil soils in South Dakota. These suggest that forest communities were in this area in the Late Eocene and Early Oligocene, but that they gave way first to savannas and then grasslands in the later Oligocene. This raises the possibility that a corridor of forest existed across the central- northern plains in the early Tertiary, perhaps invading drier areas along river courses. However, no evidence exists as to the composition of this forest or as to its extent beyond South Dakota. Some boreotropical elements are found in the Miocene Kilgore Flora of Nebraska (MacGinitie, 1962), but these are gen- erally of cool-temperate affinity and have limited relations with the modern flora of East Asia. No evidence exists for the nature of Tertiary floras in the glaciated portions of Canada; it is possible that forest could have stretched across the higher latitudes of central North America in the early Tertiary. In summary, evidence for the potential and actual movement of elements of the boreotropical flora across mid-continental North America is scanty. Logic Suggests that climatic changes attendant upon the retreat of first the Mid- Continental Seaway and then the Cannonball Sea, together with the rise of the Rocky Mountains, would have created a filter to the movement of moisture- loving plants. However, the timing of these events, and the nature of mid- continental climates and floras in the Paleocene and Eocene, are unknown. Further, scattered fossil evidence suggests that some elements of the boreo- tropical flora (e.g., Platycarya) did move through this area. Evidence from fossil soils suggests that closed forest may have existed in the central plains until the Early Oligocene. The Middle Eocene Clarno Flora of Oregon contains several presumably evergreen boreotropical elements (Manchester, 1981); if these did not reach the west coast of North America by way of the Bering bridge (see data of Wolfe, in press), then they must have achieved their distribution via central North America. As long as evidence for the early to middle Tertiary environments of the Great Plains is unclear, the potential importance of this area aS a migration route of the boreotropical flora remains moot. 256 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 THe EUROPEAN—EASTERN NORTH AMERICAN CONNECTION A paleofloristic link between Europe and eastern North America has been viewed as “‘possible” by many authors (e.g., Graham, 1964; Raven & Axelrod, 1974: Wolfe, 1975, 1977). In general, it has never been given the importance of the Beringian connection, although I suggested it earlier (Tiffney, 1980b), and Wolfe (manuscript submitted) has recently concluded that it was probably more important than the Bering bridge. A similar opinion has been held by some paleozoologists (see McKenna, 1975), who originally claimed that the Eocene faunal similarity of North America and Europe was attained by a trans- Asiatic migration route. Recent evidence, both geologic and paleontological, has suggested that this is incorrect, and McKenna (1972, 1975, 1983a) has cogently argued for the importance of North Atlantic land connections in explaining the distribution of early Tertiary vertebrates. Similarly, I believe that the North Atlantic connection has played a major part in the spread of the boreotropical flora and in the development of the similarity of the East Asian and eastern North American floras. Consideration of the North Atlantic connection will be on three levels: geologic, paleozoological, and botanical. GEoLoaIC DATA. The potential of a North Atlantic land bridge has been rec- ognized since Wegener’s original suggestion of continental drift, but only within the last decade has definite evidence for this bridge been produced. A land link between Europe and America involves two stages: Europe to Greenland and Greenland to North America. It is appropriate to consider each separately. The geologic evidence for a Europe-Greenland connection is excellent and has been exhaustively reviewed by McKenna (1983a), from which much of the following summary is drawn, and to which the reader is referred for references and details. McKenna recognizes two geographically and temporally separate links between Greenland and Europe: a northerly ‘“‘-DeGeer’’ route from north- ern Scandinavia to northern Greenland, and a southern “Thulean” route from northern Scotland through the Faeroes and Iceland to southern Greenland (Map 3). The DeGeer route is of somewhat less interest to a discussion of the bo- reotropical flora for two reasons. First, it lay ten to fifteen degrees higher in latitude than the Thulean route, although it was still at a lower paleolatitude than the coeval Beringian bridge situated at almost 75°N latitude (McKenna, 1972). Second, the DeGeer route terminated in northern Scandinavia, which according to McKenna (1983a), was separated from direct contact with Europe for much of the Paleogene by the Danish-Polish trough and its southerly ex- tension, the “Moravian portal,” linking the trough to the Tethys (Pozaryska & Cuik (1976), Pozaryska (1978); see McKenna (1983a) for discussion). How- ever, there is not agreement on the presence of this sea barrier throughout the Eocene. Plaziat (1981, figs. 21, 22; 1983, fig. 5) suggested that southwestern Europe was isolated from Fennoscandia in the Paleocene, but that the respon- sible seaway retreated by the Early Eocene, reconnecting the two land masses. I follow McKenna (1983a) in showing a marine barrier between southwestern Europe and Fennoscandia in Maps 3, 4, and 6, but this is a moot point. Similarly, the Turgai Straits isolated Fennoscandia from eastern Asia for much of the Paleogene (Hoch, 1983, McKenna, 1983a). The DeGeer route was prob- 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 2a7 NORTH AMERICA FENNOSCANDIA / EUROPE , NORTH “ATL ANTIC. Map 3. Generalized paleogeography of North Atlantic area in Early Eocene, showing possible routes of connection between Europe and North America. Connection “a” = McKenna’s DeGeer route linking Fennoscandia and northern Greenland (GLD); **b” = McKenna’s Thulean route from southwestern Europe to southern Greenland; ‘‘c” links northern Greenland to Queen Elisabeth Islands (QEI); “‘d” = potential link ahs central Greenland and Baffin Island (BI). Dispersal may have occurred in either direction resulted in several entry/exit route patterns. Shaded area = sea; heavy lines = paleo- coastlines; light lines = present coastlines. ee from, but not necessarily adhering to, McKenna (1972, 1983a, 1983b, pers. comm.), Pozaryska (1978), Heissig (1979), Buchardt (1981), Srivastava ef a/. (1981), and Pomerol (1982). ably present as early as the Danian, although the climate of that time (Buchardt, 1978; Wolfe, 1978; Hickey, 1981a) suggests that it would be restricted to cold- tolerant organisms. This route functioned through the latest Eocene or Early Oligocene, when it was terminated by the linkage of the Greenland-Norwegian Sea and the Arctic Ocean. During the Early Eocene, warm climates may have made it passable to thermophilic biota, but the effect of winter day-length is uncertain. The Early Eocene flora from Ellesmere Island (Hickey ef a/., 1983; Hickey, pers. comm.) appears to include only deciduous angiosperms in con- Junction with a thermophilic fauna (Estes & Hutchison, 1980). This suggests that winter day-length was the limiting factor. The initiation of active sea-floor spreading northwest of the British Isles in 258 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the Late Paleocene resulted in the first appearance of the Thulean bridge. Again, the cool climates of the time restricted biotic access to this route. However, the succeeding Early Eocene was a time of widespread warm climates (Wolfe, 1978: Buchardt, 1978; Collinson et a/., 1981), which opened the Thulean route to passage by warm-adapted organisms. Further, since this route lay between 45° and 50°N paleolatitude, winter sunlight would have been sufficient to permit the passage of evergreen taxa (MAP 3). Most evidence suggests that this con- nection was suddenly broken in the Early Eocene (McKenna, 1983a) or latest Paleocene (Hanisch, 1983) and was never reestablished (but see Gronlie (1979), who suggested that it may have persisted piecemeal until the mid-Miocene, and Strauch (1970, 1972), who suggested that a fairly substantial land bridge existed throughout most of the Tertiary). The linkage between Greenland and northeastern North America across the Davis Strait is the subject of considerably more debate (e.g., Dawes & Kerr, 1982). The Davis Strait, and its extension through Baffin Bay and the Kane Basin, apparently linked the Atlantic and Arctic oceans in the latest Cretaceous and Early Paleocene. Invertebrate fossils suggest that a bridge between Green- land and the Queen Elisabeth Islands may have come into being in the Danian and have continued through much of the Eocene. Circumstantial evidence (e.g., terrestrial sediments beneath the Davis Straits (McKenna, 1983a, and pers. comm.)) exists for a land connection to the south between Greenland and Baffin Island, but the assembled data (McKenna, 1983a) are not as conclusive. The northern bridge falls at nearly the same latitude as the DeGeer route; thus, winter day-length might restrict its importance to deciduous angiosperms and conifers. The southern route is at a substantially lower latitude and would have permitted passage of evergreen taxa. In summary, the geologic evidence suggests a clear northern connection from Scandinavia to northern Greenland and from northern Greenland to the Queen Elisabeth Islands from Late Paleocene to Late Eocene (MAp 3). A second connection from the British Isles to southern Greenland existed briefly in the Late Paleocene and Early Eocene. This probably was matched by a lower- latitude bridge from central Greenland to Baffin Island and northeastern Can- ada at the same time, although the geologic evidence is not clear. Certainly southwestern Europe was in connection with North America via the Thulean bridge on the east and the northern Greenland—Queen Elisabeth Islands bridge on the west during a brief portion of the Early Eocene. PALEOZOOLOGICAL DATA. Vertebrate paleontology supports the existence of a European-North American connection. The similarity of the Early Eocene faunas of North America and Europe was recognized by earlier workers (see McKenna, 1975, for a summary and a list of taxa in common). The degree of correspondence of the two faunas began to rise in the Late Paleocene, peaked in the Early Eocene when roughly 60 percent of the known European genera were held in common with North America (Lehmann, 1973), and then declined precipitously by the Middle Eocene. The decline in faunistic similarity probably lagged behind the actual geographic isolation, as biologic differentiation of the isolated populations took time. The rise and fall of this similarity parallels the 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 259 projected appearance and demise of the Thulean route. Data concerning the early Tertiary vertebrate paleontology of Greenland are presently lacking (Hoch, 1983; McKenna, 1983a), curtailing a more exact description of the exchange. BOTANICAL DATA. Paleobotanical and botanical data regarding the Atlantic bridge are less common than paleozoological data. However, in the context of the geologic and vertebrate paleontological information given above, I believe that a convincing, if inferential, case can be made for passage of the boreo- tropical flora across the Atlantic bridge. Four lines of botanical data are con- sidered. First, several fossil taxa of eastern North America are specifically similar to fossils known from the Tertiary of Europe. Nypa (Arnold, 1952; Tralau, 1964) and Wetherellia (Mazer & Tiffney, 1982) are classic European early Tertiary taxa, and the New World species are virtually identical to their Old World counterparts. Similarly, Microdiptera parva from Brandon (Tiffney, 1981b) has previously been described only from Europe and western Siberia. Second, several genera from the Brandon Lignite (Phellodendron, Euodia, Tur- pinia, Alangium, and Symplocos) are thermophilic elements that were also common in the European Paleogene. Symp/ocos provides a particular example of this pattern, because the genus is very diverse in the European Tertiary (Mai, 1970) and is disproportionately represented in the Brandon Flora by at least three species. Third, several modern taxa known as fossils in the European Tertiary presently survive only in eastern North America. Among flowering plants these include Asimina Adanson (Annonaceae), Calycocarpum Nutt. ex Torrey & Gray (Menispermaceae), Comptonia L’Hér. ex Aiton (Myricaceae), Decodon J. F. Gmelin (Lythraceae), Dulichium Pers. (Cyperaceae), Fothergilla L. (Hamamelidaceae), Leitneria Chapman (Leitneriaceae), Polanisia Raf. (Cleomaceae), Proserpinaca L. (Haloragidaceae), Prelea L. (Rutaceae), Robinia L. (Leguminosae), and Saba/ Adanson and Serenoa Hooker f. (Palmae). An interesting parallel is provided by the hickory aphid (Longistigma caryae Har- ris), which is presently restricted to North America but is reported from Upper Miocene—Lower Pliocene sediments in Iceland (Heie & Friedrich, 1971). An additional group of taxa is common to the extant floras of Europe and North America. Although many of these taxa attained this range in the later Tertiary 1973) appear to represent remnants of generally dispersed boreotropical taxa. Fourth, as discussed above, several boreotropical taxa are known as fossils from eastern North America. If the Bering bridge 1s less important as a North American access route for evergreen boreotropical taxa (see Wolfe, manuscript submitted), then these taxa presumably came and went from North America via the North Atlantic bridge. In summary, the plant evidence is scattered and circumstantial. Taken alone, any of the above examples is weak since it is never clear where a single taxon may have occurred in the past in addition to those places from which it is presently known as a fossil. However, in its entirety, the plant evidence does not contradict the existence ofa North Atlantic bridge and appears to support it. 260 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 \ GREENLAND : NORTH AMERICA FENNOSCARDIA NORTH. -ATLANTIC. Map 4. Generalized paleogeography of North Atlantic area in Late Eocene, showing changes in land continuity following spreading in Greenland-Norwegian Sea and Davis Straits between Greenland and Baffin Island. Connections between Queen Elisabeth Islands and Greenland, and Greenland and northern Europe, probably existed but were likely closed to thermophilic organisms by Late Eocene climatic decline. Conventions and sources as in Map 3. In conclusion, geologic data indicate the presence of two Early Eocene bridges between Greenland and Europe (one to Fennoscandia and one to southwestern Europe), and two Early Eocene land bridges from Greenland to North America (one via the Queen Elisabeth Islands, and a less well defined one from Greenland plants must also have passed across these same bridges, but evidence of their nature (deciduous or evergreen; cool tolerant or intolerant) is not directly avail- able. However, it is unlikely that the vertebrates common to Europe and North America would have strayed far from familiar vegetational environments or food sources. For this reason, it can be assumed that the vertebrates migrated across the North Atlantic land bridge in conjunction with the boreotropical flora. Further, a significant proportion of this fauna was herbivorous or om- nivorous (McKenna, 1975), and such animals would be expected to disperse their food plants. Thus, while the individual elements of evidence do not clearly indicate passage of the boreotropical flora across the Early Eocene North At- lantic land bridge, the sum of information argues strongly that this was the case 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 261 24° 48° 72° : ooo EARLY TO MIDDLE PALEOCENE LATE EOCENE OLIGOCENE . Sequential generalized p geography s! g d retreat of Turgai Straits (shaded area) in central Asia from Paleocene through Oligocene time. Heavy lines = paleocoastlines, light lines = present coastlines. After Vinogradov (1967-1968). EARLY TERTIARY FLORISTIC LINKS BETWEEN EUROPE AND EASTERN ASIA If eastern North America shared an appreciable portion of the boreotropical flora with Europe, then some degree of the present similarity between the floras of eastern Asia and eastern North America must have involved early or middle Tertiary floristic exchange between Europe and eastern Asia. The evidence for a Tertiary European-Asian link is scattered. The Turgai Straits (Map 5) sep- arated Europe from western Siberia from the mid-Mesozoic to the end of the Eocene and are generally presumed to have formed a biogeographic barrier to animals (Kurtén, 1966; Muller, 1970; McKenna, 1975, 1983a; Russell, 1975; Hoch, 1983), although the severity of this barrier has been disputed (Savage & Russell, 1983). Its effect on plants is unclear. This seaway may have been 262 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 bridged intermittently in the Eocene, linking western Siberia with Fennoscandia (Russell, 1975; Heissig, 1979; Chow & Zheng, 1980; McKenna, 1983a, 1983b). According to McKenna (1983a), Fennoscandia and southwestern Europe were not directly linked in the Paleocene and Eocene (but note the different opinion of Plaziat (1981) mentioned above). If so, biotic exchange between western Siberia and southwestern Europe in the Eocene would have involved dispersal from Fennoscandia to Greenland via the DeGeer route, and then from Green- land to southwestern Europe by the Thulean route—a roundabout track, and one crossing several climatic zones. There is no particular plant evidence ap- plicable to this possibility. The final closure of the Turgai Straits commenced in the Early Oligocene, initiating an influx of Asiatic and southeastern European vertebrate taxa into southwestern Europe (but see Heissig, 1979, who believes that the influx is largely Balkan 1n origin, coming up connected islands in the Tethys from the southeast). This resulted in what Stehlin (1909) termed the ““Grande Coupure,” an Early Oligocene event in which roughly 50 percent of the preceding mammal fauna went extinct and was replaced by new taxa (McKenna, 1983b). The new mam- mals were presumably accompanied by new plants, and indeed the Early Oli- gocene was a time of change and modernization of the western European flora, although the details of this transition have not been worked out. Probably the most important avenue of dispersal of the boreotropical flora across Eurasia involved the Tethys Seaway, which has shaped the present and past distributions of a variety of organisms (e.g., corals and seagrasses (McCoy & Heck, 1976), and echinoderms (Ali, 1983)). The classic boreotropical assem- blage is the London Clay Flora, located on the ““midpoint”’ of the Eocene Tethys Seaway (Map 6). Floras of similar composition exist in the Eocene of central Europe (Palamarev, 1973) and in the Eocene and Oligocene of Egypt (Chandler, 1954; Bown et al., 1982). A single fruit of Anonaspermum Reid & Chandler from the Paleogene of Pakistan (Tiffmey, unpubl. data) hints at the further eastward extension of elements of this flora. It is unclear how far east along the Tethys the flora ranged. McKenna (1983b) notes that the Paleocene ter- restrial faunas of China (C. K. Li & Ting, in press) are quite distinct from those of the rest of the Northern Hemisphere, suggesting a distinct biotic province at the eastern end of the Tethys in the earliest Tertiary. Thus, although the Eocene flora of western Europe is similar to the modern flora of Southeast Asia, it may have been less so to the Eocene floras of Southeast Asia. The similarity between the extant floras of eastern Asia and the Tertiary floras of Europe continued through the latest Tertiary, often involving similarity on the species level in the later Miocene and Pliocene (Tralau, 1963). This suggests that some amount of European-Asian interchange occurred after the decline in importance of the North Atlantic land bridge, and even as the Tethys Seaway began to fragment. ORIGINS AND DIRECTIONS This discussion has often implied a place of origin and a direction of sub- sequent spread of the boreotropical flora. This is a complex topic and is treated 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 263 Ee | es “~) °) FENNOSCANDIA AFRICA M . Generalized paleogeography of the Tethys Seaway, Early to Middle Eocene, showing possible routes of movement of boreotropical flora along seaway (arrows) and known occurrences of floras similar to that of London Clay (stars). Assembled from, but (1977), Pozaryska (1978), Heissig (1979), Buchardt (1981), Plaziat (1981), Srivastava et al. (1981), Parrish et al. (1982), Pomerol (1982), and McKenna (pers. comm.). separately (see Tiffney, 1985), but certain aspects of it require consideration here. The boreotropical flora could have evolved in tropical, temperate, or polar regions during the early Tertiary. Our present knowledge of the Tertiary pa- leobotanical record of the tropics is too poor to provide any but the most speculative evidence. Knowledge of temperate regions is far better, but even with the information available we lack the temporal resolution to determine place of first appearance. Knowledge of the boreal zone is limited but contrib- utes some information. Contrary to the geofloral hypothesis (e.g., Axelrod, 1966), the Late Cretaceous—early Tertiary North Pole is not an important center of origin. Instead, it appears to have supported a species-poor flora of deciduous taxa (see Wolfe, 1977; Hickey ef a/., 1983; Hickey, pers. comm.), several members of which intermingled with the boreotropical flora when it appeared. However, this deciduous polar forest generally appears to have remained to the north of the boreotropical forest. Thus, although these deciduous taxa played a part in the boreotropical forest, the Beringian and/or Atlantic land bridges cannot be considered the points of origin of the boreotropical flora but only as passageways in its spread Spread implies direction. However, I do not believe that it is presently possible to trace the direction of spread of elements of the boreotropical forest across any of the bridges or barriers discussed above. For this reason I have attempted to describe biogeographic corridors in a neutral manner; if any 264 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 phraseology in the preceding seems to imply directionality, it is unintentional. It is quite likely, however, that spread will ultimately be found to involve the movement of different lineages at different times by different routes (see Tiffney, 1985). Elucidation of this assumption will only follow from careful biogeo- graphic analysis of individual plant taxa. The use of cladistic methodology in this study (e.g., Donoghue, 1983a, 1983b, for Viburnum) may be very useful in demonstrating the geographic history of movement within or between taxa. POST-EOCENE HISTORY OF THE BOREOTROPICAL FLORA IN EASTERN NORTH AMERICA If the boreotropical flora had full access to eastern North America in the Early Eocene, the question remains as to whether its lower current diversity 1s a function of the Eocene-Oligocene climatic deterioration, of the Pleistocene deterioration, or of a combination of the two. Wang (1961) and Wolfe (1977) suggested that the Eocene-Oligocene climatic deterioration caused outright ex- tinction of many boreotropical taxa, including the majority of the thermophilic elements, in eastern North America. Wolfe further suggested that the subse- quent diversification of the eastern North American mixed mesophytic forest was restricted by the absence of these thermophilic evergreen taxa. This is in contrast to the situation in western North America, where a residual evergreen vegetation contributed greatly to the growth in diversity of the mixed meso- phytic forest in the Miocene (Wolfe, 1969, 1977). Perhaps the only fossil evidence that bears on this supposition is that of the Brandon Lignite. The age of the deposit is presently accepted as post-Eocene (Wolfe & Barghoorn, 1960; Frederiksen, 1984 and pers. comm.), although Berry (1919) once suggested that it was Eocene. This flora includes several thermophilic boreotropical taxa (e.g., Euodia, Alangium, Turpinia) no longer extant in eastern North America, This implies that—at least in some portion of eastern North America—boreotropical elements survived the Late Eocene—Early Oligocene climatic deterioration but went extinct in the later Tertiary or Quaternary. Although it is not presently possible to indicate a particular period of time for this extinction, suggestions can be made as to why extinction had a stronger effect in eastern North America than in eastern Asia. Eastern North America is geographically smaller than eastern Asia and would be expected to have a smaller flora measured on a species per area basis. The lower topography of eastern North America offers a more limited range of habitats than is encoun- tered in eastern Asia (Wolfe, 1977). Further, the Appalachian Mountains are oriented north-south, and in conjunction with the Mississippi River valley, they provide a geographic funnel conveying cold Arctic air masses directly to the Caribbean. This contrasts with the geography of eastern Asia, where many of the mountain ranges serve as shields from cold air masses. As a result, locations in eastern North America and eastern Asia may have similar mean monthly minimum temperatures, but the absolute minima in North America are considerably lower (Wolfe, 1979). Finally, starting in the Middle Eocene, the rain shadow of the western mountains of North America created a barrier of dry environments in central North America. The southerly extent of this 1985] TIFFNEY, NORTH ATLANTIC LAND BRIDGE 2605 barrier, and its effect on floristic exchange between southeastern North America and the highlands of Mexico and Central America, is unclear. Boreotropical elements are known from the Oligocene of Puerto Rico (Graham & Jarzen, 1969). Temperate elements of the boreotropical flora were present in Mexico in the Middle Miocene and appear to have moved southward in the later Tertiary (Graham, 1973, 1976). The history of more thermophilic boreotropical taxa in this area is unknown. It is possible that the zone of central North American dry climates caused the extinction of those boreotropical taxa forced southward by winter temperature extremes. Although this situation would have been most dramatic in the Quaternary (e.g., Delcourt & Delcourt, 1981), similar events could have occurred earlier in the Tertiary, incrementally curtailing the floristic diversity of eastern North America. Like the biogeography and envi- ronments of the mid-continental area in the early and middle Tertiary, those of the southeastern United States and northern Central America offer fertile ground for synthetic inquiry. In conclusion, the Eocene-Oligocene climatic deterioration may have influ- enced the diversity of the eastern North American boreotropical flora, but it did not decimate the flora. The specific pattern and timing involved in the depauperization of the eastern North American flora during the later Tertiary cannot be discerned at this time. SUMMARY The early Tertiary boreotropical flora of eastern North America was probably as diverse as that of any other portion of the contemporary Northern Hemi- sphere. This conclusion is supported by limited paleobotanical data from east- ern North America and the strong paleozoological and paleogeographic evi- dence that eastern North America and southwestern Europe were linked by North Atlantic land bridges in the latest Paleocene or the earliest Eocene when the boreotropical flora was reaching its maximum extent Western North America and eastern Asia probably derived their shared component of the boreotropical flora by both the Atlantic and Bering land bridges; the relative contribution of each is unclear at this time. The potential for early Tertiary fl c exchange between eastern and western North America is an important question for which few data exist. Although dry environments may have been present in central North America by the Middle Eocene, they may have been broken by bands of forest or by riverine gallery forests. The similarities of the modern floras of eastern Asia and eastern North America are probably due to an early Tertiary linkage between the two areas involving the North Atlantic land bridges and Europe. However, the flora of eastern North America cannot be considered as solely the product of exchange across a North Atlantic bridge; it is a composite of elements derived from Atlantic, Polar, Mexican and Central American, and western North American sources, in which the Atlantic element may dominate. This assumption can be tested by careful examination of European and eastern and western North American fossils in light of modern taxa of eastern North America, Mexico and Central America, and Asia. This implies that modern systematists studying 266 JOURNAL OF THE ARNOLD ARBORETUM [vVoL. 66 plants with Tertiary relict distributions must consider that eastern North Amer- ica may have harbored Sie tect cai distinct and important taxa in the Tertiary, but that these are now extin The present lower diversity of the Rou of eastern North America relative to that of eastern Asia appears to be a ‘“‘post-boreotropical flora” phenomenon. The geography of eastern North America is less diverse than that of eastern Asia and favors greater winter extremes. Further, a moisture barrier may oc- casionally or consistently have separated eastern North America from Mexico and Central America. As a result of these features, the mid- and late Tertiary derivatives of the boreotropical flora in eastern North America suffered greater extinction than did their counterparts in eastern Asia. 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PEABODY MUSEUM OF NATURAL HISTORY AND DEPARTMENT OF BIOLOGY New Haven, Connecticut 06511 AL-SHEHBAZ, RAPHANUS BOISSIERI 213 RAPHANUS BOISSIERI (CRUCIFERAE), A NEW SPECIES FROM THE MIDDLE EAST IHSAN A. AL-SHEHBAZ In 1842 Edmond Boissier described Brassica aucheri from a specimen col- lected by Aucher-Eloy near Mosul in Mesopotamia (Iraq). He later (1849) transferred the species to Raphanus L. (R. aucheri (Boiss.) Boiss.) and cited two additional collections from western Persia (Iran) and Galilee (northern Israel). Finally, in 1867 he placed the species in the monotypic section Hes- peridopsis Boiss. and cited new collections from what is now southern Lebanon. However, Boissier did not realize that he was dealing with two very distinct species, one from Iraq and Iran and another from the eastern Mediterranean area (Lebanon and Israel) (see Map 1). Schulz (1919) was the first to recognize two species in this complex by retaining the eastern Mediterranean plant as Raphanus aucheri and transferring the Iraqi-Iranian species to Sinapis L. (S. aucheri (Boiss.) O. E. Schulz). How- ever, he did not realize that both names were based on the same type, collected by Aucher-Eloy. Many subsequent authors, particularly Hedge and Lamond (1980), Hedge and Rechinger (1968), Mouterde (1970), and Zohary (1966), have followed Boissier by considering the plants of both areas as conspecific, while Zohary and colleagues (1980) accepted two species following Schulz. Greuter and Burdet (1983) have raised sect. Hesperidopsis sensu Schulz to a genus (Quidproquo Greuter & Burdet) without presenting supporting evidence for its distinctness from Raphanus. In my opinion, the eastern Mediterranean plant is appropriately assigned to Raphanus. However, it is described below as a new species, R. boissieri, because the name R. aucheri (Boiss.) Boiss. that has been applied to this species is based on Brassica aucheri, the type specimen of which (Aucher-Eloy 203) is the nomenclatural type of Sinapis aucheri. Quid- proquo confusum Greuter & Burdet cannot be used because a type specimen was not designated. Raphanus boissieri Al-Shehbaz, sp. nov. Raphanus aucheri (Boiss.) Boiss. Diagn. Pl. Orient. Nov. 2(8): ay 1849, in part. Quidproquo confusum Greuter & Burdet, Willdenowia 13: 94. 1983. Herba annua erecta, 2—6(—8) dm alta, retrorse hispida. Folia basalia petiolata, subrosulata, lyrata vel pinnatisecta, (5.5-)8—11(—20) cm longa, 2-7 cm lata. Racemi ebracteati; pedicelli floriferi recti, ascendentes, fructiferi valde curvati, 5—10(-13) mm longi. Sepala erecta vel patentia, (3—)5—8(—1 1) mm longa. Petala obovata, unguiculata, flava, (8—)10—15(—20) mm longa; unguicula 4—8(—12) mm © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 275-278. April, 1985. 276 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 a ate ae x i a Map 1. Distributions of Raphanus boissieri (left; Israel-Lebanon) and Sinapis aucheri (right; [raq-Iran). longa. Siliqua indehiscens, suberosa, cylindrica, pendula, retrorse hispida, S— 10 cm longa, 2-4.5 mm lata; segmenta inferiora asperma, obsoleta; rostrum subtorulosum, lomentaceum, 8-12 spermum. Semina oblonga, humiditate nonmucilaginosa, 2—2.5 mm longa. Annual erect herb, retrorsely hispid throughout, rarely glabrescent above, 2- 6(-8) dm high. Basal leaves nearly rosulate, petiolate, lyrate to pinnatisect, oblong to oblanceolate, (5.5-)8-11(-20) by 2-7 cm; terminal lobe broadly obovate or ovate, dentate to crenate, larger than lateral lobes. Upper cauline leaves subsessile or short petiolate, oblong to linear or lanceolate, rarely lyrate, entire or dentate. Inflorescence an ebracteate corymbose raceme, greatly elon- gating in fruit; flowering pedicels ascending, straight; fruiting pedicels strongly curved and usually forming loop, 5—10(—13) mm long. Sepals erect or sometimes spreading, saccate, oblong to nearly linear, obtuse, (3-)5—8(-11) mm long, glabrous or setulose; petals obovate, clawed, (8—)10-—15(-—20) mm long, claw 4- 8(-12) mm long, yellow or rarely whitish, without or rarely with dark veins; lateral nectar glands usually flat, median ones ovoid or cylindrical; stamens tetradynamous, anthers oblong. Siliques pendulous, indehiscent, lomentaceous, subtorulose, cylindrical, straight or slightly curved, 5-10 cm by 2-4.5 mm, corky, retrorsely hispid or scabrous, smooth or slightly striate; lower segment seedless, abortive or obsolete; beak 8- to 12-seeded; style 1-2 mm long, stigma 1985] AL-SHEHBAZ, RAPHANUS BOISSIERI 2a os men ee watt’ Ficure 1. Mature fruits of Raphanus boissieri (left) and Sinapis aucheri (right). capitate. Seeds oblong, 2-2.5 mm long, brown, nonmucilaginous when wet; cotyledons conduplicate. Type. Palestine [Israel], Galilee, April-May 1846, F. Boissier s.n. (holotype, GH!; 1sotypes, G-BoIs!). SPECIMENS EXAMINED. Israel: Hunin, Galilee, Bornmiiller 114 (G-pois); Banias, Boissier s.n., April-May 1846 (G-Bols); Mt. Tabur, Boissier s.n., May 1846 (G-Bots). Lebanon: Saida, Blanche s.n. (G-Bots); between Rachaya and Hasbaya, Gaillardot s.n. (G-Bols). Raphanus boissieri is endemic to southern Lebanon and northern Israel. Zohary and colleagues (1980) and Mouterde (1970) have listed it as R. aucheri from southern Sinai (Egypt) and Iskenderun (Turkey), respectively. Raphanus boissieri resembles Sinapis aucheri in the curvature of the fruiting pedicels, the orientation and the corky texture of the fruits, and the retrorse pubescence of the fruits and stems. It is very difficult to distinguish between the two from specimens lacking fruits, and this may have been the main factor behind Boissier’s failure to treat the eastern Mediterranean and the Iraqi- Iranian plants as distinct species. To my knowledge, only one specimen of S. aucheri with mature fruits is present in Boissier’s herbarium, and this was described by Boissier (1888) as Enarthrocarpus tragicerus Boiss. & Hausskn. Raphanus boissieri is easily distinguished from S. aucheri by its oblong seeds and its fruits with a smooth, straight upper segment and a seedless, indehiscent, abortive or obsolete lower segment. In SS. aucheri the seeds are globose, and 278 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the fruits usually have a falcately curved upper segment with coarse tubercles or thickenings opposite the seeds and a dehiscent, several-seeded, well-devel- oped lower segment (see FIGURE 1). Sinapis aucheri is anomalous in this genus because of its several-seeded, torulose, corky beaks and its haploid chromosome number of seven (Al-Sheh- baz & Al-Omar, 1982; Aryavand, 1975). The other species of Sinapis have 1- or 2-seeded, nontorulose, noncorky beaks and a chromosome number of n = 9 or 12 (G6mez-Campo & Hinata, 1980). ACKNOWLEDGMENTS I wish to thank P. F. Stevens for checking the Latin, B. Nimblett for typing the manuscript, J. Lupo for photographing the fruits, C. GOmez-Campo for sending the seeds of Sinapis aucheri, and E. B. Schmidt and S. A. Spongberg for editorial help. LITERATURE CITED AL-SHEHBAZ, I. A., & M. M. At-Omar. 1982. Jn: A. Léve, ed., IOPB chromosome number reports LXXVI. Taxon 31: 587-589. eres A. 1975. Contribution a l’étude cytotaxonomique de quelques Cruciféres de l’Iran et de la Turquie. Bull. Soc. Neuchateloise Sci. Nat. 98: 43-58. Boissier, E. 1842. Plantae Aucherianae orientales enumeratae, cum novarum speci- erum descriptione. Ann. Sci. Nat. Bot. II. 17: 45-90. 49. Raphanus Aucheri Boiss. Diagn. Pl. Orient. Nov. I. 2(8): 4 ——. 1867. [Raphanus.] Sect. I]. Hesperidopsis. F. ees 1: 401. . 1888. Enarthrocarpus tragicerus. Fl. Orient. Suppl., GoOmez-Campo, C., & K. Hinata. 1980. A check list oe aia ne numbers in the tribe Brassiceae. Pp. 51-63 in S. TsuNopaA, K. Hinata, & C. GOmMeEz-Campo, eds., Brassica crops and wild allies. Japan Scientific ser ches Press, Tokyo. [Greuter, W., & H. M. Burpet.] 1983. Quidproquo. In: W. GREUTER & T. Raus, eds., Med-checklist notulae, 7. Willdenowia 13: 94. Henae, I., & J. M. LAaMonp. 1980. Brassiceae. Jn; C. C. TOWNSEND & E. GUEST, eds., Fl. Iraq 4: 845— 885. & K. H. Recuincer. 1968. Cruciferae. Jn: K. H. RECHINGER, ed., Fl. Iran. 57: 38, 39. MouTerpDE, P. 1970. Raphanus aucheri. Nouv. Fl. Liban Syrie 2: 118 Scuutz, O. E. 1919. Cruciferae-Brassiceae. Part 1. Jn: A. ENGLER, ed., Pflanzenr. IV. 105(Heft 70): 1-290. ZOHARY, M. 1966. pe ate aucheri. Fl. Palaestina 1: 326, 327. _C. C. Hern, & D. HeELLer. 1980. Sinapis aucheri. Raphanus aucheri. Consp. a0 Orient. 1: 60, 62. ARNOLD ARBORETUM UE CAMBRIDGE, MASSACHUSETTS 02138 Biology of Leguminosae An International Symposium Sponsored by The Missouri Botanical Garden and The Royal Botanic Gardens, Kew 23-27 June 1986 in St. Louis For further information, contact Dr James L. Zarucehi Legume Conference Coordinator Missouri Botanical Garden P.O. Box 299 St. Louis, Missouri! 63166 U.S.A. Journal of the Arnold Arboretum April, 1985 CONTENTS OF VOLUME 66, NUMBER 2 The Subfamilies and Tribes of Gramineae (Poaceae) in the South- eastern United States. Crrismorpmer 8S. CAMPBELE 6666654505 8o Ro baa RR eee 123 A Biosystematic Study of the Poa secunda Complex. Pi ABET ANE GELLOGG c62oiisd4000565440eseeeeeeeea ress 201 The Eocene North Atlantic Land Bridge: Its Importance in Tertiary and Modern Phytogeography of the Northern Hemisphere. BRUCE iis LIPRNEY 6245 icdeeene eos op eees ev E See GS SERS vA 243 Raphanus boissieri (Cruciferae), a New Species from the Middle East. TAR Ph. le SUMMERS joi 6 oo 4us0ib0eeees daandemee se dese Seis Volume 66, Number |, including pages 1-121, was issued January 22, 1985. JOURNAL OF THE ARNOLD ARBORETUM HARVARD UNIVERSITY VOLUME 66 NUMBER 3 ISSN 0004-2625 Journal of the Arnold Arboretum The Journal of the Arnold Arboretum (ISSN 0004-2625) is published quarterly in January, April, July, and October for $50.00 per year, plus $5.00 postage for addresses outside of the United States, by the Arnold Arboretum of Harvard University. It is printed and distributed by the Allen Press, Inc., 1041 New Hampshire Street, Law- rence, Kansas 66044. Second-class postage paid at Lawrence, Kansas. POSTMAS- TER: send address changes to Journal of the Arnold Arboretum, Yo Allen Press, Inc., P. O. Box 368, Lawrence, Kansas 66044. Subscriptions and remittances should be sent to Journal of the Arnold Arboretum, 1041 New Hampshire Street, Lawrence, Kansas 66044, U. S. A. Claims will not be accepted after six months from the date of issue. Volumes I-51, reprinted, and some back numbers of volumes 52-56 are available from the Kraus Reprint Corporation, Route 100, Millwood. New York 10546, U.S.A; EDITORIAL COMMITTEE S. A. Spongberg, Editor E. B. Schmidt, Managing Editor P.S. Ashton K. S. Bawa P. F. Stevens C. E. Wood, Jr. Printed at Allen Press, Inc., Lawrence, Kansas COVER: The stylized design appearing on the Journal and the offprints was drawn by Karen Stoutsenberger. JOURNAL OF THE ARNOLD ARBORETUM VOLUME 66 JuLty 1985 NUMBER 3 THE GENERA OF BRASSICEAE (CRUCIFERAE; BRASSICACEAE) IN THE SOUTHEASTERN UNITED STATES'? IHSAN A. AL-SHEHBAZ Tribe Brassiceae [A. P. de Candolle, Syst. Nat. 2: 152. 1821.] Annual, biennial, or perennial herbs [sometimes subshrubs or shrubs], un- armed [rarely spiny], glabrous or with simple trichomes only. Inflorescence usually an ebracteate ibose raceme, often greatly elongated in fruit; flowers few to many [rarely sian, eon erect or spreading, saccate at base or not. Petals usually obovate, clawed. Stamens 6; filaments without [very rarely with] a basal appendage. Median nectar glands present or absent. Stigmas entire or 2-lobed, the lobes sometimes decurrent. Siliques usually differentiated into lower (valvular) and upper (beak) segments, sometimes transversely jointed and breaking into parts, occasionally lomentaceous [or samaroid or nutlike], 'Prepared for the Generic Flora of the Southeastern United States, a long-term project made possi- lished in the first (Jour. Arnold 96-346. 1958) and continued to the present. The area covere the eric Flora includes North and South Carolina, Georgia, Florida, Tennessee, abama, Mississippi, Arkansas, and Louisiana. The descriptions are based primarily on the plants this area, with information about eciha yen members of a family or genus in brackets [ ]. The references that I have not verified are marked with asterisks. most grateful to Carroll wal for his continuous advice and help during the Siang of onG n pee Se, I am grateful to Elizabeth B. Schmidt and Stephen A. Spongberg for their editorial ae es were made by Karen Stoutsenberger (FiGure 1) and Rachel A. Wheeler (FIGURE 2) under earlier 2For an coun tote family and its tribes, see Al-Shehbaz, The tribes of Cruciferae (Brassicaceae) in the southeastern United States. Jour. Arnold Arb. 65: 343-373. 1984. © President and Fellows of Harvard College, 1 Journal of the Arnold Arboretum 66: 279-351. ae 1985. 280 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 terete, angular, or flattened parallel [rarely perpendicular] to the septum, vari- able in length, shape, and size; lower segment dehiscent or indehiscent, 1- to many-seeded, rarely seedless and abortive or altogether lacking; upper segment indehiscent, 1- to several-seeded, rarely seedless and resembling the style or obsolete. Seeds mucilaginous or not when wet, wingless [or winged], uniseriately or biseriately arranged in each locule; cotyledons conduplicate, very rarely accumbent or incumbent, usually emarginate. Base chromosome numbers 6— 13, 15, 17. (Including Cakilineae DC., Calepineae Godron, Erucarieae DC., Psychineae DC., Raphaneae DC., Velleae DC., Zilleae DC.) Tyre GENus: Bras- sica L. A natural tribe of 52 genera and about 230 species in six subtribes centered in the southwestern Mediterranean region, particularly Algeria, Morocco, and Spain (where some 41 genera are either endemic or exhibit maximum diversity), and extending eastward into India and Pakistan and southward into South Africa, with a poor representation in the New World. Three genera, Conringia Heister ex Fabr. (six species), Enarthrocarpus Labill. (five species), and Eru- caria Gaertner (eight species), have diversified in the eastern Mediterranean, while Physorrhynchus Hooker (two species) and the monotypic Chalcanthus Boiss., Douepia Camb., Fortuynia Shuttlew., and Pseudofortuynia Hedge are endemic to parts of Iran, Afghanistan, and Pakistan. The tribe is represented in the southeastern United States by 11 genera and 21 species, of which only four of Cakile Miller are indigenous; the remainder are weeds most likely introduced from Europe or southwestern Asia. The Brassiceae are the most distinctive and the most natural of all tribes of the Cruciferae. The great majority of members are characterized by having conduplicate cotyledons and/or two-segmented (occasionally called heterocar- pic) siliques that contain seeds in one or both segments. These features are unknown elsewhere in the family. Segmented siliques are found in 32 genera of the tribe, and with the exception of Ammosperma Hooker f. (monotypic), Pseuderucaria (Boiss.) O. E. Schulz (three species), and Conringia, all of which have accumbent or incumbent cotyledons, the remaining genera with unseg- mented siliques have conduplicate cotyledons. Nonconduplicate cotyledons characterize all species of Cakile and the closely related Erucaria, but these have strongly two-segmented siliques. Calepina Adanson (monotypic), Ory- chophragmus Bunge (monotypic; China), and Spryginia Popov (six species; Central Asia) have traditionally been placed in the Brassiceae but have been excluded by GOmez-Campo (1980a) because they lack the typical features of the tribe. The removal of the last two genera is justified, but Ca/epina has somewhat conduplicate cotyledons (FiGuRE 10) and is without close relatives outside the tribe. It seems, therefore, more appropriate to retain it here. Gomez-Campo (1980a) has proposed significant alterations to the compre- hensive subtribal classification of Schulz (1919, 1923). Subtribes Zillinae (DC.) O. E. Schulz (four genera) and Vellinae Prantl (ten genera including those of the Savignyinae Hayek) are not represented in our flora. Subtribe Cakilinae (DC.) O. E. Schulz (cotyledons lanceolate or linear, accumbent or incumbent; AL-SHEHBAZ, BRASSICEAE 281 Ficure 1. Fruits and seeds of selected Brassiceae. a, b, Brassica ee sale a, fruit, x 2; b, seed, x 6. c-f, Sinapis alba: c, fruit—note beak, x 2; d, fruit after removal of valve. x 2; e, embryo, x 6; f, diagrammatic cross section of seed Aas conduplicate cotyledons, x 6. g, S. arvensis, fruit, x 2. h, Diplotaxis muralis, fruit, x 3. i, j, Eruca i Tult, anistrum. k, infructesoence, x 4: 1, fruit—note aborted lower segment ene Paes upper one, x 2. m, R. sativus, fruit, x 2. n-p, Calepina irregularis: n, fruit, x 6; dia ammatic cross eon of fruit—note woody inner part (hatched) of fruit wall ae seed with conduplicate cotyledons, x 12; p, embryo, x 12. 282 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 siliques strongly segmented, with one or few seeds in each segment) is a natural group including only Cakile and Erucaria and represented in the Southeast by five species of the former. The Moricandiinae Prantl (seven genera, including Conringia) are a heterogeneous assemblage of genera that have dehiscent, elon- gated fruits with seedless beaks and that lack median floral nectaries. Members of subtribe Brassicinae (eight genera) also have dehiscent, elongated fruits, but differ in having median nectaries and usually seeded beaks. However, the lines separating the two subtribes are undoubtedly artificial. The first six genera of the present treatment are considered typical of the Brassicinae. The Raphaninae Hayek (21 Benet) probably the most heterogeneous of all six subtribes, have and indehiscent, usually strongly segmented fruits with seeds i in both segments or in the upper one only. Raphanus L., Rapistrum Crantz, and Calepina represent this subtribe in the Southeast. The Brassiceae are the best known cytologically of all tribes of the Cruciferae. Chromosome numbers have been reported for about 180 species (nearly 78 percent of the tribe) in 44 genera. The highest number (7 = 75) has been found in Crambe Gordjaginii Sprygin & Popov (see Gomez-Campo & Hinata), while the lowest count (” = 6) was reported for Erucaria cakiloidea(DC.) O. E. Schulz (Al-Shehbaz, 1978). Polyploidy occurs in about 36 percent of the species and appears to be exclusive in all members of Crambe L., Moricandia DC., Vella L., Boleum Desv., Zilla Forsskal, and Euzomodendron Cosson. A continuous series from diploid to octoploid occurs in Erucastrum Presl. On the other hand, aneuploidy probably has played an important role in the evolution of Diplotaxis DC. and Brassica. The latter genus also exhibits the classic examples of am- phiploidy that involve six cultivated species. No single base chromosome num- ber is dominant in the Brassiceae, and the most common ones (7, 8, 9, and 15) occur in 14 to 18 percent of the species, while 10, 11, and 12 are found in 6 to 9 percent. Natural intergeneric hybridization has been well documented between the northwestern African Trachystoma Ballii O. E. Schulz and Ceratocnemum rapistroides Cosson & Balansa, and between Cordylocarpus muricatus Desf. and Rapistrum rugosum (L.) All. Their hybrids are somewhat fertile and have been named x 7rachycnemum mirabile Maire & Samuels. and x Rapistrocarpus ramosissimus (Pomel) Al-Shehbaz,’ respectively. Artificial intergeneric hybrids have successfully been made on a large scale between various genera of the tribe, particularly members of subtribe Brassicinae (Harberd & McArthur, 1980). The classic intergeneric hybrid between the remotely related Brassica and Raphanus, x Raphanobrassica, was produced by Karpechenko in 1924 (see Raphanus). Many species of the Brassiceae, especially the economically important ones, have been surveyed extensively for glucosinolates, seed proteins, oil content, and fatty acids, and on a smaller scale for alkaloids, flavonoids, and mucilage. *x Rapistrocarpus Al-Shehbaz, nothogen. nov. (Rapistrum Crantz x Cordylocarpus Desf.) — pistrocarpus ramosissimus (Pomel) Al-Shehbaz, comb. nov., which is based on x Ra pistrella ramo- sissima Pomel (Mat. Fl. Atlant. 11. 1860), should replace the latter because the nothogeneric name x Rapistrella is not a condensed formula (see ICBN, Article H.6, p. 74. 1983 1985] AL-SHEHBAZ, BRASSICEAE 283 The distribution of secondary constituents is not taxonomically useful at the subtribal level, and only in a few cases does it support the alliance of or the distinction between controversial genera. On the other hand, the distribution of glucosinolates is very useful within genera such as Cakile and Brassica. Species of the Brassiceae occupy diverse habitats, but the majority show several adaptations to xeric environments in habit or in seed dispersal. The dustlike seeds of several species of Diplotaxis, the broadly winged seeds of Savignya DC. and Oudneya R. Br., and the samaras of Fortuynia are the most notable adaptations for dispersal by wind in desert plants. Seed mucilage is produced in at least 60 percent of the taxa with dehiscent fruits and apparently is lacking in 65 species of 18 genera with indehiscent fruits. Mucilage production may be an adaptation to anchor the seeds to the ground, as well as to enable them “to endure temporal droughts during the early stages of seed germination” (Gomez-Campo, 1980a, p. 8). Dispersal of corky fruit segments by sea water has probably evolved independently in Crambe (C. maritima L.), in Raphanus (two subspecies of R. Raphanistrum L.), and in Cakile (all taxa but one). Members of 12 genera of the Brassiceae are either exclusively shrubs or herbs with a strongly woody base. In six others both herbaceous and woody taxa occur. All species of Vella, Hemicrambe Webb, Boleum, Euzomodendron, Foleyola Maire, and Sinapidendron Lowe, as well as the Canarian species of Crambe, are large shrubs or subshrubs. Carlquist, who studied the wood anat- omy of the last two genera, believes that the woody condition in the family has almost always been derived from herbaceous ancestry, while G6mez-Cam- po (1980a) suggests that it is a primitive feature in the tribe. The tribe includes the most economically important plants of the Cruciferae. Brassica and Raphanus provide many vegetables that are cultivated for their fleshy roots, swollen stems, leaves, buds, flowers, or young fruits. Edible and industrial oils are extracted from the seeds of Brassica, Crambe, and Eruca Miller, while condiments are obtained from seeds of Sinapis L. and Brassica. A few species are important fodder for livestock, and others of 13 genera (including the 11 treated here) are weeds naturalized throughout much of the world. REFERENCES: Under family references in AL-SHEHBAz (Jour. Arnold Arb. 65: 343-373. 1984), see BAILLON, BENTHAM & Hooker, De CANDOLLE (1821, 1824), CARLQUIST, CRISP, VON Hayek, HepGe, HepGe & RECHINGER, JANCHEN, Maire, MANTON, MARAIS, PRANTL, and SCHULZ AGUINAGALDE, I., & C. GOmEz-CAmMpo. The phylogenetic significance of flavonoids in Crambe L. (Cruciferae). Bot. Jour. Linn. Soc. 89: 277-288. 1984. AL- nee I. A. Chromosome number reports in certain Cruciferae ney Iraq. Iraqi Jour. Biol. Sci. 6: 26-31. 1978. [Cakile, Crambe, Diplotaxis, Eruca . The tribes of Sere oo in the southeastern United States. Jour. Arnold Arb. 65: 343-373. APPELOVIST, L.-A. eal: Ae seeds of cruciferous oil crops. Jour. Am. Oil Chem. . 48: 851-859. 1971. [Brassica, Crambe, Sinapis, fatty acids, lipids, pigments, proteins, carbohydrates, glucosinolates, and miscellaneous compounds. ] Baucu, R. Das Sattelgelenk der Brassiceen-Friichte, seine Abwandlungen und seine 284 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 he Bedeutung. Zeitschr. Bot. 37: 193-238. 1941. [Brassica, Cakile, Diplo- taxis, Rapistrum, Sinapis S.] BENGOECHEA, G., & C. GOmEz-Campo. Algunos caracteres de la semilla en la tribu Brassiceae. (English summary.) Anal. Inst. Bot. Cavanilles 32: 793-841. 1975. [Seeds of 144 taxa studied for shape, size, color, and presence or absence of mucilage and wing; seed-coat anatomy of 44 taxa; figs. 1-67. BerTOL!, I. C. Ricerche sulla cariologia di alcuni generi di Cruciferae della sezione Brassicinae. Atti Mem. Accad. Naz. Sci. Lett. Arti Modena, VI. 9: 41-46. 1967. CLEMENTE, M. Caracteres morfotaxonémicos de la tribu Brassiceae. Monogr. Esc. Técn. Sup. Tne. Agron. Madrid 70: 1-70. 1980.* & J. E. HERNANDeEz-BeRMEJO. El aparato nectarigeno en la tribu Brassiceae (Cruciferae). (English summary.) Anal. Inst. ae oe 35: 279-296. 1980a. [Morphology of nectaries in 155 taxa in 40 gene rola en la tribu Brassiceae. (English summary.) Ibid. 297-334. 1980b. [Shape, ae venation type, and measurements of petals of 161 taxa in 40 genera. ] & . El caliz en la tribu Brassiceae (Cruciferae). (English summary.) Anal. Jard. Bot. Madrid 36: 77-96. 1980c. [Shape, orientation, color, pubescence, and measurements of sepals of 155 taxa in 40 genera.] & . Clasificaci6n jerarquica de las Brasiceas segin caracteres de las piezas estériles de su flor. (English summary.) /bid. 97-113. 1980d. [Numerical analysis based on the characters of sepals, petals, and nectaries of 145 species in 40 genera of the Brassiceae.] Curran, P. L. The nature of our Brassica crops. Part 1. Nomenclature and cytology. Sci. Proc. Roy. Dublin Soc. A. 1: 319-335. 1962. [Grouping according to chro- mosome numbers and genomes; Brassica, Eruca, Raphanus, Sinapis Ertiincer, M. G., & C. P. THompson. Studies of mustard oil glucosides. ir U. S. Dep. Commerce Tech. Serv. AD290747. 105 pp. 1962. [Distribution of mustard oils in seeds of ten genera.] FinLayson, A. J. The seed protein contents of some Cruciferae. Pp. 279-306 in J. G. VauGHan, A. J. MAcLeop, & B. M. G. Jones, eds., The biology and chemistry of the Cruciferae. London, New York, and San Francisco. 1976. [Brassica, Crambe, Free, J. B. Insect pollination of crops. xii + 544 pp. London and New York. 1970. [Brassica, Eruca, Raphanus, 135-150. Gipert1, G. C. Morfologia y modo de crecimiento del fruto en los géneros Trachystoma O. E. Schulz y reas sson & Balansa (Brassiceae, Cruciferae). Anal. ard. Bot. Madrid 41: 59-81. GOMEz-Campo, C. Preservation ao Aa ‘Mediterranean members of the cruciferous tribe Brassiceae. Biol. Conserv. 4: 355-360. 1972. [Methods of preservation, notes on endemism and See oa of endangered species. ] Studies on Cruciferae: III. Hemicrambe Townsendii nom. nov. an example of geographic disjunction. a Inst. Bot. Saleen 34: 151-155. 1977. [Fabrisinapis is congeneric with Hemicrambe,; see Tow D.] Studies on Cruciferae: IV. Cis ticde is Ibid. 485-496. 1978a. [Notes on 7 taxa in 18 genera mostly belonging to the Brassiceae; Brassica, Calepina, Diplo- taxis, Erucastrum, Hutera, Sina ‘ cae fruticosa (Townsend) G6émez-Campo comb. nov. Lagascalia 7: 189, 190. 1978 a a and morpho-taxonomy of the tribe Brassiceae. Pp. 3-31 TSUNODA et al., eds., Brassica crops and wild allies. Tokyo. 1980a. conan morphology, evolutionary trends, evaluation of subtribal classification.] ™, a ramer) 1985] AL-SHEHBAZ, BRASSICEAE 285 . Studies on Cruciferae: VI. Geographical distribution and conservation status of Boleum Desv., Guiraoa Coss. and Euzomodendron Coss. Anal. Inst. Bot. Ca- vanilles 35: 165-176. 1980b. Studies on Cruciferae: V. Chromosome numbers for twenty-five taxa. Ibid. 177- 182. 1980c. [Counts ie 22 taxa of the tribe; Brassica, Diplotaxis, Erucastrum, Hutera, ee In , Chromosome number reports LX VII. Taxon 29: 347-367. 1980d. (Brassica, nea Eruca, 350.] axonomic and evolutionary relationships in the genus Vella L. (Cruciferae). Bot. Jour. Linn. ans 82: 165-179. 1981. [Cytology, numerical analysis, and scan- ning-electron peap eek comparison with Boleum.] & K. Hinata. A check list of chromosome numbers in the tribe Brassiceae. Pp. 51-63 in S. ao A et al., eds., Brassica crops and wild allies. Tokyo. 1980. [A ae of 243 first counts for 170 species, 44 subspecies, and 13 varieties in 44 gen &M. E Tortosa. Thet i d l some juvenile characters in the page Bot. Jour. Linn. Soc. 69: 105- 124. 1974, {Cotyledon morphology and evolutionary trends in juvenile characters of 140 taxa in 40 genera. ] Harserp, D. J. A contribution to the cyto-taxonomy of Brassica (Cruciferae) and its allies. Bot. Jour. Linn. Soc. 65: 1-23. 1972. [Chromosome counts for 85 species, intergeneric crosses; 45 cytodemes recognized. ] otaxonomic studies of Brassica and related genera. Pp. 47-68 in J. G. VAUGHAN, A. J. MacLeop, & B. M. G. Jones, eds., The biology and chemistry of the Cruciferae. London, New York, and San Francisco. 1976. [Origin of and hy- ea between cytodemes; cross incompatibility.] ._D. McArtHur. Two partially fertile species hybrids in the Brassiceae. ee 28: 253. 1972. [Raphanus sativus x R. Raphanistrum, Hirschfeldia vari- eties; reciprocal translocations; pollen sterility.] & —— iotic analysis of some species and genus hybrids in the Brassiceae. Pp. 65-87 in S. TsuNopa et al., eds., Brassica crops and wild allies. Tokyo. 1980. HERNANDEZ-BERMEJO, J. E., & M. CLEMENTE. Significado ecoldgico de la heterocarpia en diez especies de la tribu Brassiceae. El caso de Fezia pterocarpa Pitard. (English summary.) Anal. Inst. Bot. Cavanilles 34: 279-302. 1977. [Seed dispersal, dormancy, and ploidy levels. Zeitschr. Pflanzenz. 78: 13-30. 1977. [Interspecific and intergeneric hybrids; Brassica, Diplotaxis, Eruca, Raphanus, Rapistrum, Sinapis. Kerser, E. von, & G. BUCHLOH. Sinapine in the tribe Brassiceae (Cruciferae). Angew. ot. . 2, Kowat, E., & D. F. CurLer. The wood anatomy of Schouwia pee Ha arabica and Fabrisinapis fruticosus (Cruciferae). Kew Bull. 30: 503-507. Kumar, P. R., & S. TsuNopa. Fatty acid spectrum of Med Sea a Cruciferae. Jour. Am. Oil Chem. Soc. 55: 320-323. 1978. [Oil contents and fatty-acid com- position of 54 species, of which 48 in 23 genera belong to the Brassiceae. ] MacRoserts, D. T. Checklist of the plants of Caddo Parish, Louisiana. Bull. Mus. Life Sci. Louisiana State Univ. Shreveport 1. 54 pp. 1979. [Brassica, angi Rapha- nus, Rapistrum, 25, 26. McGrecor, S. E. Insect ae of cultivated crop plants. U. S. Dep. Agr. Handb. 496. viii + 411 pp. 1976. [Brassica, 164-169, 261, 262, 315-318, 365, 366: Raphanus, 314, 315.] 286 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 McNaucuton, I. H., & C. L. Ross. Interspecific and intergeneric hybridization in the Brassiceae with special emphasis on the improvement of forage crops. Scot. PI. Breed. Sta. Rep. 57: 75-110. 1978.* MitcHe tt, J.. & A. Rook. Botanical aia eee xill + 787 pp. Vancouver. 1979. [Brassica, Diplotaxis, Eruca, Rap 8, Rapistrum, Sinapis. MIzusHIMA, U. Karyogenetic studies ree and genus hybrids in the tribe Brassiceae ae eeuiass Tohoku Jo our. Agr. Res. 1; ls is 1950a.* bt d in the tribe Brassiceae of Cruciferae. Ibid 15 27. 1950b.* . Genome analysis in Brassica and allied genera. Pp. 89-106 in S. TsuNODA et al., eds., Brassica crops and wild allies. Tokyo. 1980. [Brassica, Diplotaxis, Eruca, Raphanus, Sinapis. NEarReE, R., & H.-N. Hovérou. Un Ammosperma nouveau: Ammosperma variabile nov. sp. Bull. Soc. Bot. France 106: 146-149. 1959. NisHtyAMa, I., & Y. INAMoRI. Polyploidy studies in the Brassiceae. III. Kyoto Univ. Res. Inst. Food Sci. Mem. 5: 1953.* ee L. Osservazioni sui fenomeni di geocarpismo nella Morisia hypogea Gay. v. Giorn. Bot. Ital. 4: 424-430. 1897. ee TS, ‘HL A., & J. E. Boppreti. Seed survival and periodicity of seedling emergence in eight species of Cruciferae. Ann. Appl. Biol. 103: 301-304. 1983. [Raphanus, Sinapis.] Rytz, W. Systematische, dkologische und geographische Probleme bei den panes Bull. Soc. Bot. Suisse 46: 517-544. 1936. [Phylogenetic relationships among m bers of the tribe excluding those of subtribes Moricandiinae and Savi ee re- ScHoLz, H. Quezelia, eine neue Gattung aus der Sahara Sammons Brassiceae, Vellinae). Willdenowia 4: 205-207. 1966. [Q. tibestica, sp. nov.; generic name is a later hom- onym for a genus of fungi; renamed as Lie er in Taxon 31: 558. 1982.] Scuutz, O. E. Cruciferae-Brassiceae. Part 1. In: A. ENGLER, Pflanzenr. IV. 105(Heft 70): 1-290. 1919. [Comprehensive treatment of all known species of 28 genera of subtribes Brassicinae and Raphaninae.] ruciferae-Brassiceae. Part 2. In: A. ENGLER, ibid. 105(Heft 84): 1-100. 1923. [Treatment of 22 genera of subtribes Cakilinae, Zillinae, Vellinae, Savignyinae, and Moricandiinae.] SH1GA, T. Male sterility and cytoplasmic differentiation. Pp. 205-221 in S. TsuNopa et al., eds., Brassica crops and wild allies. Tokyo. 1980. [Brassica, Diplotaxis, Rapha- nus. SikkA, K., & A. K. SHArMA. Chromosome evolution in certain genera of Brassiceae. Cytologia 44: 467-477, 1979. [Study of 28 taxa in 18 genera; the roles of polyploidy, aneuploidy, and structural alterations in evolution within certain genera; Brassica, Diplotaxis, Eruca, Erucastrum, Hutera (as Brassicella), Raphanus, Rapistrum, Si- napis. SINSKAIA, E.N. The oleiferous plants and root crops of the family Cruciferae. (In Russian: English summary, 555-619.) Bull. Appl. Bot. 19(3): 1-648. pis. 14, 15. 1928. [Bras- sica, Eruca, Raphanus, Sinapis; origin, taxonomy, distribution, cultivation, hybrid- ization, pollination; figs. 1-108. SOBRINO VESPERINAS, E. Serie cromosémica euploide en el género Moricandia DC. (Cruciferae). (English summary.) Anal. Inst. Bot. Cavanilles 35: 411-416. 1980. [Five species, polyploidy. TAKAHASHI, N., & : SuzuKI. Dormancy and seed germination. Pp. 323-337 in S. Tsunopa et al., eds., Brassica crops and wild allies. Tokyo. 1980. [Brassica, Cakile, Diplotaxis, ee Erucasiviun, flutera, Sinapis.] TAKAHATA, Y., & K. Hinata. A variation study of subtribe Brassicinae by principal 1985] AL-SHEHBAZ, BRASSICEAE 287 component analysis. Pp. 33-49 in S. Tsunopa et al., eds., Brassica crops and wild allies. Tokyo. 1980. [Brassica, Diplotaxis, Eruca, Erucastrum, Hutera, Sinapis.] & _ Studies on cytodemes in subtribe Brassicinae (Cruciferae). Tohoku ur. Agr. Res. 33: 111-124. 1983.* Te eae C.C. Fabrisinapis fruticosus C. C. Townsend. Cruciferae, tribus Brassiceae. Hooker’s Ic. Pl. 7: 1, 2. pi. 3673 + map. 1971. [A new genus from Socotra; reduced to Hemicrambe by Gémez- Campo (1977, 1978b).] eT S. Eco-physiology of wild and cultivated forms in Brassica and allied genera. p. 109-120 in S. Tsunopa et al., eds., Brassica crops and wild allies. Tokyo. 1980. S.] _ Hinata, & C. Gomez-Campo, eds. Brassica crops and wild allies. XVill + 354 pp. Tokyo. 1980. [Excellent account of morphology, cytology, aha ecology, chemistry, breeding, and conservation of various genera of the Brassi ae.] Ucuimiya, H., & S. G. WitpMan. Evolution of fraction I protein in ne to origin of amphidiploid Brassica species and other members of the Cruciferae. Jour. Hered. 69: 299-303. 1978. (Brassica, Diplotaxis, Eruca, Raphanus, Sinapis.] VauGHaNn, J. G. The structure and utilization of oil seeds. xv + 279 pp. London. 1970. (Brassica, He ple 49- & J.S. Hemincway. The utilization of mustards. Econ. Bot. 13: 196-204. 1959. [Brassica, ae ‘Sinapis] WIDLER, B. E., & G. BocqueT. The Messinian model and bipolar distribution of Morisia jonaninos in Corsica. (In Italian; English summary.) Giorn. Bot. Ital. 114: 37- 42. 1980. WILLs, A. B. Meiotic behaviour in the Brassiceae. Caryologia 19: 103- 116. 1966. [Bras- YARNELL, S. H. Cytogenetics of the vegetable crops. I. Cruciferae. Bot. Rev. 22: 81- 166. 1956. (Brassica, Eruca, Raphanus, Sinapis, Crambe, excellent review of cy- tology, inheritance, interspecific and intergeneric crossings. | KEY TO THE GENERA OF BRASSICEAE IN THE SOUTHEASTERN UNITED STATES + A. eae indehiscent, usuall ansversely jointed, often breaking trans- rsely at maturity into 1- or few-seeded ie valves undifferentiated, reduced, or eh ete. B. Fruits transversely jointed, 2- to many- ge haie — rarely 1-seeded, more than 6 mm long; cauline leaves petiolate; petals e C. Style absent: cotyledons accumbent, ae. incumbent; glabrous and often fleshy plants of beaches or sandy shores. ..........--..--+50+ 12. Cakile. Style present; cotyledons conduplicate; usually pubescent and nonfleshy weeds of aah land, roadsides, or waste grou to 1 cm long; upper a |- seeded, + equal to the 1- seeded (or 10. Rapi 2) ay seedless) lower segment. ..........-.. 000000 Strum. D. _ more than 2 cm long; upper oe oe seeded, more than 10 mes longer than the lower, seedless segment. ......... 9. Raphanus. B. at act jointed, 1-seeded, 2-4 mm long; pee eee auriculate; petals un- sciasis tute dsn es ate Lie i a IR ee ene seen oe ee 11. Calepina. A. Fruits ene neither lomentaceous nor es jointed, never breaking at maturity into segments; valves well develop E. Seeds biseriately arranged in each eae 288 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 F. Beak strongly sere ai stigma with decurrent lobes; petals with da rk brown or purple veins. ......0...00.0.00.000..000- 00 cee ee ruca. F. Beak usually terete, stylelike: stigma entire or with aonmale™ lobes: petal veins not dark colored. ........000 0.0000 ccc cece cece, iplotaxis. 7 . Seeds uniseriately arranged i in each locule. G. Valves with 3-7 prominent nerves; beak usually ensiform. H. Sepals erect, a at base; petal veins usually darker in color than the OSU OL PING. suas ele ne cay yan suis cave ceiuadwasaincs 5. Hutera. Sinap G. Valves with | prominent midnerve, lateral nerves usually TicOnspiauous: sometimes evident and anastomosing; beak not ensiform. I. Leaves entire, cordate-amplexicaul; fruits strongly 4-angled; cotyledons incumbent; seeds readily releasing abundant mucilage when wet. ....... Bde th a ee aia cates pays, ahaa taneous aft d aot cera, Mendel oeeee ne 13. Conringia. I. Leaves (at least the lowermost ones) pinnately lobed or dentate, au upper ones auriculate or amplexicaul; fruits terete or flattened, sometim slightly 4-angled; cotyledons conduplicate; seeds slightly or not at all mu- cilaginous when wet. J. Inflorescence ebracteate; seeds globose; inner sepals saccate; fruits usu- gled. 3. B ally terete or flattened, rarely 4-angled. ................ rassica. J. Inflorescence (at least the lower part) bracteate; seeds oblong; inner sepals not saccate; ak usually 4-angled............ 4. Erucastrum. 3. Brassica Linnaeus, Sp. Pl. 2: 666. 1753; Gen. Pl. ed. 5. 299. 1754.4 Herbaceous annuals [or perennials with woody base], rarely biennials, glau- cous or not, glabrous or with simple trichomes. Stems erect, branching above [or below], leafy [very rarely leafless]. Lower leaves petiolate, usually forming a rosette, undivided or lyrately pinnatifid [or pinnatisect]; lateral lobes few [to many or absent], smaller than the terminal one. Upper leaves short petiolate or sessile, sometimes auriculate or amplexicaul, and entire, dentate, or lobed. Inflorescence an ebracteate, few- to many-flowered raceme, much ca ac in fruit. Sepals erect or ascending, rarely spreading, oblong or ovate, green yellow-green, glabrous [or pubescent]; outer pair sometimes slightly ea inner pair usually saccate at base. Petals clawed, yellow [rarely white or pink], broadly [to narrowly] obovate [or rarely oblanceolate]. Lateral nectar glands flat, reniform or prismatic; median glands oval [or filiform or oblong, very rarely absent]. Stamens tetradynamous, not appendaged; anthers oblong or ovate. Ovary sessile [or borne on a gynophore], glabrous, many ovulate; style conspicuous; stigma capitate or 2-lobed. Siliques narrowly [to broadly] linear [or occasionally oblong], dehiscent, torulose [or not], terete or sometimes com- pressed parallel to the septum, rarely 4-angled, erect to spreading [or reflexed]; valves convex, thin or thick [very rarely woody], obtuse or emarginate at apex, prominently [or obscurely] 1-nerved, lateral veins usually i inconspicuous, some- times finely anastomosing; beak long or short, conical or cylindrical, seedless or I [to 3]-seeded, usually forming a stylelike distal portion. Seeds uniseriately [or very rarely biseriately] arranged, globose [rarely oblong or slightly flattened], “Genera are numbered as in the treatment of tribes of Cruciferae in the southeastern United States (Jour. Arnold Arb. 65: 343-373. 1984). Genera 1 and 2 appeared in ibid. 66: 95-111. 1985 1985] AL-SHEHBAZ, BRASSICEAE 289 wingless, slightly mucilaginous or not when wet, yellow or light to dark brown or black, finely to coarsely reticulate; cotyledons conduplicate, usually emar- ginate at apex. Base chromosome numbers 7-11. (Including Brassicaria (God- ron) Pomel, Brassicastrum Link, Guenthera Andrz. ex Besser, Melanosinapis Schimper & Spenner, Rapa Miller.) Lecrorype species: B. oleracea L.; see Britton & Brown, Illus. Fl. No. U. S. ed. 2. 2: 192. 1913. (Name from classical Latin for several kinds of cabbage; a few authors believe that it is from the Greek brazo, I cook, in reference to the vegetables of the genus.)— MusTarD, COLE, TURNIP. The largest genus of the Brassiceae, with some 35 species mostly centered in the Mediterranean region, particularly in southwestern Europe and north- western Africa, extending eastward into southwestern Asia to Afghanistan, and southward into Ethiopia and Somalia. Although the native ranges of the weedy and the cultivated species are uncertain, it is unlikely that they have originated outside the Mediterranean region and western Asia. Of the eight species intro- duced to the United States, at least four are naturalized in the Southeast. The sectional classification of Brassica is controversial, and the three highly artificial sections recognized by Schulz (1919) have recently been divided by Salmeen into nine largely natural ones. The boundaries of sect. MICROPODIUM DC. have been arbitrarily redrawn by Salmeen to include a few unrelated species that differ in chromosome numbers and in morphology. On the other hand, sect. BRASSICARIA (Godron) Cosson (three species; southwestern Europe and northwestern Africa) is morphologically distinct from the rest of the genus, and on the basis of seed anatomy (Bengoechea & Gdmez-Campo), chromosome numbers (Gomez-Campo & Hinata), juvenile characters (G6mez-Campo & Tortosa), and glucosinolates (Horn & Vaughan), the section is somewhat anom- alous in Brassica and closely resembles the Madeiran Sinapidendron. However, B. Gravinae Ten. of sect. BRASSICARIA is intermediate between the typical members of this section and the rest of Brassica. Most taxa (including the type species) of sect. LiGNosAE Widler & Bocquet are very closely related to B. oleracea and should be placed with it in sect. BRAssicA as defined by Stork and colleagues. Section MELANOSINAPIS (DC.) Boiss. (sect. Sinapioides Peterm.) (annuals, upper leaves petiolate, sepals spreading, petals long clawed, fruiting pedicels appressed to the rachis, siliques torulose and 4-angled, valves 5-27 mm long, beaks seedless, seeds 4-10) has been reduced by Salmeen to include only Bras- sica nigra (L.) W. D. Koch (Sinapis nigra L.), black mustard, charlock (Small), 2n = 16. The species may be a native of the Middle East. It is a cosmopolitan weed that grows in fields, roadsides, orchards, and waste places throughout much of the United States. It is locally common in scattered counties in Al- abama, Louisiana, Mississippi, and Tennessee and may occur in the remaining states of the Southeast as well. Section RAPA (Miller) Salmeen ex Al-Shehbaz* (annuals or biennials, basal 5Brassica sect. Rapa (Miller) Salmeen ex Al-Shehbaz, comb. nov. Based on Rapa Miller (Gard. Dict. abr. ed. 4. Vol. 3 (alph. ord.). 1754). The new combination was originally proposed by the late O. J. Salmeen in her Ph.D. dissertation (see references). 290 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 leaves not forming a rosette, cauline leaves auriculate, sepals erect or ascending, valves 2.5-8 cm long, beaks seedless or 1-seeded) is represented in our area by its two species that are both crop plants and naturalized weeds. Brassica Rapa L., turnip, turnip rape, bird’s rape, field mustard, 2n = 20, grows in waste places, cultivated fields, orchards, disturbed sites, and gardens, and on roadsides in all of the Southeastern States. The native range of the species is obscure, but both the Mediterranean region and eastern Afghanistan—Pakistan are con- sidered the main centers for the origin of the cultivated forms (McNaughton, 1976a). Complete interfertility, similar chromosome numbers, and lack of sufficient morphological discontinuities between this species and B. campestris L. justify the reduction of the latter to varietal rank (B. Rapa var. campestris (L.) W. D. Koch).° The fleshy roots and the biennial habit of B. Rapa var. Rapa vs. the nonfleshy roots and annual habit of var. campestris, which are the only characters separating the two, become unreliable differences when plants of the former escape from cultivation. Brassica Rapa is characterized by bright yellow flowers that overtop the floral buds, ascending (“erect-spread- ing” of some authors) sepals, green and usually setose-ciliate lower leaves, auriculate cauline leaves, and short (6-10 mm) petals. The closely related B. Napus L. (B. Napobrassica (L.) Miller), rape, colza, swede, rutabaga, Swedish turnip, 2” = 38, is an amphidiploid that originated in the Mediterranean region a few hundred years ago (McNaughton, 1976b) but does not presently occur in the wild state. It differs from B. Rapa in having creamy or pale-yellow flowers not overtopping the floral buds, longer (10-18 mm) petals, and glaucous and glabrous or sparsely pubescent lower leaves. Although B. Napus has been reported as a weed from nearly all of the Southeastern States, it is very likely that most reports represent misidentifications of plants of B. Rapa. It is very difficult to distinguish between the two species from specimens that lack flowers and lower leaves. Several authors (e.g., Jones, Radford et al., and E. B. Smith) have listed one of the two species in the synonymy of the other, but it is obvious that they are morphologically and cytologically very distinct, and that over- whelming evidence (see below) supports the amphidiploid origin of B. Napus from B. Rapa and B. oleracea. Brassica juncea (L.) Czern. (Sinapis juncea L., B. juncea var. crispifolia Bailey, B. integrifolia (West) O. E. Schulz, B. cernua (Thunb.) Forbes & Hems- ley), Chinese or Indian mustard, brown mustard, leaf mustard, mustard greens, 2n = 36, an amphidiploid species originated from B. nigra and B. Rapa some- where in the Middle East or Central Asia, is widely distributed in all the states of the Southeast. It is an escape from cultivation and a weed of disturbed sites, roadsides, abandoned fields, and waste grounds elsewhere in North America, the West Indies, and Central and South America. The greatest diversity of forms occurs in India and China, where the species is grown as a vegetable or as an oil-seed crop. Brassica juncea has short-petiolate or sessile cauline leaves; *Brassica Rapa and B. campestris were simultaneously described by Linnaeus (Sp. Pl. 1: 666. 1753). Metzger, who was the first to unite the two species, adopted B. Rapa for the combined species, and consequently this name has priority (see ICBN Article 57.2. 1983). 1985] AL-SHEHBAZ, BRASSICEAE 291 ascending iim Lage torulose siliques 3-6 cm long; and seedless, slender beaks 5-10 m g. Small listed B. japonica Sieb. from our area, but it is very likely that ae Bie dealing with plants of B. juncea with narrower siliques and more divided leaves. The sectional disposition of B. juncea has not been adequately resolved. Salmeen assigned it to sect. MicRopopiuM but placed its parental diploid species in different sections. Other authors put B. juncea and B. Rapa in the same section. Brassica oleracea L., 2n = 18, has been listed as a weed in a few checklists covering parts of our area (e.g., Duncan & Kartesz, Lakela et al., Rich & Thomas). However, I have not seen any specimens from the Southeast, and it is doubtful that the species is a successful weed there. Wild plants of B. oleracea are perennials that occupy sea cliffs in Europe, as do their relatives of sect. Brassica (sect. Brassicotypus Dumort., sect. Pseudobrassica Presl, sect. Lig- nosae Widler & Bocquet) that have erect sepals, large (15-30 mm long) petals, auriculate, somewhat fleshy cauline leaves, conical, seedless to two-seeded beaks, and a haploid chromosome number of nine. Brassica carinata Braun, Abyssinian mustard, Ethiopian rape, 2n = 34, has been cultivated in Florida as an experimental plant for seed-oil production but has not become naturalized in the United States. Both B. Tournefortii Gouan (2n = 20) and B. elongata Ehrh. (2n = 22) are widespread weeds in some of the Pacific and Mountain states, but neither one has reached the Southeast. The generic limits of Brassica changed a great many times in the treatments of early authors. Most North American botanists follow Bailey (1922) and Wheeler in merging Sinapis with Brassica, while those elsewhere maintain both genera. The boundaries between Brassica and some of its nearest relatives (Sinapidendron, Diplotaxis, and Erucastrum) are not sharply defined. Section BRASSICARIA shows close ties with Sinapidendron, and according to Gémez- Campo & Tortosa, the ancestors of Br assica amay nave resembled plants of this section or mayh lved along an y represen ted by the sequence Diploiwas: Erucastrum- Bieta ‘Brassica 1S distinguished from these in being herbs with usually saccate inner sepals, obovate petals, terete or flattened siliques, one-nerved valves, and usually uniseriately arranged globose seeds. Sinapidendron differs from Brassica in its shrubby habit, basal rosette of leaves, narrowly oblong petals, and oblong seeds, while Erucastrum is dis- tinguished by its oblong seeds, usually four-angled siliques, keeled valves, non- saccate sepals, and sometimes bracteate inflorescences. Diplotaxis has biseri- ately arranged, small (usually less than 1 mm long), oblong to elliptic or oval seeds. All species of Sinapis, Hirschfeldia Moench, and Hutera Porta have valves with three to seven prominent nerves, while Brassica has one prominent midnerve and occasionally inconspicuous lateral ones (FIGURE la, ¢, g). Nomenclatural instability and lack of agreement on the number and rank of recognizable taxa among the cultivated brassicas have created persistent taxo- nomic problems. Bailey (1922, 1930, 1940) recognized 22 species in cultivation, while Helm (1963a) accepted more than 40 varieties and forms within Brassica oleracea alone. However, it is generally agreed that all the cultivated forms with n = 10 belong to B. Rapa because they are completely interfertile (P. G. Smith & Welch) and differ only in leaf characters that may be controlled by a 292 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 few genes (McNaughton, 1976a). Similarly, all the cultivated forms with n = 9 are interfertile and clearly belong to the B. oleracea complex. Species of Brassica are pollinated by numerous kinds of insects (Knuth), but the most constant pollinators are various species of the bee genera Apis, An- drena, and Halictus (McGregor). The flowers of B. nigra and B. oleracea have highly patterned ultraviolet reflectance (Horovitz & Cohen) and usually secrete abundant nectar daily (estimated at 0.1 ml for each of three days). The sugar concentration in nectar varies among the cultivated species but usually reaches 50 percent, except in some cultivars of B. Rapa, where it may approach 69 percent. Protogyny, self-incompatibility, and male sterility are well known in several species. In male-sterile plants, pollen develops normally, but the anther wall fails to dehisce because of the formation of a thick, compact layer (Chow- dhury & Das). The cytogenetic relationships of the six crop species of Brassica have been thoroughly investigated (see the reviews of Prakash & Hinata and Yarnell). Three basic diploid species, B. nigra (n = 8, genome B), B. oleracea (n = 9, genome C), and B. Rapa (n = 10, genome A), are the immediate progenitors of the amphidiploids B. carinata (n = 17, genome BC), B. juncea (n = 18, genome AB), and B. Napus (n = 19, genome AC). The allotetraploid origin of the last three species was elucidated first cytologically by Morinaga and U. Extensive supporting evidence obtained from the artificial synthesis and breed- ing (U; Frandsen, 1943, 1947; Olsson, 1960b, d; Olsson & Ellerstr6m; Prakash, 1973b), seed morphology and anatomy (Berggren, 1962; Mulligan & Bailey), karyotype analysis (Sikka), nuclear DNA content (Verma & Rees), chloroplast DNA (Palmer et al., Erickson et a/.), glucosinolate distribution (Ettlinger & Thompson; Vaughan, Hemingway, & Schofield; Rébbelen & Thies, 1980b), phenolics (Das & Nybom), and proteins (MacKenzie & Blakely; Robbins & Vaughan; Uchimiya & Wildman; Vaughan, 1977; Vaughan & Waite, 1967b; Vaughan, Denford, & Gordon; Vaughan, Phelan, & Denford; Yadava et al.) undoubtedly makes the cultivated brassicas the best-documented example of evolution through allotetraploidy. Contrary to the overwhelming evidence sup- porting the origin of B. carinata from B. nigra and B. oleracea, Yadava and colleagues have suggested that it is derived from B. nigra and B. Rapa. Except in four amphidiploid species (the three above and Brassica balearica Pers.) polyploidy is uncommon and probably has not played a major role in the evolution of Brassica. Diploid and tetraploid infraspecific taxa are known in both B. fruticulosa Cyr. (x = 8) and B. Gravinae (x = 10), while plants of B. dimorpha Cosson & Durieu (” = 22) are exclusively tetraploids. The re- maining species of Brassica are diploids with n = 7-11. On the basis of the maximum number of secondarily associated chromosomes during the first metaphase, Catcheside and Alam have speculated that the original base chro- mosome number for Brassica is six. Their hypothesis is supported by many cytological observations on chromosome homology within the genome of a given species (autosyndesis) or among genomes of different species (allosyn- desis) in haploid, diploid, and polyploid plants and in hybrids. According to Rébbelen (1960a), balanced secondary polyploidy derived from x = 6 is found in the three diploid cultivated species that have six chromosome types rec- 1985] AL-SHEHBAZ, BRASSICEAE 293 ognizable by certain structural features (e.g., chromosome length, symmetry of arms, and especially shapes of the heterochromatin regions). However, no extant species of Brassica is based on six, and all earlier counts reported as having n = 12 belong to species of Sinapis and Hutera. Although a large number of artificial interspecific and intergeneric hybrids have been obtained (Harberd, 1976; Harberd & McArthur), natural interspe- cific hybridization is very rare in Brassica. Hampered by hybrid sterility (caused by endosperm deficiency and embryo abortion), hybridization among the three cultivated diploid species is very difficult, and the original natural formations of the three cultivated amphidiploid species must have been extremely rare events. All diploids with 2” = 18 (including B. oleracea) are interfertile and produce hybrids with normal meiosis, viable pollen, and good seed set (Sno- gerup, 1980). However, the species are geographically isolated, and their ranges rarely overlap. The intergeneric hybrid xRaphanobrassica is discussed under Raphanus. The chemistry of the cultivated species, particularly in relation to selection of cultivars high or low in oils, erucic acids, or glucosinolates, has been ade- quately covered in the reviews of Appelqvist (1976), Appelqvist & Ohlson, Josefsson (1970), and Rébbelen & Thies (1980a, b). The distribution of glu- cosinolates appears to be most useful taxonomically at the specific level. Chem- ical differences between Brassica and Sinapis are found, and the latter contains 4-hydroxybenzylglucosinolate, which is generally lacking in the former. How- ever, Horn & Vaughan have found this compound in sect. BRAssicarRIA; both the compound and the section are believed to be anomalous in Brassica. Other chemical differences between the two genera have been reviewed by Vaughan (1977). In B. juncea two chemical races are recognized: an Indian race with a preponderance of 3-butenylglucosinolate and without mucilage in the seed coat, and an oriental (eastern Asiatic-European) race rich in allylglucosinolate and with a mucilaginous seed coat (Vaughan, Hemingway, & Schofield). Vaughan & Gordon suggested that either B. juncea has evolved independently in the two regions (thus agreeing with Olsson (1960b) on the polyphyletic origin of the species) or, more likely, the Indian race has resulted from human selection for edible oil-producing cultivars that lack the toxic allyl isothiocyanate. The seed-protein data, however, do not support such racial distinctions (Denford). The types and amounts of glucosinolates in a given plant may be directly related to its allelochemic defense against certain herbivores or fungal pathogens. The susceptibility of many cultivated brassicas to several fungal diseases, such as the downy mildew (caused by Peronospora parasitica (Pers. & Fries) Fries), may have resulted from man’s selective breeding for more tasty cultivars with lower concentrations of glucosinolates (Greenhalgh & Mitchell). Wild cabbage (Brassica oleracea subsp. oleracea) and all of its relatives of sect. BRASSICA have isolated and spotty distributions along sea cliffs and rocky islets of the Mediterranean, western Europe, and the Canary Islands. Baker has indicated that B. oleracea escaping from cultivation has reverted to occupy sea-cliff habitats on the northern side of San Francisco’s Golden Gate. Long- distance dispersal of seeds of sect. BRAssICA may be accomplished by sea birds. According to Mitchell & Richards (1979), the wild cabbage may perennate for 294 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 20 years and may produce as many as 70,000—100,000 seeds annually. Although it is not known how long these seeds remain viable, those of B. nigra included in the classic experiments of Beal (see Darlington) survived in the soil for 50 years. Crops of Brassica are the most important economic plants of the Cruciferae. Probably the earliest known utilization of mustards dates from Sanskrit records in India to 3000 B.C. (Mehra). Some authors have suggested that the ancestral cabbage was cultivated in coastal northern Europe nearly 8000 years ago. Undoubtedly several brassicas of European origin were cultivated long before the Christian Era, but at least three (Brussels sprouts, kohlrabi, and rape) originated only a few hundred years ago. The cultivated members with n = 9 have traditionally been treated as va- rieties of Brassica oleracea but were listed as groups without formal rank by Bailey and colleagues. The most common types grown in our area are Brussels sprouts (var. gemmifera Zenk), cabbage (var. capitata L.), cauliflower (var. botrytis L.), kohlrabi (var. gongylodes L.), kales and collards (var. acephala DC.), and sprouting broccoli (var. italica Plenck). Several authors have stated that the diversity among these varieties could not have evolved from the limited variation presently existing in the wild cabbage and have therefore suggested a multiple origin from more than one ancestral species. A wide range of leafy forms has been selected in China from plants originally introduced from western or central Asia for seed oils. All of the Far Eastern forms except the Chinese kale (known as B. alboglabra Bailey but probably a form of B. cretica Lam.) belong to B. Rapa and B. juncea. The classification of these oriental forms is not settled, and various specific, subspecific, and varietal ranks have been assigned to them (Kitamura; McNaughton, 1976a; Nishi, Helm, 1961, 1963b). The Chinese mustard or pak-choi (B. Rapa var. chinensis (L.) Kitam.) and the Chinese cabbage or pe-tsai (B. Rapa var. am- plexicaulis Tanaka & Ono), commonly known as B. pekinensis Rupr., have the same chromosome number as—and produce fully fertile hybrids with—B. Rapa, from which they differ in leaf characters only. Hakuran, a newly devel- oped Japanese vegetable crop, is a leafy form of B. Napus that produces “heads” instead of fleshy roots and has been synthesized from crossing the Chinese cabbage with our common cabbage (Nishi). Various fresh parts of Brassica crops are eaten raw, stewed, cooked, fer- mented in brine, or pickled in vinegar. Many are important fodder for farm animals, and some colorful cabbages and kales are ornamentals. The seeds contain 30-40 percent oil, which is the principal cooking oil in India and is also used as a substitute for olive oil and in the manufacture of margarine in Europe. The seed-cake remaining after the expression of oil contains 25-35 percent protein and is used as a fertilizer. Oil of B. napus ranks fifth in terms of the world tonnage of vegetable oil production. It is used in the manufacture of general-purpose grease, lubricants, varnishes, lacquers, soft soap, plastics, resins, vinyl stabilizers, synthetic flavors and odors, flotation agents, insect repellents, nylons, and pharmaceuticals (Ohlson). Table mustard is manufac- tured from the seeds of Sinapis alba L. (contributing the hot principle 1985] AL-SHEHBAZ, BRASSICEAE 295 4-hydroxybenzy] isothiocyanate) and B. juncea or B. nigra (providing the pun- gent principle allyl isothiocyanate). The seeds also are used as a spice in the preparation of pickles and in the seasoning of food items Seeds of Brassica nigra and B. juncea have been used extensively as laxatives, vesicants, stimulants, irritants, rubefacients, emetics, tonics, and antiseptics; employed as remedies for colds, stomach disorders, abscesses, rheumatism, and lumbago; and also used in the preparation of ointments to relieve neuralgia, bronchitis, arthritis, and pneumonia (Perry). Hartwell has listed several species employed in the preparation of plasters, poultices, and juices as remedies for indurations and tumors. Preparations from the vegetative parts are used in China and India as antiscorbutics, antidysenterics, resolvents, and depuratives, and for the treatment of diabetes, chronic coughs, and bronchial asthma. Plas- ters are applied to swellings or blistered surfaces to promote free discharge and are used to cure warts. In addition to being obnoxious weeds, several species of Brassica are harmful or poisonous to humans and livestock. Some of the weedy and cultivated members cause photosensitization, goiter, pulmonary emphysema, and several serious disorders in the digestive, nervous, and urinary systems of cattle and sheep that may eventually lead to death. REFERENCES: Although the references listed below may appear excessive, they represent approxi- mately 26 percent of those consulted during the preparation of this treatment! The wealth of literature dealing with the agronomic, industrial, pathological, physiological, pesti- ae and many related agricultural aspects of the cultivated species is irrelevant to this tudy and has not been surveyed here. The reader is advised to consult the indexes of ie Bibliography of Agriculture for leads. Under family references in AL-SHEHBAz (Jour. Arnold Arb. 65: 343-373. 1984), see AL-SHEHBAZ (1977); APPELQVIST (1971, 1976); BAEZ MAyYor; BAILLON; BATEMAN (1955a), BENTHAM & Hooker; BERGGREN; BOUMAN; Carus; CoLe (1976); Crisp; HARTWELL; VON H ; Won KE Pant & KIpwal; PERRY; Prasab (1975, 1977); RADFoRD et al.; ROLLINS (1981); SAMPSON; SCHULZ; SMALL; E. B. SMITH; VAUGHAN, PHELAN, & DENFORD; WAUGHAN & WHITEHOUSE; and Vieai et al. Under tribal references see APPELQVIST, BAUCH, BENGOECHEA & GOMEZ-CAMPO, BER- TOLI, CLEMENTE & HERNANDEZ-BERMEJO (1980a-d), CURRAN, ETTLINGER & THOMPSON, FINLAYSON, FREE, GOMEZ-CAMPO (1972; 1978; 1980a, c, d), GOMEz-Campo & HINATA, Gomez-Campo & TorTosA, HARBERD (1972, 1976), HARBERD & McARTHUR (1980), NANDEZ-BERMEJO & CLEMENTE, KUMAR & TSUNODA, MCGREGOR, MITCHELL & ROOK, MizusHMa (1980), Rytz, SCHULZ (1919), SHIGA, SIKKA & SHARMA, SINSKAIA, TAKAHASHI SUZUKI, TAKAHATA & HINATA (1980), TsUNODA, TSUNODA et al., ieee MAN, VAUGHAN, VAUGHAN & HEMINGWAY, WILLS, WUNDERLIN, and YARNEL AnusA, Y. R., & P. N. BHApuRI. The embryology of Brassica campestris L. var. toria Duth. & Full. Re ieee ene 63-67. 1956. Ata, Z. Cytological studies of some Indian oleiferous Cruciferae. IJ. Ann. Bot. 50: 85-102. 1936. [B. Rapa, B. juncea, secondary pairing.] 296 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ANpbersson, G., & G. Oxsson. Cruciferen-Olpflanzen. Pp. 1-66 in H. Kappert & W. uporrF, eds., Handbuch der Pflanzenziichtung. Vol. 5. Berlin. 1961. [The biology of B. Napus, B. Rapa (as B. campestris), and Sinapis alba. Appe.gvist, L.-A. Lipids in Crucife erae. III. Fatty acid composition of diploid and tetraploid seeds of Brassica campestris and Sinapis alba grown under two climatic extremes. Physiol. Pl. 21: 615-625. 1968a. [Polyploidy increased seed size but did not aes fatty-acid composition or oil content.] ids in Cruciferae. IV. Fatty acid patterns in single seeds and seed populations of various Cruciferae and in different tissues of Brassica Napus L. Hereditas 61: 9- 44. 1968b. [B. 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[Resis- tance to white rust is conferred by dominance at any one of three loci; plants with recessive alleles at all three loci are susceptible. ] Feeny, P., & L. ROSENBERRY. Seasonal variation in the glucosinolate content of North American Brassica nigra and Dentaria species. Biochem. Syst. Ecol. 10: 23-32 1982. FERGUSON, L. B. = balearica. Bot. Mag. 179: ¢. 641. 1973. FRANDSEN, K. J. The experimental formation of Brassica juncea Czern. et Coss. Dansk Bot. Ark. He 1-17. 1943. . The experimental formation of Brassica Napus L. var. oleifera DC. and Brassica carinata Braun. Ibid. 12(7): 1-16. 1947. FRIEND, D. J. C., & V. A. HELSON. Brassica campestris L.: floral induction by one long day. Science 153: 1115, 1116. 1966. FuKusHIMA, E., T. Matsu, & H. EGucui. Phylogenetic studies on Brassica species by means of serological method. Jour. Fac. Agr. Kyushu Univ. 14: 341-348. 1968.* FusseLl, G. E. History of cole (Brassica sp.). Nature 176: 48-51. 1955. [B. Napus, B. apa.| Gates, R. R. 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V., & G.I. eee A morphological and anatomical characteristic of root formations in some species of the genus Brassica L. os es ssian; English pee Prikl. Bot. Cae Selek. 72(3): 103-112. 1982 Lon, C. C., & D. S. INGRAM. Production of haploid plants from anther cultures and ear tee embryoids of winter oilseed rape, Brassica Napus ssp. oleifera. New Phytol. 91: 507-516. 1982. MacKenzie, S. L., & J. A. BLAKELY. Purification and characterization of seed globulins from Brassica juncea, B. nigra, and B. hirta. Canad. Jour. Bot. 50: 1825-1834. 1972. [Support for the allotetraploid origin of B. juncea; B. Ra MacLeop, A. J., & G. MacLeop. Volatiles of cooked cabbage. Jour. Sci. Food Agr. 19: 273-277. 1968. [Thirty-five components; thiols, aldehydes, sulphides, ketones, al- cohols, cyanides, and isothiocyanates. MansFELD, R. Vorlaufiges Verzeichnis landwirtschaftlich oder gartnerisch kultivierter Pflanzenarten (mit Ausschluss v: von Zierpflanzen). Kulturpflanze, Beih. 2. 659 pp. 1959. ieee 77-93; 6 species, 46 varieties, and 14 for McNAuUGHTON, "L i. Brassica napocampestris L. (2n = 58). 1. Synthesis, cytology, fer- tility and general se aaa Euphytica 22: 301-309. 1973. [Name mistakenly attributed to Linn Turnip and as Brassica campestris (Cruciferae). Pp. 45-48 in N. W. S ionbe, ed., Evolution of crop plants. London and New York. 1976a. . Swedes and rapes: Brassica Napus (Cruciferae). Pp. 53-56 in N. W. Simmonps, ed., ibid. 19 MEHRA. K. L. ane and ethno-botany of mustard in India. Advance. Front. Pl. Sci. 19: 51-59. 1968. 1985] AL-SHEHBAZ, BRASSICEAE 301 Metzcer, J. Systematische Beschreibung der kultivirten Kohlarten. 68 pp. + pl. Hei- 8. MitcHeELt, N. D. The status of Brassica oleracea L. subsp. oleracea (wild cabbage) in the British Isles. Watsonia 11: 97-103. 1976 & A.J. Ricuarps. Variation in Brassica oleracea L. subsp. oleracea (wild cab- ay detected by the picrate test. New Phytol. 81: 189-200. 1978. iological flora of the British Isles. Brassica oleracea L. ssp. oleracea (B. ee ) Miller). Jour. Ecol. 67: 1087-1096. 19 ag U. P a studies on some wild Brassica species. Tohoku Jour. Agr. 19: 83-98. Nec a Ue Ae hybridization in Brassica. VI. The cytology of F, hybrids of B. juncea and B. nigra. Cytologia 6: 62-67. 1934. [Genome constitution and chromosome numbers of the six (listed as a cultivated species. ] MUKHERJEE, P. Interstrain differences in karyotype of Brassica oleracea L. Curr. Sci. Bangalore 43: oe 594. 1974. PVariesies capitata, botrytis, and caulocarpa. | . The structural and numerical alterations of chromosomes in Brassica campestris L. ‘Cytologia 42: 181-187. 1977. Mutucan, G. A., & L. G. Bamtey. Seed coats of some Brassica and Sinapis weedy and cultivated in Canada. Econ. Bot. 30: 143-148. 1976. [Scanning-electron microscopy; five species of Brassica and two of Sinapis.] Musi, A. F. Distinguishing the species of Brassica by their seed. U. S. ea Agr. Misc. Publ. 643. 35 pp. 1948. [Key, descriptions, and illustrations of 17 t Nair, P. K. K., & R. K. SHARMA. Pollen morphology of cultivated pene New Botanist 3: 115- 153. 1976. [Light and electron microscopy. Namal, H., & T. Hosopa. Interspecific and intervarietal variations in content of volatile isothiocyanate in seed meals of cruciferous crops. Jap. Jour. Genet. 30: ase 51.1975. ASHIMA, & T. Hosopa. I tion breed- ing in en Pp. 191-203 in S. TsuNODA, K. HINAT A, & C. con Campo, eds., Brassica crops and wild allies. Tokyo. 1980. aoe ’ Raphan Nasra._aH, M. E. Self-incompatibility antigens and S gene eben in Brassica. Heredity 43: 259-263. 1979. [Varieties of B. oleracea, immunodiffusion. ] NeLson, A. Fertility in the genus Brassica. Jour. Genet. 18: 109-135. 1927. [B. oleracea, . Rapa, B. Napus, B. nigra, Sinapis.] Nieuwuor, M. Cole crops. 353 pp. London. 1969.* Nisut, S. Differentiation of Brassica crops in Asia and the breeding of hakuran, a newly eine leafy vegetable. Pp. 133-150 in S. Tsunopa, K. HIN Gomez-Campo, eds., Brassica crops and wild allies. Tokyo. 1980. OuLtson, J.S.R. Rapeseed oil. Jour. Am. Oil Chem. Soc. 60: 385, 386. 1983. [Industrial usage. OLpHaM, C. H. Brassica crops and allied cruciferous crops. 295 pp. London. 1948. [Botanical a history, geographic areas of production, cultivation, marketing, diseases, pes OLsson, G. caer within the campestris group of the genus Brassica. Hereditas 40: 398-418. 1954. [B. Rapa, B. Tournefortii, and the Chinese taxa with n = 10; several new combinations at the subspecific level.] me relations between number of seeds per pod, seed size and oil content and the effects of selection for these characters in Brassica and Sinapis. Ibid. 46: 29-70. 1960a. [B. Rapa, B. Napus, S. alba. Species crosses within the genus Brassica. 1. Artificial Brassica juncea Coss. Ibid. 171-223. 1960b. . Se FSU MLE and outcrossing in rape and white mustard. /bid. 241-252. 1960c. [Brassica, Sinapi . Species crosses aaa the genus Brassica. II. Artificial Brassica Napus. Ibid. 351-386. 1960d. 302 JOURNAL OF THE ARNOLD ARBORETUM [vVOL. 66 —— &S. ELterstr6m. Polyploidy breeding in Europe. Pp. 167-190 in S. Tsunopa, K. Hinata, & C. GOmez-Campo, eds., Brassica crops and wild allies. Tokyo. 1980. [Auto- ae allopolyploidy; B. Napus, B. juncea;, synthesis of Brassica-Raphanus hybrids. Onno, M. Die Wildformen aus dem Verwandtschaftskreis “Brassica oleracea.” Osterr. Bot. Zeitschr. 82: 309-334. 1933. [The wild relatives of B. oleracea are grouped in Six species, eight subspecies, and seven varieties; keys, descriptions, nomenclature, distributions. ] Orr, A. R. Inflorescence development in Brassica campestris L. Am. Jour. Bot. 65: 466- 470. 1978. Pater, J. D., C. R. Suie_ps, D. B. CoHEN, & T. J. ORTON. Chloroplast DNA evolution and the origin of amphidiploid Brassica species. Theoret. Appl. Ge net. 65: 181- 189. 1983. [Maternal inheritance; possible role of introgressive hy ; strong a for the origin of the three amphidiploid species from three diploid ancestors: e ERICKSON et al.] Papp ‘E. Species of Brassica genus eareens by the photometric study of the color substances complex in the seed. Acta Agron. Acad. Sci. Hung. 22: 59-66. 1973.* ee Morphologic variation in the mas en Proc. Iowa Acad. Sci. 65: 86— 95. 1958. ae O. H. A suggested classification of the genus Brassica. Proc. Am. Soc. Hort. Sci. 25: 105-110. 1929. [Groups the cultivated species according to chromosome numbers. PHELAN, J. R., & J. G. VAUGHAN. A chemotaxonomic study of Brassica oleracea with particular reference to its relationship to Brassica alboglabra. Biochem . Syst. Ecol. 4: 173-178. 1976. oe and isothiocyanates do not support maintaining B. alboglabra as a distinct specie Potpinl, L. Brassica pen a new species from oa Italy. (In Italian; English summary.) Giorn. Bot. Ital. 107: 181-189, PRAKASH, S. Haploidy in Brassica nigra Koch. aa 613, 614. 1973a. ——.. Artificial synthesis of Brassica juncea Coss. Genetica 44: 249-263. 1973b. ———.. Haploid meiosis and origin of Brassica Tournefortii Gouan. Euphytica 23: 59 1- 595. 1974. . Cruciferous oilseeds in India. Pp. 151-163 in S. Tsunopa, K. Hinata, & C. Gomez-Campo, eds., Brassica crops and wild allies. Tokyo. 1980. [B. juncea, B. & K. Hinata. Taxonomy, cytogenetics and origin of crop brassicas, a review. Op. Bot. 55: 1-57. 1980. [Historical account, poualncitags of six species, chro- mosome morphology, hybridization, polyploidy, aneuploid origin. } RAIN. Genomic status of Brassica Tournefortii Gouan. an Appl. Genet. 4: 203, 204. 1971. [Hybridization with B. Rapa, sterility, genom Ricu, C. N., & R. D. THomaAsS. A checklist of the vascular plants of Madison Parish, Louisiana. Proc. Louisiana Acad. Sci. 44: 93-101. 1981. [B. juncea, B. nigra, B. , 96.] RicHHariA, R. H. Cytological investigation of 10-chromosome species of Brassica and their F, hybrids. Jour. Genet. 34: 45-55. 1937. [B. Rapa, B. chinensis, B. pekinensis.] R6ssBeELEN, G. Beitrage zur Analyse des Brassica-Genoms. Chromosoma 11: 205-228. 1960a. [B. Rapa, B. nigra, B. oleracea Uber die Kreuzungsunve rtraglichkeit verschiedener Brassica-Arten als Folge eines gehemmten Pollenschlauchwachstums. Ziichter 30: 300-312. 1960b. [Crosses in all combinations between six cultivated species, pollen germination and pollen- tube growth, self sterility. ] . THlEs. Biosynthesis of seed oil and breeding for improved oil quality of rapeseed. Pp. 253-283 in S. Tsunopa, K. Hinata, & C. GOMEz-CAMPO, eds., Bras- 1985] AL-SHEHBAZ, BRASSICEAE 303 sica crops and wild allies. Tokyo. 1980a. [B. Rapa, B. Napus, selection for low erucic-acid content. —— Variation in rapeseed glucosinolates and breeding for improved meal quality. Pp. 285-299 in S. Tsunopa, K. Hinata, & C. GOmeEz-Campo, eds., ibid. 1980b. Rossins, M. P., & J. G. VAUGHAN. Rubisco in the Brassicaceae. Pp. 191-204 in U. JENSEN & D. E. FAIRBROTHERS, eds., Proteins and nucleic acids in plant systematics. Berlin, Heidelberg, New York, and Tokyo. 1983. Roserts, I. N., & H. G. Dickinson. Intraspecific Hee ira on the stigma of Brassica. Phytomorphology 31: 165-174. 1981. [B. olerace Roacen, H. P. J. R. Scanning electron microscopical observations on compatible and Ro.uins, R. C. Another cruciferous weed establishes itself in North America. Contr. Gray Herb. 210: 1-3. 1980. [B. elongata subsp. Gece in Nevada.] ae F.. Jr. The book of spices. xiii + 489 pp. Wynnewood, Pennsylvania. 9. [B. nigra, history, uses, and recipes, 296- 305] a . Morphology of the curd of cauliflower. Am. Jour. Bot. 49: 290-297. 1962. SALMEEN, O. J. A systematic revision on the genus Brassica L. in the Mediterranean region. vi + 310 pp. Unpubl. Ph.D. dissert tation, Univ. Reading, U. K. 1979 SAMPSON, D. R. The genetics of self- and cross- -incompatibility in Brassica oleracea. Genetics 42: 253-263. 1957. New light on the complexities of anthocyanin inheritance in Brassica oleracea. Canad. Jour. Genet. Cytol. 9: 352-358. 1967. [Pigment inheritance is controlled by several groups of clcsely linked genes. ] Scuenck, H. R., & G. ROBBELEN. Somatic hybrids by fusion of Pr from Brassica oleracea and Brassica campestris. Zeitschr. Pflanzenz. 89: 278-288. 1982 SCHROEDER, W.P., M. E. DAXENBICHLER, G. F. SPENCER, D. WEISLEDER, & H. L. TOOKEY. 4-Hydroxy a new glucosinolate in seeds of Brassica eleneaias our Nat. Prod. 46: 667-670. 1983. ScHWETKA, A. Inheritance of seed color in turnip rape (Brassica campestris L.). Theoret. Appl. Genet. 62: 161-169. 1982. [Maternal inheritance, two epistatic and four hy- postatic genes control seed-color inheritance SEEGELER, C. J. P. Oil plants in Ethiopia, their taxonomy and agricultural significance. Belmontia, II. 16. x + 368 pp. 1983. [B. Rapa, B. carinata, B. nigra, 46-82.] SHARMA, M. Ontogenic studies of the myrosin idioblasts in Brassica Napus and Bras- sica montana. Bot. Tidsskr. 66: 51-59. 1971. SikKA, S. M. Cytogenetics Brassica hybrids and species. Jour. Genet. 40: 441-509. 1940. [Chromosome numbers, secondary associations, meiotic irregularities, hy- bridization; includes Sinapis and Hutera.] Situ, P. G., & J. E. WELCH. Nereis of vegetables and condiment herbs grown in the ere States. Proc. Am. Soc. Hort. Sci. 84: 535-548. 1964. [Brassica, 536, ‘| 537, 544 SNOGERUP, S. Seer and cytological studies of the “Brassica oleracea” group. Webbia 34: 357-362. 1979. The wild forms of the Brassica oleracea group (2n = = and their possible relations to the cultivated ones. Pp. 121-132 in S. Tsun , K. Hinata, & C. Gomez-Campo, eds., Brassica crops and wild allies. tee 1980. [Suggests a mul- tiple ess the European cultivated brassica sson. Hybridization between Brassica insularis Moris and B. balearica Pers. Hereditas 99: 187-190. 1983. [B. balearica is an area ie having a B. oleracea genome (n = 9) and another unidentified one w SrevENS, B. J. H., & R. R. SELVENDRAN. Pectic pee de of ihade (Brassica oleracea). Phytochemistry 23: 107-115. 1984. Stork, A. L., S. SNoGERUP, & J. Wiest. Seed characters in Brassica section Brassica 304 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 and some related groups. Candollea 35: 421-450. 1980. [Light and scanning-electron microscopy; 17 species of Brassica, Sinapis, and Sinapidendron SuLBHA, K. Embryology of Brassica juncea Czern. & Coss. Jour. Indian Bot. Soc. 36: 292-301. 1957. Sun, V. G. The evaluation of taxonomic characters of cultivated Brassica with a key to species and varieties—I. The characters. Bull. Torrey Bot. Club 73: 244-281. 46a. . The evaluation of some taxonomic characters of cultivated Brassica with a key to species and sas The key. /bid. 370-377. 1946b. [Recognizes seven species and 25 varieties. ] SwARvpP, V., &S.S. oe Origin and genetic improvement of Indian cauliflower. Econ. Bot. 26: 381-393. 1972. THompson, K. F. Cabbages, kales, etc.: Brassica oleracea (Cruciferae). Pp. 49-52 in N. W. SIMMONDS, ed., Evolution of crop plants. London and New York. 19 aR: Tavior, Self-incompatibility in kale. Heredity 27: 459-471. 1971. TSUNODA, S., & S. Nisui. Origin, differentiation and breeding of cultivated Brassica. Proc. XII. Int. Congr. Genet. 2: 77-88. 1968. U, N. Genome-analysis in Brassica with special reference to the experimental formation of B. Napus and peculiar mode of Scere Jap. Jour. Bot. 7: 389-452. pi. 5. 1935. [B. carinata, B. juncea, and B. Napus each evolved through allopolyploidy from two of the three diploids B. on B. oleracea, and B. Rapa; genomes, hy- bridization, meiotic irregularities.] VANETTEN, C. H., M. E. DAXENBICHLER, P. W. WILLIAMS, & W. F. Kwo ek. Glucosi- nolates and derived products in crac ieious eee cia of the edible part from twenty-two varieties of cabbage. Jour. Agr. Food Chem. 24: 452-455. 1976. VAUGHAN, J. G. The seed coat structure of Brassica negro ps O. E. Schulz var. carinata (A. Br.) [sic]. Phytomorphology 6: 363-367. 1956. [B. carinata.] The testa of some Brassica seeds of oriental origin. bid. 9: 107-110. 1959. [The Chinese members of B. Rapa Seed protein studies of Bist and Sinapis species. Pp. 103-110 in J. G. Hawkes, ed., Chemotaxonomy and serotaxonomy. London and New York. 1968. [B. Rapa, B. nigra, B. oleracea, S. alba; serological data support the distinction of the two genera.] . Amultidisciplinary study of the taxonomy and origin of Brassica crops. BioScience 27: 35-40. 1977. [Utilizes chemical data to solve some taxonomic problems in the genus. ] K. E. Denrorp. An acrylamide gel electrophoretic study of the seed proteins of Brassica and Sinapis species, with boa referenc ce to their taxonomic value. Jour. Exper. Bot. 19: 724-732. 1968. [Se I maintaining both genera.] ,& . Gorpon. A study [ the seed proteins of Sarees Brassica Napus with respect to its aie Jour. Exper. Bot. 21: 892-898. 0. & E. I. Gor nomic study of Brassica juncea using me techniques of ee gas- ‘liquid ae ke and serology. Ann. Bot. II. 37: 167-183. 1973. —— , & D. Rosinson. The identification of myrosinase after the electropho- deste of Brassica and Sinapis seed proteins. Phytochemistry 7: 1345-1348. 1968 » J. 9. HeminGway, & H. J. ScHorietp. Contributions to a study of variation in Brassica j ee Coss. & Czern. Jour. Linn. Bot. 58: 435-447. 1963. [Two races recognized; seed-coat mucilage, isothiocyana AITE. Comparative Bees hea studies of the seed proteins of certain species of Brassica and Sinapis. Jour. Exper. Bot. 18: 100-109. 1967a. [Chemotax- onomic value.] & Comparative electrophoretic studies of the seed proteins of certain amphidiploid species of Brassica. Ibid. 269-276. 1967b. [Data support the amphi- ens origin of three species from three ancestral diploids.] ——., D. Bouter, & S. Warrers. Comparative studies of the seed proteins 1985] AL-SHEHBAZ, BRASSICEAE 305 of Brassica campestris, Brassica oleracea, and Brassica ees a Exper. Bot. 17: 332-343. 1966. [Serology, electrophoresis; globulins, album VERMA, S. C., & H. Rees. Nuclear DNA and the evolution of cilbeeaplola Brassicae. WALLBANK, B. E., & G. A. WHEATLEY. Volatile constituents from cauliflower and other crucifers. Phytochemistry 15: 763-766. 1976. [B. oleracea, B. Rapa, B. juncea, Raphanus, Cheiranthus.] Watson, A. G., & K. F. Baker. Possible gene centers for resistance in the genus Brassica to Plasmodiophora brassicae. Econ. Bot. 23: 245-252. 1969. [Suggest the western Mediterranean area as the center.] Watts, L. E. Levels of compatibility in Brassica oleracea. Heredity 23: 119- 125. 1968. WELLINGTON, P. S., & C. E. QuartLey. A practical system for classifying, naming and pepures some cultivated brassicas. Jour. Natl. Inst. Agr. Bot. (U. K.) 12: 413- 432. acai ‘s é The names of three species of Brassica. Rhodora 40: 306-309. 1938. [Proposes three combinations in Brassica for taxa now assigned to Hirschfeldia and Sinapis. Winter, B. E., & G. Bocquet. Brassica insularis Moris: example of a messinian pattern of distribution. (In German; English summary.) Candollea 34: 133-151. 1979. [Pro- pose section Lignosae to include 15 Mediterranean species of perennial brassicas.] Wicitams, P. H. Chemistry and breeding of cruciferous vegetables. Pp. 2 se in T. Swain & R. KLEIMAN, eds., The resource potential in phytochemistry. R ad- vances in phytochemistry. Vol. 14. New York. 1980. [Six cultivated ane of Brassica.] Yapava, J. S., J. B. CHowpuury, S. N. Kaxar, & H. S. NAINAWATEE. Sig aan electrophoretic studies of proteins and enzymes of some Brassica species. Theoret Appl. Genet. 54: 89-91. 1979. 4. Erucastrum K. B. Presl, Fl. Sicula 1: 92. 1826. Annual, biennial [or perennial] herbs [rarely subshrubs], usually with simple, appressed, retrorse [or spreading] trichomes [rarely glabrous]. Basal leaves in a rosette or not, petiolate, lyrately pinnatifid [sometimes pinnatisect, runcinate, or undivided]. Cauline leaves resembling the basal ones, usually less divided [rarely pectinate or pinnatisect], short petiolate [or sessile and sometimes au- riculate at base]. Inflorescence a terminal, bracteate [or ebracteate], corymbose raceme, conspicuously elongated in fruit. Sepals erect [or spreading], oblong [or linear], not saccate; outer pair sometimes cucullate, narrower than the inner one. Petals yellow or white, short [or long] clawed, obovate [rarely oblanceolate or oblong]. Nectar glands 4; lateral pair flat, prismatic or reniform; median pair usually ovoid [sometimes oblong or cylindrical]. Stamens tetradynamous; filaments not appendaged; anthers oblong or linear, obtuse at apex, sagittate at base. Ovary many ovulate; style distinct; stigma capitate, entire [rarely 2-lobed]. Fruiting pedicels slender lor stout], ae hea [sometimes erect and subappressed to rachis] Siliques linear, q arely subterete, torulose, glabrous [sometimes sparsely nilose or retrorsely eee subsessile [or oc- casionally borne on short gynophores]; valves somewhat keeled, with a prom- inent midnerve and slender, usually anastomosing lateral veins, obtuse or emarginate at apex; beak conspicuous [rarely obsolete], usually 3-nerved, seed- less [or 1- or 2- (or 3-)seeded], slender, stylelike [sometimes conical]. Seeds uniseriately arranged in each locule, oblong or oval [very rarely globose], usually reticulate, wingless, brown, slightly mucilaginous [or not] when wet; cotyledons longitudinally conduplicate, usually emarginate at apex. Base chromosome 306 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 numbers 7, 8, 9. (Including Conirostrum Dulac.) LECTOTYPE SPECIES: Sinapis virgata J. S. & K. B. Presl = E. virgatum (J. S. & K. B. Presl) K. B. Presl; see Maire, Fl. Afr. Nord 12: 204. 1965. (Name from Eruca, a genus of the Cru- ciferae, and astrum, indicating an incomplete resemblance.) A genus of about 20 species primarily distributed in the western Mediter- ranean region and in most of Africa (except the Sahara and the western part of the continent), with extensions into central and eastern Europe, the Canary Islands, and the Arabian peninsula. Many taxa are endemic to the Iberian peninsula and northwestern Africa, and a few species are indigenous to the Canaries (two), tropical East Africa (two), and South Africa (two). Erucastrum arabicum Fischer & Meyer, probably a native of Ethiopia, is a weed widely distributed in Africa, while £. nasturtiifolium (Poiret) O. E. Schulz and E. gallicum are native in southwestern Europe and naturalized in most of that continent. The last species was introduced to the New World about the turn of the century and has since become abundant in many parts of Canada and the United States. Erucastrum gallicum (Willd.) O. E. Schulz (Sisymbrium gallicum Willd., S. Trio L. var. gallicum (Willd.) DC., S. Erucastrum Poll., S. hirtum Host, E. Pollichii Schimper & Spenner, FE. vulgare Endl., E. inodorum Reichenb., £. ochroleucum Calestani), dog mustard, rocket weed, 2n = 30, has been reported from several localities in Dade and Palm Beach counties in Florida (Wunderlin) and from Caddo Parish in Louisiana (MacRoberts). The first report of EF. gallicum in North America was based on two independent introductions in Massachusetts and Wisconsin (Robinson). The species is naturalized in all the provinces of Canada and in many parts of the United States, particularly the Midwest, where it grows in fields, waste places, gardens, and orchards, on roadsides, and along railways. From the other crucifers of our area, E. gallicum is easily distinguished by having deeply pinnatifid basal leaves, retrorsely ap- pressed trichomes on the stem, pale yellow flowers, bracteate racemes, torulose linear siliques, strongly one-nerved valves, and slender, seedless beaks. Patman listed Erucastrum abyssinicum (Rich) O. E. Schulz as a cultigen in Florida, but it is very likely that the record is based on a misidentification of plants of Brassica carinata Braun that were collected by G. Killinger and E. West and distributed under the former name. The establishment of E. nasturtiifolium as a successful weed in North America needs confirmation. Although several earlier authors have reduced Erucastrum to a subgenus or a section of Brassica (De Candolle, 1821, 1824: Bentham & Hooker) or Hirschfeldia (Von Hayek), recent students of the Cruciferae maintain it as a genus intermediate between these two but more closely related to the former. No sections have been recognized in Erucastrum. The genus is distinguished by having usually quadrangular siliques; somewhat keeled, prominently one- nerved valves; oblong or oval, uniseriately arranged seeds; nonsaccate sepals; and occasionally bracteate inflorescences. Brassica differs in having terete or flattened siliques, convex valves, globose seeds, ebracteate inflorescences, and usually saccate inner sepals. The boundaries between the two genera are not always clearly drawn, and the distinction between them may rest on a single 1985] AL-SHEHBAZ, BRASSICEAE 307 character. Hirschfeldia can easily be confused with some species of Erucastrum that have swollen beaks and subappressed siliques, but it is recognized by its erect sepals and three-veined siliques. The venation of valves is a difficult character to assess in mature fruits of Hirschfeldia, and young siliques are more useful for this purpose. Chromosome numbers are known for at least 14 species of Erucastrum, and more than half of the taxa are based on eight. Diploid (2” = 16) and tetraploid infraspecific taxa are found in E. rifanum (Emberger & Maire) Gomez-Campo, E. nasturtiifolium, and E. leucanthemum Cosson & Durieu, while diploids, tetraploids, and hexaploids (based on eight) occur in E. /ittoreum (Pau & Font Quer) Maire. Octoploidy has recently been reported in E. meruense Jonsell (2n = 64), a species endemic to Tanzania. Both E. gallicum and E. elatum (Ball) O. E. Schulz have 2n = 30 and appear to be amphidiploids. Harberd & McArthur observed eight bivalents in the triploid hybrids obtained from cross- ing E. gallicum with diploid plants of E. nasturtiifolium and have suggested that the former is an allotetraploid that may have originated from a parent (with n = 8) very closely related to the latter and from another diploid, not yet determined, having n = 7. No experimental evidence supports the amphidip- loid origin of E. elatum, but according to Gomez-Campo (1983), its putative parents probably are very close to E. littoreum (n = 8) and either £. virgatum or Hirschfeldia incana (L.) Lagréze-Fossat (both with = 7). Erucastrum abyssinicum (n= 16) apparently has unselective stigmas that allow foreign pollen from unrelated genera of the Brassiceae to germinate and penetrate the style (Harberd, 1976). The triploid hybrids, obtained from crossing this species with several unrelated diploids, always have eight bivalents in meiosis—an indication of the autotetraploid origin of E. abyssinicum. No diploid popula- tions, however, have been found in this species, but the closely related E. arabicum and E. pachypodum (Chiov.) Jonsell are diploids. Seeds of a few species have been analyzed for glucosinolates and fatty acids. Large amounts of allylglucosinolate and traces of three other compounds have been identified from Erucastrum gallicum, while 3-methylsulfinylpropyl and 3-methylthiopropyl glucosinolates are the major components in E. abyssini- cum. Nearly 52 percent of the fatty-acid composition of E. cardaminoides (Webb) O. E. Schulz is erucic acid, which makes the species a potentially useful source of industrial oils. Except for the three weedy species mentioned above, the genus has very little economic importance. Erucastrum arabicum is occasionally grown in Ethiopia for seed oils, and the leaves are used as a vegetable. REFERENCES: Under family references in AL-SHEHBAZ (Jour. Arnold Arb. 65: 343-373. 1984), see BAYER: BENTHAM & HooKER; BERGGREN; De CANDOLLE (1821, 1824); Von HAYEK; MUENSCHER: MULLIGAN ( 1957): Mur ey: PATMAN; POLATSCHEK; QUEIROS; Roiuins(1981): SAMPSON; and SCHULZ. Under tribal references see BENGOECHEA & GOMEZ-CAMPO, CLEMENTE & HERNAN- 308 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 DEZ-BERMEJO (1980a—d), ETTLINGER & THOMPSON, GIBERTI, GOMEZ-CAMPO (1978; 1980a, c), GOMEz-Campo & Hinata, GOmeEz-Campo & TorTosa, HARBERD (1972, 1976), HAR- BERD & McARTHUR (1980), KUMAR & TsuNopA, MAcCRopserts, Rytz, SCHULZ (1919), SIKKA & SHARMA, TAKAHASHI & SUZUKI, TAKAHATA & HINATA (1980), and WUNDERLIN. BLAKE, S. F. Erucastrum Pollichii in West Virginia. nee a 26: 22, 23. 1924. LE. gallicum from Vermont, North Dakota, and Minnesota.] . Erroneous record of Diplotaxis erucoides from ana ee oe Ibid. 55: 291, 292. 1953. [E. gallicum from Glacier National Park, Mon GOMEz- sate C. Studies on Cruciferae: IX. Erucastrum rifanum ee & Maire) ez-Campo, comb. nov. Anal. Jard. Bot. Madrid 38: 353-356. 1982. [Geography, ne taxonomy; a new variety.] . Studies on Cruciferae: X. Concerning some west Mediterranean species of Eru- castrum. Ibid. 40: 63-72. 1983. [E. virgatum, E. littoreum, E. elatum: several new sas va ee ] Stu n Cruciferae: XI. Erucastrum ifniense Gomez-Campo, sp. nov its allies. gy 41, 83-85. 1984. — to four species with n = 9; E. oe Gomez-Campo, stat. & com Grou, H. Some recently noticed ae Sci. Agr. Ottawa 13: 722-727. 1933. [E. gallicum, 722-725. Range extensions for some crucifers. Canad. Field-Nat. 55: 54, 55. 1941. [E. gallicum occurring in all provinces of Canada. JONSELL, B. New taxa of Cruciferae from East Tropical Africa and Madagascar. Bot Not. 132: 521- ay 1979. [E. elgonense and E. meruense, spp. nov.; chromosome numbers; 528-5 KIRSCHNER, J., J. eae & J. SrEpANKovA. In: A. Live, ed., IOPB chromosome number reports LX XVI. Taxon 31: 574-598. 1982. [E. gallicum, 2n = 30; E. nas- turtiifolium, 2n = 16; 574. EMOW, K. M., & D. J. RAyNAL. Population biology of an annual plant in a temporally variable habitat. Jour. Ecol. 71: 691-703. 1983. [E. gallicum, survival, seed pro- duction ranging from 24 to 1675 seeds per plant.] Kotov, see I. Species of Erucastrum oo to the Ukrainian flora. (In Ukrainian.) kr. Bot. Jour. 15(no.?): 83-86. 8.* LarRsEN, K. Cytological and ea studies on the aia plants of the Canary Islands. Biol. Skr. 11(3): 1-60. 1960. [E. canariense, 5, pl. 1, fig. 17. ontribution to the cytology of the ie Canarian Glemient, Il. Bot. Not. 116: 409- 424. 1963. [Erucastrum, 409-41 PopenoE, J., & D. B. Warp. Three additions : the flora of Florida. psi Scientist 41: 24. 1978. [E. gallicum from several localities near Miami, Dade County.] Rosinson, B. L. Erucastrum Pollichii adventive in America. Rhodora 13: 10- 12.1911. [First record of E. gallicum.] Scuinz, H., & A. THELLUNG. Weitere Beitrige zur Nomenklatur der Schweizerflora VII. Vierteljahrsschr. Naturf. Ges. Ziirich 66: 257-310. 1921. [Erucastrum, 276-282. ] STANDLEY, P. C. Records of United States plants, chiefly from the hes region. Rhodora 34: 174-177. 1932. [E. gallicum from Indiana and Montana.] VINDT, J. Les earns d’Erucastrum varium Dur. Compt. Rend. Se Sci. Nat. Phys. Maroc. 5: 96-99. a VIVANT, J. Eruc ees nasturtiifolium (Poiret) Schulz ssp. Sudrei Vivant, ssp. plante méconnue des Pyrénées occidentales et centrales. Bull. Soc. Bot. eee 124. 231-236. 1977 5. Hutera Porta, Atti Imp. Regia Accad. Rovereto, II. 9: 109. 1891. Annual, biennial, or perennial herbs with well-developed taproots [or much- branched rhizomes], sparsely to densely hispid [or glabrous]. Stems erect [rarely 1985] AL-SHEHBAZ, BRASSICEAE 309 procumbent], simple or branched at base. Basal leaves in a rosette [or not], usually long petiolate, pinnatipartite or pinnatisect, with 3-10 pairs of lateral lobes [rarely undivided], entire, repand, or dentate. Cauline leaves petiolate, with fewer and narrower lobes than the basal ones [or undivided]. Inflorescence an ebracteate, corymbose raceme, greatly elongated in fruit. Sepals erect, obtuse, setulose below the apex [or glabrous]; outer pair narrowly oblong; inner one broader, saccate at base. Petals long clawed, obovate [rarely oblong or elliptic], obtuse [rarely emarginate], yellow [or white], usually with dark brown or violet veins; claws slender, usually longer than the sepals. Lateral nectar glands flat, median ones cylindrical [or absent]. Stamens tetradynamous; anthers linear [or oblong], sagittate at base, usually recurved at apex. Ovary many ovulate; style very short; stigma capitate, 2-lobed. Siliques linear, subsessile, torulose [or not], 2-segmented [very rarely transversely jointed], spreading, erect, or re- flexed; lower segment dehiscent, terete [or slightly 4-angled], usually many seeded, with 3- or 5-nerved valves; upper segment (beak) indehiscent, persis- tent, 1-6-seeded, as wide as [or wider] and shorter [or equaling to longer] than the lower segment, linear [or oblong or ovoid], smooth [or torulose to monili- form], ensiform [very rarely inflated and corky]. Seeds uniseriately arranged in each locule, globose, dark brown to black, reticulate, wingless, slightly mu- cilaginous [or usually not] when wet; cotyledons longitudinally conduplicate, emarginate. Base chromosome number 12. (Including Brassicella Fourr. ex O. E. Schulz, Coincya Rouy, Rhynchosinapis Hayek.) Type species: H. rupestris Porta. (Name honoring Rupert Huter, 1834-1919, an Austrian clergyman, amateur taxonomist, plant collector, and distributor of exsiccatae.) A genus of 12 species distributed in southern and southwestern Europe, particularly the Iberian peninsula, with two species endemic to western and southwestern Britain, one to northern Greece, and one to northwestern Africa. The genus is represented in North America by the naturalized weed Hutera Cheiranthos (Vill.) Gomez-Campo (Brassica Cheiranthos Vill., Rhynchosinapis Cheiranthos (Vill.) Dandy, Coincya Cheiranthos (Vill.) Greuter & Burdet), 2 = 24, 48, a native of western Europe. It is extremely variable, with several sub- species recognized. The species was first recorded from the New World in 1880 (Brown). It is locally common in pastures and on roadsides in Jackson and Yancey counties, North Carolina (Ahles & Radford; Rollins, 1961) but has not yet been reported from the other states of the Southeast. It is easily distinguished from other crucifers of our area in having pubescent, pinnatisect basal leaves; erect sepals; long-clawed, dark-veined yellow petals; siliques 3-8 cm long; three- veined valves; and ensiform, one- to three-seeded beaks 8-22 mm long. Rad- ford and colleagues have listed the species as Brassica Erucastrum L., but according to Pugsley, this name is based on immature plants of Raphanus Raphanistrum L. Both Hutera and Coincya were published in October, 1891, but the former was published five days earlier (Lacaita, Gonzalez-Albo). Heywood recognized both Hutera and Rhynchosinapis and separated them by their siliques, which are transversely jointed in the former but not so in the latter. However, the extensive morphological (G6mez-Campo, 1977a; Clemente & Hernandez-Ber- mejo, 1980a—d; Gémez-Campo & Tortosa) and cytological (Harberd, 1972; 310 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Harberd & McArthur, 1972) data strongly support merging Rhynchosinapis with Hutera. Although Hutera has been associated with Brassica, Erucastrum, Hirsch- feldia, and Erucaria, its nearest relative is probably Sinapis, which it resembles in having three- or five-veined valves, similar chromosome numbers (x = 12), globose seeds, and well-developed, usually ensiform, few-seeded beaks. From Sinapis, Hutera is easily distinguished by its erect, saccate sepals and its dark- veined petals. The relationship between Hutera and Brassica is somewhat remote. The latter has one-nerved valves, seedless or few-seeded, nonensiform beaks, and chromosome numbers that are never based on 12. Little is known about the floral biology of Hutera. Knuth suggested that the flowers of H. Cheiranthos (listed as Sinapis) form long floral tubes (ca. 1 cm) by the close coherence of the sepals and petal claws and are therefore adapted to pollination by Lepidoptera, such as members of the butterfly genus Antho- charis. Cross-pollination occurs as the insect probes its proboscis between the anthers of the median stamens and touches the stigma before reaching the nectar that accumulates in the pouches of the lateral sepals. According to Knuth, the large median nectaries do not secrete nectar but the small lateral ones do. Chromosome numbers have been reported for all species of Hutera, and all except H. nivalis (Boiss. & Heldr.) Gbmez-Campo are diploids or tetraploids based on 12. Although this species has 2m = 20 (Strid & Franzén), further counts are needed to establish whether or not such a number is constant for it. Tetraploidy is known in H. Johnstonii (Samp.) Gomez-Campo and in some subspecies of H. pseudoerucastrum (Brot.) Gomez-Campo and H. Cheiranthos. The last species was first known as a tetraploid, and on the basis of its forming 24 bivalents at meiosis, Sikka suggested that it is an allotetraploid derived from H. Wrightii (O. E. Schulz) Gomez-Campo and H. monensis (L.) Gomez- Campo. However, the discovery of diploid populations in H. Cheiranthos (Favarger, 1965) and bivalent-forming autotetraploids in Hutera (Harberd, 1976) do not support Sikka’s hypothesis. Although natural hybridization has not yet been reported in Hutera, artificial crossing between H. Cheiranthos and H. monensis and between each of these and H. hispida (Cav.) Gomez-Campo, H. longirostra (Boiss.) Gomez-Campo, and H. leptocarpa Gonzdlez-Albo show an almost complete bivalency in the hybrids (Harberd & McArthur, 1972). On the other hand, artificial intergeneric hybrids between Hutera and Brassica and between Hutera and Diplotaxis gave mean numbers of bivalents of 2.2-4.7 (Harberd & McArthur, 1980). The chemistry of Hutera is poorly understood. A single glucosinolate (5-methylthiopentyl) has been identified from the seedlings of H. monensis (Cole, 1976), and the fatty-acid composition of the seeds of H. Cheiranthos (listed as Brassicella Erucastrum), H. leptocarpa, and H. longirostra show a preponderance of linolenic and erucic acids, with substantial amounts of pal- mitic acid in the last species (Appelqvist, 1971; Kumar & Tsunoda, 1980). As in several genera of the Brassiceae, Hutera shows reductional trends in fruit length accompanied by elaboration of the beak. The ensiform beaks prob- ably aid in dispersal by animals. Beaks can persist for a few years in the soil, 1985] AL-SHEHBAZ, BRASSICEAE 311 and seed germination takes place only after their walls disintegrate or break open. Except for the weedy Hutera Cheiranthos, the genus has no economic im- portance. REFERENCES: Under family references in AL-SHEHBAZ (Jour. Arnold Arb. 65: 343-373. 1984), see AppELavisT (1971), Cote (1976), Von HAYEK, HEywoop, KNUTH, KUMAR & TsUNODA, Maire, MARKGRAF, QUEIROS, RADFORD ef al., ROLLINS (1981), SCHULZ, and VAUGHAN & WHITEHOUSE. Under tribal references see BENGOECHEA & GOmEZz-CAMPO, BERTOLI, CLEMENTE & HERNANDEZ-BERMEJO (1980a—d), ETTLINGER & THOMPSON, GOMEZ-CAMPO (1978; 1980a, BERD & MCARTHUR (1980), HERNANDEZ-BERMEJO & CLEMENTE, KUMAR & TSUNODA, Rytz, ScHuLz (1919), SikKKA & SHARMA, TAKAHASHI & SUZUKI, TAKAHATA & HINATA (1980), and Tsunopa. Under references for Brassica, see SIKKA. Au es, H. E., & A. E. RADForD. Species new to the flora of North Carolina. Jour. Elisha Mitchell Sci. Soc. 75: 140-147. 1959. [H. Cheiranthos (reported as Diplotaxis mu- ralis) abundant in Yancey County, ie see ROLuins, | Brown, A. Ballast plants in and near New York City. Bull. Torrey Bot. Club 7: 122- 126. 1880. [H. Cheiranthos (listed as ar from ballast near Hoboken, New Jersey, 123.] Cassip1, M. D. The status of ay cabbage, RAynchosinapis Wrightii. Ann. Rep. Lundy Field Soc. 31: 64-66. 1981.* Danby, J. E. Rhynchosinapis. Watsonia 4: 41, 42. 1957. [The nomenclature of H. FavarceEr, C. Notes de caryologie alpine IV. Bull. Soc. Neuchateloise Sci. Nat. 88: 5- 60. 1965. [H. Cheiranthos subsp. Cheiranthos (as Rhynchosinapis), 14, 2n = 24.] . Notes de ma alpine V. Ibid. 92: 13-30. 1969. [H. Richeri (as Rhyncho- sinapis), 20, ee? FERNANDEZ Casas, J. a meros cromosomicos de plantas espafiolas, II. Anal. Inst. Bot. Cavanilles 32, 301-307. 1975. [H. coincyoides (as Rhynchosinapis), 302-304, fig. 2, 2n = 24, Gomez-Campo, C. Clinal variation and evolution in the Hutera-Rhynchosinapis com- plex of the Sierra Morena (south-central Spain). Bot. Jour. Linn. Soc. 75: 179-194. 1977a. [Numerical analysis of four species; argues for merging Rhynchosinapis with Hutera, new combinations; key to taxa. . Studies on Cruciferae: II. New names for RAynchosinapis species under Hutera. pe ay Bot. a a 34: 147-149. 1977b. [Fifteen new combinations; see ER & BURDE oot J. Hutera Porta. Cavanillesia 6: 175-177. 1934. [H. leptocarpa, sp. nov.; H. rupestris.] [GREUTER, W., & H. M. Burpet.] Coincya. In: W. GREUTER & T. Raus, eds., Med- checklist aGtulae: 7. Willdenowia 13: 79-99. 1983. [Species of Pile: transferred GUTERMANN, W., F. EHRENDORFER, & M. FiscHer. Neue Namen und kritische Be- merkungen zur Gefdsspflanzenflora Mitteleuropas. Osterr. Bot. Zeitschr. 122: 259- 273. 1973. [H. Cheiranthos, 269, 270.] Harserp, D. J., & E. D. McArTHUR. Cyto-taxonomy of Rhynchosinapis and Hutera (Cruciferae- “Brassiceae). Heredity 28: 254-257. 1972. [Crosses between five species. ] 312 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Heywoop, V. H., & P. W. BALL. Taxonomic and nomenclatural changes in the Spanish flora. Feddes Repert. Sp. Nov. 66: 149- ra 1962. [New combinations in Rhyn- chosinapis, 154; see also ibid. 68: 196, 197. KIERNAN, J. A. RAynchosinapis—the Sara econ Watsonia 8: 293. 1971. [H. KUprer, P. Recherches cytotaxonomiques sur la flore des montagnes de la péninsule Ibérique. Bull. Soc. Neuchateloise Sci. Nat. 92: 31-48. 1969a. [H. Cheiranthos, 33, 40,415.27 = - awe, ——._I[n: , IOPB chromosome number reports XXII. Taxon 18: 433- 442, 1969b. iH. oo ena subsp. nevadensis, 437, 2n = 24. Lacaita, C. Novitia quaedam et notabilia hispanica. Cavanillesia 3: 20-47. 1930. [H. rupestris, 28, 29. LeADLeyY, E. A. The biology and systematics of the genus Hutera Porta. Unpubl. Ph.D. dissertation, Univ. Reading, U. K. 1978.* . HEywoop. Endemic species of Rhynchosinapis (Cruciferae). In: Con- ference report: Recent advances in the study of the British flora. (Abstr.) Watsonia 13: 71, 72. 1980. [Rhynchosinapis merged with Hutera; six species recognized, one with six subspecies and two varieties. ] Mareen, P. R. The Lundy cabbage. Ann. Rep. Lundy Field Soc. 22: 27-31. 1972.* [Another paper, ibid. 23: 51, 52. 1973.*] PuGs.ey, H. W. The Brassica of Lundy Island. Jour. Bot. London 74: 323-326. 1936. [The British species of Brassicella (= Hutera).] Ro .iins, R. C. A weedy crucifer again reaches North America. Rhodora 63: 345, 346. 961. [H. Cheiranthos, nomenclature, first report from North Carolina; see AHLES & RADFOoRD.] Rouy, G. Diagnoses d’espéces nouvelles ou peu connues pour la flore de la péninsule Ibérique. Naturaliste Paris, II. 13: 248. 1891. [Coincya, gen. nov.; relationships to Raphanus and Hemicrambe.] Srrip, A., & R. Franzén. In: A. Léve, ed., Chromosome number reports LX XIII. Taxon 30: 829- 842. 1981. [H. a 834, 2n = 20. VALDES-BERMEJO, E. Estudios cariolégicos en cruciferas espafiolas de los géneros Mor- icandia DC., Vella L., Carrichtera Adans. y Hutera Porta. (English summary.) Anal. Inst. Bot. Cavanilles 27: 125-133. 1970. [H. rupestris, 132, 2n = 24.] WRIGHT, F.R.E. The Lundy Brassica, with some additions. Jour. Bot. London 74(suppl.): 1-8, pls. 1-17. 1936. [H. Wrightii, H. Cheiranthos.] 6. Sinapis Linnaeus, Sp. Pl. 2: 668. 1753; Gen. Pl. ed. 5. 299. 1754. Annual [rarely perennial] herbs, glabrous or with simple, retrorse or spreading trichomes. Stems erect, leafy, often branched above. Basal leaves petiolate, usually not in a rosette, lyrate or pinnatifid to pinnatisect, rarely undivided [or bipinnatipartite], usually coarsely dentate; terminal lobe larger than the lateral ones. Upper cauline leaves short petiolate or sessile, entire or shallowly divided. Inflorescence an ebracteate, corymbose raceme, greatly elongated in fruit. Sepals yellowish, widely spreading, rarely reflexed, not saccate at base, oblong or linear, glabrous or sparsely [to densely] hispid or villous on the dorsal side. Petals yellow, obovate; claws nearly as long as the sepals. Nectar glands 4, the lateral ones prismatic, flat [rarely lobed], the median ones oval, usually not lobed. Stamens tetradynamous; filaments linear, not appendaged; anthers oblong, obtuse. Ovary sessile, glabrous or pubescent; style long; stigma large, 2-lobed. Fruiting pedicels slender or stout, straight [rarely curved], ascending to divar- icate [sometimes erect or recurved and appressed to rachis]. Siliques strongly 1985] AL-SHEHBAZ, BRASSICEAE 213 beaked, linear or oblong, terete or somewhat flattened or angled, glabrous or hispid [or villous] with long trichomes and with or without much shorter, retrorse ones; lower (valvular) segment dehiscent, few to many seeded, usually torulose; valves convex, with 3-7 prominent veins, thin or thick [rarely hard- ened and inconspicuously veined]; upper segment (beak) indehiscent, 0- 2[-10]-seeded, straight [or recurved], terete or strongly compressed, ensiform or conical, thick [or corky], equaling or shorter [or much longer] than the lower segment, usually smooth [rarely torulose, ribbed, or tuberculate]. Seeds uni- seriately arranged in each locule, globose [very rarely slightly flattened], wing- less, mucilaginous or not when wet, pendulous in the valvular part, erect in the beak, yellow or brown, sometimes black, slightly to strongly reticulate or alveolate; cotyledons longitudinal duplicate, much wider than long, emar- ginate, glabrous or pubescent. Base chromosome numbers 7,9, 12. (Including Agrosinapis Fourr., Bonannia K. B. Presl, Leucosinapis Spach, Rhamphosper- mum Andrz. ex Besser, Sinapistrum Chev.) Lecroryre species: S. alba L.; see Britton & Brown, Illus. Fl. No. U. S. ed. 2. 2: 191. 1913. (Name from Greek sinape or sinapi, mustard, in reference to the flavor of the seeds.) —CHARLOCK, MUSTARD. A genus of seven species, all except Sinapis Aucheri (Boiss.) O. E. Schulz, an endemic of western Iran and eastern Iraq, native to the Mediterranean region. Two species are indigenous to Egypt, and two others are restricted to southwestern Europe and northern Africa. Both S. alba and S. arvensis L. are weeds widely naturalized throughout the world. They occur in all the South- eastern States in gardens, grainfields, cultivated land, waste places, and dis- turbed grounds, on roadsides, and along railroad tracks. Four well-defined sections have been recognized by Schulz (1919). Section Sinapis (sect. Leucosinapis DC.) (annuals; siliques generally with long, spread- ing trichomes usually mixed with more numerous short, retrorse ones, rarely glabrescent; beaks ensiform; seeds mucilaginous when wet) contains S. flexuosa Poiret of southern Spain and northwestern Africa and S. alba L. (Brassica alba (L.) Rabenh., B. hirta Moench), white mustard, yellow mustard, 2n = 24, prob- ably native to the Mediterranean region and Crimea. The latter is distin- guished by the sectional characters above and by its dissected lower leaves and short (2-4 cm) siliques with two- to four-seeded locules. Section CERATOSINAPIS DC. (annuals; siliques glabrous, rarely sparsely hispid; beaks conical, straight, one- or two-seeded; seeds many, not mucilaginous when wet) includes the cosmopolitan weed Sinapis arvensis and the Egyptian en- demics S. Allionii Jacq. and S. turgida (Pers.) Delile. Sinapis arvensis L. (Bras- sica arvensis (L.) Rabenh., B. sinapistrum Boiss., S. orientalis L., S. Kaber DC., B. Kaber (DC.) Wheeler, S. Kaber var. pinnatifida (Stokes) Wheeler), charlock, field kale (Muenscher), wild mustard (Small), less commonly known as field mustard, crunchweed, and California rape, 2n = 18, is one of the most widely distributed weedy crucifers in our area. It can easily be recognized by its subsessile cauline leaves, spreading sepals, strongly three-nerved valves, and conical, one- or two-seeded beaks. The two remaining sections are monotypic, and neither is represented in our flora. Section ERIOSINAPIS Cosson contains Sinapis pubescens L., 2n = 18, in- 314 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 digenous to northern Africa, Italy, Sicily, and Sardinia and easily recognized by its perennial habit and villous siliques with recurved beaks. Sinapis Aucheri of sect. CHONDROSINAPIS O. E. Schulz is anomalous in the genus because of its long, torulose, corky, six- to ten-seeded beaks and its haploid chromosome number of seven. Sinapis can be separated from its closest allies in the Brassiceae by its com- bination of nonsaccate sepals; uniformly colored yellow petals; and strongly beaked fruits with one- or two- (to ten-)seeded beaks, three- to seven-veined valves, and uniseriately arranged globose seeds. It is closely related to Hutera, from which it is distinguished by its spreading, nonsaccate sepals and its lack of dark venation in the petals. Recent North American authors follow Bailey and Wheeler by merging Sinapis with Brassica, while botanists elsewhere main- tain both genera. The latter has one-nerved valves and erect to ding (rarely spreading) sepals, with the lateral pair usually saccate. The two genera also differ in their mustard oils and seed proteins. However, in lipid content S. arvensis shows more affinity to Brassica than does S. alba (Appelqvist, 1976), and some authors (e.g., Takahata & Hinata, 1980) have suggested that S. arvensis may be the connecting link between the two genera Numerous infraspecific taxa have been recognized in Sinapis pubescens, S. arvensis, and S. alba, but the majority of them are based primarily on characters such as the amount of pubescence, the orientation of the fruits, the lobing of the lower leaves, and the color of the seeds, all of which exhibit continuous variation that may be encountered within the same population. Therefore, no subordinate taxa are recognized here for plants of the last two species. Because the sepals are spreading, the nectar in Sinapis may appear to be accessible to insects from the side of the flower. However, the dense grouping of the flowers makes it more convenient for sizeable insects to approach the nectar from the top of the flower, thus effecting pollination. The flowers of S. alba and S. arvensis have highly patterned ultraviolet reflectance and differ in the shape of their nectar guides (Horovitz & Cohen). More than 60 species of bees, butterflies, flies, and wasps have been recorded by Fogg and Knuth as visitors of the latter species, which is a very important source of nectar and pollen for honey bees (Apis mellifera) in fields that it heavily infests. The flowers of S. alba are odoriferous and secrete abundant nectar with a sugar concen- tration of 60 percent (Free). These floral adaptations (including the ultraviolet pattern) clearly contradict Hemingway’s suggestion of pollination by wind in . alba. The sectional classification of the genus is supported by data on chromosome numbers. Members of sect. Sinapis have n = 12, and those of sects. ERIOSINAPIS and CerATOosINAPIs have 1 = 9, while sect. CHONDROSINAPIS has n = 7. Easterly (1963) has reported n = 8 and n= 16 for Sinapis arvensis, but the counts probably are erroneous and have not been reported again. Naturally occurring polyploids have not been found in the genus. Mukherjee described the karyo- type of S. alba (as Brassica alba) as consisting of one pair of long chromosomes with two constrictions and 11 pairs of short chromosomes with median or submedian constrictions. Both Sinapis alba and S. arvensis have been thoroughly surveyed for sterols, 1985] AL-SHEHBAZ, BRASSICEAE aD fatty acids, tycophenols, paraffins, mustard oils, alkaloids, flavonoids, and seed proteins, but the other species of the genus have received only minimal attention in chemical studies. The two species contain 4-hydroxybenzylglucosinolate, which has not been found in the typical members of Brassica (see the treatment of this genus). Smaller amounts of 3-butenyl and 2-phenylethy] glucosinolates are found in Sinapis, but these are more abundant in Brassica. Other chemical differences, particularly in seed proteins, support the maintenance of Sinapis as a genus distinct from Brassica. In seed-coat anatomy Sinapis arvensis resembles several species of Brassica and Hutera: all have a nonmucilaginous epidermis followed by radially elon- gated palisade cells. In S. alba two layers of subepidermal collenchyma are located between the mucilaginous epidermis and the isodiametric palisade cells (Vaughan & Whitehouse). The seed coat is coarsely reticulate in S. a/ba and minutely so in S. arvensis (Mulligan & Bailey, 1976), although Murley listed the former as having alveolate seeds, and Berggren indicated that both have an indistinct reticulum. Sinapis arvensis is one of the most obnoxious weeds, and it is notoriously difficult to eradicate from crop fields. Factors contributing to its success and persistence in arable land include the immense productivity (estimated at a maximum of 25,000 seeds per plant (Markgraf)), the seed longevity (up to 75 years (Vaughan & Hemingway)—exceedingly high for a crucifer), the enforced dormancy when the seeds are buried at depths of many centimeters, the rapid germination when the seeds are exposed to favorable conditions, and the high relative growth rates of its vegetative organs (Fogg). The ability of the seeds to remain viable in the droppings of birds that feed on them probably plays an important role in the natural dispersal of S. arvensis. The seeds contained in the beak of the fruit may not germinate until the beak has rotted. Sinapis alba subsp. dissecta (Lag.) Bonnier, a weed of flax fields in the Mediterranean region and Crimea but not yet introduced to our area, differs from subsp. a/ba in having bipinnatifid leaves, slender growth, glabrous or very sparsely pubescent siliques and stems, and flattened, reddish brown seeds. All these features have their analogues among other flax weeds and, according to Hjelmqvist, may have evolved through the selection of flax characters. It is quite difficult to remove the seeds of S. alba subsp. dissecta from those of flax (Linum usitatissimum L.) by winnowing because of their similarity in shape, weight, and size (Malzev). The seeds of Sinapis alba are used for the manufacture of table mustard (see Brassica) and for the production of oils for making soap and mayonnaise, lubrication, and cooking (Vaughan & Hemingway). The seed cake contains 25— 35 percent protein, and because of its high nitrogen content it is used as a fertilizer. The seeds of S. arvensis are used in eastern Europe for making poor- quality table mustard, while the young green parts are eaten as a salad in some parts of the Caucasus. The whole plant also is used as a green fodder. The seeds have been used as a carminative, a diuretic, an emetic, an expec- torant, a stimulant, a rubefacient, and a diaphoretic; as a remedy for bronchitis and dyspepsia; and in the preparation of an ointment to relieve neuralgia, arthritis, and rheumatism (Perry, Rosengarten). Hartwell has listed Sinapis 316 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 alba asa source for p ti to cure t , sarcoma, carcinoma, endotheli- oma, and indurations of the skin. Sinapis arvensis reduces the yield of some cereals (and probably other crops) to 53-69 percent in heavily infested fields (Mulligan & Bailey, 1975). Feeding on S. alba and S. arvensis may cause gastroenteritis, diarrhea, and irritation of the upper digestive tract and mouth of cattle and sheep, and the two species have been suspected of evoking phot itis (Kingsbury; Mitchell & Rook). In addition to being obnoxious weeds, these species are hosts for viruses and fungi that also attack many cruciferous vegetable crops. REFERENCES: Under family references in AL-SHEHBAz (Jour. Arnold Arb. 65: 343-373. 1984), see AL-SHEHBAZ & AL-OMAR; AppPELQvisT (1971, 1976); ARYAVAND; BAYER; BERGGREN: AN; BRITTON & BROwn; BUNNING; DE CANDOLLE (1821, 1824); CoLe (1976); Crisp; EASTERLY (1963); E1GNeR; HARTWELL; Hasapis et al; VoN HAYEK: HEBEL; HEDGE & A MUENSCHER, MUKHERJEE; Mur_ey; Perry; POLATSCHEK; QuEIROS; ROLLINS (1981); SCHULZ, SHIVANNA et al.; SMALL; VAUGHAN, PHELAN, & DENFORD; and VAUGHAN & WHITEHOUSE. Under tribal references see ApPELQvIST, BAUCH, BENGOECHEA & GOMEZ-CAMPO, BER- TOLI, CLEMENTE & HERNANDEZ-BERMEJO (1980a—d), CURRAN, ETTLINGER & THOMPSON, FINLAYSON, FREE, GOMEZ-CaAmpo (1978b; 1980a, c), GOmMEz-CAMPo & HINATA, Goues-Caniro & Tortosa, HARBERD (1972, 1976), HARBERD & McCARTHUR (1980), HERNANDEZ-BERMEJO & CLEMENTE, KUMAR & TSUNODA, MITCHELL & ROOK, MIZUSHIMA (1980), Roberts & BoppRELL, Rytz, SCHULZ (1919), SIKKA & SHARMA, SINSKAIA, TAKA- HASH] & SUZUKI, TAKAHATA & HINATA (1980), bead. UcHIMIYA & WILDMaN, VAUGHAN, VAUGHAN & HEMINGWAY, WILLS, and YARNE Under references to Brassica, see ANDERSSON & OLSSON; APPELQVIST (1968a); APPEL- gvist et al.; AUGUIERE et al.; BAILEY (1922); DURKEE & HARBORNE; HEMINGWAY; MULLI- GAN & BaILey; MusiL; NeLson; OLsson (1960a, c); ROSENGARTEN; SIKKA! STORK ef al.; VAUGHAN (1968, 1977); WaAUGHAN & DENFORD; VAUGHAN, GORDON, & ROBINSON; VAUGHAN & Waite (1967a); and WHEELER. Arex, J. F. Competition of Saponaria Vaccaria and Sinapis arvensis in wheat. Canad. Jour. Pl. Sci. 50: 379-388. 1970. [Experimental plots.] BAGNARD, C. Inflorescence and reversion in Sinapis alba. 11. Morphological character- istics of reversion carrier plants. (In French; English summary.) Canad. Jour. Bot. 58: 2335-2342. 1980. [Photoperiodic changes lead to the formation of bracts or anomalous structures in the inflorescence.] BalLey, K., & F. W. Norris. The nature and composition of the mucilage of the seed of white mustard (Brassica alba). Biochem. Jour. 26: 1609-1623. 1932. Basas, Y. P. S., & M. Bopp. Growth and reer formation in Sinapis alba tissue cultures. Zeitschr. Pflanzenphysiol. 66: 378-381. 1972. BALESTRINI, S., & N. VIRTANIAN. aie variability in morphogenetic reaction to drought stress of the root system a Sinapis alba L. (In French; English summary.) Bull. Soc. Bot. France 130: 27-32. Bazzaz, F. A., & J. L. Harper. eee nship between plant weight and numbers in mixed populations of Sinapsis alba (L.) Rabenh. [sic] and Lepidium sativum L. Jour. 1985] AL-SHEHBAZ, BRASSICEAE 317 Appl. Ecol. 13: 211-216. 1976. [Experimental plots; L. sativum has the highest mortality rate; S. alba, the most growth. BERGFELD, R., T. KUHNL, & P. ScHoprFER. Formation of protein pate bodies during embryo ogenesis in cotyledons of Sinapis alba L. Planta 148: 146- 980. BERNIER, G. Sinapis alba L., a new long- a plant requiring a sae photoinductive cycle. ere contenafien, 50: 101. 1 _ J.-M. Kinet, A. JacgmMarp, A. HAVELANGE, & M. Bopson. Cytokinin as a possible component of the floral stimulus in Sinapis alba. Pl. Physiol. 60: 282-285. 1977. BoeLckE, O. Una variedad de Sinapis arvensis adventicia en Balcarce. (English sum- mary.) Revista Argent. Agron. 16: 168-172. 1949. [S. arvensis var. Schkuhriana.] ee I. H. Inhibition of germination of the white mustard (Brassica hirta) by bryony mus communis) juice. Proc. Linn. Soc. London 169: 62, 63. 1958. Care, I. Isolation and characterization of satellite DNA from mustard seedlings. PI. Evol. 133: 1-13. 1979. [S. atba.] ne S., O. Otsen, & H. SoreNSEN. 4-Hydroxybenzoylcholine: a natural product present in Sinapis alba. Phytochemistry 21: 917-922. 1982. Dace, W.T., & L.I. Scott. Structural characteristics of the testa in Capsellaand Sinapis. Proc. Leeds Philos. Lit. Soc. Sci. Sect. 4: 111-122. 1943. [Mucilage deposition in epidermal cells.] Epwarps, M. M. Dormancy in seeds of charlock. I. Developmental anatomy of the seed. Jour. Exper. Bot. 19: 575-582. 1968. [Other parts of the series are: II. The influence of the seed coat. [bid. 583-600; III. Occurrence and mode of action of an inhibitor associated with dormancy. /bid. 600-610; IV. Interrelationships of growth, oxygen supply and concentration of inhibitor. /bid. 20: 876- 894. 1969. ae of the population ecology of charlock. Jour. Appl. Ecol. 17: 151-171. 1980. [Permanent quadrats, experimental plots; seedling emergence; death rate; relationship of climate to the reproductive capacity.] Foaa, G. E. Biological flora of the British Isles. Sinapis arvensis L. Jour. Ecol. 38: 415- 429. 1950. HyeLmovist, H. e flax weeds and the origin of cultivated flax. Bot. Not. 1950: 257- 298. 1950. ni ha subsp. dissecta, S. Allionii, 274-278. Hopre, W. Befruchtungsregulierung und ihre Wirkung bei der Ziichtung von Senf (Sina- pis alba). ae 28: 60-62. 1958 JosEFSsON, E. Content of p-hydroxybenzylglucosinolate in seed meals of Sinapis alba as affected by aes ae environment and seed part. Jour. Sci. Food Agr. 21: 94-97. 1970. Kinet, J. M. Sinapis alba, a plant requiring a single long day or a single short day for flowering. Nature 236: 406, 407. 1972. Lamp, R. J. Hairs protect pods of mustard (Brassica hirta ‘Gisilba’) from flea beetle feeding damage. Canad. Jour. Pl. Sci. 60: 1439, 1440. 1980. [S. alba, removal of hairs caused feeding damage by Phyllotreta cruciferae.] MacDonaLp, I. R., & J. W. Hart. An inhibitory effect of light on the germination of J Mauzev, A. I. Brassica dissecta Boiss. as a special weed of the flax sowings in the south of Russia. (In Russian; English summary.) Bull. Appl. Bot. 13(2): 277, 278. 1923. Mattick, F. Die Verbreitung des Hederich (Ackerrettich, Raphanus Raphanistrum, und Ackersenf, Sinapis arvensis) in Deutschland. Notizbl. Bot. Gart. Berlin 14: 1- 24. 1938. MuLLIGAN, G. A., & L. G. BAILEY. _ biology of Canadian weeds. 8. Sinapis arvensis L. Canad. Jour. PI. cig 55: 171-183. 1975. Otsson, G., & B. RUFEL Set crossing between diploid and tetraploid Sinapis alba. Hereditas 34: 351 365. 1948. 318 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 PHELAN, J. R., & J. G. VAUGHAN. Myrosinase in Sinapis alba L. Jour. Exper. Bot. 31: 1425-1433. 1980. [Three patterns of isoenzymes localized to different parts of plant.] REINHARD, E. Ein Vergleich zwischen diarchen und triarchen Wurzeln von Sinapis alba. Zeitschr. Bot. 44: 505-514. 1956 Rest, J. A., & J. G. VAUGHAN. The development of protein and oil bodies in the seed of Sinapis alba L. Planta 105: 245-262. 1972. [Aleurone and myrosin grains, oil bodies; light and electron microscopy.] ee @. H. Sinapidendron palmense (Brassicaceae) is Sinapis pubescens. Norweg. Bot. 27: 301-305. 1980. Sane D. J., & A. T. Witson. Studies of the early reactions in the germination of Sinapis alba seeds. Phytochemistry 7: 897-901. 1968. VAUGHAN, J. G., & E. I. Gorpon. Comparative serological studies of myrosinase from Sinapis alba and Brassica juncea seeds. Phytochemistry 8: 883-887. 1969. ViGFusson, E. On polyspermy in charlock (Sinapis ar ea L.). I. Fertilization studied by means of labelled pollen. Hereditas 70: 23-38. 1972. [Radioactivity in fertilized ovules suggests that as many as 33 pollen tubes Lee their contents in a single ovule. WERKER, E., & J. G. VAUGHAN. Anatomical and ultrastructural changes 1n caer and myrosin cells of Sinapis alba during germination. Planta 116: 243-255. & Ontogeny and distribution of myrosin cells in the shoot Sinapis alba L.:a light and rena -microscope study. Israel Jour. Bot. 25: 140-151. 1976. Witcomsg, J. R., J. R. HILtMAN, & W. J. WuittinGTon. Growth inhibitor in the seed coat of charlock. Nature 222: 1200, 1201. 1969. [Chemical nature of inhibitor was not elucidated; a of gibberellic acid on inhibitor. ] TINGTON. The effects of selection for reduced dormancy in charlock (Sinapis oe: Heredity 29: 37-49. 1972. [Black seeds showed nee rheneete than brown ones, effects of gibberellic acid on germination. Woops, D. L., & R. K. Downey. Mucilage from yellow mustard. Canad. Jour. Pl. Sci. 60: 1031-1033. 1980. [Seeds of S. alba contain 2 percent mucilage; variation in content among seeds from different sources. ] 7. Diplotaxis A. P. de Candolle, Syst. Nat. 2: 628. 1821. Annual or perennial herbs, sometimes woody at base, glabrous or with spreading or retrorse trichomes [rarely scabrous], sometimes glaucous. Stems erect or ascending [rarely procumbent]. Basal leaves petiolate, forming a rosette or not, pinnatifid to pinnatisect or lyrate to sinuate-dentate, rarely entire [or bipinnatipartite]. Cauline leaves present or absent, short petiolate or sessile [occasionally auriculate]. Inflorescence an ebracteate, corymbose raceme [rarely with lowermost flowers from axils of uppermost leaves], greatly elongated in fruit. Sepals oblong or linear, erect or spreading, obtuse or acute, sometimes scarious at margin, glabrous or with a subapical tuft of hairs [or hairy on entire abaxial side]; inner pair as wide as [or much wider than] outer pair, usually not [rarely strongly] saccate at base. Petals broadly [or narrowly] obovate, attenuate to short [or long] claws, usually yellow [sometimes violet, lilac, or white]. Nectar glands 4, the lateral pair flat, usually prismatic or reniform, the median pair filiform or oval [sometimes clavate], lobed or not. Stamens tetra- dynamous; filaments free, linear, not appendaged; anthers oblong, cordate or sagittate at base, all fertile [or rarely the lateral pair sterile], median ones introrse or extrorse. Ovary usually with very numerous (to 260) ovules; style short [or obsolete]; stigma capitate or conical, 2-lobed [sometimes the lobes decurrent]. Fruiting pedicels somewhat stout [or slender], erect-ascending to divaricate [or 1985] AL-SHEHBAZ, BRASSICEAE ais reflexed]. Siliques dehiscent, linear, torulose, compressed parallel to the septum [or terete], borne on short [or long] gynophores [or subsessile]; valves l-nerved, glabrous, somewhat thick [or membranaceous], obtuse or emarginate at apex; beaks 3-veined, seedless [or 1- or 2-seeded], narrower than [or as wide as] the valves, slightly flattened [or terete], cylindrical [or conical or obconical, rarely obsolete]. Seeds biseriately arranged in each locule, slightly compressed, usually very small (0.4-0.7(-1) mm long), ovoid, elliptic, or oblong, light brown, mi- nutely reticulate or smooth, wingless, not [or slightly] mucilaginous when wet; cotyledons longitudinally conduplicate. Base chromosome numbers 7, 8, 9, 10, 11, 13. (Including Pendulina Willk.) LecroryPe species: Sisymbrium tenuifo- lium L. = Diplotaxis tenuifolia (L.) DC.; see Britton & Brown, Illus. Fl. No. U.S. ed. 2. 2: 194. 1913. (Name from Greek, diplods, double, and taxis, row or arrangement, in reference to the two-rowed (biseriate) arrangement of seeds in each locule of the fruit.) —SAND ROCKET. About 25 species distributed in central Europe and the Mediterranean region, particularly in northwestern Africa, and extending eastward to Pakistan and western India, with a group of five species endemic to the Cape Verde Islands (Rustan & Borgen). Diplotaxis nepalensis Hara (isotype at A!), recently de- scribed from the Karnali Valley in western Nepal, extends the range of the genus much farther to the east. In nearly all aspects of the plant, D. nepalensis can easily be treated as a minor variant of the highly polymorphic D. Harra (Forsskal) Boiss., a species distributed from Morocco to Pakistan. At least four species are weedy in much of Europe, western Asia, and northern Africa. Of these, three have been brought to the New World as ballast plants during the last third of the nineteenth century; two are naturalized and sporadically dis- tributed in the southeastern United States. The sectional classification of Dip/otaxis has not been treated adequately. The four sections recognized by Schulz (1919) have been raised by Négre (see Markgraf) to three subgenera, of which two are monotypic. Characters such as the number of ovules, the length of the gynophore, and the orientation of the sepals have been emphasized in recognizing infrageneric groups in Diplo- taxis, but these may vary between the populations of a given species. Section DipLoTaxis (sect. Catocarpum DC.) (perennials, rarely annuals; se- pals spreading or ascending, not saccate at base; ovules (50-)80-150; gynophore (1-)2-8 mm long; beak obsolete, or seedless and to 2 mm long) is represented in our flora by D. tenuifolia (L.) DC. (Sisymbrium tenuifolium L., Sinapis tenuifolia (L.) R. Br., Brassica tenuifolia (L.) Fries), wall rocket, slim-leaf wall rocket, flixweed (Small), 2” = 22, a species native to southern and central Europe but naturalized elsewhere on that continent and in North America. Although D. tenuifolia has been reported from ballast and waste places in Florida, Alabama, and Louisiana (Small, Mohr), it has not been included in any of the recent plant checklists covering these states. It may have been overlooked, or it may have failed to become a successful weed in the Southeast. Plants of D. tenuifolia can easily be recognized; they are suffruticose perennials with pinnatipartite, petiolate cauline leaves, yellow petals two to three times longer than the sepals, and ascending siliques with seedless beaks and short gynophores 1-3 mm long. Section ANocARPUM DC. (annuals, rarely perennials: sepals spreading or 320 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ascending, equal at base; ovules 20-60; gynophores absent or to 1 mm long; beak 1- or 2-seeded, rarely seedless, conical or cylindrical) is represented in the southeastern United States by Diplotaxis muralis (L.) DC. (Sisymbrium murale L., Sinapis muralis (L.) R. Br., Brassica muralis (L.) Boiss.), sand rocket, stinking wall rocket, cross weed (Small), 2n = 42. A native of southern and central Europe, D. muralis is widely naturalized in Canada, the United States, and the West Indies, but is less so in Mexico and South America. It grows in disturbed sites, abandoned fields, waste places, and grasslands, and along beach- es and roadsides. Smith has reported it from Arkansas (Howard County), but earlier records from Alabama, Florida, and Louisiana have been based on ballast plants that may have failed to persist. The record of D. muralis from North Carolina was based on misidentification of plants of Hutera Cheiranthos (under Hutera see Ahles & Radford). From the other crucifers of our area, D. muralis can be distinguished by its annual habit, its rosette-forming, lyrately lobed or sinuately dentate leaves, its leafless or few-leaved stems, its yellow flowers, and its usually sessile, erect-ascending siliques 15-45 mm long with seedless beaks. Diplotaxis has been considered by Von Hayek and Rytz to be basal to the rest of the Brassiceae, and nearly all of the primitive characters suggested by Gémez-Campo (1980a) for the tribe are found in the genus. However, the relationships between Dip/otaxis and its nearest relatives of subtribe Brassicinae have not been established adequately. The genus has biseriate, small (usually less than | mm long), oblong or oval seeds; siliques with gynophores and one- nerved flattened valves; and two-lobed stigmas. Brassica can be separated from Diplotaxis by its larger, globose, and uniseriately arranged seeds. The bound- aries between the two, however, become less sharply defined if some north- western African taxa with subbiseriate seeds are considered. Sinapidendron differs from Dip/otaxis in its terete siliques, uniseriate seeds, and entire stigmas. The two species of sect. Hesperipium O. E. Schulz (D. acris (Forsskal) Boiss., of northern Africa and Arabia, and D. Griffithii (Hooker & Thomas) Boiss., of the Punjab, Afghanistan, and western Pakistan) resemble Moricandia in nearly all aspects of the flower and in certain features of the fruit. However, Moricandia differs from Dip/otaxis in lacking median nectaries and in having sessile, terete or tetragonal siliques and larger, usually margined or winged seeds. Little is known about the breeding systems and pollination ecology of Diplo- taxis, and the scant data indicate that a few species of flies, bees, butterflies, and beetles visit the flowers of D. muralis and D. tenuifolia (Knuth). The former is self-compatible, while the latter and D. erucoides (L.) DC. are usually self- incompatible. The last species was introduced to this country more than a century ago, but it appears to be restricted to a few places along the east coast north of our area. The median anthers of D. tenuifolia and D. muralis are extrorse, and in the latter they and the sepal tips reflect ultraviolet light, while the rest of the flower absorbs it (Markgraf). In D. acris the veins of the petals absorb UV light, but the rest of the blade reflects it (Horovitz & Cohen). Chromosome numbers are known for at least 20 species, and with the ex- ception of n = 12, which has not yet been found, a continuous series of haploid numbers from seven to 13 is present in Diplotaxis. Aneuploidy may have played an important role in the evolution of the genus. Species with n = 13 1985] AL-SHEHBAZ, BRASSICEAE S21 (D. Harra, its relatives, and the Cape Verdean species) are treated as diploids, and although Harberd (1976) agreed with that, he believed that they may have originated either by allotetraploidy between a species with 2n = 14 and an unrecorded one with 2n = 12, or by the aneuploid loss from tetraploids with 2n = 28. However, there is no evidence to support either of these hypotheses. Earlier chromosome counts deviating from 2” = 42 for D. muralis may have been erroneous. Harberd & McArthur (1972) have presented experimental evidence supporting the allotetraploid origin of this species from D. tenuifolia (2n = 22) and D. viminea (L.) DC. (2n = 20). Hybrids resulting from the cross D. muralis x D. tenuifolia almost always showed 11 bivalents and ten uni- valents at meiosis, while those obtained from D. muralis x D. viminea gave ten bivalents and 11 univalents. Furthermore, the occasional occurrence of reduced lateral stamens in D. muralis is most likely inherited from D. viminea— the only species in the genus with sterile and highly reduced lateral stamens. Natural interspecific hybrids in Diplotaxis appear to be very rare. Schulz (1919) described D. xSchweinfurthii from Egypt as a hybrid between D. acris and D. Harra and cited a few collections from Germany, Yugoslavia, and Sweden (see also Johansson) as hybrids between D. muralis and D. tenuifolia. Little experimental work has been conducted on interspecific hybridization in the genus, but extensive intergeneric crosses between Diplotaxis and Brassica, Erucastrum, Hirschfeldia, Hutera, Sinapidendron, and Sinapis have success- fully been made by Harberd (1976) and Harberd & McArthur (1980). Four species have been surveyed for glucosinolates. Diplotaxis viminea and D. tenuifolia have high concentrations of 4-methylthiobutylglucosinolate, but the latter also contains a few related nonvolatile compounds. Allylglucosinolate is the principal component in both D. erucoides and D. muralis. The scant chemical data show some differences between species. Analyses of the fatty- acid composition of ten species show that the pattern of Diplotaxis is distinct from that of the closely related Brassica. The latter has higher concentrations of erucic acid and usually lower amounts of linolenic and palmitic acids than does Diplotaxis. Diplotaxis has the smallest and lightest seeds in the Brassiceae. They are usually less than a millimeter long and may weigh as little as 0.05 mg (D. Harra), which is less than one two-hundredth the seed weight of some species of Cakile and Crambe that have the heaviest (10-15 mg) seeds in the tribe. Plants of D. acris and D. Harra produce enormous numbers (more than 200 per silique) of dustlike seeds that can easily be transported by strong winds for several hundred miles. Both species are widely distributed in the Sahara and in Arabia, and the latter species has an almost conti s distribution extending more than 7400 km (4500 mi) from Morocco to western Pakistan. No local uses have been reported for the genus, and except for the four weedy species mentioned above, Dip/otaxis has no economic importance. Mitchell & Rook mentioned that D. erucoides and D. tenuifolia have irritant properties. REFERENCES: Under family references in AL-SHEHBAZ (Jour. Arnold Arb. 65: 343-373. 1984), see Arser (1931b); BAEZ MAyor; BERGGREN; BRITTON & BROWN; De CANDOLLE (1821); Co.e (1976); Hasapis et al.; Von Hayek; HEywoop; Horovitz & COHEN; JARETZKY 322 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 (1932); KyAeR (1960); KNUTH; KUMAR & TsuNODA; MAIRE; MANTON: MARKGRAF; MIL- LER, EARLE, WOLFF, & JONES; MUENSCHER; MURLEY; POLATSCHEK; QUEIROS; ROLLINS (1981): SCHULZ; SMALL; E. B. SMITH; VAUGHAN & WHITEHOUSE; and VIEGI ef a Under tribal references see AL-SHEHBAZ (1978), BAUCH, BENGOECHEA & GOMEZ-CAMPO, CLEMENTE & HERNANDEZ-BERMEJO (1980a-d), ETTLINGER & THOMPSON, GOMEZ-CAMPO een 1980a, c), Gomez-Campo & Hinata, GOMEz-CAmpo & TORTOSA, HARBERD (1972, 76), HARBERD & McArtHur (1980), Kumar & TsUNODA, MITCHELL & Rook, Msn (1980) Rytz, SCHULZ (1919), SHIGA, SIKKA & SHARMA, TAKAHASHI & SUZUKI, TAKAHATA & HINATA (1980), TsuNoDA, and UcHimiya & Wii DN MAN. Amin, A. In: A. Love, ed., IOPB chromosome number reports XX XVIII. Taxon 21: 679-684. 1972. [D. acris, n= 11; D. Harra, n= 13; 679.] BeuAeva, L. E., E. A. CHAaskA, & N. S. Fursa. Development of anther, ovule and gametogenesis of Diplotaxis tenuifolia DC. (In Ukrainian; English summary.) Ukr. Bot. Zhur. 35: 175-179. 1978. Bou_os, L., & W. JALLAD. Studies on the ae of Jordan. I. Diplotaxis villosa sp. nov. (Cruciferae). Bot. Not. 128: 365-367. 5. Boynton, K. R. Diplotaxis tenuifolia. oe 3, 4. pl. 162. 1920. Brown, ' Ballast plants in and near New York City. Bull. Torrey Bot. Club 7: 122- 126. 1880. [D. muralis ae D. erucoides, 123. Caso, O. a Physiology 7 ie aan of Diplotaxis eg ee (L.) DC. (In Spanish; English summary.) B c. Argent. Bot. 14: 335-346. & M. R. Guirman, aoe of orientation of root ae | pies Si aes (L.) DC. on the origin of adventitious buds. (In Spanish: English summary.) D winiana 19; 520-527. 1975. Cresti, M., E. Pacini, & C. Simonciout. Uncommon paracrystalline structures formed in the ‘endoplasmic reticulum of the Pea cells of Diplotaxis erucoides ovules. Jour. Ultrastruct. Res. 49: 218-223. Deritipps, R. A. Diplotaxis tenuifolia in Mlinois ie other records. tee 66: 54, 55. 1964. [Also the distribution of D. muralis in Chicago-area cou DELAVEAU, P., & R. Paris. Sur la composition chimique de cons de Diplotaxis tenuifolia (L.) DC. Ann. Pharm. Frang. 16: 81-86. 1958. [Various parts of the plant yield 4-methylthiobuty] isothiocyanate. ] Dotya, V. S., K. E. Koresucuuk, & N.S. FuRSA. Morphological-anatomical study of fruit and meeds oo tenuifoia (L.). (In Ukrainian; English summary.) Farm. Zhur. Kiev 29(2): 67-70. 4. [Seed coat of four layers, the palisade layer with thickened inner tangential nate ] EL-SADEK, L. M., .M. AsHour. Chromosome counts of some Egyptian plants. Bot. Not. 125: 536. 1972. [D. viminea, n= 8; count deviating from 2n = 20 reported by other authors. J Eye, J. Hul : de Diplotaxis erucoides DC., Helleborus niger L, et Seid Compt. Rend. Acad. Sci. Paris, D. 262: 1629-1632. 1966, [Nectar accumulates in the endoplasmic reticulum of secretory cells and is then transported to the plasmalemma; : ls.] Fursa, N. S., & L. E. BELJAEVA. Qualitative composition and quantitative content of glycosides i in flowers of Aes ae (In Russian.) Rastit. Resm. 14: 387- 390. 1978.* GOMEz- oo C. Studies on Cruciferae: VII. Nomenclatural adjustments in Diplotaxis DC. Anal. Jard. Bot. Madrid 38: 29-35. 1981. [Morphological, cytological, and genetic data support the specific status of D. Siettiana and D. ibicensis instead of their treatment as subordinates of D. catholica: D. erucoides, D. virgata. Hara, H. New or noteworthy flowering plants from eastern Himalaya (14). Jour. Jap. Bot. 49: 129- 137. 1974. [D. nepalensis, sp. nov., 129-131, fig. 1.] 1985] AL-SHEHBAZ, BRASSICEAE 323 HARBERD, D. J. Diplotaxis DC. Pp. 139, 140 in C. A. Stace, ed., Hybridization and the flora of the British Ae Esai 1975. [D. muralis x D. fenuiolia= = D. x Wirt- genil; D. tenuifolia x D. viminea = D. muralis.] & E. D. McCARTHUR. The chromosome constitution of Diplotaxis muralis (L.) DC. Watsonia 9: 131-135. 1972. [The allotetraploid origin of D. muralis from D. tenuifolia and D. viminea.] IparRA, F. E., & J. LA Porte. Las cruciferas del género Diplotaxis adventicias en la Argentina. Revista Argent. Agron. 14: 261-272. 1947. [D. muralis, D. tenuifolia; ytology, descriptions, and distributions.] JOHANSSON, K. Tv a hybrider fran Gotland. Bot. Not. 1895: 166-171. 1895. [D. mu- ia. KasapuiciL, B. Additamenta ad floram Jordanicae. Jour. Arnold Arb. 47: 160-170. na [D. kerakensis, sp. nov.; isotype at A! is indistinguishable from D. Harra J. Muntinc. Pollen-germination and pollen tube growth in Diplotaxis pe after cross-pollination. Acta Bot. Neerl. 16: 182-187. 1967. [Electron ees ae 10 figs. LARHER, : HAMELIN. L’acide diméthylsulfonium-5 pentanoique de Diplotaxis ea Phytochemistry 18: 1396, 1397. 1979. Lippert, G. Vergleichende cytologische, morphologische und physiologische Unter- suchungen innerhalb der Gattung Diplotaxis. Beitr. Biol. Pflanzen 28: 254-295. 1951. [D. ee D. catholica, D. tenuifolia; D. muralis is a polyploid with n = 22 and 2n MARTINDALE, L ah introduction of foreign plants. Bot. Gaz. 2: 55-58. 1876. [D. tenuifolia and D. muralis listed as Brassica. Monur, C. Foreign plants introduced into the Gulf States. Bot. Gaz. 3: 42-46. 1878. [D. tenuifolia from Pensacola, Florida.] Mu Lucan, G. A. Chromosome numbers of Canadian weeds. II. Canad. Jour. Bot. 37: 81-92. 1959. [D. tenuifolia, 2n = 22. eee G. Citosistematica del gen. Diplotaxis L. (Cruciferae). Atti Mem. aa Naz. i. Lett. Arti Modena, VI. 10: 37-47. 1968. [D. Harra, n= 11; D. viminea, n= 10: discusses the cytology of ten species grouped in four sections.] NéGreE, R. Les Diplotaxis du Maroc, de l’Algérie et de la Tunisie. Mens Soc. Sci. Nat. Phys. Maroc. Bot. 1: 1-120. 1960.* Pacuéco, H. Biochimie comparée des pigments colorant les fleurs des Cruciféres. I. Diplotaxis cage Bull. Soc. Chim. Biol. 36: 667-674. 1954. [For part II see ibid. 37: 723-728. Pacint, E., S. Simoncioui, & M. Cresti. Ultrastructure of nucellus and endosperm of Diplotaxis erucoides during embryogenesis. Caryologia 28: 525-538. 1975. [Endo- sperm differentiation before and after cell formation; 19 figs.] Pevtier, J.-P. Contribution a l’étude de Diplotaxis erucoides (L.) DC. Ann. Fac. Sci. Mars eille 42: 243-269. 1969. [Effects of soil texture and chemistry on germination and development.] RussEL, W. Note sur la structure du Sinapidendron oma Bull. Mus. Hist. Nat. Paris, II. 7: 373, 374. 1935. [Leaf epidermis of D. g Rustan, @. H., & L. BorGen. Endemic species of enn (Brassicaceae) i in the Cape Verde Islands. Bocagiana 47: 1-5. 1979. [Recognition of five species and listing of several differences between Diplotaxis and Sinapidendron.] SALMON, C. E. oo tenuifolia DC. var. intesrifolia Koch. Jour. Bot. London 66: 204-206. Sxiscna . Species nova generis Diplotaxis DC. e systemate fl. Tanais. (In ssian.) Not. Syst. eee 22: 150-154. 1963. [D. tanaitica, sp. nov., from ape probably a variant of D. muralis.] SIMONCIOLI, C. ea ea of Diplotaxis erucoides (L.) DC. suspensor. 324 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Giorn. Bot. Ital. 108: 175- 189. 1974. [Embryogeny of the Onagrad type; possible functions of the suspen transport of tissues. ] 8. Eruca Miller, Gard. Dict. abr. ed. 4. Vol. 1 (alph. ord.). 1754. Annuals [or caespitose and rhizomatous perennials], hispid or pilose with simple, spreading or retrorse trichomes, sometimes glabrous. Stems leafy [or scapose]. Basal leaves petiolate, [forming or] not forming a distinct rosette, usually lyrately pinnatifid or pinnatipartite, rarely bipinnatisect or undivided. Cauline leaves (when present) sessile or short petiolate, divided or coarsely dentate to subentire. Inflorescence an ebracteate, many-flowered, corymbose raceme, greatly elongated in fruit. Sepals erect, oblong or linear, caducous [or persistent until fruit matures], green or violet, glabrous or with a subapical tuft of trichomes, sometimes pilose or setulose along abaxial side; outer [and inner] sepals cucullate, inner ones saccate at base. Petals broadly obovate [or oblan- ceolate], cream or yellow with dark brown or violet veins [or entire blade violet]; claws well developed, as long as or longer than the sepals. Nectar glands 4 [2], lateral pair prismatic, median pair ovoid or oblong [or absent]. Stamens tetradynamous, not appendaged; filaments linear; anthers oblong or linear, sagittate at base. Ovary many ovulate; style present; stigma 2-lobed, the lobes usually decurrent. Fruiting pedicels glabrous or pubescent, erect to ascending, subappressed to the rachis [rarely divaricate]. Siliques subsessile, dehiscent, linear or oblong to elliptic, inflated, terete or slightly tetragonal, glabrous or retrorsely hispid or scabrous; valves strongly 1-nerved, slightly keeled, convex, somewhat coriaceous; beaks seedless, prominently |-nerved, occasionally with obscure lateral nerves, flattened [rarely tetragonal], ensiform, acute or acu- minate, shorter to longer than the valves. Seeds biseriately arranged, oval, wingless, reticulate, slightly to copiously mucilaginous when wet, orange or brown; cotyledons longitudinally conduplicate, emarginate. Base chromosome number 11. (Including Euzomum Link, Velleruca Pomel.) LECTOTYPE SPECIES: Eruca sativa Miller (Brassica Eruca L.) = E. vesicaria (L.) Cav. subsp. sativa (Miller) Thell.; see Maire, Fl. Afr. Nord 12: 303. 1965. (Name the classical Latin name for the above species, but its origin uncertain; most likely derived from eructo (or the Greek ereugomai), to belch or eruct, or from uro, to burn, in reference to the hot taste of the plant.)—GARDEN ROCKET, ROCKET SALAD. Three species, of which Eruca loncholoma (Pomel) O. E. Schulz and E setulosa Boiss. & Reuter are endemic to Algeria; the third, E. vesicaria, is probably a native of the Mediterranean region but is naturalized throughout Europe, in much of Asia and Africa, and sporadically in Australia and North and South America. The genus is represented in the southeastern United States by £. vesicaria (L.) Cav. subsp. sativa (Miller) Thell. (Brassica Eruca L., E. sativa Miller, E. Eruca(L.) Ascherson & Graebner, Raphanus Eruca (L.) Crantz), garden rocket, rocket salad (less commonly: rocket, edible rocket, and roquette), 2n = 22, a weed of cultivated fields, roadsides, and waste places. Although I have not seen specimens of this taxon from the southeastern United States, there is no doubt that it occurs there. The species is found in all of the states 1985] AL-SHEHBAZ, BRASSICEAE 325 bordering our area and is included in the treatments of Small and Rickett. Eruca vesicaria subsp. sativa is easily distinguished from the other crucifers of our flora by its yellow or cream-colored petals with dark brown or violet veins, erect sepals, appressed siliques, one-nerved valves, ensiform beaks, and bise- riately arranged seeds. Subspecies vesicaria, which is endemic to Spain, the Balearic Islands, and northwestern Africa, differs from subsp. sativa in its cucullate inner oo and its persistent calyx that remains attached until the fruits are nearly rip Eruca is well al by its erect sepals, biseriately arranged seeds, one- nerved valves, somewhat decurrent stigmas, and long, seedless, ensiform or tetragonal beaks. It is related to Diplotaxis, particularly to sect. HESPERIDIUM E. Schulz, from which it differs in the ensiform beaks of the siliques and in the larger and fewer seeds. Some authors (e.g., Von Hayek and Rytz) have suggested a direct relationship between Eruca and Sinapis, but the two should be loosely associated. The latter is readily distinguished from Eruca by its spreading sepals, uniseriately arranged seeds, and three- to seven-veined valves. Both E. setulosa and E. loncholoma resemble Brassica sect. BRASSICARIA, but the relationship between the two genera is not entirely clea The petals of Eruca vesicaria exhibit high absorbance of elt light in the blade and low reflectance in the claw (Horovitz & Cohen). More than 100 species of insects have been reported as visitors of the flowers, but the most common pollinators appear to be members of the bee genera Apis, Andrena, and Halictus. Self-incompatibility has been reported by many authors, but the expression of this character is not absolute, and selfing may lead to the for- mation of short siliques with few seeds. Unlike that of the rest of the Cruciferae, the incompatibility system in FE. vesicaria is controlled by at least three pairs of complementary genes, each with several alleles (Verma et al., Lewis). Chromosome numbers are known only for Eruca vesicaria. Although 11 bivalents have usually been found, Wills observed quadrivalents and hexa- valents, as well as frequent chromosomal bridges. Despite these meiotic irreg- ularities, pollen stainability was nearly 99 percent. The karyotype consists of single pairs of long and short and nine pairs of medium-sized metacentric chromosomes, of which the long pair has median and subterminal constrictions and one medium-sized pair has satellites (Mukherjee). Artificial intergeneric hybridization between certain members of the Bras- siceae and Eruca vesicaria has been successful if the latter is used as the maternal plant and the crossing is done at the bud stage. The stigmas of Eruca are unselective for foreign pollen and allow germination of and style penetration by pollen tubes of members of several genera (Harberd, 1976; Sampson). On the other hand, the pollen of Eruca always fails to germinate on foreign stigmas. The seeds of Eruca vesicaria yield 22-36 percent oil, and the plant is con- sidered to be among the crucifers richest in erucic-acid content. The unsapon- ifiable matter contains sterols dominated by G-sitosterol (49 percent) and cam- pesterol (32 percent). The seeds contain high concentrations of 4-methylthiobu- tylglucosinolate and an enzyme that converts the glucosinolates to thiocyanates (Schliiter & Gmelin) The earliest cultivation of Eruca vesicaria dates back to the ancient Romans 320 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 and Greeks. It is currently grown in Europe (and infrequently in North America) as a Salad plant and is cultivated extensively in central and western Asia for seed oil. The oil is used in pickling and as an illuminant and a lubricant; in India it is used for massaging the body, applied to the hair, and employed in the treatment of vitiligo and as a vesicant. However, it is known to cause allergic dermatitis, photodermatitis, and persistent melanosis of the skin (Mitchell & Rook). The seed cake and the entire plant are used as fodder for domestic animals. In southern Europe the young leaves are used as a stimulant, an antiscorbutic, a diuretic, and a stomachic, but a strong dose may cause vomiting. In India the whole plant is considered to be an aphrodisiac (Caius), and electuary preparations have been used to cure indurations of the liver (Hartwell). Finally, the species is an obnoxious cosmopolitan weed and is a host for several fungi and viruses that also attack cruciferous crops. REFERENCES: Under family references in AL-SHEHBAz (Jour. Arnold Arb. 65: 343-373. 1984), see Baez Mayor, BAILLON, BENTHAM & Hooker, Caius, CoLe (1976), Crisp, GOERING et al., HARTWELL, VON Hayek, Horovitz & CouEN, JARETZKY (1932), KJAER (1960), KNIGHTS & Berrie, KNUTH, KuMAR & TsuNopa, LA Porte, Maire, MANTON, MUENSCHER, MUKHERJEE, Mur.ey, Prasap (1977), QueirRos, RicKeETT, ROLLINS (1981), SAMPSON, SCHULZ, SMALL, VAUGHAN & WHITEHOUSE, and Vieci et al Under tribal references see BENGOECHEA & GOmeEz-CAMPO, CLEMENTE & HEr- NANDEZ-BERMEJO (1980a—d), CURRAN, ETTLINGER & THOMPSON, FREE, GOMEZ-CAMPO cei d), GOMEz- ete & HInaAtAaA, Sa CAMEO & gene ee Mee, nH Rytz, SCHULZ (1919), pera & SHARMA, SINSKAIA, creseaets % Su. ZUKI, TAKAHATA & HINATA (1980), aa, UcHIMIYA & WILDMAN, VAUGHAN, VAUGHAN & HEMINGWAY, WILLS, and YARN ALAM, Z. Cytological studies of some Indian oleiferous Cruciferae. III. Ann. Bot. 50: 85-102. 1936a. . Self-sterility in Eruca sativa Lam. Jour. Genet. 32: 257-276. 1936b. Arora, B. B., & L. C. Lampa. Structure and dehiscence mechanism of fruit wall in Eruca sativa Mill.—an oleiferous crucifer. Curr. Sci. Bangalore 49: 62-64. 1980a. & . Stomata in the pericarp of Brassica oleracea ee on ‘ytis Linn. and Eruca sativa Mill. Proc. Pl. Sci. India Acad. Sci. 89: 23- 28. Betiue, M. K. Garden rocket, Eruca sativa Mill., a “new” flax sa Bull. Dep. Agr. Calif. 25: 280-282. 1936.* Corsi, G. The suspensor of Eruca ote i (Cruciferae) during embryogenesis in vitro. Giorn. Bot. Ital. 106: 41-54. —., G. C. Renzoni, & L. Vieci. i high ene and high reproductive output have low survivorship and low od output. ] Loon, J.C. van. A cytological investigation of flowering plants from the Canary Islands. Acta Bot. Neerl. 23: 113-124. 1974. [C. maritima, 116, 2n = 18.] Love, A., & D. Love. Studies on the origin of the Icelandic flora I. Cytoecological Spl oeee on Cakile. Univ. Iceland Inst. Appl. Sci. Rep. B. 2: 1-29. 1947. [Report n= 18 and 2n = 36 for C. arctica (listed as C. edentula subsp. islandica), counts apparently oe ds see RODMAN (1974), GORENFLOT. ] MILLSPAUGH, C. F. Plantae Utowanae. Part la. Cakile. Publ. Field Mus. Bot. 2: 125- 133. [Recognizes ten species and two hybrids.] eae A. M. The ecology and population dynamics of Cakile edentula var. lacustris n Lake Huron beaches. Unpubl. M.S. dissertation, Univ. Western Ontario, London oo Canada. 1980.* & M. A. Maun. Dispersal and floating ability of dimorphic fruit segments of Cakile edentula var. lacustris. Canad. Jour. Bot. 59: 2595-2602. 1981. & Reproduction and survivorship of Cakile edentula var. lacustris along the Lake Huron shoreline. Am. Midl. Nat. 111: 86-95. a [Population density, fruit production, dispersal, factors eon seedling mort Posepimova, E. Notae de genere Cakile 1. (In Russian) Not. Syst. Leningrad 15: 62-77. sae [Two new sections and ee new spec —. A review of the genus Caki/e Mill. (In Russian; English cae Bot. Zhur. 48: 1762- 1775. 1963. [History, systematic position, and evolutio . Genus Cakile Mill. (pars eee (In Russian.) Novit. ee Pi. Vasc. 1: 90- 128. 1964. [Systematic treatment, 15 species in four sections.] RieFner, R.E., Jk. Studies on the Maryland flora IX: Cakile maritima Scop. naturalized in the Chesapeake Bay region. Phytologia 50: 207, 208. 1982. [Collected from Anne Arundel County in 1958 and in 1981, probably persisting; also from Queen Annes ear RODMAN, J The taxonomic value of glucosinolates in the genus Cakile (Cruciferae). (Abstr.) aoe 24: 127. 1972. Systematics and evolution of the genus Cakile (Cruciferae). Contr. Gray Herb. 205: 3-146. 1974. [The basic and most comprehensive treatment; more than 280 references are cited.] 348 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 . Differentiation and migration of Cakile (Cruciferae): seed glucosinolate evi- dence. Syst. Bot. 1: 137-148. 1976. In: A, L6ve, ed., IOPB chromosome opens eon LXI. Taxon 27: 375-392. 1978. [Counts for five species of Cakile, 391, J . Population needs and hybridization in sea-rockets (Cakile, Cruciferae): seed glucosinolate characters. Am. Jour. Bot. 67: 1145-1159. 1980. [C. edentula subsp. edentula and C. cae subsp. a chemical analysis of hybrids.] & n: A. LévE es romosome number reports LIII. HAR Taxon 25: 483- 500. ie [C. fae 498, J Rose, L. S. An unreported species of Cakile in "California, Leafl. West. Bot. 1: 224. 1936. [C. maritima. RozeMa, J., F. But, T. Dueck, & H. Wess rani Salt- Fela} stimulated growth in strand-line species. Physiol. Pl. 56: 204-210. 1982. [C. ma , T. Dueck, H. WESSELMAN, & F. Bu. saan pena growth s stimulation by salt in strand- line species. Acta Oecol. 4: 41-52. 1983. [C. maritim Scorr, R. Variation in Cakile maritima. Watsonia 9: 203, 204. 1972 Sims, E. Sea kale. South Austral. Nat. 42: 76, 77. 1968.* SMOLENSKI, S. J., H. Sitinis, & N. R. FARNSWORTH. Alkaloid screening. IV. Lloydia 37: 0-61. 1974. [C. edentula var. lacustris, 33. Stace, C. A. Cakile Mill. Pp. 141, 142 in C. A. Srace, ed., Hybridization and the flora ee the British Isles. London. 1975. es — of interspecific hybridization n Britain eases crossings within C. ma cee J. F. Enige opmerkingen over de sean van de zeeraket (Cakile ma- ritima Scop. ) aan het strand. (English summary.) Gorteria 5: 227-231. 1971. [Eco- logical requirements. ] WRIGHT, J. Notes on strand plants. II. Cakile maritima Scop. Trans. Bot. Soc. Edinb. 29: 389-401. 1927. [Anatomy of the seedling, leaf, and flower; role of plants in the formation of sand mounds.] 13. Conringia Heister ex Fabricius, Enum. 160. 1759. Annual or rarely perennial, glabrous and usually glaucous herbs. Stems erect, simple or branched at base. Basal leaves undivided, obovate or spatulate, subsessile, usually entire, slightly fleshy. Cauline leaves cordate-amplexicaul, rarely auriculate, oblong to elliptic or ovate [or suborbicular], entire, rarely crenulate. Inflorescence an ebracteate, corymbose raceme, usually elongated in fruit. Sepals erect or slightly ascending, obtuse; outer pair linear to narrowly oblong or lanceolate, sometimes cucullate; inner pair broader, slightly [to strongly] saccate [or not] at base. Petals yellow or white [rarely with purple veins], narrowly [to broadly] obovate, rarely oblanceolate, attenuate at base; claws usually as long as sepals. Median nectar glands usually absent, lateral ones lobed [or flat]. Stamens slightly tetradynamous; filaments not appendaged, linear, free; anthers oblong, slightly sagittate at base, equal in length [or the lateral pair 3—4 times longer than the 2 median pairs]. Ovary glabrous, many ovulate. Fruiting pedicels ascending to spreading [or erect], slender [or as thick as the fruit]. Siliques sessile, linear, dehiscent, quadrangular [or terete, 8-angled, or strongly compressed parallel to the septum], torulose [or not], beaked [or beakless], acuminate [or clavate] at apex; valves convex [or flat], somewhat keeled [or not], usually with a prominent midnerve and 2 obscure [or promi- nent] lateral nerves [or nerveless]; stigmas capitate, entire [or 2-lobed and the lobes sometimes decurrent]. Seeds uniseriately arranged, copiously [or not at 1985] AL-SHEHBAZ, BRASSICEAE 349 all] mucilaginous when wet, wingless, oblong or elliptic, brown [or reddish or black], papillose [or smooth]; cotyledons incumbent [or subconduplicate]. Base chromosome numbers 7, 9. (Including Goniolobium Beck, Gorinkia J. & K. Presl.) Lectotype species: Brassica orientalis L. = Conringia orientalis (L.) Dumort.; see Britton & Brown, Illus. Fl. No. U. S. ed. 2. 2: 174. 1913. (Name honoring Hermann Conring, 1606-1681, German professor of medicine, phi- losophy, and jurisprudence at Helmstedt University.)— HARE’S-EAR MUSTARD. A well-defined genus of six species centered in the eastern Mediterranean, particularly in Turkey (where all species occur), and extending eastward to Afghanistan and western Pakistan. Two species are widely distributed in south- ern and central oe and one (Conringia grandiflora Boiss. & Heldr.) is a narrow known only from a few localities in Antalya Vilayet, a province in southwestern Turkey y. The genus is represented in North America by the alien weed C. orientalis (L.) Dumort., hare’s-ear mustard, rabbit’s-ear, treacle mustard, 2n = 14, which grows in cultivated land, disturbed sites, abandoned fields, and waste places, and along roadsides. It is most common in the plains states of the United States and in the plains and prairie peovanices of Canada (Rollins). It has been recorded from all the Sout! t Louisiana and South Carolina, but it probably grows there as well. Conringia orientalis, easily distinguished from the other mustards of our area, is a glabrous annual with deeply cordate-amplexicaul cauline leaves, white or yellow flowers, tetrag- onal siliques 6-15 cm long, and incumbent cotyledons. Conringia has often been associated with Moricandia of subtribe Morican- diinae Hayek, but Botschantzev has questioned its disposition in the Brassiceae without adequately placing it in another tribe. Features such as the conduplicate cotyledons and/or segmented siliques, typical of most members of the Bras- siceae, are not found in Conringia, Ammosperma, and Pseuderucaria. The last two genera have always been associated with Moricandia, and there are no solid grounds for not placing Conringia with them. In one species, C. plani- siliqua Fischer & Meyer, the cotyledons are nearly conduplicate, and this may support retaining the genus in the Brassiceae. Hardly anything is known about the floral biology of Conringia. The diversity in flower size among species is very striking. The flowers of C. persica Boiss., the smallest in the genus, are only 0.5 cm long and have nonsaccate sepals, while those of C. grandiflora exceed 2 cm in length and have strongly saccate inner sepals with pouches usually longer than 1 mm. All anthers of C. gran- diflora are polliniferous, but those of the lateral pair of stamens are nearly four times longer than those of the median ones. To my knowledge, such anthers have not been encountered elsewhere in the Cruciferae, except in flowers of some species of Streptanthus Nutt. that have aborted median ones. Unfortu- nately nothing is known about the pollinators of C. grandiflora. Chromosome numbers are known for all species except Conringia grandi- flora. One species, C. austriaca (Jacq.) Sweet, is a tetraploid based on seven. The haploid number for C. persica is seven, but counts of n= 7 and n=9 have been reported for both C. planisiliqua and C. clavata Boiss. (= C. per- foliata (C. A. Meyer) N. Busch) 350 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 A few cardenolides (erysimosid, erycorchosid, and helveticosid) have been found in Conringia orientalis (Kowalewski), but it is not known whether cardiac glycosides are present throughout the genus. In C. planisiliqua allylglucosi- nolate has been identified, and in C. orientalis 2-hydroxy-2-methylpropyl and 2-methylpropy] glucosinolates are the dominant pungent constituents. It has been suggested that C. orientalis may be a potentially new oil-seed crop because of its high ratio of linoleic to linolenic acid, but the presence of cardenolides may be an obstacle to such utilization. The seeds of Conringia orientalis exude abundant mucilage immediately after soaking in water. The mucilage forms series of stiff separate conical masses, each with a cap representing the outer wall of the epidermal cell that exuded it. Other species contain very little or no seed mucilage. Except for the weedy Conringia orientalis, the genus has no economic im- portance. Young plants of this species are said to make a good salad. REFERENCES: Under family references in At-SHEHBAz (Jour. Arnold Arb. 65: 343-373. 1984), see AL-SHEHBAZ & AL-OMAR; APPELQVIST (1971); BRirron & BROWN; DAXENBICHLER et al.: Wo rr, & Jones; MUENSCHER; Murry; RADFORD ef al.; RICKETT; ROLLINS (1981): SCHULZ; SMALL; E. B. SMitH; and VAUGHAN & WHITEHOUSE. Under tribal references see BENGOECHEA & GOMEz-CAMPo, CLEMENTE & HER- NANDEZ-BERMEJO (1980a-d), GOmeEz-Campo (1980a, d), GOMEz-CAmMpo & HINATA, Gomez-Campo & Tortosa, and ScHuLz (1923). AryaAvanp, A. In: A. Love, ed., IOPB chromosome number reports LVIII. Taxon 26: 557-565. 1977. 2 orientalis 561, = 7. ae HANTZEY, V. P. Die cruciferis notae criticae, 5. (In Russian.) Bot. Mater. Gerb. t. Inst. Akad. Nauk SSSR. 1966: 122-139. 1966. [Conringia, 126. a E. W. Range extensions and first reports for some Tennessee vascular plants. Castanea 40: 56-63. 1975. [C. orientalis from Montgomery County, 59. Dewey, L. H. Three new weeds of the mustard family. U. S. Dep. Agr. Bot. Circ. 10. 6 pp. 1897. [C. orientalis.] FerAKovA, V., & A. Murin. In: A. Léve, ed., IOPB chromosome number reports LX. Taxon 27: 223-231. 1978. [C. austriaca, 224, 2n 8.] Hepag, I. C. Conringia. In: P. H. Davis, ed., FI. Turkey 1: 275-278. 1965. Kuaer, A., R. GMELIN, & R. B. JENSEN. Isothiocyanates XVI. Glucoconringiin, the natural precursor of 5,5-dimethyl-2-oxazolidinethione. Acta Chem. Scand. 10: 432- 438. 1956. KowALewskI, Z. Papierchromatographische Untersuchung der Cardenolide von 8 E rysi- mum—Arten und zwei vertretern verwandter Gattungen. Helvet. Chim. Acta 43: 1314-1321. 1960. [C. orientalis.] MatTTHeEws, J. F., R. L. Kotociski, T. L. MELLICHAMP, et al. Additional records to the vascular flora of the Carolinas. Castanea 349-360. 1974. [C. orientalis, 352.] Naasui, A. R., & G. N. JAverp. Jn: A. Love, ed., IOPB chromosome number reports LIV. Taxon 25: 631-649. 1976. [C. ae 648, n= 9, PopLecH, D., & A. DIETERLE. Chr pmospimenstudicn an afghanischen Pflanzen. Can- dollea 24: 185-243. 1969. [C. persica, 204, 2n 4. a. K. E., & F. D. Bowers. Notes o fa eaneuee plants III. Castanea 38: 335-339. 973. [C. orientalis added to the state flora, 337.] 1985] AL-SHEHBAZ, BRASSICEAE ou! UNDERHILL, E. W., & D. F. KirkLAND. A new thioglucoside, 2-methylpropylglucosi- nolate. Phytochemistry 11: 2085-2088. 1972. [C. orientalis.] ARNOLD ARBORETUM ENUE CAMBRIDGE, MASSACHUSETTS 02138 VERKERKE, POLYGALACEAE 353 OVULES AND SEEDS OF THE POLYGALACEAE W. VERKERKE Tue ovu_es of the Polygalaceae are anatropous, bitegmic, and crassinucellate, and they frequently have a long exostome (Davis, 1966). The often-hairy seeds contain flattened or thickened cotyledons; the seed coat is endotestal, often in the form of long palisade cells, or is reduced. The larger seeds have a multi- plicative testa and an extensive, postchalazal vascularization (Netolitzky, 1926; Corner, 1976). The seeds generally have a mostly white exostome aril that is highly variable in size; the raphal and chalazal regions can be swollen (Chodat, 1890-1893; Blake, 1916; Adema, 1966). The exostome and the swollen chalazal region function as an elaiosome in at least some species of Polygala and Co- mesperma (Sernander, 1906; Berg, 1975). Detailed morphological studies of polygalaceous seeds are scarce (Corner, 1976, Polygala venenosa subsp. pulchra (Hassk.) Steenis; Rao, 1964, pause cantoniensis Lour.; Wirz, 1910, Epirixanthes, Verkerke & Bouman, 1980, P. lygala vulgaris L.; Verkerke, 1984, Xanthophyllum). Rodrigue (1893) [O (A s-van Rijn, pers mm. ) AVAOVIVDATOd “ANNAN AAA [S861 LSE 358 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 propionic acid, and ethyl alcohol. Alcohol-preserved flowers and immature seeds were dehydrated in an ethanol/normal butyl alcohol series, embedded in glycol methacrylate, sectioned at 5 um with glass knives, stained with periodic acid-Schiff (PAS) reagent (Feder & O’Brien, 1968), and counter-stained with aqueous methylene blue. Ripe seeds obtained from the herbarium were soaked either for three days in a detergent mixture (Alcorn & Ark, 1953) or for two days in 10 percent aqueous ammonia. After imbibition the seeds were directly dehydrated and subsequently infiltrated with glycol methacrylate, without fix- ation. These seeds gave better results than freshly collected and fixed ones. Hand sections were also made. For SEM studies alcohol-preserved material was dehydrated with dimeth- oxymethane (Gersterberger & Leins, 1978), critical point-dried with liquid CO,, gold/palladium sputter-coated for 3 minutes, and studied on a Cambridge Stereoscan Mark 2A. Phloroglucinol-HCl, Sudan IV, ruthenium red, and iodine in potassium-iodide solution stains were used for specific color tests. Placentation terminology follows Bjérnstad (1970) and Radford et al. (1974). Descriptions of embryos and endosperm are adapted from Martin (1946) and Smith (1983). In measurements of cells, the radial dimensions are given first, followed by tangential dimensions; descriptions of symmetrical plane figures are done according to Radford et al. (1974). Preliminary research (Verkerke & Bouman, 1980; Verkerke, 1984) has ex- plained the ontogeny of ovules and seeds in Polygala and Xanthophyllum. For Comesperma and Monnina ample alcohol-preserved material was available for study of ovules and seeds, and this allowed a description of the complete ontogeny. These results have allowed the ontogeny of incomplete series of other genera to be reconstructed. Many species were only represented by a few (min- imum number, 5) seeds obtained from herbarium specimens (see TABLE). To avoid repetition, not all species are equally illustrated: illustrations are intended to show variations in ontogeny leading to differences in seed morphology. Depending on the quality of the material and the purpose of the illustration, a photomicrograph, a scanning electron micrograph, or a camera-lucida draw- ing has been included. Insofar as possible, stages were described for each spec- imen in the following sequence: ovule primordium, integument initiation, ma- ture ovule, postfertilization development, and mature seed (inside to outside— embryo, endosperm, nucellar remains, inner integument, outer integument, color, shape, dimensions, indumentum, and appendages). RESULTS POLYGALA Secr. HeBecarpa. In the ripe seed of Polygala durandii (Ficures 1A, 2A), the spatulate embryo has flattened cotyledons measuring 220 x 1700 um in cross section with an adaxial subepidermal parenchymatic palisade layer. The co- pious endosperm is up to 175 um thick and consists of thick-walled cells. Except for the prominent cuticle, nucellar remains are only discernible on the antiraphal side and in the micropylar region. In the outer integument, cells of the inner epidermis have divided periclinally and are slightly elongated. The 1985] VERKERKE, POLYGALACEAE a59 OTS (TPP I} ] I {|| TNT | Meeene ‘es USS ai G- ee 7 4 0 STE a ant end ta at x A / = 2 DAO IO | WW } 7 a eo es ee za : £ tL J NY oi man Talay aoe Ficure 1. censis; : P. klotzschit; 4 membranacea; B. floribunda; H, B. papuana; 7 Comesperma eae K, M eee spinosa. (01 = see integument, il = inner integument, nuc = nucellus, end = endosperm, cot = cotyledon, h = hair.) Cross sections of polygalaceous seeds: A, Polygala durandii, B, P. jamai- PY iola acea; F, Bredemeyera lucida; G, 360 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 B at FiGure 2. Seeds and ovules of species of Polygala. A, seeds: top left, P. jamaicensis; top center, P. durandit; top right, P. klotzschit; bottom, P. membranacea. B, P. durandii, surface of seed. C, P. microspora, seed. D-F, P. vergrandis: D, mature ovule, cross section; E, mature seed, cross section; F, seed. (Scale bars = 1 mm (A), 100 um (B, C, E, F), 50 um (D); symbols as in FiGurE 1985] VERKERKE, POLYGALACEAE 361 short endotesta cells measure 10-12 x 20-22 um; the distal ends are split along the middle lamella but adhere to the nucellar cuticle. The cell-wall thickening is more pronounced at the distal ends, and frequently the lumina contain a rhombic calcium oxalate crystal. The subdermal mesophyll layer occurs only on the antiraphal side, where it is up to 180 um thick and consists of globose cells with slightly thickened walls and prominent pits. Since the mesophyll layer is not present on the sides, the seed is strongly laterally flattened. The thin-walled epidermal cells are radially elongated and measure 33 x 13 um. Some have formed an acicular hair up to 500 um long with a striate cuticle See 2B). The seed is black, slightly flattened, triangular in outline, 5 x 2.8 x 1.2 mm, and has a slightly protruding chalaza. A large, white, bilobed exostome aril extends 2.5 mm over the seed (FiGuRE 2A). In the ripe seed of Polygala jamaicensis (FiGuRES 1B, 2A), the spatulate embryo has flattened cotyledons measuring 220 x 2500 um in cross section with an adaxial, subepidermal parenchymatic palisade layer and a thick-walled epidermis. Nucellar remains adhere to the outer integument; the inner integ- ument is crushed. In the outer integument, cells of the inner epidermis are divided anticlinally but are only very slightly radially elongated; the distal portions of the inner epidermal cell walls are thickened. The short endotesta cells measure 10-12 x 15-17 um. The subdermal mesophyll layer consists of parenchymatic cells and is well developed on the antiraphal side, where it is up to 150 wm thick. On the sides of the seed, it is strongly reduced and only 30 um thick. The epidermis consists of elongated cells, which have thickened distal walls with a crenulate cuticle. A few cells develop a brown, thick-walled, acicular hair up to 750 um long. The seed is brown, elliptic in long section and transversely elliptic in cross section, 6 x 2.8 x 1.4 mm, and has a large, yellow exostome aril. The chalaza is located on the ventral side of the base of the seed. Only immature seeds were available for Polygala macradenia and P. amer- icana; they were similar to those of P. durandii. Secr. ACANTHOCLADUuS. In the ripe seed of Polygala klotzschii (Ficures 1C, 2A), the investing embryo has large cotyledons. The nucellar remains adhere to the endotesta. In the outer integument the cells of the inner epidermis have divided periclinally and are radially elongated. Distally, a weakly developed cell-wall thickening is present and the lumina remain large. The slightly elon- gated endotesta cells measure 18 x 9 um. The parenchymatic subdermal me- sophyll layer is compressed and up to 15 um thick. The epidermis consists of irregularly shaped, thin-walled, more or less elongated cells with a cuticle. Some cells have a curled, thick-walled, acicular hair. The seed is light brown, elliptic in long section and transversely elliptic in cross section, 6.3 x 3.3 x 1.5 mm, and has a whitish exostome aril. Sect. LiGustrina. In the ripe seed of Polygala membranacea (Ficures 1D, 2A), the investing embryo has thick cotyledons measuring 1500 x 3700 um in cross section. Of the nucellus only the epidermis and the prominent cuticle remain discernible; the inner integument is crushed. In the outer integument the inner epidermis forms an endotesta of elongated palisade cells measuring 30 x 9 wm. The subdermal mesophyll layer consists of thick-walled cells and 362 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 is up to 60 wm thick. The mesophyll is not restricted to the antiraphal side but occurs throughout the outer integument, as recorded in P. chamaebuxus (Ver- kerke & Bouman, 1980). The epidermis consists of radially elongated cells measuring 30 x 15 um with thick walls. The seed is brown, orbicular in cross section and elliptic in long section, and 7 x 3.8 x 3.8 mm. The hairy testa has faint ridges running from the apex to the base of the seed, where a firm, pointed chalazal projection 2 mm long is present. The seed of Polygala ligustroides has an investing embryo with thick coty- ledons measuring 2000 x 1000 um in cross section surrounded by a thin layer of endosperm. The nucellus and inner integument are resorbed. In the outer integument, cells of the inner epidermis divide periclinally and are strongly elongated. The palisade cells measure 30 x 15 um. The subdermal mesophyll layer is up to 50 wm thick. The epidermal cells are not radially elongated and form many unicellular hairs. The seed is black, elliptic in long section and orbicular in cross section, 3 x 2.3 x 2.3 mm. The large, white exostome aril extends over the antiraphal side. Sect. HeBEcLADA. In the ripe seed of Polygala violacea (FiGurE 1E), the spat- ulate embryo has flattened cotyledons measuring 250 x 1300 um in cross section with a subepidermal palisade layer. The endosperm is copious. The nucellus and inner integument are resorbed, and only the nucellar cuticle re- mains discernible. In the outer integument, cells of the inner epidermis divide periclinally and are strongly radially elongated. The palisade cells measure 70 x 90 wm. The subdermal mesophyll layer is 40 um thick; it consists of cells with slightly thickened walls and invests the entire seed. The epidermis consists of slightly thickened, short cells, some with a long, acicular hair. The seed is black, elliptic in long section and orbicular in cross section, 2.7 x 1.7 x 1.7 mm, and has a large trilobed exostome aril; a small chalazal appendage is also present. In Polygala floribunda the immature seed has an endotesta of long palisade cells measuring 50 x 9 um. The subdermal mesophyll layer is 30 um thick. In all other seed characters P. floribunda is similar to P. violacea. Sect. PoLyGALa. The ripe seed of Polygala microspora (FiGguRE 2C) has a spatulate embryo with plano-convex cotyledons measuring 30 x 80 wm in cross section. The endosperm is copious. In the outer integument an endotesta of strongly elongated palisade cells is formed; the testa does not contain a subdermal mesophyll layer. The epidermal cells are flattened and without hairs. The seed is black, obpyriform in long section and transversely elliptic in cross section, 0.5 x 0.3 x 0.26 mm, and glabrous. Next to the minute white exo- stome aril is a white raphe and a small chalazal appendage. In the mature ovule of Polygala vergrandis, the nucellus is surrounded by a dermally initiated, 2-layered inner integument. The outer integument is also dermally initiated and completely 2-layered (FiGurE 2D). The subdermal cells on the antiraphal side, seen in P. vulgaris (Verkerke & Bouman, 1980), are completely lacking. In the ripe seed (FiGuRE 2E) the spatulate embryo has plano-convex cotyledons measuring 150 x 300 um in cross section. The em- bryo is surrounded by a thin layer of endosperm, and both are rich in fatty substances. The nucellus is resorbed, with only the epidermis remaining dis- 1985] VERKERKE, POLYGALACEAE 363 cernible at maturity; the inner integument is compressed. In the outer integ- ument the inner epidermis has a well-developed endotesta of elongated palisade cells measuring 20-50 x 7-10 um. The mesophyll layer is lacking. Cells of the outer epidermis either have formed acicular hairs up to 300 um long or are swollen and thin walled, containing numerous PAS-positive inclusions (FIGURE 2E). The small raphe contains an amphicribral strand and is externally char- acterized by longitudinally enlarged cells; no stomata are present. The seed is black, narrowly elliptic in long section and orbicular in cross section, and 2 0.5 x 0.4 mm. It has a white chalazal swelling approximately 100 um long and a trilobed exostome aril (FIGURE 2F). Polygala semialata and P. conferta differ little from each other in the shape of the seed and aril, but in other seed characters they are similar to P. vergrandis. BREDEMEYERA n Bredemeyera densiflora (FiGurE 3A) the mature ovule is anatropous; the crassinucellate nucellus has a row of 5 parietal cells and a dermal cap 4 cells thick; the embryo sac fills the upper half of the nucellus. The dermally initiated inner integument is 2-layered. In the micropylar region, periclinal divisions in the outer epidermis render the endostome massive. The outer integument is also dermally initiated and 2-layered. A massive exostome develops by repeated periclinal divisions in the inner epidermis. No subdermal cells contribute to the formation of the outer integument (FiGuReE 3A). The raphe is 6 or 7 cells thick and contains an amphicribral vascular strand that runs into the unswollen chalazal region, where it branches into a fan of xylem elements. The nucellus- chalaza connection is narrow The ripe seed of Bredemeverd lucida (FiGuRE 1 F) contains a spatulate embryo with several collateral strands. The flattened cotyledons measure 240 x 1540 um in cross section. At the adaxial side of the cotyledon is a subepidermal layer of palisade parenchyma, but a differentiated epidermis is lacking. The embryo is surrounded by a considerable amount of endosperm, both are rich in fatty substances. The nucellar tissue is resorbed, and only the prominent cuticle remains, together with the fully crushed inner integument. In the outer integument the cells of the inner epidermis have divided anticlinally but are only slightly radially elongated; their walls are distally thickened. The lumina are frequently minute and do not contain crystals. The short endotesta cells measure 8-9 x 11-12 um. The testa lacks a subdermal mesophyll layer. The cells of the outer epidermis are frequently crushed and have thin anticlinal walls. Some cells have long, acicular, thick-walled hairs that are circular in cross section and measure 15 x 15 x 1000-2000 um. The seed is brown, narrowly elliptic in long section and oblate in cross section, and 7-8 x 1.7 x 1.3 mm. The chalaza, located on the ventral side near the base of the seed, contains vascular tissue and is not swollen. The small raphe is not protruding and contains an amphicribral vascular strand. The thickened, unlobed, hook- shaped, yellow exostome aril is 0.5 mm long; from its apex arises a tuft of thin- walled, white hairs up to 12 mm long and elliptic in cross section. Upon drying, the thick-walled hairs stand erect and the thin-walled ones tend to spread, thus forming an umbrellalike structure. 364 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ee a a Cy JS RT EO <9 Lo aS Sh PS . yy Sea ej PAV) - J Oe ~The QS: S25 a 1, a =, al oe w-4 6, 3 Ce Ne b ~ } Sa" na rate Aha hy = Bans * as i 4: res ‘eo J ’ ° .. An O Oo:y | TT » Ficure 3. Seeds and ovules of species of Bredemeyera and Comesperma. A, B. densiflora, mature ovule, cross section. B, B. floribunda, mature seed, long section, micropylar region. C, B. papuana, seed. D, E, C. ericinum: D, mature ovule, cross section 1985] VERKERKE, POLYGALACEAE 365 In Bredemeyera floribunda the testa has a subdermal mesophyll layer 10-30 um thick that consists of parenchymatic, loose tissue with large intercellular spaces. The epidermis consists of irregularly shaped, thin-walled cells (FIGURE 1G). Next to the hook-shaped exostome aril (FiGURE 3B) is a pronounced, vascularized, acicular chalazal appendage measuring 2200 x 500 um with hairs up to 300 um long. The seed is brown, narrowly elliptic in long section and orbicular in cross section, and 6.5-7 x 1.1 x 1.1 mm. These characters are in contrast to those of B. lucida. In the ripe seed of Bredemeyera papuana (Ficures 1H, 3C) the embryo is surrounded by a considerable amount of endosperm, the outermost layer of the nucellus, and the partly crushed inner integument. In the 2-layered outer integument the very slightly elongated cells of the inner epidermis measure 19-25 x 25-31 wm and have distally thickened walls. The outer epidermis consists of flattened cells, some of which have developed long hairs with uneven wall thickenings. The raphe is small, not protruding, and contains an amphi- cribral vascular strand that branches in the chalazal region to form a fan of xylem elements. The ripe seed is brown, narrowly elliptic in long section and transversely elliptic in cross section, and 65-70 x 12 x 10 mm. The chalaza and exostome each have a small appendage. COMESPERMA In Comesperma ericinum an anatropous ovule with a crassinucellate nucellus develops from a trizonate ovular primordium. The ovule has reduced parietal tissue and a small dermal cap. First the inner integument is initiated in the dermatogen; its primordium is ring shaped. Subsequently, the dermally initi- ated outer integument appears—on the antiraphal side only, due to the anat- ropous curvature of the ovule. As soon as the ring of the outer integument has grown to reach the level of the nucellus apically, subdermal cells start dividing and contribute to the outer integument on the antiraphal side. In the mature ovule (FiGuRE 3D) this small subdermal contribution to the outer integument is wedged in between the inner and outer epidermal layers. The embryo sac has extended to fill the upper half of the nucellus; a few parietal cells are still discernible. The inner integument is completely 2-layered. A thickened exostome is formed by repeated periclinal divisions in the inner epidermis of the outer integument. The chalazal region is thickened consid- erably by periclinal divisions in the subdermal layer, leading to the development ofa swelling up to 500 um long. The nucellus-chalaza connection is very narrow. The raphe is 10 to 12 cells thick and contains a strand of provascular tissue. After fertilization the ovule enlarges considerably. As soon as the embryo has developed incipient cotyledons, the nuclear endosperm starts resorbing the nucellar tissue. The inner integument is not crushed, and the cells of the outer epidermis enlarge and become radially elongated. In the outer integument, cells (arrow indicates subdermal cells in outer integument); E, immature seed, cross section. F, C. calymega, seed. (Scale bars = 10 um (A, D), 100 um (B, C, E, F); ra = raphe, hi = hilum, ar = aril, other symbols as in Ficure 1.) 366 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 of the inner epidermis divide anticlinally and elongate radially. Subdermal tissue 1s present as 3 or 4 isolated parenchymatic strands on the antiraphal side. The outer epidermis has divided anticlinally, and some cells have de- veloped long unicellular hairs. The chalaza is distinctly swollen, and the raphe is pronounced (FiGure 3E); it contains an amphicribral vascular strand that ends in the chalazal region as a fan of xylem elements. In the ripe seed of Comesperma virgatum (Ficure 1J), the spatulate embryo has plano-convex cotyledons measuring 170 x 500 um in cross section; they contain provascular strands and lack a differentiated epidermis. The embryo is surrounded by a considerable amount of cellular endosperm; both are rich in fatty substances. Of the nucellus, only the epidermis with the prominent cuticle persists; the inner integument is not crushed. In the outer integument the elongated cells of the inner epidermis form an endotesta of long palisade cells that measure 40-45 x 6-7 um and have strongly thickened but unlignified walls; the lumina are small, and each contains a rhombic calcium oxalate crystal. The palisade cells are arranged in a regular pattern of domelike struc- tures. The subdermal strands in the testa become completely crushed at ma- turity. Cells of the outer epidermis lack thickened walls but have a very prom- inent, finely echinate cuticle up to 4 um thick. Long, unicellular, white hairs elliptic in cross section and with unevenly thickened walls emerge from the entire surface of the seed. The ripe seed is black, elliptic in long section and oblate in cross section, and 1.5 x 0.9 x 0.7 mm.The seed lacks a large exostome aril but has a minute apical beak and a white chalazal appendage. In Comesperma confertum the entire raphe is white and swollen due to an elongation of the epidermal cells. The seeds of C. calymega lack an apical beak. The hairs are straight and appressed to the seed when wet; upon drying they become helically twisted (FiGuRE 3F). In all other seed characters C. confertum and C. calymega are similar to C. virgatum. Previously, Rodrigue (1893) described the endotesta of Comesperma polyga- loides F. Mueller as having short endotestal cells; no material of this species was available for the present study. MURALTIA In the ripe seed of Muraltia heisteria, the spatulate embryo has plano-convex cotyledons and is surrounded by copious endosperm. The 2 outer cell layers and the distinct cuticle of the nucellus are persistent. The inner integument persists, and cells of the outer epidermis are greatly enlarged. The inner epi- dermis of the outer integument constitutes a palisade layer, with cells measuring 20-35 x 15-20 um (Ficure 1K). The cells are arranged in a regular pattern of domelike structures, with the inner integument filling the domes. The me- sophyll consists of | or 2 parenchymatic cell layers. The outer epidermis con- tains stomata, and a few cells have long, acicular hairs. The raphe contains an amphicribral vascular strand; the mesophyll lacks any post-chalazal vascular- ization. The seed is brown, elliptic in long section and orbicular in cross section, and 3.8 x 2.6 x 2.5 mm. In the micropylar region there is a white, faintly lobed, 500 x 700 um exostome aril consisting of parenchymatic tissue. Led RTS : os TS ~& Ficure 4. Polygalaceous seeds. A, Nylandtia spinosa, mature seed, long section. B, C, Salomonia oblongifolia: B, surface of seed; C, seed. D, E, Epirixanthes elongata: D, immature seed, cross section; E, seed. (Scale bars = 100 um (A, C, E), 10 um (B), 50 um (D); te = testa, fw = fruit wall, ch = chalaza, nuc = nucellus.) AVAOVIVOATOd “ANNAN UAA [S861 Lot 368 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ses i ae Ns ra =ssee ry d mo Lt ae, eae eH oa: rom iq ( fs we AS | VA 4 J LAK SA ¢ ry \ Ak iT = a ae e { / | Wig ee ae / ry IGURE 5. Polygalaceous seeds and ovules. A, B, Epirixanthes elongata: A, mature ovule after fertilization, long section; B, mature ovule, cross section. C-F, Securidaca mature seed, cross section. (teg = tegumentary part of seed coat, chal = chalazal part of seed coat, other symbols as in FiGure 1.) NYLANDTIA In the ripe seed of Nylandtia spinosa (Ficure 1L), the spatulate embryo has large plano-convex cotyledons 300 x 750 um in cross section; these contain 1985] VERKERKE, POLYGALACEAE 369 P| provascular strands and lack ad idermis. The copious endosperm contains a few scattered, swollen cells. The nucellus has been resorbed except for the epidermis with a prominent cuticle; the enlarged cells of the outer epidermis of the inner integument are still discernible. In the 2-layered outer integument, the elongated, thick-walled palisade cells of the inner epidermis measure 50 x 8 um; the reduced lumina contain calcium oxalate crystals. A subdermal mesophyll layer is lacking. The cell walls of the outer epidermis are thin and are sparsely beset with acicular hairs. The seed is brown, widely elliptic in long section and orbicular in cross section, and 5 x 3 x 3 mm. A white exostome aril (FIGURE 4A) with membranaceous lobes extends up to '4 the length of the seed. SALOMONIA In the ripe seed of Salomonia oblongifolia, the plano-convex cotyledons measure 180 x 500 um in cross section and completely fill the seed; no en- dosperm is present. The embryo is rich in fat but lacks starch. Except for some thick-walled cells in the micropylar region, the nucellus is resorbed; only the prominent cuticle is still discernible. The inner integument is crushed. The outer integument is 2-layered, and the inner epidermis has formed an endotesta of strongly elongated, thick-walled palisade cells measuring 55-65 x 7-8 um. The outer epidermis consists of thin-walled, flattened cells that collapse at maturity (FiGuRE 4B). The faintly protruding chalaza is not swollen; the raphe has longitudinally elongated cells. The black, exarillate seed is widely obovate in long section and transversely elliptic in cross section, 0.9 x 0.6 x 0.5 mm, and glabrous (FiGurE 4C). EPIRIXANTHES The mature ovule of Epirixanthes elongata (Ficure SA, B) is much smaller than those of the other polygalaceous genera. The crassinucellate nucellus con- tains reduced parietal tissue and a small dermal cap. The inner and outer integuments are dermally initiated and 2-layered throughout. The raphe is 7 to 9 cells thick and encloses a provascular strand. The small, slightly pointed chalazal region lacks provascular tissue. After fertilization the ovule enlarges only slightly. The young embryo is initially surrounded by a thin layer of nuclear endosperm, which gradually resorbs the nucellus from the inside outward. The nucellar epidermis develops a prominent cuticle. As the seed ripens, the inner integument is gradually crushed and eventually disappears. In the outer integument, cells of the inner epidermis divide anticlinally and elongate radially (Ficure 4D). The base of the testa thus becomes 3 cells thick while the distal portion remains 2-layered. In each of the ripe seeds available for this study, the embryo has incipient cotyledons surrounded by a considerable amount of cellular endosperm, which is rich in fatty substances but contains no starch. Cells of the nucellus top have thickened walls and persist at maturity in the micropylar region of the seed, but the remainder of the nucellus is resorbed except for the epidermis and its prominent cuticle. The endotesta consists of radially elongated, thickened pal- 370 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 isade cells with a hexagonal cross section measuring 45-50 x 7-12 um; the lumina are small and generally contain a calcium oxalate crystal. Cells of the outer epidermis have slightly thickened walls; they do not develop any hairs and are strongly adherent to the endocarp. The white faphals cia Swelling strongly contrasts with the testa. The black, exarill FIGURE 4 with a flattened apex in long section and transversely eilipae in cross section, 0.8 x 0.4 x 0.3 mm, and glabrous. In Epirixanthes cylindrica the outer integument is thickened in the micro- pylar region by periclinal divisions in the inner epidermis. Ultimately, the testa contains parenchymatic tissue located outside the palisade layer in the micro- pylar region. The ripe seed is obovate in long section and transversely elliptic in cross section, measuring 0.7 x 0.3 x 0.2 mm. In all other seed characters, E. cylindrica is similar to E. elongata. MONNINA The ovule primordium of Monnina ciliolata (Figure 6A) has a trizonate structure. The 2 tunica layers, the dermatogen (I,) and the subdermatogen (I,), enclose the corpus (I,). In the subdermatogen the archespore divides into the megaspore mother cell and the parietal cells. In a young ovule (FiGurE 6B) the chalazal megaspore enlarges. The inner integument is dermally initiated, lead- ing to a ring-shaped primordium 2 cells thick. The outer integument is also dermally initiated and 2 cells thick, but due to the anatropous curvature of the ovule, it appears only on the antiraphal side. When the outer integument is about 10 cells long, subdermal cells start dividing on the antiraphal side (FiGureE 6C) and contribute to its growth. The nucellus has parietal cells and a small dermal cap; the embryo sac has extended, and the oblique orientation of the chalaza-nucellus connection results in the elon- gation of the integuments on the antiraphal side. In a mature ovule (FiGuRE 6D) the parietal tissue is not resorbed. The micropyle is formed by the inner integument; the top of the outer integument is thickened by periclinal divisions of the inner epidermis. In cross section the subdermal contribution to the outer integument appears as a crescent-shaped group of cells between the inner and outer epidermal layers (FiGURE 7A); in long section the cells are discernible as a subdermal wedge in the proximal part of the outer integument. The prefertilization development of Monnina xalapensis is very similar to that of M. ciliolata, but in M. wrightii there is no subdermal contribution to the outer integument, so the outer integument is 2-layered throughout. After fertilization in Monnina wrightii, the growing endosperm resorbs the nucellus and the inner integument is crushed. In the outer integument the cells of the inner epidermis elongate radially only slightly. Because anticlinal divi- sions cannot keep pace with the growth of the ovule, these cells become sep- arated by extensive intercellular spaces (FiGuRE 7B, C). In the ripe seed (FiGure 7D) the spatulate embryo has flattened cotyledons measuring 300 x 1400 um in cross section. These lack a differentiated epi- dermis but have an adaxial, subepidermal layer of palisade parenchyma and 1985] VERKERKE, POLYGALACEAE 371 eT ERA a ID wart yy” “4 ‘7? Pe nel 8 \ lo ay 1 Dryrys Wy 2 ag ¥ a ra Wy 5 4 rg a2 | on Sake Th Sane: ee ers , °° ery ar) val OTE BTEC IY earner * 2 S883 om "i ’ oP “agi wet ae ORLY Es ? ler Tom ren $373 I Dang RAL Lee ptr 5 a 2 75 > Ficure6. Ovules of Monnina ciliolata: A, ovule primordium, cross section; B, young ovule, long section; C, developing ovule, long section; D, mature ovule, long section, micropylar region. (Scale bars = 75 um (A, B), 10 um (C, D), 50 um (E); es = embryo sac, 1, = dermatogen, 1, = subdermatogen, 1, = corpus, other symbols as in FiGure 1.) well-developed collateral strands. The embryo is surrounded by 3 or 4 cells of endosperm that strongly adhere to the nucellar cuticle. Neither the endosperm nor the embryo contains any starch grains, but both are rich in fatty substances. The inner epidermis of the testa consists of distally thickened cells measuring a2 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 FiGure 7, Seeds and ovule of 2 species of Monnina. A, M. ciliolata, mature ovule, cross section (arrows indicate subdermal cells in outer integument). B-D, M. wrightii: endotesta cells). (Scale bars = 100 um (A), 50 um (B, D), 5 um (C); ic = intercellular space, other symbols as in FiGure 1 1985] VERKERKE, POLYGALACEAE 373 10-11 x 6-7 um. In growth this is disrupted, and the cells become separated from one another. The cells of the outer epidermis lack hairs and are crushed at maturity. The strongly tanniferous chalazal region, located near the base of the seed on the ventral side, is relatively long and narrow. The raphe contains a small amphicribral vascular strand ending in the chalazal region. The thin, translucent testa follows the form of the embryo. The seed is white, obpyriform in long section, transversely elliptic in cross section, and measures 3 x 1.2 x 0.6 mm. Externally, the isolated, thickened cells of the disrupted inner epi- dermis are visible as brown dots in the testa; these are more abundant in the micropylar region, where the cells are less separated. In the ripe seeds of Monnina ciliolata and M. xalapensis, the inner testal layer is not disrupted and the slightly thickened, light-colored cells still adhere to one another. The seeds are elliptic in long section, transversely elliptic in cross section, and measure 5.5 x 2.3 x 2mm SECURIDACA Long sections of young gynoecia of Securidaca diversifolia show an anatro- pous ovule with a crassinucellate nucellus (FIGURE 5C), which contains a small embryo sac, a row of 3 parietal cells, and a dermal cap 2 cells thick. The dermally initiated inner integument is 2 or 3 cells thick. The subdermally initiated outer integument is 3 cells thick and has a small, exclusively dermal apex. Periclinal divisions enlarge the chalazal region. The chalaza-nucellus connection is 70 um wide, and the raphe is 10 cells thick. The cross section of a mature ovule (FiGuRE 5D) shows a nucellus with a large embryo sac and an undivided epidermis. The inner integument is 2 or 3 cells thick. The outer integument is 4 or 5 cells thick and consists of an inner epidermis, a mesophyll layer, and an outer epidermis. The mesophyll layer does not contain any pro- vascular tissue. The raphe is 10 to 12 cells thick and contains an amphicribral vascular strand sa runs into the thickened chalazal region, branching into a fan of xylem elem After ailaion a chalazal region enlarges manyfold, and a pachychalazal development gradually reduces the portion of the seed coat that is formed by the integuments. Initially, the globular embryo is surrounded by a scanty nu- clear endosperm, but as the cotyledons develop the endosperm disappears. The nucellus is not yet resorbed, and the inner integument forms a massive en- dostome by periclinal divisions in the outer epidermis (FicuRE SE). In the outer integument the cells of the inner epidermis divide anticlinally and elon- gate radially only very slightly. The mesophyll layer remains parenchymatic, and large intercellular spaces develop (FiGures 5E, 8A). In the ripe seed the investing embryo is rich in fatty substances and has large cotyledons 1500 x 3000 um in cross section. The radicle is located apically, near the micropyle and hilum. The seed is pachychalazal, and the tegumentary part of the testa is restricted to the micropylar region, extending 1.5 mm apically (FiGuRE 5F). The vestigial nucellar and inner tegumentary tissues are strongly compressed. In the outer integument the slightly elongated cells of the inner epidermis have faintly thickened walls and contain calcium oxalate crystals 374 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 (FiGurE 8A). The mesophyll layer consists of parenchymatic cells with large intercellular spaces; the outer epidermis is not crushed in the tegumentary portion of the testa. The chalazal part of the testa is strongly compressed (FiGure 8B) and translucent, which makes the extensive and often branching vascularization externally discernible. The ripe seed is yellow and brown in the chalazal portion and dark brown in the tegumentary area; it is elliptic with pointed ends in long section, orbicular in cross section, and measures 6-6.5 x 3 x 2.5mm The ripe seeds of Securidaca lanceolata, S. ecristata, S. inappendiculata, S. corymbosa, S. atroviolacea, S. philippinensis, and S. volubilis are very similar to those of S. diversifolia. The postfertilization development of S. /ongepedun- culata and S. welwitschii is very different from that of all other species of Securidaca. After fertilization in Securidaca longepedunculata, the chalazal region en- larges and shifts toward the dorsal side; no growth occurs in the micropylar region, and as the seed becomes more globose, the micropyle and hilum become located in the middle of the seed on the ventral side. The seed is not pachy- chalazal, but there is a postfertilization chalazal shift. The investing embryo has thick cotyledons 4 x 9 mm in cross section; the cotyledons contain several collateral strands not confined to the median plane, lack a palisade layer, and have the small radicle located near the micropyle. In the outer integument the elongated els or the: inner i epadejanis have distally thickened walls (FiGURE 8C). Th 22-25 x 10-12 wm and are arranged in a regular pattern of domelike structures (FiGureE 8D). The mesophyll and outer epidermis are strongly compressed. The dark brown chalazal region con- stitutes the dorsal side of the seed; it is elliptic in outline, 3 x 7 mm, and contains vascular tissue but is not tanniferous. The tegumentary portion of the testa is yellow, and the seed is elliptic in long section and orbicular in cross section, measuring 9 x 8 x 8 mm CARPOLOBIA The ovule primordium of Carpolobia gossweileri is trizonate and develops into a crassinucellate nucellus with a small amount of parietal tissue. The mature ovule (FiGures 5G, 8E) has a large nucellus and a small dermal cap; the embryo sac extends toward the chalazal region. The dermally initiated inner integument is 2- or 3-layered and forms an endostome. The subdermally initiated outer integument consists of an inner epidermis, a middle layer of 3 to 5 parenchyma cells, and an outer epidermis. At the level of the nucellus top, the inner epidermis has divided periclinally to form a massive exostome. A small dermal apex is formed on the outer integument. The chalazal region is rather large; the raphe is 1 1 to 15 cells thick and contains a bundle of provascular tissue that branches in the chalazal region and runs with several small pro- vascular strands into the outer integument. After fertilization the ovule enlarges manyfold. In Carpolobia lutea (FIGURE 5H, J) the nucellus is almost completely resorbed except for fragments of the epidermis and the uninterrupted cuticle; the inner integument is crushed. In afte ‘* woe Pad = oo Lit Oe) ash ny aes ° a * weakly developed endotesta cells); B, chalazal part of seed coat (arrow), long section. C, D, S. /ongepedunculata: C, testa, cross section; D, testa, interior view. E, Carpolobia gossweileri, mature ovule, long section. (Scale bars = 75 wm (A, B), 10 wm (C, D), 50 wm (E); te = testa, ex = i t exostome, 01 = outer integument.) [S86I AVAOVIVOATOd ‘AMUAAAAA ee 376 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 the outer integument, cells of the inner epidermis divide anticlinally and slightly enlarge radially, while those of the mesophyll layer enlarge tangentially and develop intercellular spaces, and those of the outer epidermis either dif- ferentiate into moderately elongated cells with thin walls or develop long uni- cellular hairs with thickened walls (FiGuRE 5H). In the ripe seed the spatulate embryo has a small radicle near the micropyle. The flattened cotyledons measure 130 =x 4000 um in cross section. The en- dosperm is copious; both embryo and endosperm are rich in fatty substances but poor in starch. Cells of the nucellus and inner integumentare still discernible at the chalazal connection, but in the rest of the seed only the nucellar cuticle and compressed vestiges of the inner integument, both strongly adherent to the testa, remain. In the outer integument the cells of the inner epidermis have thickened distal walls, thin proximal walls, and large lumina without crystals; the unlignified short endotestal cells measure 11-13 x 7-8 um. The mesophyll layer is 60-80 um thick and consists of faintly thickened, strongly depressed cells. The outer epidermis consists mainly of moderately enlarged thin-walled cells that are rich in fatty substances and measure 50-70 x 40-45 um; some cells form unicellular, thick-walled hairs up to 2 mm long with a prominent cuticle (FiGURE 5J). The hairs are abundant, especially on the raphe and the antiraphe. The orbicular chalazal region, 800 um in diameter, is at the base of the seed; it contains vascular tissue but is not tanniferous. The thick am- phicribral raphal strand is disrupted in the center; it branches in the chalazal region and runs into the outer integument to form many small strands and a thick antiraphal, amphicribral vascular strand. The long funicle, which shows no traces of aril formation, is near the micropyle at the apex of the seed. The seed is rust colored, elliptic in long section and transversely elliptic in cross section, and 9-11 x mm. The examined species of Carpolobia vary appreciably in seed-coat structure. In C. gossweileri (FiGURE 9A) the endotesta has slightly more elongated cells with less pronounced wall thickenings and thus larger lumina. The distal ends of the short endotesta cells are often slightly split, forming small cavities. The parenchymatic mesophyll is compressed and ca. 20—25 um thick. As in C. lutea, the outer epidermis has differentiated into 2 types of cells, but the thin- walled cells form a layer up to 250 um thick at the sides and 50 um at the raphe and antiraphe. The seed is pubescent with many hairs up to 2 mm long; these are eee abundant on the raphe and antiraphe but also protrude on the si The ae a of Carpolobia alba (FiGure 9B) does not form an endotesta. As the seed grows, anticlinal divisions in the inner epidermis do not keep pace with the tangential growth of the mesophyll cells. Eventually, the inner epi- dermis is disrupted and the compressed inner integument adheres to small, isolated cells on the inside of the testa. Only in the micropylar region is the inner epidermis undisturbed; here it consists of thin-walled, radially enlarged cells. The mesophyll is compressed as in C. gossweileri, but the post-chalazal vascularization is restricted to a single antiraphal strand. The outer epidermis has differentiated as in C. /utea; the thin-walled cells measure 50-140 x 40- 50 um. The long hairs are sometimes wavy and appressed to the testa. The seed measures 10-12 x 8 x 5 mm—somewhat larger than in the other species. ‘ oe Were yg nee ae Aa OTS + est Ta’. 2 . wir Wey wer Wao eh hy jl bh | yy wo tah Bre — aa SS Se Zh, Pies 3. Ammannia coccinea: a, habit, x 0.4; b, basal part of plant with roots, x 0.4; c, pedunculate inflorescence subtended by auriculate leaf base, x 3; d, flower, x 4, (Reprinted with permission from Mason, 1957. FiGure 4c originally published as Ammannia auriculata. 410 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 TABLE 2. Variation in floral features of Ammannia auriculata, A. coccinea, and A. robusta.* SPECIES n PETAL LENGTH PETAL WIDTH PEDUNCLE WIDTH A. auriculata 42 1.33 + 0.41 1.42 + 0.38 7.0 + 2.70 A. coccinea 37 2.01 + 0.30 2.03 + 0.23 1.74 + 2.13 A. robusta 26 2.50 + 0.55 2.96 + 0.40 0.11 + 0.33 FLOWERS PER CYME CALYX LENGTH CAPSULE WIDTH A. auriculata 7.12 + 3.90 1.95 + 0.22 2.54 + 0.51 A. coccinea 5.59 + 2.29 2.86 + 0.62 3.98 + 0.18 A. robusta 2.36 + 1.18 3.50 + 0.61 4.93 + 0.61 *Measurements in mm; first figure = mean, second figure = standard deviation. short- to long-pedunculate 3- to 5- (to 14-)flowered cymes; peduncle, when present, to 9 mm long, sturdy, bibracteolate; pedicels mostly 2 mm or less, bibracteolate, bracteoles '4 or less length of floral tube. Floral tube urceolate to slightly campanulate, (2.5-)3-5 mm long, longitudinal ridges present but not conspicuously enlarged; cae lobes triangular, alternating with thickened equal in length to lobes, mostly oriented outward from floral tube i in bud: petals 4 (or 5), obovate, usually 2 by 2 mm, deep rose- purple, sometimes with deeper purple spot at base; stamens 4 (to 7), exserted, anthers deep yellow; style long, slender, equal to or longer than ovary, exserte at anthesis; ovary incompletely 2-locular. Capsule 3.5—5 mm in diameter, equal to or exceeding calyx lobes, rarely enclosed. n = 33. As a successful amphidiploid derived from Ammannia auriculata and A. robusta, A. coccinea displays a range of morphological variability that, at its extremes, closely approaches the putative parent species. Since species of Am- mannia on the whole are very similar, distinction between parent species and hybrid derivatives can be subtle. The number of characters separating 4. au- riculata, A. robusta, and A. coccinea are few and primarily quantitative. TABLE 2 summarizes variation in size of the floral features, and the key characters of the three species are compared in TABLE 3. Most specimens of A. coccinea resemble A. robusta more closely than they do A. auriculata. In the field A. coccinea is easily distinguished from 4. robusta by its deep petal and anther color. On herbarium specimens the species is usually identified by the com- bination of stout peduncles, 3- to 5-flowered cymes, and mature capsules that are intermediate in size between those of A. robusta and those of A. auriculata. Occasional specimens that approach A. auriculata in peduncle length are best recognized by the usually larger flowers of A. coccinea. o original material of Ammannia coccinea is extant (Maule, pers. comm.). Rottbell (1773) described the species in careful detail from cultivated plants at the Copenhagen Botanical Garden. According to the protolog, these were grown from seeds brought to the Garden by a Belgian gardener, Kaesemaker. The neotype is selected from a Caribbean collection, because the original seeds were most likely collected in that region. The name Ammannia teres Raf. has long been applied to the petal-bearing 1985] GRAHAM, AMMANNIA Tas_e 3. Comparison of major morphological features distinguishing taxa of the Ammannia coccinea complex TAXON FEATURE A. auriculata A. robusta A. coccinea Chromosome 15, 16 17 33 count Aspect Delicate obus Robust Leaves Membranaceous, Seah lanceolate, Membranaceous to wly lan- often spathulate fleshy, lanceolate at lower node Peduncles 3-9 mm long, fili- Lacking Lacking or ag 4(-9) mm long, st Flowers 1-3 mm long, 2.5-5 mm long, 2-3.5 mm eae usually usually 3 o usually 1 to 3 3 or more per axil more per axil axil Petal color ose-purp] Pale lavender Rose-purple Anther color Deep yellow Deep yellow Capsules Usually 2.5 mm 4—6 mm in diame- 3.5-5 mm in diameter, in diameter, ter, usually en- equal to or exceeding equal to or ex- lobes closed to equal- ceeding lobes ing lobes *Table modified from S. Graham (1979). form of A. latifolia (Merrill, 1949). The correct application, determined by examination of the Rafinesque type located at p, is as a synonym of A. coccinea. 4. Ammannia latifolia L. Sp. Pl. 1: 119. 1753. Type: Savage H 156.1 (lectotype, LINN, IDC 177. 99: II. 7!).4 Map 3. Ammannia lythrifolia Salisb. Prodr. Stirp. 65. 1796, nomen illegit. et superfl. Isnardia subhastata Ruiz & Pavon, Fl. Peru. & Chil. 1: 66. t. 86, fig. b. 1798. Jussiaea sagittata Poiret in ne Encycl. Méth. Bot. Suppl. 3: 198. 1813. Type based La ee from Santo Domingo, grown in Paris and described from Herb. Desfon- s. Description a latifolia ae hastata Sprengel, ee es ed. 16 [17]. 1: 446. [1824] 1825. Basionym: Isnardia subhastata Ruiz & P Ammannia hastata DC. Prodr. Syst. tht Regni Veg. 3: 78. 1828. BASIONYM: Isnardia i Pav. sibel aa DC. ibid. 80 gulata Griseb. Catal. Pl. Cubens. 106. 1866. Type: Cuba, eat oat Hoitpe GH!—this specimen annotated Ammannia lingulata Gr. in Wright’s hand, with Wright’s original field note attached, and labeled Ammannia latifolia, not at GOET or k). Ammannia koehnei Britton, Bull. Torrey Bot. Club 18: 271. 1891. Type: U. S., New Jersey, Hackensack Flats, 28 July 1868, W. H. Leggett s.n. (holotype, Ny!; isotype, NY!). 4This specimen bears the annotation “‘latifolia 1” in Linnaeus’s eee The number indicates the position of the species in Species Plantarum, indicating that it wa by Linnaeus prior to pub- lication of this work or soon after and is therefore the obligate oe (Stearn, 1974, and pers. 412 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 A. latifolia : SS - ( Ce Ne poke FEA C4 petalous 4 apetalous laf. —e ey a Map 3. Distribution of Ammannia latifolia. Ammannia friesii Koehne in Engler, Pflanzenr. IV. 216(Heft 17): 50. 1903. Type: Argentina, Prov. Jujuy, Quinta, near Laguna de la Brea, R. FE. Fries 94 (holotype, B, presumably destroyed; isotype, s!). Ammannia koehnei var. exauriculata Fern, Rhodora 38: 437. t. 449, figs. 4, 5. 1936. Type: U. S., Vir ak goo Princess Co., Fernald, Long, & Fogg 4954 (holotype, GH!; isotypes, Mol Ny!, US Ammannia teres var. ee (Fern.) Fern. Rhodora 46: 50. 1944. Me Robust erect annuals to 10 dm tall, unbranched or sparsely branching mainly from lower portions of stem, the branches ascending, shorter than stem. Leaves mostly linear-lanceolate to oblong, elliptic, or spathulate, 15—70(-100) by 4— 15(-21) mm, usually equal to or longer than internode above, mature leaves mostly uniform in size, not significantly smaller toward apex of stem, the apex obtuse to subacute, the base strongly to moderately auriculate and rarely cu- neate on middle and upper leaves, cuneate on lower ones. Inflorescences ax- illary, short-pedunculate or sessile, closely flowered cymes; flowers (1 to) 3 to 10 per cyme; peduncle, when present, to 3 mm long. Floral tube 4-merous, urceolate in bud, globose and 4—6 mm in diameter in fruit, subtended by linear bracteoles 1—1.5 mm long; lobes of fruiting calyx broad, apex very small or mucronate (occasionally slightly cucullate), disappearing with enlargement of capsule; appendages short, thick; petals lacking or | to 4 (to 6), obovate, to | 1985] GRAHAM, AMMANNIA 413 mm long, pale pink to white; stamens 4 (to 8), included; style thick, 0.5 mm long, much shorter than ovary. Capsule incompletely 2- to 4-locular, included to barely exserted. n = 24. Ammannia latifolia is a robust, erect, sparsely branched species in which the flowers are short styled, sessile, and usually three in each axil, with petals lacking or one to four. Broad calyx lobes with minute, mucronate apexes are distinctive. The species is distributed in brackish to fresh-water marshes and ditches along the Atlantic and Gulf coasts from New Jersey southward to Florida, west to Texas, throughout the Caribbean, and in widely scattered, primarily coastal localities in South America. The species is not present in California; specimens so identified are A. coccinea. An initial survey of variability in Ammannia latifolia in the United States and the Caribbean led me to consider the eastern North American and Carib- bean specimens to be a single species. A study of many more collections from throughout the entire range of the species now confirms that decision and leads me also to include A. friesii Koehne of northern Argentina within A. /atifolia. The two have been distinguished weakly at best, but since the recognized species of Ammannia are often separated by few characters, an intensive comparison of characters was made. In Koehne’s treatment (1903), A. /atifolia is described as having calyxes 4-5 mm long, flowers apetalous, and lower leaves cordate to auriculate. Ammannia friesii differs from A. /atifolia in having 4 to 6 petals | mm long. The eastern North American A. koehnei (later incorrectly referred to A. teres Raf.; see discussion under A. coccinea) is distinguished by its calyxes 5-6 mm long, 4 petals 1.5 mm long, lower leaves cuneate, lobes retuse margined, and bracteoles larger than those of A. friesil. xamination of herbarium specimens indicates that the species are not con- sistently separable on these or any other characters. When leaves are present at the lowest nodes, they are cuneate based. Calyx length varies from 3.5 to 6 mm throughout the range, mature calyx lobes are the same shape, and bracteole length varies insignificantl Petalous and apetalous plants are found throughout most of the range (see Map 3). Although all specimens collected north of approximately 28°30'N latitude in the eastern United States have petals, 24 percent of the collections studied from south of that latitude also have them, and these collections are from widely separated localities. A previous figure of 30 percent petalous plants (S. Graham, 1975) is based on fewer collections. In a Manatee Co., Florida, population surveyed (Graham 698, micu) 10 percent of the plants had petals. Flowers from a single plant were either petalous or apetalous, with the single exception of a primarily apetalous plant that bore one-petaled flowers on one branch. Petalous flowers typically bear four fully developed petals, but they may also be found with one to three rudimentary ones. Presence of petals appears to be a sporadic phenomenon in all but the northernmost part of the range, and their presence there is difficult to determine unless mature buds are present. Since no other morphological character is correlated with presence or absence of petals and at least four other species of Ammannia have either no petals or one to four of them, maintenance of the species on this basis alone is not justified. 414 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Tas_e 4. Geographic variation of selected characters of Ammannia latifolia. MEAN MEAN LEAF PERCENT CAPSULE LENGTH/ PETALOUS — DIAMETER WIDTH REGION PLANTS (mm) QUOTIENT Maryland—North Carolina 100 5.5 4.05 tear aaa Florida 100 4.8 5.97 ee 50 4.5 5.61 Bahama 17 4.5 7.81 Greater Anes, Yucatan 30 4.2 7.71 Lesser Antil 0 4.4 6.53 South eaanis Panama 25 4.3 7.36 Geographic variation in leaf length/width quotient, mature capsule size, and percent petalous specimens is summarized in TABLE 4. Leaves are spathulate to mainly lanceolate in the northern part of the range, and commonly linear- lanceolate from North Carolina southward, with infrequent spathulate-leaved specimens found in the Caribbean area. The spathulate leaf with a cuneate base is ajuvenile leaf-form typical of the first set of leaves in the seedling. Collections of Ammannia latifolia from Virginia, scattered localities in the Caribbean, and Peru with only this leaf type represent cases of arrested development of the mature leaf-form. Ammannia teres var. exauriculata (Fern.) Fern. is based on plants with predominantly spathulate leaves and cuneate bases. Leaf length/width quotients initially increase southward, reaching a maxi- mum in the Bahamas and Greater Antilles, and thereafter decrease slightly, suggesting that vegetative growth for this taxon is optimum in the northern Caribbean region. Capsule size is most variable in the north, but the difference in mean size between the largest and smallest capsule on all specimens is only 1.3 mm. There are no significant discontinuities in morphology over the approxi- mately 7500 km north-south distribution that would justify retention of more than one species. Ammannia latifolia is, in fact, remarkably uniform consid- ering its extensive range. Autogamy, particularly cleistogamy (the common mode of fertilization in the apetalous plants), is probably the major factor in maintaining this uniformity. On the basis of Koehne’s monographic descriptions, Ammannia latifolia is most similar to A. urceolata Hiern, an African endemic. Koehne’s (1880b) suggestion that A. /atifolia (n = 24) could have been ae from ye coccinea (n = 33) is discarded due to the difference in chromosome numbers. Ammannia latifolia, with n = 24, is more likely a hexaploid derived from an ancestral x = 8 5. Ammannia robusta Heer & Regel, Index Sem. Horto Bot. Turic. adn. 1. 1842. Type: Brazil, Rio de Janeiro, Piratininga, 23 July 1875, Glaziou 5340 (neotype (here designated), R!). Map 4. Ammannia sanguinolenta subsp. robusta (Heer & Regel) Koehne im Martius, Fl. Brasil. 13(2): 208. 1877. 1985] GRAHAM, AMMANNIA 415 Lo yo ; J? a> : 4 A. robusta So ST fy Ls ys Map 4. Distribution of 4mmannia robusta in Western Hemisphere. (Collections from LAF, DUKE, and Ncu not included.) Ammannia coccinea subsp. robusta (Heer & Regel) Koehne, Bot. Jahrb. Syst. 1: 250. 1880 Ammannia alcalina Blank. Montana Coll. Agric. Sci. Stud., Bot. 1: 1905. Type: U. S., Montana, Lake Bowdoin, near Malta, 25 Aug. 1903, J. W. Blankinship s.n. (lectotype (here designated), MONT). Robust annual herbs to | m tall, unbranched or branching from base, the lowest pairs of branches decumbent, often equaling height of main stem, the upper branches fewer, shorter. Leaves linear-lanceolate, less often elliptic to spathulate, 15-80 by 4-15 mm, usually 1-3 times length of internode above, tending to be fleshy, the apex obtuse to generally acute, the base auriculate- cordate, clasping, occasionally cuneate on lowermost leaves. Inflorescences axillary, sessile, 1- to 3- (to 5-)flowered cymes. Floral tube urceolate, frequently prominently 4-ridged or subalate, averaging 3.5 by 2 mm, subtended by 2 linear bracteoles 2 height of tube; calyx lobes broadly triangular with acute apex, alternating with thickened appendages equal to lobes in length; append- ages usually erect in bud; petals 4 (to 8), obovate, usually 2.5 by 3 mm, pale lavender, sometimes with deep rose spot at base of midvein or with rose-purple midvein; stamens 4 (or 5 to 12), exserted, anthers pale yellow to yellow; style long, slender, slightly exserted at anthesis; ovary incompletely 2- (to 4-)locular. Capsule 4-6 mm in diameter at maturity, enclosed in or equal to calyx lobes, rarely exceeding lobes. n = Ammannia robusta has been overlooked in the North American flora because of its morphological similarity to 4. coccinea (under which most specimens have been determined). In the field it is easily distinguished from A. coccinea 416 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 by a combination of features: pale lavender petals and light yellow anthers, one to three large, sessile flowers with four exaggerated ribs, and large, sessile capsules 4-6 mm in diameter. Mature herbarium specimens occasionally pose problems in identification due to change of petal and anther color in drying, but the presence of one to three large, sessile capsules at each axil is generally sufficient for determination. Variability in size of floral parts among A. robusta, A. coccinea, and A. auriculata is summarized in TABLE 3. Mixed collections of these species are not unusual in the herbarium since they may grow side by side at a single site and have been assumed by collectors to represent mor- phological variability within a single species. Ammannia robusta is widely distributed in North America except in the southeastern United States and is most frequently collected in the Plains States. It is uncommon in the Caribbean, and it is limited to the coast north of Rio de Janeiro in South America, where it is apparently an early, but persistent, introduction. The species was described from cultivated material of Brazilian origin. A type has not been located. Regel may have taken herbarium and library material with him to St. Petersburg on leaving Zurich (C. D. K. Cook, pers. comm.), but the type material of Ammannia robusta has not been located at Le. Since the description leaves no question as to the application of the name, a neotype has been selected from a Brazilian collection. EXCLUDED NAMES* Ammannia alata Steudel, Nomencl. Bot. ed. 2. 1: 76. 1840, nomen nudum. Ammannia auriculata auct., non Willd., Raf. Atlantic J. 1: 146. 1832 = A. ramosior sensu Torrey, Ann. Lyceum Nat. Hist. New York 2: 199. 1827 = Rotala ramosior (L.) Koehne. Ammannia catholica Hooker & Arn. ex Seemann, Bot. Voy. Herald, 284. 1856, pro syn. = Rotala ramosior (L.) Koehne. Ammannia catholica var. brasiliensis Cham. & Schldl. Linnaea 2: 379. 1827 = Rotala ramosior (L.) Koehne; see Van Leeuwen (1974) and Cook en Ammannia coccinea auct., non Rottb., Pers. Synopsis Pl. 1: 147. 1805 = A. octandra L. Ammannia coccinea subsp. pubiflora Koehne, Bot. Jahrb. Syst. 1: 250. 1880. Tyee: Iran, Hohenacher 2948. Authentic material unknown; not at BM or cas. Description inadequate. Ammannia dentifera A. Gray, Pl. Wright. 2:55. 1853 = Rotala dentifera (Gray) Koehne, Bot. Jahrb. Syst. 1: 161. 1880 = R. ramosior var. dentifera (A. Gray) Lundell, Bull. Torrey Bot. Club 69: 395. 1942. Ammannia diffusa Raf. Aut. Bot. 1: 39. 1840, non Willd., 1809, nomen du- bium. The description is applicable to both A. auriculata and A. coccinea. Authentic material unknown. Ammannia humilis Michaux, Fl. Bor. Amer. 1: 99. 1803 = Boykiana humilis (Michaux) Raf. Neogenyton, 2. 1825 = Rotala ramosior (L.) Koehne. ‘Including misidentifications and misapplications listed by Koehne (1903) and Index Kewensis for the Western Hemisphere species 1985] GRAHAM, AMMANNIA 417 Ammannia humilis auct., non Michaux, Chapman, Fl. So. U.S. 134. 1860, ex escr. = R. ramosior, pro parte, and A. coccinea, pro parte. Ammannia hyrcanica Fischer ex Steudel, Nomencl. Bot. ed. 2. 1: 77. 1840, nomen nudum Ammannia latifolia auct., non L., Wallich, Catal. no. 2096. 1829, nomen nu- dum (not validated by G. Don, Gen. Syst., 1831-1838), nec Walp. Rep. Bot. Syst. 2: 102. 1843. Ammannia linearifolia Raf. Aut. Bot. 1: 39. 1840, ex descr. = Rotala ramosior (L.) Koehne Ammannia longifolia Raf. ibid., nomen dubium (description inadequate), syn- onym for either A. coccinea or A. robusta. Authentic material unknown. Ammannia mexicana (Cham. & Schldl.) Baillon in Grandidier, Hist. Nat. PI. (Madagascar Atlas) 3: ¢t. 363. 1895 = Rotala mexicana Cham. & Schldl. Ammannia monoflora Blanco, Fl. Filip. ed. 1. 64. 1837, nomen dubium (de- scription inadequate) = Rotala ramosior (L.) Koehne (Cook, 1979) Ammannia multicaulis Raf. Aut. Bot. 1: 39. 1840, ex descr. = Rotala ramosior (L.) Koehne pes nuttallii A. Gray, Man. ae No. U. S. ed. 4. Add. 92. 1863, ex descr. = Didiplis diandra (DC.) W Ammannia occidentalis DC. Prodr. | Nat. Regni Veg. 3: 78. 1828 = Rotala ramosior (L.) Koehne. Ammannia occidentalis var. ppgmaea Chapman, Fl. So. U.S. 134. 1860. Tye: U. S., Florida, Key West, Dr. Blodgett s.n., ex descr. = Rotala ramosior (L.) Koehne. Ammannia pallida Lehm. Index Sem. Horto Bot. Hamburg, 3. 1823, Linnaea 3: 9. 1828, nomen dubium. Authentic material unknown, not at kK. Koehne followed DC. in regarding A. pallida as synonymous with A. J/atifolia, but description inadequate and even country of origin unknown Ammannia racemosa Hill, Veg. Syst. 11: 14. 1767. An erroneous citation in Index Kewensis for A. ramosior L Ammannia ramosior L. Sp. Pl. 1: 120. 1753, ed. 2. 175. 1762, non sensu L. Mant. Pl. Alt. 332. 1771. Type: U.S., Virginia, Clayton 774 (Savage H 156.2, LINN). = Rotala ramosior (L.) Koehne. Ammannia ramosior auct., non L., Elliott, Sketch Bot. S. Carolina & Georgia 1: 219. 1817, ex descr. = A. latifolia L. Ammannia sanguinolenta auct., non Sw., Cham. & Schlidl. Linnaea 5: 568. 1830 = A. auriculata fide Koehne, who probably saw this specimen at B. Ammannia sanguinolenta auct., non Sw., Heyne ex Steudel, Nomencl. Bot. ed. 2.1: 77. 1840, pro syn. Ammannia sanguinolenta auct., non Sw., Hooker & Arn. ex Seemann, Bot. Voy. Herald, 284. 1856, pro syn Ammannia wormskioldii Fischer & Meyer, Index Sem. Hortus Imp. Petrop. 7: 42. 1841. Not from Brazil as cited by Koehne in Martius, Fl. Brasil. 13(2): 205. Type (LE!) bears notation “‘C[ult.] e semina Congo allatis.”” A specimen from Koehne’s herbarium (Gu!) initially determined by him as A. worm- skioldii was corrected by him to 4A. /atifolia and may be the basis for the erroneous report of this species in the New Worl 418 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Ludwigia scabriuscula Kellogg, Proc. Calif. Acad. Sci. 7: 78. 1876. Equated by Koehne with Ammannia latifolia, but A. latifolia does not occur in Califor- nia, and by description, the species (with scabrulose, small-toothed leaves, clawed petals, and a 4-lobed stigma) does not belong to the genus Ammannia. Authentic material unknown; not at BM. Lythrum apetalum Sprengel, Syst. Veg. ed. 16 [17]. 2: 454. 1825. Erroneously equated with Ammannia latifolia in Index Kewensis, ex descr. non Amman- nia. = Heimia myrtifolia fide Koehne, 1903. ACKNOWLEDGMENTS Collections of the following herbaria were studied: A, CAS, CHAPA, DS, ENCB, F, GH, ILL, IND, ISM, JEPS, KANU, MEXU, MICH, MO, NY, OKL, OSU, R, SDU, SP, TEX, UC, US, VEN, WIS; the cooperation of the curators is gratefully acknowledged. Distribution data are based on specimens from these herbaria and on collections studied earlier from LAF, LTU, MISS, NCSC, NCU, TENN, vpB (S. Graham, 1975). I wish to thank William T. Stearn (British Museum), Werner Greuter (Bo- tanischer Garten und Botanisches Museum, Berlin-Dahlem), and Edward Voss (University of Michigan) for nomenclatural advice and Alan Graham (Kent State University) for SEM photographs. Becky Klingenworth prepared Figure 2. LITERATURE CITED AspA, G. 1977. An adventive plant new for the Italian flora. Inform. Bot. Ital. 9: 286- 288. Apams, C. D. 1972. Flowering plants of Jamaica. Univ. West Indies, Mona ARBER, A. 1920. Water plants. A study of aquatic angiosperms. Cambridge ae Press, Cambridge, England. Baas, P., & R. C. V. J. ZWEYPFENNING. 1979. Wood anatomy of the Lythraceae. Acta Bot. Neerl. 28: 117-155. BENTHAM, G., & J. D. Hooker. 1867. Genera plantarum 1: 773-785. (Facsimile ed.) Wheldon & Wesley, Codicote, England. Bir, S. S., & M. Sipnu. 1975. IOPB chromosome number reports XLIX. Taxon 24: 515. Cook, C. K., ed. 1974. Water plants of the world. W. Junk, The Hague 9. "A revision of the genus Rota/a (Lythraceae). Boissiera 29: 1- 156. Corner, . J. H. 1976. The seeds of dicotyledons. Vol. 1. Cambridge Univ. Press, Cambridge, England. Darwin, C. R. 1859. On the origin of species by natural selection. John Murray, London. Do.sBearE, B. L. 1973. Plant collections of Rollo T. Rexroat. Trans. Illinois State Acad. Sci. 66: 81-93. FERNANDES, A., & M. A. Diniz. 1955. Lythraceae Africanae novae. Bol. Soc. Brot. 29: 87-99 GRAHAM, A., J. Nowicke, J. SKVARLA, S. GRAHAM, V. PATEL, & S. Lee. 1985. Paly- nology and systematics of the reeset . iets and genera Adenaria through Ginoria. Amer. J. Bot. 72 (in pre GRAHAM, S. 1975. Taxonomy of the ean the southeastern United States. Sida ——.. 1979. The origin of Ammannia x coccinea Rottboell. Taxon 28: 169-178. 1985] GRAHAM, AMMANNIA 419 , B. N. TIMMERMAN, & T. J. MABry. 1980. Flavonoid glycosides in Ammannia coccinea (Lythraceae). J. Nat. Prod. 43: 644, 645. HAnsEN, C., .F. Maute. 1973. Pehr Osbeck’s collections and Linnaeus’s Species Plantarum (1753). J. Linn. Soc., Bot. 67: 189-212. Josut, A. C., & J. VENKATESWARLU. 1936. Embryological studies in the Lythraceae. Proc. Indian Acad. Sci. 3: 377-400. KoeEHNE, E. 1880a. Lythraceae. I. Rota/a L. (ampl.). Bot. Jahrb. Syst. 1: 145-178. —. 1880b. Lythraceae. I]. Ammannia “Houst.” L. (restr.). Ibid. 240-262. . Ammannia. In: A. ENGLER, ed., Pflanzenr. I. 216(Heft 17): 42-56. ichisenapes, D.G. 1971. Cyt Proc. Indian Acad. Sci. 73: 179-185. a B. L. J. vAN. 1974. A preliminary revision of the genus Rotala (Lythraceae) n Malesia. Blumea 19: 53-5 oa C. 1737. Critica botaniea: C. Wishoff, Leiden . 1771. Mantissa plantarum altera. (Facsimile ed.) J. Cramer, Lehre Mason, H. L. 1957. A flora of the marshes of California. Univ. Calif. Press, Berkeley. MerRILL, E. D. 1949. Index Rafinesquianus. Arnold Arboretum of Harvard Univ., Jamaica Plain, Massachusetts Mo FINO, J. F. 1926. Adiciones a la flora same adventicia de la Argentina. Anales Museo Nac. Hist. Nat. Buenos Aires 34: 89-119. PANIGRAHI, S. G. 1979. Studies on generic rei see of the four genera Rotala, mmannia, Nesaea, & Hionanthera (Lythraceae). Bull. Bot. Surv. India 18: 178- 193 . Contribution of anatomy to the systematics of Ammannia. Phytomor- phology 30: 320-330. Rotrse it, C. F. 1773. Plantas horti universitatis rariores programmatae. Sander & Morthorst, Copenhagen. SARKAR, A. K., N. Datta, & U. CHATTERJEE. 1980. IOPB chromosome number reports LXVII. Taxon 29: 361. ,& D. Hazra. 1982. IOPB chromosome number reports LXXVI. Taxon 31: 578. SHetty, S. V. R., H. S. Girt, & L. S. Brar. 1975. Weed flora of rice (Oryza sativa L.) in the Punjab. J. Res. Punjab Agric. Univ. 12: 43-51. Situ, B. B., & J. M. Herr, Jr. 1971. Ovule development, megagametogenesis, and early embryogeny in Ammannia coccinea Rothb. J. Elisha Mitchell Sci. Soc. 87: 192-199. STEARN, W. T. 1957. An introduction to the Species Plantarum and cognate botanical works of Carl Linnaeus. /n: C. LINNAEUS, Sp. PI. (facsimile ed.) 1: 1-176. Ray Society, London. 1974. Typification of Cannabis sativa L. Bot. Mus. Leafl. 23: 325-336 STEHLE, H., M. STEHLE, & L. QuENTIN. 1948. Flore de la Guadeloupe et dépendances et de la Martinique. Vol. 2. Catalogue des phanérogames et fougéres. Clément Brunel, Srusss, J. M., & A. R. Stasas. 1982. Ultrastructural and biochemical characterization of the epidermal hairs of the seeds of Cuphea procumbens. Planta 155: 392-399 Tose, H., & P. H. Raven. 1983. An embryological analysis of Myrtales: its definition and ape Ann. Missouri Bot. Gard. 70: 71- Voss, E. G., comm. chrmn. 1983. International code of botanical nomenclature. W. Junk, ee Hague. 420 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 APPENDIX. Index of cited plant names.* py eiaHas se Steudel = excl A. alcalin ank. = rob A. arenaria ae = aur A, auriculata Ledeb. ex Koehne = aur Ild. = A. auriculata var. arenaria ia (HBK.) Koehne ur A, auriculata var. arenaria f. brasiliensis (St. Hil.) Koehne coc A. coccinea subsp. longifolia (Koehne) Koehne = coc A. coccinea subsp. pubiflora Koehne = excl A. coccinea subsp. purpurea (Lam.) Koehne = coc A. coccinea subsp. robusta (Heer & Regel) Koehne = ro A. dentifera A. ak = excl A. diffusa Raf. = . friesii Koebne = — er hastata DC. = lat humilis Chapman = excl . humilis Michaux = excl . hyrcanica Fischer ex Steudel = excl . koehnei Britton = lat koehnei var. exauriculata Fern. = lat latifolia L. = lat latifolia Wallich = excl latifolia var. octandra A. Gray = coc linearifolia Raf. = excl lingulata Griseb. = lat longifolia Raf. = excl . longipes Wright = aur . lythrifolia Salisb. = mexicana (Cham. & a ) Baillon = excl A, monoflora Blanco = excl A, multicaulis Raf. = excl — oo DEPARTMENT OF BIOLOGICAL SCIENCES KENT STATE UNIVERSITY KENT, Onto 44242 A. nuttallii A. Gray = ex . paceaia) (Sprengel). DC. = ccidentalis var. pygmaea eee - a ae pains Cham. & Schldl. = coc pallida Lehm. = excl pedunculata Rusby = coc purpurea Lam. = coc pusilla Sonder = aur ramosior Elliott = excl ramosior L. = exc robusta Heer & Regel = rob sagittata DC. = lat sagittata var. angustifolia A. Rich. coc A, sanguinolenta Cham. & Schldl. = excl ee or oa eS g Q S % S 9 oH Q Sy lI o ~ &. A. sanguinolenta Heyne ex Steudel = excl . sanguinolenta Hooker & Arn. ex See- mann = excl A, sanguinolenta Sw. = coc A. sanguinolenta subsp. longifolia Koehne, = coc A, as ae subsp. purpurea (Lam.) Koehne A. ea ene eee robusta (Heer & Regel) Koehne A, ig var. brasiliensis St. Hil. = A, ce Fischer & Meyer = coc A. teres Raf. = coc A. teres var. exauriculata (Fern.) Fern. = lat A. texana Scheele = A, wormskioldii Fischer & Meyer = excl A, wrightii A. Gray = aur Isnardia subhastata Ruiz & Pavon = lat Lythrum apetalum a = excl Ronconia triflora Raf. = *Explanation of abbreviations: aur = Ammannia eee bace = A. baccifera, cocc = A. coccinea, robus excl = excluded name, lat = A. /atifolia, rob = A. 1985] DONOGHUE, VIBURNUM 421 POLLEN DIVERSITY AND EXINE EVOLUTION IN VIBURNUM AND THE CAPRIFOLIACEAE SENSU LATO! MICHAEL J. DONOGHUE STUDIES OF POLLEN DEVELOPMENT and function (Heslop-Harrison, 1971), along with correlations between pollen morphology, incompatibility system, and mode of pollination (DeNettancourt, 1977; Lee, 1978; Plitmann & Levin, 1983), have prompted speculation about the adaptive significance of pollen characteristics (Heslop-Harrison, 1976, 1979; Lewis, 1977). At the same time considerable attention has been devoted to the related but logically separate task of determining the actual course of pollen evolution, with special emphasis on the exine (Erdtman, 1966; Walker & Doyle, 1975; Ferguson & Muller, 1976; Nowicke & Skvarla, 1979). A particular hypothesis about pollen evolution is usually established by considering pollen diversity in the context of presumed relationships. Pollen characters are mapped onto a classification (which is usually based on many other kinds of characters), and the most plausible sequence of evolutionary events for the pollen is established in this context. This procedure is basically sound, but clearly the results obtained can be no better than the hypothesis of relationships employed. Unfortunately, relation- ships have not yet been rigorously established for most plant groups, and present classifications do not always reflect these accurately or unambiguously. Thus, although considerable progress has been made in tracing the course of pollen evolution, the level of resolution has not always been very satisfactory. Cladistic analysis can be a powerful tool for the study of character evolution. A cladogram provides a test of the congruence of characters and establishes the simplest hypothesis of the direction and sequence of character transfor- mations. In addition, it is a rigorous means of assessing the nature and extent of homoplasy—i.e., of convergent evolution and reversal. One can also deter- mine the relative timing of the origin of traits, information that is critical for the historical analysis of adaptation. Thus it is possible to establish the level at which a particular character transformation (e.g., from small to large pollen) occurred relative to changes in other characters of interest (e.g., style length). Unfortunately, cladograms are now available for only a small number of plant groups, and with only a few exceptions (e.g., Kress & Stone, 1983) pollen evolution has not been studied in a cladistic context. The primary purpose of this paper is to provide a cladistic analysis of exine evolution in Viburnum L. This genus is especially well suited for the purpose for three reasons. First, its pollen is quite well known from previous studies, and the present survey sig- 'A portion of a thesis submitted to the aaron of Biology, Harvard University, in partial fulfillment of the requirements for the Ph.D. deg © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 421-469. October, 1985. 422 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 nificantly increases the number of species sampled and gives a clear under- standing of the taxonomic distribution of pollen characters. We can now be quite confident that we know the range and pattern of pollen variation in the genus. Second, a corroborated hypothesis of the cladistic relationships of Vi- burnum to other genera is available (Donoghue, 1983b), enabling evaluation of the polarity of pollen characters using outgroup analysis (Maddison et al., 1984). Finally, a preliminary cladistic analysis of the genus has been carried out (Donoghue, 1983a), making it possible to assess the congruence of pollen characters with other characters and to establish the most parsimonious hy- pothesis of exine evolution. An equally rigorous analysis of pollen evolution in other Caprifoliaceae is not yet possible. However, cladistic reasoning can still be applied, and it is possible to generate preliminary hypotheses that can be tested in the future. Throughout this paper I refer to Caprifoliaceae sensu stricto (s.s.) and Ca- prifoliaceae sensu Jato (s.l.). The family Caprifoliaceae s.s. is equivalent to the subfamily Caprifolioideae of Hara (1983) and contains 11 genera that he as- signed to four tribes: Leycesteria Wallich and Lonicera L. of the Caprifolieae; Diervilla Miller and Weigela Thunb. of the Diervilleae; Triosteum L. of the Triosteae; and Abelia R. Br., Dipelta Maxim., Heptacodium Rehder, Kolkwitzia Graebner, Linnaea L., and Symphoricarpos Duhamel of the Linnaeeae. The Caprifoliaceae s./. consist of the Caprifoliaceae s.s. plus Viburnum, Sambucus L., and Adoxa L. The last genus is frequently placed in its own family, Adox- aceae, but many characters point to a close relationship between Adoxa and Sambucus, and of these genera to Viburnum (Donoghue, 1983b). It is therefore essential to include Adoxa in evolutionary studies involving Sambucus and Viburnum. Two new species, Adoxa omeiensis Hara (Wu, 1981; Hara, 1981, 1983) and Sinadoxa corydalifolia C. Y. Wu, Z. L. Wu, & R. F. Huang (Wu et al., 1981) have recently been described in the Adoxaceae. These resemble Adoxa mos- chatellina L. and should probably also be included in the Caprifoliaceae s./. They are excluded here simply because they are very poorly known and their pollen was unavailable for study. Since Wu’s (1981) scanning electron micro- graphs show that the pollen of both new species is very similar to that of Adoxa and Sambucus, the results of the present analysis would not have been signif- icantly altered by the inclusion of these taxa. POLLEN DIVERSITY IN THE CAPRIFOLIACEAE S.L. PREVIOUS STUDIES Light microscopic (LM) studies have revealed considerable variation in pol- len morphology in the Caprifoliaceae s./., and to a lesser extent within Viburnum (see Erdtman, 1966, and Thanikaimoni, 1972, for references to the early lit- erature; see also Punt ef a/., 1974; Reitsma & Reuvers, 1975). Punt and col- leagues (1974) published scanning electron micrographs (SEMGs) of the pollen of three species, Rader (1976) used the SEM to study several species in V/- burnum sect. LENTAGO, Reitsma and Reuvers (1975) published SEMGs of Adoxa moschatellina, and Adams and Morton (1979) presented SEMGs of 1985] DONOGHUE, VIBURNUM 423 18 species in five genera. More recently, BOhnke-Giitlein and Weberling (1981) published the first part (tribes Sambuceae, Viburneae, and Diervilleae) of a careful and extensive LM and SEM survey of the pollen of the Caprifoliaceae, and Hara (1983) included SEMGs of the pollen of 30 specimens in his treatment of the Caprifoliaceae of Japan. Unfortunately and despite considerable previous study and the evident di- versity of pollen in the Caprifoliaceae s./., pollen characters have been used littke—or uncritically—by phylogenists. Because most palynological work on the group has been conducted within the last decade, information pertaining to pollen morphology is entirely lacking from the most recent comprehensive revision of the tribes of the family (Fukuoka, 1972). It has been noted, however, that the pollen of Adoxa is very similar to that of Sambucus (Cronquist, 1968, 1981) and that the pollen grains of Viburnum and Sambucus are similar, but that all differ markedly from the pollen of the four tribes of Caprifoliaceae s.s. (Ferguson, 1966; Lewis, pers. comm. in Hillebrand & Fairbrothers, 1970; also cited in Bohm & Glennie, 1971). The genera of the Caprifoliaceae s.s. are palynologically similar (Erdtman, 1966; Lewis & Fantz, 1973), but there is significant variation in pollen size (apparently correlated with chromosome number) in Symphoricarpos (Bassett & Crompton, 1970), and pollen differences in Abelia (Ikuse & Kurosawa, 1954; Erdtman, 1966, 1969) prompted the seg- regation of the genus Zabelia Makino. Bohnke-Giitlein and Weberling (1981) discussed some taxonomic implications of pollen diversity in the family but reached few conclusions about phylogenetic relationships or the evolution of pollen morphology in the group. However, additional discussion is expected in the second portion of their survey (MS in press, fide Bohnke-Giitlein & Weberling, 1981). MATERIALS AND METHODS Pollen from mature anthers was afhixed to aluminum stubs with double-stick tape. All samples are vouchered by annotated herbarium specimens (see TABLES 1, 2), most of which are deposited in the Harvard University Herbaria (A or GH). Prepared stubs were coated with approximately 200 A of gold-palladium in two 1.5-minute steps using a Technics Hummer IJ sputter coater. Specimens were examined with an AMR model 1000a scanning electron microscope, in the secondary electron mode, using accelerating voltages up to 20 kv. SEMGs were recorded on Polaroid Type 55 P/N 4x5” film. All photomicrographs were taken at the Museum of Comparative Zoology Scanning Electron Microscope Laboratory, Harvard University. The method of preparation of pollen grains for the SEM can sometimes significantly affect the results obtained (Hanks & Fairbrothers, 1970). In the initial phases of this study, pollen was acetolyzed (according to Erdtman, 1960) prior to scanning. However, when it was found that unacetolyzed and aceto- lyzed pollen of Viburnum differed little (1.e., ““Pollenkitt” is limited), acetolysis was discontinued. The transmission electron microscope (TEM) was not uti- lized in this study, but cross sections of the exine were obtained for SEM study by spreading pollen on a glass plate, cutting it with a razor blade, and trans- ferring it with a brush to a stub. TABLE l. The pollen of Viburnum. POLLEN DIMENSIONS“ VOUCHER SPECIMEN® ; Polar axis Equatorial POLLEN POLLEN TAXON’ (P) in um axis (E) in um P/E? SHAPE’ TYPE° Locality Collection Odontotinus Rehder V. acerifolium — — — an (L)a -S.A.: Churchill Lise Connect- Siethes icut (MSC) V. dentatum L. — ai as ame (L)a U.S.A Hermann 4240 New Jersey . dilatatum L650 33 48.6 16, 5°17 471826 0.98 O-S la Japan: Ohashi,, Thunb. s = 0.576 s = 0.785 Izu Pen- Nakaike, & insula Tateishi 70627 (A) . ellipticum 22.6(24.4)25.8 19 5122.26) 2487 1.08 P-S la U.S.A Hunt 36 (A) Hooker s = 0.840 s = 1.427 Oregon V. foetidum 18.6(20.7)21.6 12.4(14.0)15.5 1.48 EU la China: Forrest Wallich Ss = 1.112 = 0.750 Yunnan 18129 (A) V. japonicum 23.4(24.5)26.5 17.3(18.6)20.4 1.31 SP la Japan: Ichikawa 26 (Thunb. ) 5 = is) s = 0.821 Kyushu (A) Sprengel WOLAYOKUV ATONUV AHL JO TWNANOL PCP 99 “T0A] V. kansuense Batalin V. orientale ~ Pallas Ve. Tear anes quianum Schultes V. wrightii Miq. Oreinotinus (Oersted) Bentham & Hooker V. sempervirens Koch V. acutifolium Bentham V. caudatum Greenman V. ciliatum Greenman 7 e318 6) 19 0 24 16.5(18.1)19.6 103 s = 0.789 eh Le0sd 2000 165417 718 eG fe ye = 0.930 s = 0.718 et 42352) 2020 Lo734l0.5) L826 L4o3 = 1.102 = 0.775 EU EU (L)a (I)a (I)a China: Sichuan Turkey U.S.A.: Michigan ) Guandong Japan: Hizen Mexico: Oaxaca Mexico, sine loco Mexico: Hidalgo Rock 16440 S) Balls 1927 (A) Penfield S14 u 1909 (MICH) Gressitt 1247 (A) Hatusima 4206 (A) Stevens, Donoghue, & Scott 2492 (MSC) Gutierrez 54 (MICH) Maury 5786 (NY) [S861 WONYUNAIA “ANHDONOG Scr TABLE | (continued). POLLEN DIMENSIONS? VOUCHER SPECIMEN® 9CP Polar axis Equatorial POLLEN POLLEN TAXON? (P) in um axis (E) in um P/E* SHAPE’ TYPE° Locality Collection V. costaricanum (Ida Costa Rica: Lellinger & (Oersted) San Jose White 1588 Hemsley (F) V. hartwegii (Il)a Mexico: Stevens, Bentham Chiapas Donoghue, & Scott 2423 (MSC) V. jucundum (I)a Mexico: Stevens, Morton Chiapas Donoghue, & Scott 2350 (MSC) V. loeseneri (I)a Mexico: Stevens, Graebner Michoacan Donoghue, & Seott 2547 (MSC) V. mendax (I)a Guatemala: Skutch 1065 Morton Huehue- (US) tenango V. microcarpum 23.7(25.4)27.8 18.5(20.1)22.7 1.26 SP Ia Mexico: Ventura A. Schlecht. & Ss. =. 1.337 = 7 Veracruz 819 (ENCB) Cham. WOLAYOKUV ATIONYV AHL JO TVNANOL 99 “10a] V. stenocalyx Mexico: Purpus 163 (US) (Oersted) Puebla Hemsley Z are zs (@) - be ma ) vs ete ee : (I)a Ecuador: = _ ann uay = leo rT We Peat: sce ere (1)a < beewsl ool — = x g ie I sw = 7 19.6(20.3)21.6 1.10 P-S la s = 0.617 20.6 (22 4)23..7 18.6(20.3)21.6 1.10 P-S Ta s = 0,744 s = 0.798 7 1 . 35 Ta 26. ee 5)30.9 21.6(22.8)24.7 1.25 SP Ta China: BS = Lode s = 1.115 Hubei S i @ ie - “ i & aS —~] TABLE | (continued). POLLEN DIMENSIONS2 VOUCHER SPECIMEN® Polar axis Equatorial POLLEN POLLEN TAXON? (P) in um axis (E) in um P/E? SHAPE* TYPE® Locality Collection V. odoratissimum 22.7(23.9)24.7 20.6(22.4) 23.7 1.07 P-S la Philip- Alcasid 70 Ker Gawler s = 0.883 s = 0.840 pines (A) Mountain Province V. odoratissimum == ae — —S (I)a China H, H, Hu. 770 Ker Gawler Sichuan (A) V. oliganthum 26.8(28.8) 30.9 23.7(25.0)26.8 1.15 SP La China: H. Smith 1961 Batalin s = 1.172 s = 1.077 Sichuan (A) V. sieboldii ees aa ae aaa (I)a Japan: Maruyama 10 Miq Musashi (MICH) V. suspensum 22.7(23.8)25.8 20.6(22.0)22.7 1.08 P-§S Ta Japan: Hatusima 864 Lindley s = 1,112 = 0.770 Kyushu (GH) FIRMS (Miller) ie a Clarke V. atrocyaneum 23.7(25.2)26.8 19.6(21.0)23.7 1.20 SP Ia China: Rock 8905 C. Be Clarke s = 0.960 s = 1.386 Xizang (A) V. cinnamomi- 21.6(24.6)26.8 16.5(17.6)18.6 1.40 EU la China: i 537 4A) folium Rehder s = 1.325 s = 0.929 Sichuan WOLAYOUUV GIONYV AHL AO TVNANOL 8CP 99 “10A] V. davidii Franchet V. propinguum Hemsley V. tinus L. Tomentosa Nakai V. hanceanum Maxim. Vv. plicatum Thunb. Opulus DC. V.. edule (Michaux) Raf. V. sargentii Koehne V. sargentii ~ Koehne 25 Ol 27 a 2a. s = 0.828 L7s51(19;.0)20.6 s = 1.090 36.1(38,6)42.3 s = 1.700 22.7(24.7)26.8 s = 1.036 13.6(20,9) 22.7 Sso= 1253 22.7(24.7)25.8 1.11 s = 0.91 16.5(17.3)18.6 1.10 = 0.901 22.4 oso) 2aed 1,69 s = 0.861 14.4(15.8)16.5 1.56 s = 0.729 RSMo @ Ro geop aller ges) dyed = 0.755 2A 6122.9) 2447 19.261 20% 7921.6 oleae oe s = 0.797 =-O0.915 (Iya Cryo? Western China: Hubei Italy: Istria Hong Kong Japan: Sagami U.S.A.: Washing- ton Japan: Shinano Japan: Iwashiro Wilson 3728 (A) Henry 3415 A) Marchesetti 2752 (GH) Chun 5314 (A) Ohwi & Okamoto 502 (MICH) Suksdorf 2063 (A) e s.n., ~20 June 1961 (A) Furuse s.n., 9 June 1958 (A) WONYUNGIA ANHDONOG [S861 6cP TABLE | (continued). POLLEN DIMENSIONS? VOUCHER SPECIMEN® Polar axis Equatorial POLLEN POLLEN TAXON! (P) in um axis (E) in um P/E* SHAPE* TYPES Locality Collection Pseudotinus C. B. Clarke V. cordifolium 26.8(28.9)30.9 18.6(20.9)22.7 1.38 EU Ic China: Forrest 11892 Wallich ex DC. S = 1,427 s = 1.045 Yunnan (A) V. furcatum 17.5(19.5)21.6 17.5(18.2)18.6 1.07 P-S Ta Japan: Togashi 7145 Blume = 56 s = 0.557 Niigata (A) V. lantanoides 17.5(18.4)19.6 17.5(19.3)20.6 0.95 O-S la U.S.A.: Andrews s.n., Michaux s = 0.718 s = 0.831 Massa- 1897 (GH) chusetts Megalotinus (Maxim.) Rehder V. cylindricum 24.7(26.3)30.9 19.5(20.7)21.6 1.27 SP la China: Forrest Ham. ex D. Don s = g s = 0.516 Yunnan 11513 (A) V. cylindricum Sa — ——= —_—— (I)a Thailand: Iwatsuki, Ham. ex D. Don Chiang Koyama , ai Fukuoka, & Nalampoon 9424 (A) WOLAXYOUUV CATONYYV FHL AO TYNUANOL OtP 99 “IOA] V. punctatum ~ Ham. ex D. Don V. ternatum ~ Rehder Viburnum V. burejaeticum ~ Regel & Herder V. carlesii Hemsley V. lantana L. y. macrocephalum Fortune Va macrocephalum Fortune V. mongolicum ~ (Pallas) Rehder Va. Tyrie phyllum Hemsley Ma V. shensianum xim. 20.62 Lad y23% s = 1.088 27 (2OGa 29s s = 1.645 17.5(19.8)21 S 1220 23.7(24.5)25 s = 0.808 2991 S242)39 ith 7 245 742543) 20% $= 07835 rs) al 8 Nos ass Glare 8 ara s = 0.854 ZA wO( 2239) 20% S216 38h 23.7(25.3)26. Ss 60 1800 (2053)-215 6 = 0,978 PEREZ po) eT 892 Ss = 20.6(23.2)24., s = 1.008 Leo (2057 eos s = 1.033 China: Sichuan China: Guizhou N. Korea: N. Hamkyong Japan: Honshu England, sine loco China: Zhejiang China: Hubei China: Gansu China: Hubei China: Shanxi Schneider 691 (A) Teng 90584 (A Ishidoya s.n., 1918 (A) Togashi 7/61 (A) i Soe n 1883 (MICH) (A) Wilson 1835 (A) Rock 12480 Wilson 654 (US) Tang 776 (A) [S86 WONUNAIA ‘ANHDONOG ler TABLE | (continued). POLLEN DIMENSIONS* VOUCHER SPECIMEN® Polar axis Equatorial POLLEN POLLEN TAXON? (P) in um axis (E) in um P/E* SHAPE* TYPE Locality Collection V. urceolatum 20.6(21.8)23.7 19.6(20.6)21.6 1.06 P-S Ta Japan: Tashiro s.n., Siebe & AiueG. s = 1.060 s = 0.539 Kyush 1917 (A) V~ utile 20.6(22.7)23.7 22.7(24.5)25.8 0.93 O-S Ib China: H. C. Chow Hemsley s = 0.879 s = 0.989 Hubei 145 (A) V. veitchii 17.5(18.6)19.6 19.6(20.5)21.6 0.91 O-S Ic China: Lingnan Univ. GC. He “Wrient s = 0.561 s = 0.639 Zhejiang Herb. 78294 (A) Lentago DC. V. elatum 25.8(27.1)28.8 19.6(21.3)22.7 1.27 SP Te Mexico: Alexander Bentham s = 1.032 s = 1.015 Chiapas 1049 (NY) V. nudum L. —— —_— — — (1)b WU. SeA.% Churchill Florida 5 56 (MSC) V. nudum var. 28.8(33.8)36.1 19.6(22.3)24.7 152. EU Ie U.S.A.:! Russell s.n., cassinoides s 1.906 = 1.438 New Hamp- 1924 (GH) (L.) Torrey i & Gray WOLAYOUdV ATONYV AHL JO TYNUNOL ctr 99 “10A] V. prunifolium 30 (9525) 508k 19.6(21.0)22.7 1.69 EU Ie U. Sena? Bartholomew Dive § = 1.214 s = 1.222 West 1518 (GH) Virginia V. prunifolium (I)c U.S.A.: Bush 7939 ie Missouri (GH) Vv. rufidulum (I)c U.S. Godfrey 61912 Raf. oe MSC) ‘Sp ecies arranged alphabetically within sections sensu Hara (1983); sections arranged according to pollen type as in Plates I-XI. “Measurements made from scanning electron micrographs as described under materials and methods above. First figure = smallest grain; second figure = mean; third figure = largest grain; s = stand- ard deviation; sample size = 15 grains; dash = measurement not obtained. °Mean polar length (P) divided by mean equatorial length (E). “Shapes classified according to Walker and Doyle (1975): EU = euprolate; O-S = oblate-spheroidal; P-S = prolate-spheroidal; SO = suboblate; SP = subprolate 5size-shape class (I) and exine structure-sculpture class (a, b, c) define pollen type (see text). Size-shape class in parentheses if grain size determined solely by comparison with grains of known size ®Locality data consist of country and state or province provided on herbarium label. Chinese provinces spelled according to the Pinyin system. Herbaria: Arnold Arboretum (A), Escuela Nacional de Ciencias Biologfas (ENCB), Field Museum of Natural History (F), Gray Herbarium (CH), University of Michigan Herbarium (MICH), Beal-Darlington Herbarium, Michigan State University (MSC), New Yor Botanic Garden (NY), and U. S. National Herbarium (US). "This grain from unopened (not fully mature?) anther not assigned to an exine structure-sculpture class. [S861 WONYUNAIA “ANHDONOG SA TABLE 2. The pollen of the Caprifoliaceae s.l. (except Viburnum).! ver POLLEN DIMENSIONS? VOUCHER SPECIMEN’ Polar axis Equatorial POLLEN POLLEN TAXON? (P) in um axis (E) in um P/E* SHAPE° TYPE® Locality Collection Adoxaceae Trautv. Adoxa 32.0(33.9)37.1 15.5(18.2)19.6 1.86 EU la Japan: PuLUse 5.74 moscha- s = 1.577 s = 1.096 Shinano 15 May ice tellina L. (A) Caprifoliaceae A. serra (Endl. ) Pi eeoaee Sambucus 22.7(24.2)25.8 12.4(13.5)14.4 1.79 EU la U.S.A. Forbes 3433 s = 0.847 s = 0.516 Massa- Michaux chusetts Caprifolioideae Caprifolieae Leycesteria 43.6(46.4)48.7 48.7(51.6)56.4 0.90 O-S IId China: Schneider formosa s = 1.783 s = 2,535 Sichuan 1394 (A) Wallich Le Sractlis — —. — — (II)d China: Forrest 9377 (Kurz) Yunnan (A) Airy Shaw WOLAYOUUV GIONAV AHL AO TVWNYNOFL 99 “10A] Lonicera chrysantha LurezZ. L. semper- virens L. L. tatarica L. Diervilleae C. Meyer Diervilla lonicera Miller (Bunge) DC. Triosteae Hutch. Triosteum aurantiacum Bickn. Ls perfoliatum Lis (II)d China: Weichang Chijd UySehat Virginia (11)d Canada: Québec TI(f)°® Canada: Newfound- and Ilf S. Korea: Anyang Ile Us Sass. 8 Pennsyl- vania (II)e US Ae Kansas Purdum 6b (A) Fernald & Long 7973 (GH) Bro. Victorin 181 (A) Jamison(?) s.n., 1930 (GH) Moran 4257 Pennell s.n., 1924 (GH) McGregor 14287 (GH) [Sg6I WOANYUNAIA ANHDONOG Ser TABLE 2 (continued). POLLEN DIMENSIONS? VOUCHER SPECIMEN’ Polar axis Equatorial POLLEN POLLEN TAXON? (P) in um axis (E) in um P/E” SHAPE’ TyYPE® Locality Collection Linnaeeae Dumort. Abelia 45.0(47.0)50. 50.0(55.8)60.0 0.84 SO IId Japan: Furuse s.n., spathulata s = 2,297 s = 3.493 Kai 7 May 1957 Sieb. & Zucc. (A) Dipelta 43.6(49.1)53. 43.6(49.2)56.4 0.99 O-S IId China: Rock 16150 yunnanensis s = 2,728 s = 2.582 Sichuan (A) Franchet Heptacodium 47.5(50.0)52. 50.0(51.5)55.0 0.97 O-S IId Keng 1068 jasminoides s = 1.636 Se ea a as Zhejiang (A) Airy Shaw Kolkwitzia ae aa — — (II)d U.S.A.: Rehder, amabilis Massa-— Arnold Arb Graebner chusetts 6475 (GH) (native to China) Linnaea 33.0(35.4)37. 35.1(36.8)38.1 0.96 O-S IId Canada: Woodworth borealis L. s = 1.423 s = 1.182 Labrador 388 (GH) Symphoricarpos 26.8(27.5)28. 30.9(32.5)34.0 0.85 SO Ile Canada: ase & Bean albus (L. s = 1.154 s = 1.180 Ontario 26146 (GH) 9th WOLAYOUAV GTIONYV AHL JO TVNUNOL 99 “10A] Valerianaceae Nardostachys 46.2(49.9)56.4 51.3(54.0)56.4 0.92 O-S IId China: Rock 14168 jatamansii Ss 3.158 s = 1.939 Xizang (GH) (D. Don) DC. ‘Ccaprifoliaceae s.l. includes Adoxaceae (Donoghue, 1983b); one species of Valerianaceae included for comparison. *Species arranged alphabetically within families, subfamilies, and tribes sensu Hara (1983). 3Measurements made from scanning electron micrographs as described under materials and methods above. First figure = smallest grain; second figure = mean; third figure = largest grain; s = stand- ard deviation; sample size = 15 grains; dash = measurement not obtained. "Mean polar length (P) divided by mean equatorial length (E). °Shapes classified according to Walker and Doyle (1975): EU = euprolate; O-S = oblate-spheroidal; SO = suboblate. ®Size-shape class (I, II) and exine structure-sculpture class (a, d, e, f) define pollen type (see text). Size-shape class in parentheses if grain size determined solely by comparison with grains of known size. ’Locality data consist of country and state or province provided on herbarium label. provinces spelled according to the Pinyin system. Herbaria: Arnold Arboretum (A) and Gray Herbarium Chinese 8 . . Cross section of exine not seen. [Sg6l WONUNAIA ‘ANHOONOG Ley 438 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Pollen of 63 Viburnum species and 18 species of 14 other genera was ex- amined. In preliminary investigations a number of specimens were studied from different parts of the geographic range of several species (e.g., Viburnum acutifolium, V. hartwegii, V. prunifolium, V. elatum, Sambucus pubens, and Diervilla lonicera). There was little variation in the size, shape, structure, and sculpturing of the grains within or between individuals of a species (with the exception of one specimen of V. sargentii—see footnote 7, TABLE 1, and PLATE VB). Therefore, for the majority of species, pollen from only one specimen was photographed and measured. All size measurements were obtained from SEMGs of air-dried, unacetolyzed pollen. Low-magnification (x 200 or x 500) SEMGs were taken to include at least 15 grains. By means of the bar scale, micrometers were converted to millimeters, and polar and equatorial measurements were obtained directly from the photographs. The bar scale is presumed to be accurate to within 5— 10 percent. Sample sizes were small; however, standard deviations were uni- formly low. Grain sizes of different individuals of the same species were not compared, so statistical significance was not calculated. The measurements presented in Tastes | and 2 can therefore serve only as rough indicators of grain size. Measurements made by this method were compared in several instances to those of acetolyzed grains mounted in glycerin jelly, as well as to published LM measurements. In all cases there was good correspondence be- tween SEM and LM measurements. The terminology used throughout this paper is taken from Walker and Doyle’s (1975) modification and consolidation of the terminologies developed by Erdt- man (1969) and Faegri and Iversen (1975). Precise definitions of some terms, especially those relating to exine sculpturing, are given by Reitsma (1970). POLLEN MORPHOLOGY SIZE-SHAPE CLASSES. The range of pollen sizes, the mean size, and the standard deviation are recorded in TaBLes | and 2 for 52 of the 81 species examined. Quotients of polar/equatorial (P/E) axis-length were obtained from the mean sizes, and these were converted into shape classes using Walker and Doyle’s (1975) classification. In FiGure | mean polar length is plotted against mean equatorial length for each species measured. There is a wide range of pollen sizes, but within this range there are correlated differences in grain length and width, with the wider grains tending to be longer. In addition, shape and size differences are clearly correlated. Perfectly spherical grains would lie along the 45° line in Figure 1, with oblate grains above this line and prolate ones below it. Note that the larger grains are oblate, while the smaller ones are generally prolate. There are several exceptions to this correlation in Viburnum, especially within sect. ViBURNUM, and the possible significance of these is discussed below. On the basis of the correlation between size and shape, two size-shape classes are recognized. Pollen in class I ranges from 16.5 (Viburnum dilatatum) to 42.3 um long (V. tinus), and from 12.4 (V. foetidum and Sambucus pubens) to 26.8 um wide (V. oliganthum, V. ternatum, and V. burejaeticum). The mean length 1985] DONOGHUE, VIBURNUM 439 20 + P (im) FiGure 1. Pollen size-shape and structure-sculpture classes in Caprifoliaceae s./. = length of polar axis, E = length of equatorial axis, 45° dashed line = spherical grains, I and II = size-shape classes. Symbols for structure- oS classes: closed circles = class a, open triangles = class b, open squares = class c, closed squares = class d, Sine circles = class e, closed triangles = class f. a = Ado. oxa moschatellina, s = Sambuc pubens, c = Viburnum perrnen sy = Symphoricarpos albus, t = Triosteum auran- tiacum. (P) of pollen in this class is 24.4 um (s = 4.719), the saan — (E) is 20.4 um (s = 2.995), and the mean P/E quotient is 1.23 (subpr Pollen in size-shape class II ranges from 26.8 (S. a albus) to 56.4 um long (Triosteum aurantiacum), and from 30.9 (S. albus) to 64.1 um wide (7. aurantiacum). The mean length (P) of pollen in this class is 43.6 wm (5 = 8.481), the mean width (E) is 47.4 um (s = 8.942), and the mean P/E quotient is 0.91 (oblate spheroidal). Those species for which size data were not obtained have been tentatively assigned to one of the two size-shape classes based on visual comparisons with 440 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 pollen of known size. There is little chance of misclassification because the two classes are nonoverlapping and readily contrasted. EXINE STRUCTURE-SCULPTURE CLASSES. There is great diversity in exine structure and sculpture within the Caprifoliaceae s./., and to a lesser extent within V7- burnum. The pollen of each species was assigned to one of six exine structure- sculpture classes described below. Within some of the classes there is consid- erable variation, and they may be subdivided as SEM studies are extended and augmented by LM and TEM investigations. Class a. Exine semitectate, + regularly reticulate; reticulum elevated on col- umellae (height variable both within and between grains); muri psilate, variable in width; lumen dimensions variable; free-standing bacula and/or pila present, generally visible in lumina, variable in size and number (e.g., PLATE I). Class b. Exine semitectate, + regularly reticulate; reticulum + elevated on columellae (these sometimes laterally continuous); muri regularly scabrate; lumen dimensions variable; bacula present and visible in lumina, variable in size and number but often smaller and less abundant than in class a (e.g., PLATE VI). Class c. Exine intectate or with some fusion of heads of adjacent pila, + na retipilate (Erdtman, 1966) to pilate; pila short stalked or nearly sessile (gemmae), scabrate (except in Viburnum cordifolium, see PLATE VE, F, and discussion); distinct lumina absent; surfaces between pila verrucate to irregu- larly baculate (e.g., PLATE VII). Class d. Exine ey pe sir bearing spinelike processes (echinae = | um, microechinae <1 um) of variable size and abundance; surfaces between spines psilate to ae tectum UEROnES by columellae of variable height and width (e.g., PLATES XD-F, ). Class e. Similar to class d, except lacking spinelike processes on tectum (e.g., PLATE X ) Class f. Exine lacking columellae; tectum bearing large, often irregularly shaped spinelike processes; surface between spines + verrucate (e.g., PLATE IXC-F). These exine structure-sculpture classes fall into two categories. The first includes classes a—c, in which the exine is semitectate and reticulate to intectate. The second comprises classes d—f, which are characterized by a complete tec- tum, either raised on columellae (d and e) or not (f) POLLEN TYPES. Together, size-shape class and structure-sculpture class define a pollen type. Structure-sculpture classes a—c occur only in pollen grains in size- shape class I, while the structure-sculpture classes d-f are found only in grains of size-shape class II (FiGuRE 1). Hence, there are two very different kinds of pollen grains in the Caprifoliaceae s./.: those that are smaller, prolate, and lacking a complete tectum; and those that are larger, oblate to spheroidal, and completely tectate. APERTURE MORPHOLOGY AND POLLEN TYPES. Since variation in aperture mor- phology was not analyzed in detail in this study and has not received sufficient attention previously, aperture differences were not included in the descriptions of pollen types given above. Only the SEM was employed in this survey; careful 1985] DONOGHUE, VIBURNUM 44] studies with the LM and TEM are necessary to understand the nature and extent of variation in aperture structure. However, some general observations about aperture morphology in the Caprifoliaceae s./. can be made, and it is possible to relate what little is known about aperture variation to variation in the characters discussed above. These comments are based in part on the LM studies of Bassett and Crompton (1970), Richard (1970), Punt and colleagues (1974), and Béhnke-Giitlein and Weberling (1981). Pollen of all members of the Caprifoliaceae s.l. is normally triaperturate, with an occasional two- to four-apertured grain (e.g., in some specimens of Abelia spathulata, PLATE XIC). The apertures are distinctly colporate in Vi- burnum, Sambucus, and Adoxa, and brevicolporate to porate in the Caprifolia- ceae s.s. Thus, the taxonomic distribution of aperture shapes seems to correlate perfectly with the distributions of the size, shape, and exine characters just described (see below). Minor variations in aperture structure have been reported in Viburnum, and some of these may prove taxonomically useful. Presently, however, the nature of this variation is very poorly known. For example, Bassett and Crompton (1970) noted variation in the extent to which the furrows appeared open. Unfortunately, this trait appears to vary within some species and may be affected by the method of preparation. A somewhat more promising character is the presence or absence of a bridge over the colpus, a feature recorded both by Punt and colleagues (1974) and by Béhnke-Giitlein and Weberling (1981). In their combined sample of 31 species, a bridge was present in 15, including all 6 species examined with an exine of type b or c. Variation in this trait is apparently common within several sections (e.g., ODONTOTINUS) and in some cases might be useful in distinguishing between closely related species. How- ever, this character should be treated very cautiously until it is studied in more detail because there are several conflicting observations. In V. tinus, for ex- ample, BOhnke-Giitlein and Weberling (1981) reported the presence ofa bridge, while Punt and co-workers (1974) recorded its absence. The latter observation is supported in the present study (PLATE IIIC). Other similar conflicts, and the observation of apparently intermediate conditions in some grains, suggest that there can be considerable variation within species and/or that this trait can be affected by sample preparation. Within the Caprifoliaceae s.s. there appear to be slight but consistent differ- ences in aperture shape between the genera. In Heptacodium (PLATE VIIIF), Diervilla (PLATE [XC), Weigela (PLATE LXE), and Triosteum (PLATE XA, B) the apertures are porate or only slightly elongate, while in the remaining genera they are usually brevicolporate. However, in Symphoricarpos the apertures reportedly vary (Bassett & Crompton, 1970), and they may be intermediate in length (PLATE XC). Obviously, many more species will have to be examined before this character can be used with any confidence. POLLEN TYPES AND PHYLOGENETIC RELATIONSHIPS N THE CAPRIFOLIACEAE S.L The taxonomic distribution of pollen types within the Caprifoliaceae s./. is quite clear cut. Type Ia grains characterize Sambucus, Adoxa, and most species of Viburnum, types Ib and Ic are also found in Viburnum. Type Id is most 442 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 common in the Caprifoliaceae s.s., but Ile and If are also present. Thus, pollen types are congruent with many other characters that suggest the presence of two distinct lineages within the Caprifoliaceae s./. (Donoghue, 1983b). It is noteworthy that pollen size appears to be positively correlated with style length. This supports the conclusions of Plitmann and Levin (1983), who studied pollen-pistil relationships in Polemoniaceae. Style length is in turn correlated with other floral characters (e.g., length of corolla tube) that relate to mode of pollination. A cladistic analysis aimed at determining the phylogenetic relationships of Viburnum (Donoghue, 1983b) demonstrated that there are shared derived char- acter states (synapomorphies) uniting Viburnum with Sambucus and Adoxa almost regardless of what outgroup arrangement is used in assessing character polarities. The ten genera of Caprifoliaceae s.s. may form a monophyletic group, but they are probably paraphyletic (i.e., would not include all of the descendants of their common ancestor) if the Valerianaceae and Dipsacaceae are treated as separate families. There is no evidence that the Caprifoliaceae s./. are a mono- phyletic group (I have been unable to find a synapomorphy linking Viburnum, Sambucus, and Adoxa with the Caprifoliaceae s.s.). Since there is no reason to think that the Caprifoliaceae s./. form a mono- phyletic group, it is inappropriate to consider the evolution of pollen mor- Bohnke-Giltlein & Weberling, 1981). Therefore, I will consider pollen evolution only within the two distinct groups of Caprifoliaceae s./., sepecially within the Viburnum-Sambucus-Adoxa clade, for which there exists a corroborated hy- pothesis of phylogenetic relationship. Thus I will consider transformations between pollen types Ia, Ib, and Ic, and between types IId, He, and IIf, but I will not treat relationships between the two main pollen types because a direct transformation between them may never have occurred. EVOLUTION OF THE EXINE ExINE EVOLUTION IN VIBURNUM TAXONOMIC DISTRIBUTION OF EXINE CHARACTERS. Only type Ia pollen is known in Sambucus and Adoxa, and this type predominates in Viburnum. There do appear to be slight variations in pollen type Ia between the genera. On average, the lumina in Sambucus and Adoxa are smaller than those in Viburnum, and therefore the reticulum appears to be tighter (Plate VIIJA-D). Pollen of Sam- bucus and Adoxa is also somewhat smaller on average than that of most species of Viburnum. More free columellae are visible within the lumina of Viburnum and Sambucus than in those of Adoxa. Each of these differences is slight, and there is considerable overlap. Thus, without additional study ofa larger sample, they cannot be considered statistically or taxonomically significant. Type Ia pollen not only is the most common one in Viburnum but 1s also taxonomically widespread. Rehder (1908, 1940) recognized nine sections in the genus. These are widely accepted but have been subdivided in a few cases (e.g., Kern, 1951). Hara (1983) provided an overview of the subgeneric clas- 1985] DONOGHUE, VIBURNUM 443 sification and modified Rehder’s classification, recognizing 10 sections; he placed the Latin American species (Killip & Smith, 1931; Morton, 1933) in sect. OREINOTINUS. In TABLE | the species of Viburnum examined in this study are arranged according to Hara’s sections. The table shows that type Ia pollen is present in all examined members of sects. ODONTOTINUS (PLATE IA-D), OREINOTINUS (PLATE IE, F), SOLENOTINUS (PLATES ITA-F; IIIA, B), Trnus (PLATE IIIC-F), ToMENTOSA (PLATE IVE, F), and OpuLus (PLATE VA, B), as well as in V. cylindricum of sect. MEGALOTINUS (PLATE IVA, B), V. urceolatum of sect. VIBURNUM (PLATE IVC, D), and V. furcatum (PLATE VC, D) and V. lantanoides of sect. PssupoTiNus. Type Ia pollen is not known in sect. LENTAGO. There is some variation in pollen type Ia within Viburnum; upon additional study of a larger sample, this is likely to be of some taxonomic significance within sections and species complexes. Variation in the size of the lumina and in the abundance and visibility of bacula is especially pronounced in sect. SOLENOTINUS (formerly Thyrsosma (Raf.) Rehder), which contains 15 to 20 species native to Asia. In V. farreri (subsect. Lonicerorpes (Oersted) Hara; PLATE IIA) the lumina are narrow and the bacula are hardly visible. In contrast, in V. erubescens, V. oliganthum, and V. suspensum (all subsect. SOLENOTINUS), and in V. odoratissimum (subsect. MicRoTINUS (Oersted) Hara; PLATE IIE, F), the reticulum is loose and conspicuously raised. In V. brachybotryum (subsect. MIcrOTINUS; PLATE IIJA, B) the lumina are especially wide and numerous bacula are visible. Section SOLENOTINUS is generally believed to include the most primitive species in Viburnum (Wilkinson, 1948; DeVos, 1951; Egolf, 1962; Hara, 1983), and it may be paraphyletic (Donoghue, 1983a). Since there is extreme diversity within the section in leaf venation, margin, size, and shape, and in flowering time, fruit morphology, and growth pattern (Donoghue, 1982, 1983a; Hara, 1983), the range of variation in pollen morphology is not altogether surprising. It is noteworthy that the minor variations in pollen noted above do seem to distinguish some of Hara’s subsections, suggesting that these may be natural oups. Some of the range of variation in sect. SOLENOTINUS is paralleled in sect. Tinus, a monophyletic group of approximately eight species. The pollen of Viburnum atrocyaneum (PLATE IIIF) is similar to that of V. odoratissimum (PLATE IIE, F), and V. tinus pollen (PLATE IJIC, D) is like that of V. brachy- botryum (PLATE IA, B). Pollen of V. cinnamomifolium, V. davidii (PLATE IIIE), and V. propinquum, all of which have trinerved leaves (i.e., acrodromous venation), does not appear to differ significantly from that of the remaining species of sect. Tinus, which have pinnate (eucamptodromous) venation. Compared to pollen type Ia, types Ib and Ic are much less common and more limited in taxonomic distribution. Type Ib characterizes Viburnum punc- tatum of sect. MEGALOTINUS subsect. PUNCTATA Kern (PLATE VIE, F) and four of the ten species examined from sect. VIBURNUM. Section VIBURNUM, with 15 to 20 species, is divided by Hara (1983) into three subsections: subsect. VIBURNUM has pollen types Ib and Ic; V. carlesii, the only species of subsect. SOLENOLANTANA (Nakai) Hara, has type Ib; and V. urceolatum of the monotypic 444 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 subsect. URCEOLATA Nakai has type Ia. The last species may not be closely related to the others (see below and Donoghue, 1983a). Species of sect. VIBURNUM with types Ib and Ic pollen have never been placed in separate groups. Type Ib pollen is also known from sect. LENTAGO but i is extremely rare in this group; it was found in only one out of the four individuals of V. nudum var. cassinoides examined. Pollen type Ic characterizes the majority of the examined species of sects. VIBURNUM (PLATE VIID-F) and Lentaco. Viburnum cordifolium (PLATE VE, F) of sect. PSEUDOTINUS was also initially scored as having type Ic pollen, but as noted above, the pila in this species appear to lack scabrae. The analysis below indicates that this kind of pollen is best considered a distinct type. There are some differences in grain shape in groups with pollen types Ib and Ic, and these may prove taxonomically useful when examined in more detail. Most Viburnum species have prolate or subprolate grains, but there is a trend toward spheroidal or oblate ones, especially in sect. VIBURNUM (PLATES VIC, D; VIID, E). The bearing of this observation on the interpretation of exine evolution is considered below. POLARITY AND TRANSFORMATION SERIES. Only shared derived character states (synapomorphies) may be considered evidence of common ancestry; within a particular group shared ancestral states (Symplesiomorphies) are uninformative about cladistic relationship (Hennig, 1966). Hence, before the Viburnum pollen data assembled here can be used to assess phylogenetic relationships, the po- larity of the exine characters must be determined. Numerous criteria have been used to assess polarity, but outgroup comparison is now widely acknowledged to be the only generally valid one (Stevens, 1980, 1981; Watrous & Wheeler, 1981; Wheeler, 1981; Farris, 1982; Maddison et al, 1984). Elsewhere (Donoghue, 1983b), I have defended the hypothesis that Sambucus and Adoxa together are the sister group of Viburnum. Sambucus and Adoxa can therefore be used as an outgroup to assess the polarity of characters that vary in Viburnum. If Sambucus and Adoxa share a state that occurs in some members of Viburnum, then it is most parsimonious to consider that state to be ancestral within Viburnum, and the alternate state(s) to be derived (Mad- dison et al., 1984). Thus pollen type Ia can be considered the ancestral state in Viburnum, and types Ib and Ic derived. It would be desirable to include outgroups in addition to Sambucus and Adoxa in the analysis of polarity (Maddison et a/., 1984), but the sister group of the Viburnum-Sambucus-Adoxa clade is equivocal. In cases such as this, plausible sister groups can usually be substituted to see what effect they might have on polarity assessment (Donoghue & Cantino, 1984), but in this instance all plausible sister groups are highly variable in pollen morphology and/or homologies are difficult to establish. The Cornaceae, for example, are a likely secondary outgroup but are quite variable, and intrafamilial relationships are so poorly understood that the family cannot be employed in outgroup com- parison. Chao (1954) noted that pollen of the Cornaceae resembles that of Viburnum, Sambucus, and Adoxa in size, shape, and aperture number and morphology. Ferguson (1977) revealed a wide variety of pollen types in the 1985] DONOGHUE, VIBURNUM 445 Cornaceae, none of which is identical to pollen of Viburnum, Sambucus, or Adoxa. It is noteworthy, however, that species of Melanophylla Baker have pollen similar to type Ia; Kaliphora madagascarensis Hooker f. pollen resem- bles type Ib; and Aucuba japonica Thunb. pollen is similar to type Ic. Derivation of the Viburnum-Sambucus-Adoxa clade from ancestors similar to extant Cor- naceae would not have required major changes in pollen morphology but would necessitate a transformation to the trinucleate condition from the binucleate state characteristic of the Cornales (Brewbaker, 1967). y outgroup comparison it is possible to establish the most parsimonious hypothesis of ancestral state in the ingroup. For two-state (binary) characters, the derived state and its relation to the ancestral state are automatically de- termined. When there are three or more states, a transformation series must be established, specifying the relation among the states. There have been at- tempts to develop rigorous methods to establish aru series (Mick- evich, 1982), but this requires that other characters and that an initial hypothesis of cladistic relationships be formulated. In the absence of such information, transformation series have been constructed on the basis of the “logical” relations among the states and/or by reference to general trends in similar organisms (Stevens, 1980). Fortunately, in the case of the exine characters considered here, it is possible to use parsimony as a criterion to choose among the possible transformation series because the exine structure-sculpture classes involve two independently varying characters (sca- brae present or absent; regular reticulum present or absent). Furthermore, these characters are nested such that retipilate or pilate grains are scabrate (except in Viburnum cordifolium), but some grains with scabrae are reticulate. For these reasons it is most parsimonious to posit that Ia - Ib > Ic (FiGure 2A). This transformation series requires two state changes: from smooth to scabrate, and from reticulate to retipilate/pilate. Any other arrangement of pollen types (la > Ic — Ib, or Ib « Ia — Ic) requires a minimum of three steps. The most parsimonious transformation series is consistent with a supposedly common trend from semitectate and reticulate to intectate pollen (Walker & Doyle, 1975; Walker, 1976). In contrast, B6Ohnke-Giitlein and Weberling (1981) concluded that Ic — Ib — Ia, based on unsubstantiated preconceptions about phylogenetic rela- tionships and the relative advancement of species within Viburnum, and on a presumed trend (Erdtman, 1966) from pilate to reticulate grains. This conclu- sion is rejected here based on outgroup comparison. A phylogenetic analysis of relationships within Viburnum (see below and Donoghue, 1983a) also shows that it is most parsimonious to hypothesize that Ia is ancestral in Viburnum. CLADISTIC RELATIONSHIPS AND EXINE EVOLUTION. If pollen type Ia is ancestral within Viburnum, possession of this trait does not provide evidence of cladistic relationship within the genus. Types Ib and Ic are derived and provide prima facie evidence of monophyly. The simplest hypothesis, based on the transfor- mation series established above, is that type Ib evolved once and characterizes a monophyletic group, and that type Ic likewise evolved from Ib only once (FIGURE 2B). To test this hypothesis and establish the level at which these JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 a ADO SAM VIB a a ‘a b a. c b B) a Figure 2. A, hypothesized transformation of pollen structure-sculpture classes a, b, and c within Viburnum (all size-shape class I). B, simplest a priori phylogenetic hypothesis for evolution of pollen in Viburnum (VIB), with Sambucus (SAM) and Adoxa (ADO) as first outgroup. states characterize monophyletic groups, it is necessary to consider the con- gruence of the pollen characters with other characters. Such congruence will test whether plants with type Ic pollen, for example, form a monophyletic group, and hence whether Ic is truly a homology (Patterson, 1982). In practice the congruence test of homology is jacana by using a variety of characters to construct the most parsimonious cladogram. In a preliminary cladistic analysis of ue I used a data set of 23 species 1985] DONOGHUE, VIBURNUM 447 VIB [ A $s GOSTY PNCFUMLHDAJ1 BWRKEO.| Ficure 3. A, cladogram of Viburnum (VIB) used in evaluating pollen evolution; Sambucus (S) and Adoxa (A) outgroup. Clade N, C, F, U, M, L (boldface) expanded in B-D. B, most parsimonious interpretation of pollen ate using transformation series in FiGureE 2A (black bar = forward transformation; open bar = reversal; a, b, c = structure-sculpture classes of size-shape class I). C, rea Gees of cladogram A, elim- inating reversals in the pollen character but entailing extra steps in other characters. D, most parsimonious arrangement of character-state transformations on cladogram A after reinterpretation of homologies. 448 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 complexes scored for 34 characters involving buds, leaves, branching patterns, trichomes, inflorescences, flowers, and fruits (Coombs et a/., 1981; Donoghue, 1983a). Exine morphology was one character in the analysis: the states were pollen types Ia, Ib, and Ic; polarity and transformation series were assessed as discussed above. Cladograms were constructed using the WAGNER ’78 com- puter program, which searches for the arrangement of taxa that minimizes the total number of character state changes, allowing both forward and reverse transitions (Farris, 1970). Several cladograms were generated because some characters exhibiting the most homoplasy, and about which there was the most uncertainty, were removed. The cladogram obtained using 28 characters (see FiGure 3A) will serve as the basis for discussing exine evolution. The general conclusions below would not change substantially ifany of the other cladograms shown in Donoghue (1983a) were used, because most of the changes in the exine occur within “stable clades” that remained unchanged on all cladograms or, more often, within the terminal taxa used in the analysis. Detailed information about the cladistic analysis of Viburnum is given in Donoghue (1983a). It is important to note that each letter in Figure 3 sym- bolizes a species or a species complex, each of which is thought to be mono- phyletic. Of particular importance for this discussion, sect. MEGALOTINUS was split into V. cylindricum (Y) and subsect. PuNctata (M); V. urceolatum (U) was removed from sect. VIBURNUM (N); and V. cordifolium (C) was treated as distinct from V. /antanoides and V. furcatum of sect. PSEUDOTINUS (F). Section LENTAGO is symbolized by L. On the cladogram in Ficure 3A, pollen character-state changes occur only within the clade comprising taxa N through L; therefore, in FiGure 3B—D this clade is enlarged while others are represented by single lines. On this cladogram it is most parsimonious to hypothesize that Ib pollen arose once in the common ancestor of Viburnum urceolatum, V. cordifolium, and sects. VIBURNUM, LENTAGO, PSEUDOTINUS, and MEGALOTINUS subsect. PUNCTATA (FIGURE 3B). However, the arrangement of these taxa in the cladogram requires reversals to type Ia pollen in V. urceolatum (VU) and in sect. PsEUDoTINUS (F). In addition, according to this hypothesis, pollen type Ic must have been derived indepen- dently from type Ib in V. cordifolium (C) and within sects. VisuRNUM (N) and LENTAGO (L). If this cladogram of Viburnum is substantially correct, there must have been reversals and parallelisms in the pollen character. However, the relatively small change in the cladogram of Figure 3A shown in FiGure 3C makes it possible to do away with reversals from Ib to Ia that palynologists may consider to be unlikely. In this cladogram sect. ViBURNUM (N) is linked with sects. LENTAGO (L) and MEGALOTINUS subsect. PUNCTATA (M), and taxa C, F, and U are ex- cluded. Such a change would, of course, entail some additional steps overall. However, many more steps would be necessary to eliminate the need to pos- tulate the independent origin of Ic pollen; in particular, one would have to assume that C, L, and N were a clade within which sects. LENTAGO and VIBURNUM were not monophyletic. This is very unparsimonious because there is strong support from other characters for the linkage of C with F and of L with M, and for the monophyly of the terminal taxa, especially L (Donoghue, 1983a). 1985] DONOGHUE, VIBURNUM 449 From the foregoing it seems that pollen type Ib may be a homology but that type Ic is very probably not, having arisen three separate times. The hypothesis that type Ic is not a homology leads to the question of whether the exact same morphology evolved three times, or whether there are morphological differ- ences that corroborate the hypothesis of convergence. Comparison of type Ic pollen in sect. LENTAGO with that in sect. VIBURNUM reveals a rather consistent difference in shape (see Ficure 1): grains in sect. LENTAGO are subprolate or more often euprolate, while both Ib and Ic pollen in sect. ViBURNUM (excepting V. mongolicum) is spheroidal or oblate (e.g., compare PLATE VIIA to VIID, E). This difference in shape between the groups lends support to the hypothesis of convergence suggested by the cladogram. On reexamination Viburnum cordifolium pollen was found to lack scabrae on the pila, unlike type Ic pollen in sects. LENraGo and VipuRNUM. This distinction, also noted by B6hnke-Giitlein and Weberling (1981), supports the hypothesis that the pilate exine of V. cordifolium was achieved independently. Because V. lantanoides and V. furcatum (both with type Ia pollen) are the sister group of V. cordifolium in Ficure 3A, it may be that V. cordifolium pollen evolved directly from type Ia. This interpretation is more parsimonious than one that postulates a derivation through type Ib, which would require both the gain and loss of scabrae. These observations suggest the alternative explanation of pollen character- state transformations, shown in FiGure 3D. According to this interpretation, relationships remain the same as in the original cladogram (Ficure 3A, B), but there are two origins of type Ib—one in the ancestor of N (oblate grains) and the other in the ancestor of M plus L (prolate grains). Type Ic has then evolved independently within each of these groups. Viburnum cordifolium pollen is considered to have evolved directly from type Ia. This hypothesis entails no reversals and requires a total of five state changes—one less than in FiGurRE 3B In future cladistic analyses of Viburnum, pollen characters should be recoded to reflect the understanding of homologies obtained from the first cladograms. Indeed, it is now evident that pollen variation involves at least three characters that can vary independently: presence or absence of a reticulum, presence or absence of scabrae, and shape of the grain. EXINE EVOLUTION IN CAPRIFOLIACEAE S.S. TAXONOMIC DISTRIBUTION OF EXINE CHARACTERS. All species of the Caprifoli- aceae S.s. examined have pollen in size-shape class IJ, but there is considerable variation in grain size (see Figure 1). With further study of a larger sample, this variation may prove taxonomically significant. However, size differences do not appear to be correlated with differences in exine structure and sculpture, nor do they correspond to the standard tribal classification of the group. Bassett and Crompton (1970) noted that variation in grain size within Symphoricarpos was correlated with chromosome number. The size reported here for S. albus is close to that reported for tetraploid individuals; octaploids are said to have larger grains. 450 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 The most significant pollen difference within the Caprifoliaceae s.5. is in exine structure. In tribes Caprifolieae, Triosteae, and Linnaeeae the complete tectum is raised on columellae of various sizes (pollen types IId and He, PLATES IXA, B; XB, D; XID). In contrast, in Diervilla and Weigela (tribe Diervilleae) columellae appear to be lacking (pollen type IIf, PLATE LXF). The sculpturing of the exine also varies. In all species of tribes Caprifolieae and Diervilleae and most species of tribe Linnaeeae examined, spines are present. These processes vary somewhat in shape, size, and abundance. The two species of Triosteum (Triosteae) and the single species of Symphoricarpos (Linnaeeae) examined differ in lacking supratectal spines; instead the tectum is psilate or fossulate (pollen type Ile, PLATE XA-C). POLARITY AND TRANSFORMATION SERIES. Since there is no well-corroborated hypothesis of the broader cladistic relationships of the Caprifoliaceae s.s., it is difficult to employ outgroup comparison to assess polarity. Indeed, as noted above, it is not clear that the Caprifoliaceae s.s. constitute a monophyletic group. If both the Dipsacales (excluding Viburnum, Sambucus, and Adoxa) and the Caprifoliaceae s.s. were assumed to be monophyletic, then the Valeria- naceae and the Dipsacaceae could be used as outgroups to assess polarities in the Caprifoliaceae s.s. The pollen of the Valerianaceae (e.g., PLATE XIE, F) and the Dipsacaceae is most like type IId (Clarke & Jones, 1977; Patel & Skvarla, 1979), which could therefore be considered ancestral in the Caprifoliaceae s.s. There are, however, some noteworthy differences between the pollen of these families. In particular, spines of various kinds are associated with the apertures in the Valerianaceae (Patel & Skvarla, 1979; PLATE XIE) and the Dipsacaceae. Since many botanists (e.g., Wilkinson, 1949) believe that the Valerianaceae and the Dipsacaceae are derived from tribe Linnaeeae of the Caprifoliaceae s.s. through an ancestor similar to the extant genus Nardostachys DC. of the Valerianaceae, these two families may not be an appropriate outgroup. Even if the Caprifoliaceae s.s. were paraphyletic, pollen type IId might still be the ancestral condition in the Dipsacales, retained and modified in the evolution of the Valerianaceae and the Dipsacaceae. The Rubiaceae are often considered to be closely related or even ancestral to the Caprifoliaceae (e.g., Cronquist, 1968, 1981). Pollen morphology is ex- tremely variable within Rubiaceae (Erdtman, 1966), and without a better un- derstanding of phylogenetic relationships within this family one cannot use it as an outgroup for the Caprifoliaceae s.s. Lacking an outgroup, it would be possible to assess polarity tentatively if cladistic relationships were known within the Caprifoliaceae s.s. Although a cladistic analysis has not been performed, it is widely believed that tribe Capri- folieae (especially Leycesteria) is the most primitive group, from which the other three tribes have been derived (e.g., Wilkinson, 1949). Since all Capri- folieae have type IId pollen, this might provisionally be considered the ancestral state, with types Ile and IIf derived. If type IId is considered ancestral based on the circumstantial reasoning above, how are the derived types IIe and IIf related to it—i.e., what is the transformation series? Two binary characters are involved in defining these exine types: presence or absence of columellae, and presence or absence of 1985] DONOGHUE, VIBURNUM 451 DIP VAL CAP B) d Ficure 4. A, hypothesized transformation of pollen structure-sculpture classes d, e, and f within Caprifoliaceae s.s. (all size-shape class II). B, simplest a priori phylogenetic hypothesis for evolution of pollen in Caprifoliaceae s.s. (CAP), with Valerianaceae (VAL) and Dipsacaceae (DIP) as first outgroup. supratectal spines. As in the case of Viburnum, Sambucus, and Adoxa discussed above, it is possible to choose from among possible transformation series based on parsimony. In this instance it is most parsimonious to assume that Ile and IIf are independently derived from Id (FiGure 4A). Any other arrangement requires at least one additional step. The derivation of type Ile from IId simply entails the loss of spines on the tectum. The most parsimonious explanation for the derivation of type If is 452 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 that the columellae were lost, with the tectum therefore resting on the foot layer. An alternative explanation requires the loss of both the tectum sur- rounding the spines and the columellae not directly subtending spines. If this were the case, the spines in tribe Diervilleae would be derived in part from columellae and in part from tectum and supratectal spines. There is currently no evidence to support this more complicated explanation, but TEM studies might be useful. CLADISTIC RELATIONSHIPS AND EXINE EVOLUTION. If pollen type IId 1s considered ancestral, then only possession of types Ile or IIf can provide evidence of monophyly. The simplest hypothesis would be that both Ile and If evolved only once (Ficure 4B). If this is so, then type IIf indicates that tribe Diervilleae is monophyletic, which is corroborated by several other unique features (no- tably the elongate bilocular ovary that develops into a many-seeded capsule). Pollen type Ile suggests that 7riosteum and Symphoricarpos form a mono- phyletic group. Triosteum has previously been allied with Viburnum (Fritsch, 1891; Wagenitz, 1964) or has been placed in its own tribe, but Lewis and Fantz (1973) concluded that it is most similar to Lonicera. Symphoricarpos is gen- erally considered the basal member of tribe Linnaeeae (Wilkinson, 1949). A phenetic analysis (Hsu, 1983) showed that Triosteum and Symphoricarpos have much in common, but to my knowledge, a direct phylogenetic relationship between them has never been defended. It is noteworthy that both genera have dry or mealy drupes with several one-seeded endocarps, and that the seedlings and sucker shoots of Symphoricarpos often have lobed leaves similar to those of Triosteum. On the other hand, the possibility that pollen type He arose independently in the two genera is suggested by a marked difference in pollen size. Triosteum has the largest and Symphoricarpos the smallest grains of any members of the Caprifoliaceae s.s. examined (TABLE 2, FiGureE 1). Determining whether Ile is a homology or if there has been convergence will require a detailed phylogenetic analysis of the Caprifoliaceae s.s. SUMMARY Although the pollen of the Caprifoliaceae s./. is now very well known, the evolution of pollen diversity has not been considered in detail and the phy- logenetic significance of pollen characters is not widely appreciated. This study confirms that there are major differences in pollen size and shape, as well as significant variation in exine structure and sculpturing, in the Caprifoliaceae s.l. These variables define two very different kinds of pollen: the large, oblate, tectate grains of the Caprifoliaceae s.s., and the small, usually prolate, semi- tectate ones of Viburnum, Sambucus, and Adoxa. This distribution of pollen types is consistent with the idea that the Caprifoliaceae s./. are divisible into two distinct lineages and do not constitute a monophyletic group. It may therefore be inappropriate to consider the evolution of pollen morphology in the Caprifoliaceae s./. as a whole because there may never have been a direct evolutionary transition between the two main pollen types within the group. However, it is appropriate to consider pollen evolution within each of the two 1985] DONOGHUE, VIBURNUM 453 component lineages, especially within the clade comprising Viburnum, Sam- bucus, and Adoxa Previous discussions of pollen evolution in the Caprifoliaceae s./. (and in most other groups) have been based upon generally accepted but mostly un- tested ideas about which groups are relatively primitive and which ones ad- vanced, and upon presumably general trends. In the present analysis pollen evolution is considered in the context of explicitly cladistic hypotheses for the groups involved. Polarity of pollen characters is assessed by outgroup com- parison, and the most parsimonious transformation series is established. In Viburnum semitectate, reticulate grains with smooth muri appear to represent the ancestral condition; the addition of scabrae and the breakdown of the reticulum are derived. When exine characters are used along with others, a cladogram is obtained that may require reversals but quite certainly necessitates the independent evolution of retipilate or pilate grains in three separate groups. Upon reexamination of the pollen in these thie groups, slight but consistent hat fconvergence and suggest a more parsimonious interpretation of pollen evolution. The retipilate/pilate condition should not be considered a homology, and pollen characters should be recoded in subsequent phylogenetic analyses of Viburnum A detailed analysis of pollen evolution in the Caprifoliaceae s.s. is not possible at this time because this group may not be monophyletic, its outgroups are equivocal, and a hypothesis of cladistic relationships within the group is not yet available. Circumstantial evidence suggests, however, that grains with the tectum raised on columellae and with supratectal spines are probably ancestral. Spines are lacking in Symphoricarpos and Triosteum, which may indicate a sister-group relationship between these genera. The absence of columellae in the Diervilleae corroborates the monophyly of this tribe. ACKNOWLEDGMENTS I first studied pollen diversity in Viburnum at Michigan State University, where I was assisted by B. Scoviac. The SEMGs presented here were executed by E. Seling, of the Museum of Comparative Zoology SEM Laboratory, Harvard University. Funding for microscopy was provided by the Arnold Arboretum of Harvard University and by an NIH Genetics Training Grant awarded to the Department of Biology, Harvard University. I thank the directors of ENCB, MICH, MSC, NY, US, and especially 4 and Gu, for allowing me to remove pollen from specimens in their collections. N. Miller, P. Stevens, A. Tryon, and C. Wood gave encouragement and advice, and J. Doyle provided a very helpful review of the manuscript. M. Carter aided in preparing samples, S. Fansler drew the figures, and K. Horton typed the text and tables. LITERATURE CITED Apams, R. J., & J. K. Morton. 1979. An atlas of pollen of the trees and shrubs of eastern Canada and adjacent United States. Part IV. Univ. Waterloo Biol. 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Mutter, eds., The ea significance of the exine. (Linn. Soc. Symp. Ser. No. 1.) Academic Press, New 1979. Pollen walls as oe systems. Ann. Missouri Bot. Gard. 66: 813- HILLEBRAND, G. R., & D. E. FArRBRoTHERS. 1970. Phytoserological systematic survey of the Caprifoliaceae. Brittonia 22: 125-133. Hsu, P.S. 1983. A preliminary numerical taxonomy of the family Caprifoliaceae. Acta Ikuse, M., & S. KUROSAWA. 1954. Notes on sect. Zabelia Rehder of the genus Abelia. Jour. Jap. Bot. 29: 107-110. Kern, J. M. 1951. The genus Viburnum (Caprifoliaceae) in Malaysia. Reinwardtia 1: 10 0. Kixup, E. P., & A. C. SmirH. 1931. The South American species of Viburnum. Bull. Torrey Bot. Club 57: 245-258. Kress, W. J., & D. E. STONE. 1983. Morphology and Dhylorenetic significance of exine- less pollen of Heliconia (Heliconiaceae). Syst. Bot. 8: 149-167. Lee, S. 1978. A factor analysis study of the functional significance of angiosperm pollen. Syst. Bot. 3: 1-19. Lewis, W. H. 1977. Pollen exine morphology and its adaptive significance. Sida 7: 95- 102 P. R. Fantz. 1973. Tribal classification of Triosteum (Caprifoliaceae). Rho- dora 75: 120, 121. Mappison, W. P., M. J. DoNoGHuE, & D. R. MAppison. 1984. Outgroup analysis and parsimony. Syst. Zool, 33: 83-1 MickevicuH, M. F. 1982. Transformation series analysis. Syst. Zool. 31: 461-478. Morton, C. V. 1933. The Mexican and Central American species of Viburnum. Contr. U.S. Natl. Herb. 26: 339-366. Nowicke, J. W., & J. J. SkKVARLA. 1979. Pollen morphology: the sas influence in higher order systematics. Ann. Missouri Bot. Gard. 66: 633-7 PATEL, V. | & J.J. SkvARLA. 1979. Valerianaceae pollen morphology. Pollen Spores 21: 81-103. oo c 1982. Morphological characters and homology. Pp. 21-74 in K. A. Joys A. E. Fripay, eds., Problems of phylogenetic reconstruction. Academic PLITMANN, V., & D. A. Levin. 1983. Pollen-pistil relationships in the Polemoniaceae. Evolution 37: 957-967 Punt, W., T. Rerrsma, & A. A. M. L. Reuvers. 1974, The northwest European pollen flora. ’Caprifoliaceae. Rev. Palaeobot. Palynol. 17: NEPF 5-29. Raper, L. L. 1976. A biosystematic study of Viburnum prunifolium and Viburnum dat (Caprifoliaceae). 68 pp. Unpubl. M.S. Dissertation, Univ. Tennessee, REHDER, A. 1908. The viburnums of eastern Asia. Pp. 105-116 in C. S. SARGENT, ed., Trees and shrubs. Vol. 2. Houghton Mifflin, Boston. 456 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ——. 1940. Manual of cultivated trees and shrubs. ed. 2. 996 pp. Macmillan Co., ew York. ReitsMA, T. 1970. Suggestions towards unification of descriptive terminology of an- glosperm pollen grains. Rev. Palaeobot. Palynol. 10: 39- & A. A.M.L. Reuvers. 1975. The 2 European pollen flora. Adoxaceae. Rev. Palaeobot. Palynol. 19: NEPF 71- RICHARD, P. 1970. Atlas pollinique des et de quelques arbustes indigénes du Québec. Nat. Canad. 97: 241-306. STEVENS, P. F. 1980. Evolutionary polarity of character states. Ann. Rev. Ecol. Syst. 11: 333-358. 1981. On ends and means, or how polarity criteria can be assessed. Syst. Bot. 8. THANIKAIMONI, G. 1972. Index Sen asa sur la morphologie - pollens d’an- giospermes. Trav. Sect. Sci. Techn. Inst. Fr. Pondichéry 12: |- WAGENITZ, G. 1964. Dipsacales. Pp. 472-478 in H. MELcuior, ed., A. aie der Pflanzenfamilien. ed. 12. Vol. 2. Gebriider Borntraeger, Berlin WALKER, J. W. 1976. Evolutionary significance of the exine in the pollen of primitive angiosperms. Pp. 251-308 in I. K. FERGuson & J. MULLER, eds., The evolutionary significance of the exine. (Linn. Soc. Symp. Ser. No. 1.) Academic Press, New York & . DoyLe. 1975. The bases of angiosperm phylogeny: palynology. Ann. Missouri Bot. Gard. 62: 664-723. Wartrous, L. E., & Q. D. WHEELER. 1981. The out-group comparison method of character analysis. Syst. Zool. 30: 1-111. WHEELER, Q. D. 1981. The ins and outs of character analysis: a response to Crisci and Stuessy. Syst. 6: 297-306. WILKINSON, A. M. 1948. Floral anatomy and morphology of some species of the genus Viburnum of the Caprifoliaceae. Am. Jour. Bot. 35: 455-465. 1949, Floral anatomy and morphology of Triosteum and of the Caprifoliaceae in general. Ibid. 36: 481-489. Wu, C. Y. 1981. Another new genus of Adoxaceae, with special references on the infrafamiliar evolution and the systematic position of the family. Acta Bot. Yun- nanica 3: 383-388. R.F. Huanac. 1981. SinadoxaC. Y. Wu, Z. L. Wuet R. F. Huang, genus aogune familiae Adoxacearum. Acta Phytotax. Sinica 19: 203-21 DEPARTMENT OF BIOLOGY Present address: SAN DieGo STATE UNIVE DEPARTMENT OF ECOLOGY AND SAN DIEGO, CALIFORNIA 92182- 0058 EVOLUTIONARY BIOLOGY TUCSON, eons 85721 1985] DONOGHUE, VIBURNUM 457 EXPLANATION OF PLATES PLATE I Pollen of Viburnum sects. ODONTOTINUS (A—-D) and OrEINoTINUS (E, F): A, V. foetidum (Forrest 18129, a); B, V. dilatatum (Ohashi, Nakaike, & Tateishi 70627, a), C, V. ja- ponicum (Ichikawa 26, A); D, V. wrightit (Hatusima 4206, A); E, F, V. ee (Ventura A. 819, ENCB); all type Ia. Scale bars = 10 wm (A-C, E) or | wm (D, F PLATE II Pollen of Viburnum sect. SoLeNoTiNus: A, V. farreri (Rock 12142, a); B, V. suspensum (Hatusima 864, Gu); C, V. oliganthum (H. Smith 1961, a); E, V. odoratissimum (Alcasid 70, A); F, V. odoratissimum (H. H. Hu 770, a); all type Ia. Scale bars = 10 um (A-E) or 1 um PLATE III Pollen of Viburnum sects. SoLENOTINUS (A, B) and Tinus (C-F): A, B, V. brachybo- tryum 12790A, a); C, D, V. tinus (Marchesetti 2752, GH); E, V. davidii (Wilson 3728, a F, V. atrocyaneum (Rock 8905, A); all type Ia. Scale bars = 10 wm (A, C, E, F) or | uv (B, D). PLATE IV Pollen of Viburnum sects. MEGALOTINUS (A, B), VisURNUM (C, D), and TOMENTOSA (E, F): A, B, V. cylindricum (Iwatsuki, Koyama, Fukuoka, & Nalampoon 9424, a); C, D, V. urceolatum (Tashiro s.n., 1917, A); E, F, V. hanceanum (Chun 5314, a); all type Ia. Scale bars = 10 um (A, C, E) or | um (B, D, F PLATE V Pollen of Viburnum sects. OpuLus (A, B) and Pseupotinus (C-F): A, V. a (Furuse s.n., 20 June 1961, a); B, V. sargentii (Furuse s.n., 9 June 1958, a); C furcatum (Togashi 7145, a E, F, V. cordifolium oe 11892, a). A-D, type la: . F, type Ic. Scale bars = 10 um (A-C, E) or | um (D, F PLATE VI Pollen of Viburnum sects. ViaURNUM (A-D) and poe (E, F): A, B, V. macro- cephalum (Wilson 1835, a); C, D, V. utile (H. C. Chow 145, a); E, F, V. ee (Schneider 691, A); all type Ib. Scale bars = 10 um (A, C, . or | um (B, D, F PLATE VII ollen of Viburnum sects. LENTAGO (A-C) and VisuRNUM (D-F): A, B, V. prunifolium Fete: iy ee 1518, Gu), C, V. prunifolium (Bush 7939, Gu), D, V. burejaeticum ([shi- doya s.n., 1918, a); E, V. veitchii (Lingnan Univ. Herb. 78294, A); F, V. a (Rock 12480, A); all type Ic. Scale bars = 10 um (A, D, E) or | um (B, C, F). PLATE VII Pollen of Sambucus (A, B), Adoxa (C, D), and Caprifolioideae tribes Caprifolieae (E) and Linnaeeae (F): A, B, Sambucus pubens (Forbes 3433, Gu); C, D, Adoxa moschatellina (Furuse s.n., 15 May 1961, A); E, Lonicera chrysantha (Purdom 6b, a); F, Heptacodium jasminoides eid 1068, A). A-D, type Ia; E, F, type Id. Scale bars = 10 um (A, C, E, F) or | um (B, 458 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 PLATE IX Pollen of Caprifolioideae tribes Caprifolieae (A, B) and Diervilleae (C-F): A, Leyces- teria formosa (Schneider 1394, a); B, L. gracilis (Forrest 9377, a); C, D, Diervilla lonicera (Jamison(?) s.n., 1930, GH); E, F, Weigela florida (Moran 4257, Gu). A, B, type IId; C- F, type If. Scale bars = 10 um (A, C, E) or 1 wm (B, D, F). PLATE X Pollen of Caprifolioideae tribes Triosteae (A, B) and Linnaeeae (C-F): A, Triosteum aurantiacum (Pennell s.n., 1924, Gu), B, T. perfoliatum (McGregor 14287, Gu); C, Sym- Phoricarpos albus (Pease & Bean 26146, GH), D, Kolkwitzia amabilis (Rehder, Arnold rb. 6475, Gu); E, F, Linnaea borealis (Woodworth 388, Gu). A-C, type He; D-F, type IId. Scale bars = 10 um (A, C, E) or | um (B, D, F). PLATE XI Pollen of Caprifolioideae tribe Linnaeeae (A—D) and Valerianaceae (E, F): A-C, Abelia spathulata (Furuse s.n., 7 May 1957, a); D, Dipelta yunnanensis (Rock 16150, A); E, F, Nardostachys jatamansii (Rock 14168, Gu); all type Id. Scale bars = 10 um (A, C, E) or | um (B, D, F). DONOGHUE, VIBURNUM PLaTE I JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 460 PLATE II 1985] DONOGHUE, VIBURNUM PLATE III ry er OES ¢ vi PLATE IV 463 DONOGHUE, VIBURNUM 1985] PLATE V 464 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 PLATE VI DONOGHUE, VIBURNUM PLATE VII 466 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 PLATE VIII 467 DONOGHUE, VIBURNUM 1985] PLATE IX 468 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 PLATE X 1985] DONOGHUE, VIBURNUM PLATE XI 469 STEVENS, VACCINIUM AND AGAPETES 47] NOTES ON VACCINIUM AND AGAPETES (ERICACEAE) IN SOUTHEAST ASIA P. F. STEVENS AGapPETES D. Don ex G. Don subg. Agapetes and a number of sections of Vaccinium L. from mainland Southeast Asia, especially sects. Galeopetalum J. J. Smith, Aéthopus Airy Shaw, Epigynium (Klotzsch) Hooker f., and Con- chophyllum Sleumer, are clearly closely related in a number of morphological and anatomical features. Agapetes and Vaccinium can be distinguished, albeit very unsatisfactorily, mainly by inflorescence and flower size (Stevens, 1972; Agapetes subg. Paphia (Seemann) P. F. Stevens is not immediately related). Agapetes subg. Agapetes usually has inflorescences with fewer than 15 flowers; the flowers sometimes have wings on the calyx and corolla, or sometimes on only one of these; and the corolla is usually tubular, more than 1 cm long, and with thick walls. Vaccinium species of the Southeast Asian mainland ordinarily have inflorescences with more than ten flowers; the flowers are generally un- winged; and the corolla is usually urceolate, less than 1 cm long, and with thinner walls. During identification of material of the two genera, a number of previously undescribed or imperfectly known taxa of Vaccinium and Agapetes from the northwestern India-Burma—Vietnam-southern China area were found; these are described below. Huang (1983) has recently treated the genus Agapefes in Yunnan in considerable detail, and Fang and Pan (1981) described a number of new taxa of Vaccinium from China. Their findings are integrated with those presented here. Additional notes, mostly range extensions, are also given for a few species. Since the distinction between Vaccinium sect. Epigynium and Agapetes subg. Agapetes ser. Robustae Airy Shaw subser. Chartacea Airy Shaw is rather slight and new taxa are described in both groups, a combined key to all the taxa recognized in these two groups is also presented. The various taxa discussed are dealt with alphabetically by genus, section or series and subseries, and species. Full literature citations to species previously described are not given, but reference is made to the basionym and to a work where pertinent literature 1s traceable; overlooked or subsequent literature is also cited where necessary. In the descriptions “‘filament length” is the length by which the filament exceeds the anther. In all taxa described the receptacle- pedicel junction is articulated, and the fruit has a five-locular ovary with five inpushings of the ovary wall alternating with the five septae. All taxa also have a phellogen that is superficial in origin (i.e., arising just below the epidermis), and leaves that lack a hypodermis. © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 471-490. October, 1985. 472 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Four of the taxa discussed here, Agapetes rubropedicellata, Vaccinium praeces, V. lamellatum, and V. brevipedicellatum C. Y. Wu, combine the characteristics of the two genera in various ways. Two previously overlooked characters, unicellular hairs borne on epidermal papillae and mucilaginous seed coats, also occur in some of these taxa, as well as in some, but not all, species of both Agapetes subg. Agapetes and the related sections of Vaccinium, they are of limited distribution elsewhere in the Vaccinieae (both occur in South American taxa, which are not immediately related). Although it is becoming increasingly apparent that Agapetes subg. Agapetes is ae aa (as is discussed further), I have described species under that taxon below. Generic limits in tropical Vaccinieae as a whole are in paren s pees but we still need to know a great deal more about the basic variation in the tribe before radically rear- ranging these limits, as is needed. PREVIOUSLY OVERLOOKED CHARACTERS USED IN CLASSIFICATION INDUMENTUM Many Vaccinieae have unicellular hairs and also multicellular, often glan- dular hairs with short to long stalks. Unicellular hairs are nearly always scattered evenly on a smooth epidermis, although in a few taxa (e.g., Vaccinium didy- manthum Dunal, from South America, and V. acuminatissimum Migq., from Malesia) they may be aggregated around the bases of (or even borne on!) the multicellular glandular hairs. Some of the taxa described below have a minutely papillate epidermis, with the unicellular hairs borne singly or in small groups on the papillae. The occurrence of hairs on the papillae can be considered a derived condition; es are sae from only a few small-leaved species of Agapetes (e.g., A. mannii Hemsley forrestii W. E. Evans) and many species of Vaccinium sect. Sree in ne Old World Vaccinieae. In the latter taxon these hairs occur in V. manipurense (Watt ex Brandis) Sleumer, which has the same flower type as V. conchophyllum, a species that lacks hairs on papillae. Vaccinium triflorum Rehder, a member of the section with the broader flowers, also has hairs borne in groups on papillae! SEED TyPE Variation in the structure of the seed has been almost completely neglected in tropical Vaccinieae. However, this has considerable systematic and ecolog- ical significance, as a survey in progress is showing. (M ‘As was shown earlier (Stevens, 1972), the species of Vaccinium sect. Vi h) K endemic to Southeast Asia are dissimilar in details of anatomy and ee nee V. vitis-idaea L., the type species of the section. However, they agree in a ait these details with V. conchophyllum Rehder, the type of Vaccinium sect. ae a and thus belong there. Vaccinium sect. Con- chopiybumn 2 as sO ee is aiisr heterogeneous, since the type species and the species transferred from sect. Vi the ends of the twigs and have urceolate flowers, while the aiher members of the section (as delimited by Sleumer, 1941) have inflorescences often borne along the twigs and broader, urceolate-campanulate flowers. 1985] STEVENS, VACCINIUM AND AGAPETES 473 The species described below as having a testa with thin-walled cells that become mucilaginous on wetting also have an embryo that dries a dark color; the embryo was probably green when living (Airy Shaw, 1968; Stevens, 1972). Although the walls of testa cells are thin (often ca. 3 um thick or less), they have distinctive anastomosing bands of thickening running more or less down the long axes of the cells or sometimes slightly oblique to them. Between these thickened bands are elongated unthickened areas. The more common testa type in the Vaccinieae also occurs in some of the species described here. The inner periclinal and anticlinal cell walls are much thickened; the thickenings sometimes almost obscure the cell lumen, being up to 30 wm wide on anticlinal walls. Unthickened areas are minute (less than 3 um wide) and circular in surface view; they usually do not show any obvious patterning, although in a few taxa (but not in the ones discussed below) they may be in lines. The embryo is commonly, but not always, white. In both testa types the outer periclinal walls of the testa cells are very thin. The mucilaginous seed is also probably a derived condition, although it has a rather wide distribution within the Vaccinieae. In Indo-Malesian Vaccinieae it is known only in several species of Agapetes and Vaccinium sects. Aéthopus, Epigynium, and Rigiolepis (Hooker f.) Sleumer (perhaps a modified type), and in some, but by no means all, species of sect. Galeopetalum, as well as in V. piliferum (Hooker f. ex C. B. Clarke) Sleumer, a species of uncertain affinity. It is also known in a number of Vaccinieae from South America, although the crustaceous testa frequently occurs there also; variation in South America may also be at the infrageneric level, despite the narrower generic limits adopted there. SIGNIFICANCE OF CHARACTER-STATE VARIATION The described pattern of variation in seed and epidermis is not congruent with the limits of Vaccinium and Agapetes as delimited here: some taxa of both genera have the derived character states. Other distinctive characters show the same pattern of distribution. Thus, pseudoverticillate leaves in the Vac- cinieae occur in a number of the larger-leaved species of Agapetes and also in Vaccinium sect. Epigynium: expanded leaves separated by short internodes alternate with leaves reduced to scales and separated by long internodes. Such pseudoverticillate leaves can be considered a derived condition (cf. Sleumer, 1941); they are extremely uncommon elsewhere in the Vaccinieae. Characters such as the early development of lenticels and the presence of setular hairs or coarsely serrate leaf margins show a similar pattern of occurrence. Many of these characters vary independently, and none occurs only in the group of species that has been called Agapetes subg. Agapetes, let alone in Agapetes is still definable as only those Vaccinieae on mainland Southeast Asia that have large, thick-walled, often tubular corollas and few-flowered inflores- cences. These characters are loosely functionally correlated: when flowers are large, one expects fewer of them in an inflorescence. In addition, distinguishing between Agapetes and Vaccinium—even using flower size—is becoming less easy, as is Clear from the descriptions of the new taxa below. 474 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Since many taxa with the distinctive character states discussed above are placed in different genera because of differences in flower size but are similar in other characteristics (see also Airy Shaw, 1935), the evidence very strongly suggests that large flowers are of polyphyletic origin in Southeast Asian Wac- cinieae, and that Agapetes subg. Agapetes is a group that represents a grade or level of organization. As might be expected of such a group, its limits coincide only with the cl ter used to circumscribe it, and it has little predictive value. This idea is more likely than the suggestion that characters of indumentum, seed, and leaf are all of polyphyletic origin within both Agapetes and Vaccinium and agrees with the notion that ornithophily is a factor of major significance in the evolution of montane tropical Ericaceae (Stevens, 1976, 1982). KEY TO VACCINIUM SECT. EPIGYNIUM AND AGAPETES SUBG. AGAPETES SER. ROBUSTAE SUBSER. CHARTACEA? 1. Leaves pseudoverticillate, all fully developed leaves of an innovation separated by less than 1.5 cm. 2. Lamina entire. ......0. 00.0.0 ccc eee V. ardisioides Hooker f. 2. Lamina serrate or serrulate. 3. hallat bracts at base of inflorescence incon- spicuous, deciduous or not. 4. Inflorescence axis, pedicels, and flowers ei 4. rag axis, pedicels, and flowers glabrou a (10-)13-18 cm long; inflorescence axis 4-10 cm long, if less, a flowers along its length. 6. Inflorescence axis 8-10 cm long; corolla urceolate, 6-7 mm long. tee neon a Wena gee anne Pu deeh Sue aes . dispar Airy Shaw. 6. Inflorescence axis less than 5.5 cm long; corolla cylindrical, at least eee 10. V. praeces. 7. Upper surface of lamina with raised ee inflorescence axis 4-5.5 cm long; corolla ca. 1.2 cm lon _ 4. A. rubropedicellata. Upper surface of lamina with eee not a inflorescence axis less than 2.5 cm long; corolla ca. 2 cm long. ............ Wes Aah vena t Rarennaomerete areca A, ne (Griffith) Hooker f. . Lamina 4-10 cm long; inflorescence axis less than 2 cm long, with flowers Sina aaa at end. na coriaceous, with prominent continuous submarginal vein; OVaALy SIMOOUN:, sues ese4 ey a eRes V. bulleyanum (Diels) Sleumer. 8. reeves chartaceous, continuous iene et vein absent; ovary with fleshy, longitudinal lamellae (“wings”). . 8. V. lamellatum. 3. ee long- racemose; bracts at base of inflorescence sometimes con- spicuous and persisten 9. Lamina (7.5-)11- 19 cm long; inflorescences eat bracteate at base. tiki fsb ahh dung bomb ape pte Mae ee eee oe nuttallii Sleumer. 9. Lamina 3-10.5 cm long, if as ag as in V. nuttallii, (ie inflorescences not prominently bracteate at bas 10. Lamina 3-6 cm long, upper eudes drying brownish ass henaaie ssn saree a sae cette tesa a ee tse ee a tig dence ee anv a aueia ae V. leucobotrys. 10. Lamina 4-10.5 cm long, upper surface drying dark- or Series -green. 11. Lamina subcoriaceous, with lateral veins and midrib on upper surface impressed. .................0005. V. venosum Wight. nN 2Only the taxa with numbers are treated in this account. 1985] STEVENS, VACCINIUM AND AGAPETES 475 11. Lamina renee with lateral veins and midrib on upper sur- face slightly ra 12. Lamina 3- vi cm wide, with lateral veins spreading at ca. 80° from midrib; pedicels ca. 2mm long. ................... snd ree nuaete eae: V. kinedon-wardii Sleumer. . Lamina 1|-2.5 cm wide, with lateral veins te at ca. 60- 70(—80)° from midrib; pedicels (3.5—)5—12 mm long. 13. Corolla ace inside; petiole (1—-)2—3(—4) mm long. oan oe . vacciniaceum subsp. vacciniaceum. 13. Corolla a ‘inside: ae 1-2 mm long. ........ ere b. V. vacciniaceum subsp. glabritubum. l. ree — separated by internodes, although often restricted to upper half of innov 14. Peticle ca. 2 mm long; lamina to 8(-15) cm | ee N 15. Lamina less than 5 c eee base more or Fes cuneate; bracts at base of inflorescence inconspicuous. .............. . scopulorum W,. W, Smith. 15. Lamina 4-8(-15) cm ae ‘base rounded; bracts at base of inflorescence conspicuous, persistent. ..................0008. 11. V. subdissitifolium. 14. Petiole (4-)8—-13 mm long; lamina usually over 8 cm lon 16. Stem pale and smooth, not obviously lenticellate; petiole 4-6 mm long; lamina coriaceous. .......... 00.0 ee V. kachinense Brandis.? 16. Stem dark, becoming clearly lenticellate; petiole at ae 8 mm long; lamina chartaceous. 17. Corolla cylindrical, at least 12 mm long. 18. Coroll aca. 1.2 cm x ca. 1.5 mm; anthers shorter than filaments, with long nee Saray Veh desta aie atestes A. leptantha Airy Shaw. 18. oon 1.4-2.5 cm x at least 3 mm; anthers much longer than filaments, glabrous. ..............0 0.0.0 3. A. angulata. 17. Corolla urceolate, up to 12 mm lon 19. Corolla 9-12 mm long; inflorescences from foliate axils. ........ peas Guten fog oe cuieda sone sinters cue e e te ete jacobeanum. 19. Corolla 3-4 mm long; inflorescences from defoliate axils. ee ee V. acuminatum D. Don ex G. Don. RANGE EXTENSIONS AND PREVIOUSLY UNDESCRIBED TAXA‘ AGAPETES SER. LONGIFILES AIRY SHAW 1. Agapetes inopinata Airy Shaw, Kew Bull. 14: 229. 1960. Vaccinium glandulosissimum C. Y. Wu ex W. P. Fang & Z. H. Pan, Acta Phytotax. Sin. 19: ne 1981; Agapetes elandulosisimum (C. Y. Wu ex W. P. Fang & Z. H. Pan) S. H. Huang, Acta Bot. Yunn. 5: 148. fig. J. i983. Type: China, Yunnan, Tsang- at [Cangyuan], 1600 m, C. W. Wang 73251 (holotype, PE; isotype, A!). DistTRIBUTION. Burma and China (Yunnan). Wang 73251 is the only collection of Agapetes inopinata known to me from China; the species was previously known only from Burma. Wang 73251] agrees with the isotype specimen of Agapetes inopinata (Kingdon- Ward 8788, A!) very 3Despite its urceolate corollas and the facies of species in sect. Epigynium, Vaccinium kachinense is a member of sect. Galeopetalum; its relationships are unclear. ‘Herbarium abbreviations follow those given in Holmgren, Keuken, and Schofield (1981). 476 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 well, although it has a slightly longer (to 1.3 cm, vs. ca. 9 mm in the type) corolla. In both specimens the glandular indumentum on the flowers and in- florescence is so dense (and presumably sticky) that the flowers tend to stick together. 2. Agapetes pensilis Airy Shaw, Bull. Misc. Inform. 1935: 52. 1935; Hooker’s Ic. Pl. 33: ¢. 3256. 1935; S. H. Huang, Acta Bot. Yunn. 5: 150. 1983. Type: Burma, Valley of the Seinghku, 2400-2700 m, 25.1x.1926, King- don- Ward 7458 (holotype, K; isotypes, A!, K). petes dulongensis S. H. Huang, Acta Bot. Yunn. 5: 150. 1983. Type: China, Yunnan, Tenor Taru ‘Divide [Du-long-jiang], Lungnan [Gongshan], 2300 m, 28.vili.1938, T. T. Yu 20038 (holotype, KUN; isotypes, A!, E!). DISTRIBUTION. Burma and China (Yunnan). Agapetes dulongensis is distinguished from A. pensilis by its smaller, ovate to suborbicular leaves that are described as being puberulent above and glan- dular-hirsute below. The leaf surface is bullate-rugulose, and the lateral nerves are obscure. In A. pensilis the leaves are described as being 1-1.6 x 0.5-1.1 cm, ovate to elliptic-oblong, the surface rugulose above and flat below, both surfaces with a few short hairs but more or less pubescent when young. The illustration of A. pensilis in Hooker’s [cones Plantarum shows the lower surface, at least, to be rather densely covered with fine hairs. When the descriptions of the two species are compared with fragments of the type specimen of Agapetes pensilis, the specimen of the paratype of A. pensilis, and the isotype of A. dulongensis (all at A), numerous discrepancies become evident. It can be seen from the TABLE that the differences in vegetative characters used to separate the species break down. The type specimen of 4. pensilis differs from the other two specimens in lacking glandular-setular hairs on the lower surface of the leaves. It is, however, covered with long, unicellular hairs similar to those found on the upper surface of all specimens. Such uni- cellular hairs are found, albeit sparsely, on the under-surfaces of the leaves of both Handel-Mazzetti 9352 (a paratype of A. pensilis) and T. T. Yu 20038. There are no obvious differences in anatomy in the leaves of the three specimens examined, although Handel-Mazzetti 9352 and T. T. Yu 20038 both have a zone around the edge of the leaf that is only three cells thick but up to 0.15 mm wide; this zone is present but much less evident in Kingdon- Ward 7458. The floral characters of the two type specimens are very similar. The only variation of any possible importance is in the indumentum on the underside of the leaf. I do not think it wise to recognize taxa, even at the varietal level, on this character until its occurrence is better understood. Therefore, A. dulongensis is reduced to synonymy under A. pensilis. AGAPETES SER. ROBUSTAE AIRY SHAW SUBSER. CHARTACEA AIRY SHAW 3. Agapetes angulata (Griffith) Hooker f. in Bentham & Hooker f. Gen. PI. 2: 571. 1876; Ceratostemma angulatum Griffith, Ic. Pl. Asiat. pl. 503. 1985] STEVENS, VACCINIUM AND AGAPETES 477 Leaf characters used to distinguish Agapetes dulongensis from A. pensilis. Agapetes dulongensis Agapetes pensilis CHARACTER Ho.totyee* Isorype (A) PARATYPE (A) HOoOLotTyPet Length (mm) 5-7 6.5-10 (8.5-)9-11.5 7.5-14 Indumentum Pubescence on upper Present Present Present Present rface Glandular-setular Present Present Present Absent hairs on lower surface Wrinkles on surface Distant Dense Dense Subdistant Lateral veins Not evident Notevident Obscure Evident to *Details taken from the protolog +Details taken from five leaves of the type; leaf length given as 10-15 mm in protolog. 1854. See Merrill, Brittonia 4: 157. 1941, and Airy Shaw, Kew Bull. 13: 481. 1958, for additional references and typification. DISTRIBUTION. India (Assam) and Upper Burma. DESCRIPTION OF INFLORESCENCES AND FLOWERS. Inflorescences corymbose to subumbellate, the axis 0.4-1.5 cm long, 5- to 15-flowered, glabrous; bracts ovate, 0.7-1.5 mm long (also inconspicuous bracts at base of inflorescence); pedicels 0.9-2.2 cm long, slender, slightly expanded at apex, glabrous, the bracteoles inserted near base of pedicel, 1-1.5 mm long. Receptacle obpyrami- dal, 1.5-1.7 mm long, slightly 5-angled, glabrous; calyx limb 1.6-2.5 mm long, divided almost to base or to % of its length into 5 triangular lobes, glabrous; corolla 1.5—2.7 cm long, rather thinly fleshy, red to reddish yellow, with deeper- colored horizontal bands, glabrous, with 5 triangular lobes 3.5-5 mm long; stamens 10, the filaments 0.5—1 mm long, with sparse unicellular hairs, the anthers weakly connate by their tubules, the thecae 3.5—4 mm long, rounded to acute and somewhat downward-pointing at base, granulate, the tubules 1.3- 1.7 cm long, opening by introrse slits 5-6 mm long, the spurs small (ca. 0.05 mm long) or absent; disc glabrous; style 1.5-2.1 cm long. SPECIMENS SEEN. Burma: Nam Tesang, 762 m, Toppin 6356 (kK); Kachin State, Sumpra- bum Subdiv., surrounds of Hpuginhku Village, ca. 1525 m, Keenan et al. 3789 (A, E, kK), 3797 (e); banks of Hpuginhku R., at least 1220 m, Keenan et al. 3921] (A, E, K); between Ning W’Krok and Kanang, 1219-1525 m, Keenan et al. 3341 (e), ca. 1525 m, Keenan et al. 3939 (A, E, K), at least 1525 m, Keenan et al. 3950 (A, E, K); E aspect of Gwe-Kya- Kat-Bum, 1220-1525 m, Keenan et al. 3366 (A, kK); North Triangle, Arahku, 1219 m, Kingdon-Ward 20606 (k). India. Assam: Lohit Valley, Kingdon- Ward 19143 (Bm), Mish- mi Hills, Glo Lake, Kamlang Valley, 1067 m, Kingdon-Ward 18461 (a) Agapetes angulata is a rather variable species, especially in floral characters, hence the description of the inflorescence and flowers. It is less variable veg- 478 JOURNAL OF THE ARNOLD ARBORETUM [vVOL. 66 etatively, although the twigs vary from strongly ridged and angled to subterete. It is not possible to recognize infraspecific taxa. 4. Agapetes rubropedicellata P. F. Stevens, sp. nov. A Agapetes leptantha, qua floribus similibus habet, in foliis grandioribus pseudoverticillatis et corollis antherisque glabris, et a A. acuminata in foltis subsessilibus pseudoverticillatis et corollis maioribus cylindricis, non urceo- latis, eta A. dispar in foliis leviter parvioribus, calycibus parvioribus et corollis maioribus cylindricis, non urceolatis, differt. Shrub ca. 1.8 m tall or small tree to 3.6 m tall. Twigs terete, 2-2.5 mm wide, with small, subadpressed, multicellular hairs, lenticellate when older; buds with narrowly subulate perulae ca. 2 mm long. Leaves pseudoverticillate, verticils 6-12 cm apart and with 5 to 7 leaves, leaves in intervening region reduced to scales to 6 mm long; petiole very short; lamina subovate to elliptic, (7-)8.5- 13.5 x (1.7-)2.6-4.6 cm, acute at apex, narrowed toward rounded base, ser- rulate, chartaceous, glabrous, drying dark brown above and brown below, with 11 to 16 pairs of broadly ascending lateral veins, midrib and venation raised and prominent above and slightly less so below. Inflorescences from foliate axils, corymbose-umbellate, with 7 to 16 flowers, the axis 4—-5.5 cm long, with flowers restricted to distal 1-1.5 cm, glabrous; bracts narrowly subulate, to 2 mm long, with subsessile glandular marginal hairs (bracts at base and along axis inconspicuous); pedicels 1—2.2 cm long, glabrous (in fruit rather abruptly expanded and ca. 2 mm thick at apex), the bracteoles basal, ca. 1.5 mm long. Receptacle ca. 1.3 x 1.3 mm, glabrous; calyx limb 1.3-1.5 mm long, divided to base into 5 triangular lobes, glabrous; corolla (old) cylindrical, ca. 1.2 cm x 2.2 mm, glabrous, lobes ca. 1.3 mm long; stamens 10, the filaments 4.3-4.4 mm long, with unicellular hairs, the anthers ca. 8 mm long, the thecae 2.3-2.4 mm long, rounded at base, granulate, the tubules ca. 5.8 mm long, opening by introrse slits ca. 2 their length, the spurs absent; disc glabrous; style ca. 1.35 cm long. Fruits (submature) ca. 4 x 4 mm, red; seeds ca. 1.4 mm long, the testa with thin-walled cells, becoming mucilaginous on wetting, the embryo blackish. Type. Burma, Kachin State, Sumprabum Subdivision (lat. ca. 26°40'N, long. ca. 97°20’E), between Hpuginhku and N’Dum Zup, 5000-6000 ft [1524-1829 m], 15 Jan. 1962, Keenan et al. 3253 (holotype, E!; isotypes, A!, K!). DISTRIBUTION. Known only from Burma. ADDITIONAL SPECIMENS SEEN. Burma: Kachin State, Sumprabum Subdiv., near Hpuginhku village, ca. 1525 m, Keenan et al. 3830 (A, E, K). Agapetes rubropedicellata is related to a group of species in Agapetes subser. Chartacea that all have rather similar leaf texture and margin. These species differ from each other mainly in whether or not the leaves are pseudoverticillate and sessile, and in the shape and size of the corolla. Agapetes leptantha has petiolate leaves much smaller (only 5-8 x 1-2 cm) than those of A. rubrope- dicellata and scattered along the stem, there are remarkable long hairs on the 1985] STEVENS, VACCINIUM AND AGAPETES 479 anthers, and the inside of the corolla tube is hairy. The leaves of A. acuminata are scattered and petiolate, and the flowers are very small (only 3-4 mm long) and urceolate. Agapetes dispar has leaves similar in shape and arrangement to those of A. rubropedicellata, but the lamina is somewhat larger (13-18 x 6- 9.5 cm), the calyx is longer (ca. 3 mm), and the urceolate corolla is only 6-7 mm long. Agapetes rubropedicellata was collected in “‘subtropical hill jungle” (Keenan et al. 3830) at 1525-1830 m altitude; at was recorded as being locally plentiful. The Maru vernacular name d (Keenan et al. 3253) as “Burn-Baing.” AGAPETES SER. ROBUSTAE AIRY SHAW SUBSER. CORIACEA AIRY SHAW 5. Agapetes brandisiana W. E. Evans, Notes Roy. Bot. Gard. Edinburgh 15: 201. 1927. See Airy Shaw, Kew Bull. 13: 479. 1958, and S. H. Huang, Acta Bot. Yunn. 5: 145. 1983, for additional references and typification. DisTRIBUTION. Burma, China (Yunnan). CHINESE SPECIMENS SEEN. YUNNAN: Tsang-Yuan, 1550 m, C. W. Wang 7326/1 (A); Keng- Ma, 1670 m, C. W. Wang 72913 (A); Lu-Se, 1750 m, H. T. Tsai 56821 (A). These specimens are the only ones recorded from China, Agapetes brandi- siana previously having been known only from the Bhamo district of Burma. The specimens cited agree fairly well with the type (in fruit: Cubitt 351] (ho- lotype, E!)) and with the description of the flowers given by Airy Shaw (1935). The following additional details should be noted (where they differ from those in the earlier descriptions, these latter are included in parentheses): Leaves scattered, or loosely aggregated into pseudoverticels; lamina more or less entire, with 2 or 3 pairs of glandular punctations near base that sometimes project notably (margin then serrulate), the fine venation between submarginal and marginal veins prominent. Inflorescences usually from defoliate axils, sometimes (Wang 73261) from foliate ones. Calyx lobes to 3.5 mm long, with middle nerve prominent; corolla 2.2 cm long (2.4—2.6 cm), lobes to 3 mm long (5-6 mm); stamens with filaments 1.7—2.2 mm long, with + dense hairs at top [as Airy Shaw noted, filaments are strongly curved and adnate to base of corolla tube], thecae 4—-4.5 mm long (5-6 mm), tubules ca. 1.7 cm long (1.8—2 cm). VACCINIUM L. SecT. CONCHOPHYLLUM REHDER 6. Vaccinium papillatum P. F. Stevens, nom. nov. Agapetes poilanei Dop in ao Fl. Gén. Indo- See 702. 1930; non Vaccinium poilanei Dop, 1930. Type: Viet Nam, col de L6 Gui Hbé, an 9, prés de Chapa, 1000 m, 28 aott 1926, Pole 12603 ee p!; isotype, A Shrub 0.9-1.8 m tall. Twigs subterete or obscurely angled, 1.3-1.7 mm wide, with unicellular hairs arising from epidermal papillae; buds with ovate perulae 0.8-1.3 mm long. Leaves scattered; petiole 1.2-2 mm long, sparsely pubescent; lamina elliptic, 1-2.8 x 0.5-1.2 cm, rounded and retuse at apex, + cuneate at base, entire, coriaceous, with 2 glandular punctations and 1 or 2 pairs of steeply ascending lateral nerves arising near base, midrib raised on both surfaces, the 480 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 upper surface glabrous, drying brown-green, veins + impressed, the lower surface with multicellular hairs throughout and unicellular hairs on and near midrib, drying brown, veins + raised. Inflorescences from foliate or rarely defoliate axils along twigs, corymbo-racemose, with 2 to 5 flowers, the axis slender, 0.6-1.8 cm long, sparsely pubescent; bracts ovate, |-1.5 mm long; pedicels 4.5-6 mm long (in fruit 0.6—1 cm long, ca. 1.5 mm wide at apex), sparsely pubescent, the bracteoles subbasal, ca. 1.3 mm long. Receptacle 1.1- 1.2 x 1.1-1.2 mm, pubescent; calyx limb 1.5-2.1 mm long, divided almost to base into 5 triangular lobes, pubescent; corolla + campanulate, 4.5-5.5 mm long, ca. 4.5 mm wide when flattened, glabrous, with 5 triangular lobes ca. 1.5 mm long; stamens 10; the filaments ca. 0.5 mm long, flattened, fringed with hairs, the anthers ca. 4 mm long, rounded at base, minutely granulate, the connective with hairs, the tubules ca. 2.4 mm long, opening by introrse slits ca. 0.5 mm long, the spurs at anther-filament junction alternately suberect, ca. 0.7 mm long, and subspreading, ca. 0.9 mm long; disc glabrous; style ca. 5 mm long. Fruits ca. 4 x 4 mm, greenish yellow or whitish pink; seeds ovoid, 1.3-1.5 x 0.5-0.7 mm, the testa cells slightly elongated, with strongly thickened anticlinal walls and slightly thickened inner periclinal walls, the embryo 0.7- 0.8 mm long, pellucid. DISTRIBUTION. Vietnam and southwestern China. ADDITIONAL SPECIMENS SEEN. China. YUNNAN: Si-chour-hsein, Ma-chia, 1300-1500 m, chu, 1700 m, K. M. Feng 12622 (a); Tung-ting, 1500-2000 m, K. M. Feng 13586 (a). Vietnam: Chapa, 1400-1500 m, Chevalier 29469 (p), ca. 1500 m, Pételot 3755 (Pp), 4999 (p); massif [de] Sa Fan tri Pan, ca. 1300 m, Pételot s.n., 11.1931 (A, P). Agapetes poilanei Dop was originally described from material in fruit, but the unicellular hairs borne on epidermal papillae and the short, broadly cam- panulate corolla of the species show its affinity to species in Vaccinium sect. Conchophyllum. Vaccinium tonkinense Dop and V. emarginatum Hayata of this section both have similar flowers and elongated inflorescence axes, but in neither are the unicellular hairs borne on epidermal papillae. Flowering spec- imens of V. papillatum are known only from Vietnam, but there is no doubt that this material is conspecific with the specimens cited from China. Since the epithet poi/anei is occupied in Vaccinium (V. poilanei Merr.), a new epithet is required. The species was previously only imperfectly known, having been dealt with neither by Sleumer (1941) nor by sak san in his various papers on Agapetes, so a full description has been given Three of the Chinese specimens (Feng 12028, 12451, oe 13586), and Cheva- lier 29469, from Vietnam, have shoots with very characteristic subterminal, rosettelike structures. These are made up of numerous ovate perulae ca. 3.5 x 2 mm that are fringed with unicellular hairs. The rosettes probably represent teratological buds that produce nothing but enlarged perulae, instead of the few small perulae followed by fully developed leaves produced by normal buds. The type specimen of Vaccinium papillatum has swellings along the roots; the young plant is reported to have a tubercle. 1985] STEVENS, VACCINIUM AND AGAPETES 481 VACCINIUM L. Sect. EPIGYNIUM (KLOTZSCH) HOOKER F. 7. Vaccinium jacobeanum P. F. Stevens, sp. nov. A Vaccinio vacciniaceo in foliis subdissitis petiolatis laminis basibus de- currentibus subverticillatis (non subsessilibus, lamina basi cuneata vel rotun- data) et corollis grandioribus 9—10(—13) mm longis (non 5—7(-8.5) mm longis), differt Epiphytic or terrestrial shrub 0.9-1.2 m tall. Twigs subterete, 1.3-3 mm wide, with multicellular setular hairs especially at base of innovations, becom- ing lenticellate. Leaves + scattered in upper half of innovation, in lower half reduced to narrowly triangular perulae to | cm long; petiole (0.7-)1-1.5 cm long, glabrous; lamina narrowly elliptic, (4-)7-16 x (1.3-)1.9-3.2 cm, acu- minate or narrowly acute at apex, decurrent at base, serrate, chartaceous, gla- brous, drying blackish green above and dark green below, with 9 to 14 pairs of ascending lateral veins, midrib and venation raised above and slightly less so below. Inflorescences from upper foliate or perulate axils, racemose, with (7 to) 15 to numerous flowers, the axis (1.5—)3-8 cm long, glabrous; bracts narrowly ovate, to 4.5 mm long (bracts at base inconspicuous, ca. 2 mm long); pedicels 0.5—1 cm long, glabrous, not incrassate in fruit, the bracteoles subbasal, ovate, ca. 0.5 mm long. Receptacle ca. 1 x 1 mm, glabrous; calyx limb 1-1.3 mm long, divided to base into 5 triangular lobes, glabrous; corolla tubular- urceolate, 9-10 mm long, yellow to green, glabrous, with triangular lobes ca. 1 mm long; stamens 10, the filaments ca. 3 mm long, with unicellular hairs, the anthers 5 mm long, the thecae ca. 2 mm long, + rounded at base, granulate, the tubules 2.8-3 mm long, opening by introrse slits ca. 2 their length, the spurs minute, arising at junction of thecae and tubules, or absent; disc glabrous; style ca. 9.5(-12.5) mm long. Ripe fruits not known. Type. Burma, Kachin State, Sumprabum Subdivision, ca. 26°40'N, 97°20’E, surrounds of Hpuginhku village, + 5000 ft [1524 m], March 1962, Keenan et al. 3774 (holotype, A!; isotypes, E!, K!). DIsTRIBUTION. Known only from Burma. ADDITIONAL SPECIMENS SEEN. Burma. KACHIN STATE: Sumprabum Subdiv., summit of Kanat Bum, 2438 m, Keenan et al. 3449 (a, E, K); surrounds of Hpuginhku village, ca. 1524 m, Keenan et al. 3775a (E); between Ning W’Krok and Kanang, 1524 m, Keenan et al. 3954 (A, E, K), at least 1524 m, Keenan et al. 3951 (A, E, K); Sumprabum, 914 m, Kingdon-Ward 20471 (BM) Although clearly allied to Vaccinium vacciniaceum (Roxb.) Sleumer, V. ja- cobeanum differs in the characters noted in the diagnosis. Note that the petiole proper may measure only 2-3 mm in length, with ons prominent teeth on the upper part of what is apparently the peti g the extremely attenuate basal part of the lamina. Vaccinium jacobeanum is also close to Agapetes leptantha Airy Shaw, from which it can be distinguished by its slightly shorter corolla that has thicker walls and 1s twice as wide, and by its glabrous anthers that are less than half the total length of the stamens. 482 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 The specimen collected by Kingdon-Ward cited above has rather small leaves. Vaccinium jacobeanum grows in subtropical hill jungle and open mixed deciduous and evergreen forest at altitudes of 914-2438 m. Flowering speci- mens have been collected in February, March, and July. The Jingpaw name for this plant is ““Pin-lawng-Lap” (Keenan et al. 3449). The specific epithet commemorates the collector, James Keenan. 8. Vaccinium lamellatum P. F. Stevens, sp. nov. A Vaccinio bulleyano in foliis minoribus coriaceis nervis submarginalibus destitutis, receptaculis lamellis 10 longitudinalibus ornatis, et antheris valde granulatis, differt. Epiphytic shrub. Twigs terete, 1.2-2.2 mm wide, glabrous or sparsely pu- bescent when young, becoming lenticellate; buds with ovate perulae ca. 3 mm long. Leaves pseudoverticillate, 2 to 6 per verticil, intervening region (1-)4—-9 cm long with leaves reduced to lingulate scales up to 6 mm long; petiole 1-2 mm long; lamina elliptic to subovate, 3-9.7 x 1.3-3.8 cm, acute at apex, rounded at base, serrulate, subchartaceous, glabrous, drying gray-brown above and brown below, with 7 to 10 pairs of ascending lateral veins, the midrib raised above and strongly raised below, notably more prominent toward mar- gin. Inflorescences from axils of reduced leaves, corymbose-umbellate, with 5 to 12 flowers, the axis 0.7-1.4 cm long, with flowers restricted to distal part, (?)glabrous or with glandular multicellular hairs to 1 mm long; bracts subper- sistent, ovate, to 3 mm long, with marginal glands (bracts at base and along axis inconspicuous); pedicels 1.3-1.9 cm long (in fruit to 2.5 cm long, ca. 2 mm across at abruptly widened apex), glabrous, the bracteoles subbasal, ca. 2 mm long. Receptacle 1.5—2 x 1.5-2 mm, with 10 irregular, fleshy, longitudinal lamellae, glabrous; calyx limb 2.3-2.6 mm long, divided almost to base into 5 triangular lobes, glabrous, corolla urceolate, ca. 5.5 x 2.5 mm (ca. 1.3 mm wide at mouth), white, the lobes triangular, ca. 0.6 mm long, green; stamens 10, the filaments ca. 0.5 mm long, glabrous, the anthers 4.5—4.7 mm long, the thecae ca. 2.5 mm long, rounded at base, strongly granulate, the tubules ca. 2.3 mm long, opening by introrse slits ca. | mm long, the spurs absent; disc glabrous; style ca. 5 mm long. Fruits ca. 4.5 x 4.5 mm; seeds obovoid, ca. 2 x 1.2 mm, the testa with thin-walled cells that become mucilaginous on wetting, the embryo ca. 1 mm long, drying blackish. Type. India, Manipur, Sirhoi, 6500-7000 ft [1980-2135 m], 10 April 1948, Kingdon- Ward 17246 (holotype, A!; isotypes, BM!, NY!). DIsTRIBUTION. Known only from Manipur, India. ADDITIONAL SPECIMENS SEEN. India. MANIPUR: Sirhoi, 2286 m, Kingdon-Ward 17688 (BM, NY); Khaiyang, 2135-2438 m, Kingdon-Ward 17393 (A, BM). Vaccinium lamellatum is superficially similar to V. bullevanum (Diels) Sleu- mer (Agapetes bulleyana Diels) but can easily be recognized by the characters mentioned in the diagnosis. Vaccinium lamellatum has a less coriaceous leaf blade that lacks the prominent intramarginal vein of V. bulleyanum but never- 1985] STEVENS, VACCINIUM AND AGAPETES 483 theless has a very distinctive margin, since the fine venation at the very edge of the lamina is prominently raised on both surfaces. I do not know of any other species of Vaccinium with the ten irregular, fleshy lamellae on the re- ceptacle that are found in V. /amellatum. The stamens of V. /amellatum differ considerably from those of V. bullevanum, having prominently papillate thecae that are more or less rounded at the base (at least alternate stamens of V. bulleyanum are pointed at the base, with prominent papillae restricted to the base) and anthers that are abruptly incurved at the theca-filament junction. The lamellate receptacle of Vaccinium lamellatum approaches that of Aga- petes miniata, which has ten raised longitudinal lines; the latter species also has a subumbellate inflorescence. However, A. miniata has a leaf blade that is at least 10 cm long and a cylindrical corolla over 2 cm long; the latter character is responsible for the placement of A. miniata in Agapetes. The field notes on the type specimen of Vaccinium lamellatum (‘an epiphyte with water-storing tissue”) suggest that it has a swollen stem base. The fruit color of V. lamellatum is not known. 9. Vaccinium leucobotrys (Nutt.) Nicholson, Ill. Dict. Garden. 4: 130. 1886; Epigynium leucobotrys Nutt. Bot. Mag. HI. 15: t. 5/03. 1859. See Sleu- mer, Bot. Jahrb. Syst. 71: 478. 1941, for additional references and syn- onymy. DIsTRIBUTION. India (Assam), Burma, China (Tibet, Yunnan). SELECTED SPECIMENS SEEN. Burma: above Zuklang, ca. 2438 m, Kingdon-Ward 418 (a, ny); Adung Valley, 1829-2134 m, Kingdon-Ward 9219 (a); North Triangle, Tagulam Bum, 2286 m, Kingdon-Ward 21604 (aA); Kachin State, Sumprabum Subdiv., Janrawng Bum, 2134-2743 m, Keenan et al. 3179 (A, E). The first two specimens cited above have been included in Vaccinium vac- ciniaceum (Roxb.) Sleumer var. hispidum (C. B. Clarke) Sleumer (Sleumer, 1941; Merrill, 1941). However, they both agree with V. /eucobotrys in having prominently and subpersistently bracteate inflorescences and ovate, usually green-drying leaves that are usually broadly rounded at the base; these char- acters readily separate V. /eucobotrys from V. vacciniaceum. The specimens cited above are the first record of the species from Burma. Although they were collected at somewhat lower altitudes (in Assam, Tibet, and Yunnan Vaccinium leucobotrys grows at altitudes of 2100-3300 m), they agree well with other specimens of the species. 10. Vaccinium praeces P. F. Stevens, sp. nov. A Vaccinio bulleyano, V. lamellato, et Agapetes dispar, quibus in facie plus minusve similibus sunt, in inflorescentiis, pedicellis floribusque pubescentibus, differt. Epiphytic shrub. Twigs + terete, 2.3-3 mm wide, with few multicellular glandular hairs, becoming lenticellate. Leaves pseudoverticillate, 2 to 4 per verticil, the intervening stem 2.5-10 cm long, with leaves reduced to ovate to obovate scales up to 10 x 5 mm; petiole 1-1.5 mm long; lamina ovate to 484 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 elliptic, 7.5—-ca. 14 x (3.3-)4-7.3 cm, acuminate at apex, rounded to slightly cordate at base, serrulate, subchartaceous, glabrous, with ca. 14 pairs of broadly ascending lateral veins, the upper surface drying gray-green, midrib depressed but raised in center, venation + impressed, the lower surface drying olivaceous, midrib strongly raised, venation raised. Inflorescences from axils of reduced leaves, corymbose-umbellate, with ca. 20 flowers, the axis 2—2.5 cm long, with flowers restricted to distal part, subdensely pubescent; bracts subpersistent, ovate, 2—2.5 cm long, with marginal glandular hairs (bracts at base and along axis inconspicuous); pedicels 1—-1.5 cm long, slightly broadened toward apex, pubescent, the bracteoles basal, ca. 1 mm long. Receptacle ca. | x 1 mm, slightly 5-angled, pubescent; calyx limb 3.5—4 mm long, divided almost to base into 5 narrowly triangular lobes, pubescent, each lobe with prominent midrib; corolla urceolate, ca. 7 x 3.5 mm (ca. 2.2 mm across at mouth), slightly angled, green, pubescent outside, with hairs only toward apex inside, the lobes 5, broadly triangular, ca. 0.7 mm long; stamens 8 or 10, the filaments ca. 1.2 mm long, flattened, widened toward base where ca. 0.6 mm across, glabrous, the anthers ca. 3.9 mm long, the thecae ca. 1.6 mm long, rounded at base, granulate, the tubules ca. 2.3 mm long, opening by introrse slits ca. 0.9 mm long, the spurs absent; disc glabrous; style ca. 6.3 mm long. Fruits unknown. Type. Burma, North Triangle (Tagulam Bum), 2410 m, 15 Nov. 1953, King- don-Ward 21605 (holotype, BM!). DIsTRIBUTION. Known only from the type collection. Vaccinium praeces 1s closely related to the group of species straddling the dividing line between Vaccinium sect. Epigynium (to which V. praeces is as- signed) and Agapetes subser. Coriacea. From all these species (V. bulleyanum (Diels) Sleumer, V. /amellatum P. F. Stevens, and A. dispar Airy Shaw) it can be separated by its densely pubescent inflorescences and flowers. From V. bulleyanum it also differs in its larger, thinner leaves that lack a submarginal vein. Although V. praeces and V. bulleyanum have similar inflorescences, V. praeces has stamens with much longer filaments, those of V. bulleyanum being only ca. 0.5 mm long. Vaccinium lamellatum has leaves much smaller than those of V. praeces, and it also has a lamellate, rather than slightly angled, receptacle. Agapetes dispar is perhaps most closely related to V. praeces, but in addition to differing in inflorescence pubescence, A. dispar has a longer (8- 10 cm) inflorescence axis, longer (2—2.5 cm) pedicels, and somewhat pubescent stamen filaments. There is possibly another taxon in this circle of affinity. Kingdon- Ward 3050 (E; ridge above Laktang, 2453 m; specimen in young fruit) has the inflorescence type and length—as well as the indumentum—of Vaccinium praeces, but there are probably only about ten flowers per inflorescence, and the calyx lobes are up to 6.5 mm long. The leaves are falsely whorled, and the blades have a distinct submarginal vein. 11. Vaccinium subdissitifolium P. F. Stevens, sp. nov. Vaccinium vacciniaceum (Roxb.) Sleumer var. hispidum (C. B. Clarke) Sleumer, Bot. Jahrb. Syst. 71: 479. 1941, pro majore parte, excl. spec. Assamica, V. venosum Wight 1985] STEVENS, VACCINIUM AND AGAPETES 485 var. hispidum C. B. Clarke in Hooker f. FI. Brit. India 3: 452. 1882. Type: Sikkim 4000-7000 [1219-2143 ml], a n., pro parte (lectotype, K!; isolectotypes, El, GH!, NY!). See also V. vacciniace Gaylussacia eee auct. non cane Griffith, Ic. Pl. Asiat. p/. 507. 1854. A Vaccinio vacciniaceo in lamina basi plerumque late rotundata, non sub- cuneata vel anguste rotundata, foliis subdissitis, non pseudoverticillatis, perulis basi inflorescentiae persistentibus, non deciduis, et corolla 3—4.5 mm, non 5- 7(-8.5) mm, longa, differt, et a V. leucobotrys in foliis subdissitis, non pseu- doverticillatis, lamina plerumque suboblonga vel obovata, non ovata, antheris prominente granulatis, non sublaevibus, et corolla intus glabra, non pubescen- tia, differt. Epiphytic shrub. Twigs terete, 1.5—2.5 mm wide, pubescent and with mul- ticellular setular hairs to 1.7 mm long, rarely glabrous, becoming lenticellate. eaves + scattered along stem; petiole 1-2 mm long; lamina oblong to obovate, greenish brown to blackish above and brown below, with 6 to 16 pairs of ascending lateral veins, midrib and venation + raised above and below (ve- nation sometimes i below). Inflorescences from upper foliate axils, racemose or corymbo- racemose, with ca. 10 to numerous flowers, the axis |.8- 5.3 cm long, glabrous; bracts ovate, to 4 mm long, with setose margins (basal bracts persistent, scarious, conspicuous); pedicels 2.5-7 mm long, glabrous, the bracteoles subopposite, ovate to linear, to 3 mm long. Receptacle 1-1.5 x I|- + rugulose, glabrous; calyx limb 0.5—1.3 mm long, divided to base into 5 triangular lobes, glabrous; corolla urceolate, 3—4(-5) x ca. 2.5 mm (ca. 1.2 mm wide at mouth), greenish white, glabrous, sometimes minutely papillate inside at mouth, with 5 triangular lobes ca. 0.6 mm long; stamens 10, the filaments ca. 0.8 mm long, widened and slightly connate at base, glabrous, the anthers 3—3.2 mm long, the thecae ca. 1.4 mm long, narrowed and acute at base, strongly granulate, the tubules 1.6—-1.8 mm long, opening by introrse slits for 2—'4 their length, the spurs absent; disc glabrous; style ca. 4.5 mm long. Fruits ca. 1.5 x 1 mm, white or greenish white; seeds ovoid, ca. 1.5 x | mm, the testa cells thin walled, becoming mucilaginous on wetting, the embryo ca. 1 mm long, drying blackish. Type. India, Sikkim, 4000-7000 ft [1219-2143 m], Hooker s.n., pro parte (holotype, GH!; isotypes, E!, K!, Ny!). DIsTRIBUTION. Foothills of the Himalayas in Bhutan and India (Sikkim and Assam) ADDITIONAL SPECIMENS SEEN. Bhutan: sine loco, Griffith, Kew Dist. 2260 (BM, pro parte, E), Kew Dist. 3641, pro parte (BM, GH, kK), Nuttall s.n. (kK). India. Assam: SE of Apa Tani valley, Subansiri Div. of N.E.F.A., 2134 m Ox & Hutchinson 468 (£, K), 2377 m, Cox & Hutchinson 409 (£, k); Mishmi Hills, Glo, Kamlang Valley, 1219 m, Kingdon- Ward 18456 (A, K, NY). SIKKIM: Tumlong, 1981 m, Clarke 27709A (k), 27709C (BM), Pasheeting, 1676 m, Gamble 3666A (k). Vaccinium subdissitifolium can be separated from its two closest relatives, V. vacciniaceum (Roxb.) Sleumer and V. /eucobotrys, by the characters given 486 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 in the diagnosis. Vaccinium subdissitifolium is in some ways intermediate be- tween these two species, although its consistently more or less scattered leaves are characteristic of neither. In flower V. subdissitifolium is most similar to leucobotrys but differs in corolla indumentum (V. /eucobotrys has hairs on the inner surface of the corolla) and in its more granulate anthers. In these two features V. subdissitifolium approaches V. vacciniaceum, especially subsp. gla- britubum, and in leaf characters it is also perhaps more similar to V. vaccini- aceum than to V. leucobotrys. Ranking of these and other taxa related to V. vacciniaceum (V. venosum, V. nuttallii, and V. kingdon-wardii) is difficult. The inflorescence axis possibly elongates after flowering, as the field notes of Cox & Hutchinson 409 suggest. Vaccinium subdissitifolium has been typified on the same collection as the type of V. vacciniaceum var. hispidum. However, in view of confusion sur- rounding the name hispidum (see V. vacciniaceum), a new name has been chosen at the species level. Specimens of V. vacciniaceum var. vacciniaceum are sometimes mounted with the type of V. subdissitifolium. Kingdon-Ward 18456, from Assam, is a very robust specimen that has larger leaves than the others (measurements in the description in parentheses), and it also has twigs that are glabrous at maturity. However, it has persistent bracts at the base of the inflorescence and leaves that are scattered along the upper half of the innovation, so it is referred to this species. 12. Vaccinium vacciniaceum (Roxb.) Sleumer 12a. Vaccinium vacciniaceum (Roxb.) Sleumer subsp. vacciniaceum Vaccinium vacciniaceum (Roxb.) Sleumer var. vacciniaceum, Bot. Jahrb. Syst. 71: 479. nae Ceratostem[ml]a vacciniacea Roxb. Fl. Indica, ed. 2. 2: 412. 1932. Type: India, m, Garrow Hills, Roxburgh s.n., 1813 (BM!). V. vacciniaceum (Roxb.) Sleumer var. hispidum auct. non (Clarke) Sleumer: Sleumer, Bot. Jahrb. Syst. 71: 479. 1941, pro parte Assamica. Epiphytic or terrestrial shrub. Twigs terete, 1.4-2 mm wide, usually with setular hairs to | mm long at least at beginning of innovation, becoming lenticellate. Leaves pseudoverticillate, 5 to 10 together, the intervening stem 2-10 cm long, with leaves reduced to narrowly triangular scales to 7 mm long; petiole (1-)2-3(-4) mm long; lamina narrowly elliptic, 3-11 x 0.9-2.1 cm, acute at apex, narrowly cuneate to + rounded at base, serrate, chartaceous, glabrous, with 7 to 13 pairs of lateral veins, the upper surface drying black to dull green, midrib narrowly raised, venation raised, the lower surface drying brown or brownish green, midrib broadly raised, venation slightly raised. In- florescences from foliate axils, racemose or corymbo-racemose, with at least 10 flowers, the axis 1.7—-6 cm long, glabrous or very rarely with long-stalked subcapitate hairs; bracts deciduous, narrowly triangular, to 3 mm long (basal bracts inconspicuous); pedicels 7-13 mm long, slightly expanded at apex, gla- brous, the bracteoles + basal, linear to narrowly triangular, 0.8-1.3 mm long. Receptacle 0.8-1 x 0.8-1 mm, smooth, glabrous; calyx limb 0.7—1 mm long, divided almost to base into 5 triangular lobes, glabrous; corolla urceolate, 5— 7(-8.5) x ca. 2mm (1 mm across at mouth), white to greenish white or pinkish 1985] STEVENS, VACCINIUM AND AGAPETES 487 yellow, with unicellular hairs inside especially toward mouth, the lobes tn- angular, ca. 0.6 mm long; stamens 10, the filaments 1.8—2.5 mm long, flattened and widened at base, subglabrous or with unicellular hairs, the anthers 3.3- 3.7 mm long, the thecae 1-1.3 mm long, usually sharply verruculose, sometimes + smooth, the tubules 2-2.5 mm long, dehiscing by long introrse slits, the spurs absent or minute; disc glabrous; style 5.5-7 mm long. Fruits ca. 2 mm long (immature?), glistening white or yellowish; seeds (immature) ca. 1 mm long, testa with thin-walled cells that become mucilaginous on wetting. DisTRIBUTION. Meghalaya, Nagaland, and Manipur, India, and the Chin area of Burma SELECTED SPECIMENS SEEN. Burma: Haka, 1981 m, Dickason 7371] (A). India. MANIPUR: Sirhoi, 1829-2438 m, Kingdon-Ward 17269 (pm), Ukhrul, 1576 m, Kingdon- Ward 17125 (A, BM); Japoo, 1829 m, Watt 6226 (pr); Khaujang, 2134-2438 m, Kingdon- Ward 17395 (BM). MEGHALAYA: Khasia Hills, Shampung, 1524 m, Badul Khan s.n., v.1980 (P); below Upper Shillong, 1372 m, Cox & Hutchinson 553 (£, «); Pynursla, 1286 m, Cox & Hutchinson 317 (e, «); Lushai Hills, Lakher Country, 2134 m, Lorrain s.n., vi.1928 (k); Blue Mtns., 2100 m, Koe/z 33038 (£); Khasia and eae Hills, Upper Shillong, 1829 m, Ruse 61 (A); Cherrapunjee, 1200 m, Chand 5341 (£). NAGALAND: Kohima, Naga Hills, 2100 m, Koelz 25446 (e); Puhiratadza, Wee 2347 m, Prain s.n. (E); Pulebudze, 2286 m, Bor 2998 (kK); Kanku Range, 1981 m, Bor 2943 (x). Dickason 7533 (A; Haka, Burma) has bracts more conspicuous than those of the other specimens, and there are also numerous long-stalked, capitate hairs on the inflorescence axis. Although a conspicuously and subpersistently brac- teate inflorescence is characteristic of Vaccinium leucobotrys, that species has an entirely glabrous inflorescence axis. A few specimens (e.g., Ruse 6/) have almost smooth anther thecae, but this seems to be uncorrelated with other variation. 12b. Vaccinium vacciniaceum (Roxb.) Sleumer subsp. glabritubum P. F. Ste- vens, subsp. nov. V. vacciniaceum (Roxb.) Sleumer var. vacciniaceum Sleumer, Bot. Jahrb. Syst. 71: 479. 1941, pro parte. V. vacciniaceum auct. non (Roxb.) Sleumer: Sen Gupta, Rec. Bot. Surv. India 20: 137. 1973 V. serratum auct. non (Don) Wight: Biswas, Pl. Darj. Sikkim Himal. 1: 498. 1966. A subsp. vacciniacea in tubo corollae intus glabro, petiolo 1-2 mm longo, et in lamina basi plus minusve anguste rotundata, differt. As in subsp. vacciniaceum, but corolla tube glabrous inside, petiole 1-2 mm long, and lamina + narrowly rounded at base Type. Nepal, Arun Valley, Maghang Kola, E of Num, 9000 ft [2743 m], 30 April 1956, Stainton 167 (holotype, A; isotype, BM) DisTRIBUTION. Nepal and Bhutan; collected once in China (southern Tibet). ADDITIONAL SPECIMENS SEEN. Bhutan: Chukka Timpu, 1219 m, Cooper 3783 (Bm); SW Wangdi Phodrang, 1829 m, Bowes Lyon 6060 (BM), 2286 m, Bowes Lyon 6058 (Bm); 488 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Kinga Rapden, Mangde Chu, 1219 m, Ludlow et al. 18589 (BM, £); Rhine Lhakang, 1829 m, Ludlow et al. 20142 (BM, £); Sichulu [Sichula], Biswas 2014 (a); Mirik, 1676 m, Biswas 3740 (a). China. T1BeET: between Shakti and Pangshen, Nyam Jang Chu, 1825 m, Ludlow & Sherriff 1240 (£). India. SIKKIM AND ADJACENT W BENGAL: Sureil, 1524 m, Cave s.n., 19 April 1916 (a, £); Lebong, 1524 m, Cave s.n., 8 May 1912 (£); Darjeeling, Cowan s.n. (kK), Polunin 9532 (pm), 2134 m, Clarke 27535 (x); Senchal Forest, 2134 m, Lace 2223 (cE), Dhobijhna Nursery, 1829 m, Gamble 10314 (kK); below a ae toward Jakaor, ca. 1829 m, Herb. Lacaita H vii 452 (gm); Senchal, 2134 m, May 1879, anon. (Ny); Gangtok, 1524 m, Ludlow et al. 4003 (A, BM, E); Roro Chu, 1676 m, Stainton 5306 (BM); Talung Chu, 914 m, Bowes Lyon 6029 (am): Yoksam, 1981 m, Bowes Lyon 3003 (Bm); Baboo Chola, 1219 m, Griffith 6870A (k); Kinseong [Kurseong], Gamble 3663A (k), 3665A (k); Dikchu, 613 m, Biswas 6739 (a); Singlik, 1366 m, Biswas 6810 (A); Reinak, 1524 m, Clarke 27917 (x); Kalimpong, 1372 m, Ludlow & Sherriff 15834 (BM, a sine loco, 1219- 2143 m, Hooker s.n., pro parte (Ny), 1829 m, Cave s.n., 4 May 1920 (A). Nepal: Mechi Zone, Ilam Distr., Aulabari, 1700 m, Nicolson 3247 (BM); Ilam, Chintapu, 2134 m, Stainton 5780 (Bm); W ‘oflae. Mai Pokhari, 2134 m, Williams 395 (em); Arun Valley, Dhoje, N of Chainpur, 2286 m, Stainton 120 (zm); Tamur Valley, Hellok, 1676 m, Stainton 5827 (BM). Within Vaccinium vacciniaceum Sleumer (1941) recognized vars. vaccini- aceum and hispidum. The type of var. hispidum and some specimens that he cited as belonging to that variety are described above as V. ee while other specimens are to be referred to V. /eucobotrys and to V. vaccini- aceum subsp. vacciniaceum. Specimens that he cited under var. vacciniaceum are to be referred to both subspecies of V. vacciniaceum recognized abov The basis for the recognition of Vaccinium vacciniaceum var. hispidum was the presence of setular hairs at the beginning of an innovation, but the presence or absence of pucH hairs seems to be a rather trivial character. Within V. ibed, the correlation of the absence of unicellular hairs on the inside of the corolla with a shorter petiole, a more rounded leaf base, and the geographic provenance of the specimen is almost perfect. The sole exception, a possibly mislabeled specimen collected by Hooker and Thompson in Khasia (£, GH, K, P), lacks hairs on the inside of the corolla tube and has a short petiole and a rounded leaf base. VACCINIUM SECTION UNCERTAIN 13. — brevipedicellatum C. Y. Wu, Acta Phytotax. Sin. 19: 107. 1981. Typ ina, Yunnan, Mar-li-po [Malipo], 1200-1500 m, 22.x1.1947, K. M Feng 13561 (holotype, PE; isotype, A!). — chapaénsis Dop in Lecomte, Fl. Gén. Indo-Chine 3: 702. 1930; non Vaccin- um chapaénse Merr. (1938). Type: Vietnam, massif de Za Yang Puech, prés de Chava: 1 aofit 1926, Poilane 12735 ele. p!). Agapetes chapaénsis Dop var. oblonga Dop in Lecomte, ibid. Tyre: Vietnam, massif o nu Tong, prés de Chapa, 2200 m, P59 juillet 1926, Poilane 12679 (holotype, pl; isotype, A!). AMPLIFIED DESCRIPTION. Twigs with unicellular hairs borne on epidermal pa- pillae. Leaves with lamina ovate to narrowly elliptic, 1.4-3 x 0.6-1.4 cm, 1985] STEVENS, VACCINIUM AND AGAPETES 489 obtusely acuminate at apex, cuneate to rounded at base, entire, with 2 glandular spots near base, subcoriaceous, the upper surface sharply and shallowly trans- versely corrugated, drying greenish to grayish brown, the lower surface smooth, drying brown, the lateral veins 2 pairs, arising near base, steeply ascending, the midrib raised, sparsely pubescent toward base. Inflorescences from foliate axils, with 3 flowers, the axis up to 2 mm long, with glandular-capitate hairs to 1 mm long; pedicels to 1.5 mm long, with glandular-capitate hairs at apex. Corolla unknown; stamens 9 (really 10?), the filaments ca. 0.6 mm long, flat- tened, fringed with hairs, the anthers ca. 2.2 mm long, the thecae 0.9-1 mm long, + smooth, the tubules ca. 1.2 mm long, opening by introrse slits for about 4 their length, the spurs arising from tubule-theca junction, 0.5-0.7 mm long, minutely papillate; disc glabrous; style ca. 3.1 mm long. Fruits purple- black, ca. 2.5 by 2.5 mm, with 10 longitudinal ridges when dry; seeds ca. 1.2 x 0.9-1.05 mm, angled, brown, the testa cells with greatly thickened anticlinal walls and slightly thickened inner periclinal walls, the embryo ca. 0.75 mm long, + pellucid. DISTRIBUTION. Vietnam and southwestern China. ADDITIONAL SPECIMENS SEEN. China. YUNNAN: Mar-li-po, Hwang-jin-in, 1300-1600 m, K. M. Feng 13198 (4), 1400-1600 m, K. M. Feng 13014 (a). Specimens of Agapetes chapaénsis have unicellular hairs borne on epidermal papillae that are common in species of Vaccinium sect. Conchophyllum, and they apparently also have very small flowers (the stamens and the style re- mained attached on a young fruit of Feng 13561). Agapetes chapaénsis hence is best placed in Vaccinium. The epithet chapaénse is occupied in Vaccinium (V. chapaénse Merr.); the epithet brevipedicellatum chosen for this species alludes to the short pedicels. Vaccinium brevipedicellatum cannot really be assigned to a section since its corolla is not known, but it has affinities with both sect. Conchophyllum (in which Wu placed the species—the stamens and the unicellular hairs grouped on epidermal papillae are similar) and sect. Aéthopus (the pedicel indumentum and the inflorescence type are similar, but the stamens are different, those of V. paucicrenatum Sleumer lacking spurs). However, it differs from both groups in that the vascular tissue in the petiole forms a closed circle. In all the small- leaved species of Vaccinium sects. Aéthopus and Conchophyllum that have been examined, the vascular tissue in the petiole is arcuate. All the specimens of Vaccinium brevipedicellatum cited have characteristi- cally corrugated leaves. Leaf shape is variable, and there is little difference between the types of Agapetes chapaénsis vars. chapaénsis and oblonga. The leaf blades on the two specimens from Vietnam seen are narrower than those on specimens from Yunnan, and if varieties based on leaf shape are to be recognized, specimens from Yunnan may form one variety, those from Vietnam another. When Wu described Vaccinium brevipedicellatum, he was unaware of the earlier names for this taxon in Agapetes. He did not describe either stamens or styles. 490 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ACKNOWLEDGMENTS I am grateful to the directors of the institutions cited above for permission to examine material in their herbaria or for sending specimens on loan. LITERATURE CITED Airy SHAW, H. K. 1935. Studies in the Ericales: I. New and less-known species of Agapetes. Bull. Misc. Inform. 1935: 24-53 68. Studies in the Ericales: XV. New or noteworthy Agapetes from Assam and Burma. Kew Bull. 21: 471-476. FANG, W. P., & Z. H. PAN. 1981. New species of Vaccinium from China. Acta Phytotax. Sin. 19: 107-113. Hotmacren, P. K., W. Keuken, & E. K. ScHoFiELD. 1981. Index herbariorum. ed. 7. Reg. Veg. 106. Huana, S. H. 1983. A preliminary a 2 the genus Agapetes D. Don ex G. Don from Yunnan. Acta Bot. Yunn. 5: 1. MerRILL, E. D. 1941. The Upper ea ae collected by Captain F. Kingdon Ward in the Vernay-Cutting Expedition, 1938-1939. Brittonia 4: 20-188. StEUMER, H. 1941. Vaccinioideen-Studien. Bot. Jahrb. Syst. 71: 375-510. SrevENS, P. F. 1972. Notes on the infrageneric classification of Agapetes, with four new taxa from New Guinea. Notes Roy. Bot. Gard. Edinburgh 32: 13-28. 1976. The altitudinal and geographical distributions of flower types in Rho- dodendron section ae especially the Papuasian species, and their significance. J. Linn. Soc., Bot -33. . 1982. Seated and evolution of the Ericaceae of New Guinea. Jn: J. L. GressiTt, ed., Biogeography and ecology of New Guinea. Monogr. Biol. 42: 331- 354. HARVARD UNIVERSITY uma 22 Divinity AVENU CAMBRIDGE, ee HUSETTS 02138 1985] KELLOGG & WEITZMAN, MELICYTUS 491 A NOTE ON THE OCEANIC SPECIES OF MELICYTUS (VIOLACEAE) ELIZABETH A. KELLOGG AND ANNA L. WEITZMAN THE GENERA Melicytus Forster and Hymenanthera R. Br. together comprise 13 species of shrubby violets with nearly actinomorphic flowers. The genera have been distinguished primarily by the number of seeds per carpel, but Beuzenberg (1961) has shown that this cl ter varies both within and between species in such a way that the distinction between the two genera cannot be maintained. Furthermore, two species, Melicytus lanceolatus Hooker f. and Hymenanthera chathamica (F. Mueller) Kirk, produced a fully fertile hybrid, suggesting that there are no consistent breeding barriers between the genera. Although Beuzenberg suggested that species of Hymenanthera be included in Melicytus, he did not publish the relevant combinations. In this paper we will use the name Melicytus to refer to all members of Melicytus sensu stricto plus Hymenanthera, whether or not the combinations have been formally made. Most species of Melicytus occur in New Zealand or Australia, but there are also representatives on the Kermadec Islands, Samoa, Tonga, Vanuatu, Norfolk Island, Lord Howe Island, Chatham Island, the southern Solomon Islands, and Fiji. This paper will consider the status of three oceanic taxa, M. ramiflorus J. R. & G. Forster subsp. oblongifolius (Cunn.) P. Green, M. fasciger Gillespie, and M. samoensis (Christoph.) A. C. Smith, in their relationship to each other and to M. ramiflorus subsp. ramiflorus, from New Zealand. Since Beuzenberg’s 1961 publication, the genus has received little attention. Jacobs (1966) and Jacobs and Moore (1971) mistook a specimen of Melicytus fasciger (Kajewski 841) from Vanuatu for Rinorea bengalensis (Wallich) Kuntze. In 1975 Van Steenis reported a specimen of M. fasciger (Whitmore BSIP 1695) from the Santa Cruz group of the Solomon Islands. In 1970 Green transferred the New Caledonian species Hymenanthera latifolia Endlicher to Melicytus, and in the same publication he reduced the Fijian M. fasciger, the Samoan M. samoensis, and the Norfolk Island H. oblongifolia Cunn. to subspecies of the New Zealand species, M. ramiflorus. He gave little evidence for reducing the oceanic species to subspecific status. He was countered in 1978 and 1981 by Smith, who claimed that M. fasciger and M. samoensis were sufficiently distinct from M. ramiflorus to warrant specific recognition. Smith distinguished the three species on the bases of leaf serration (conspicuously serrate, subentire to crenulate or serrate, or subentire to callose-crenulate), number of serrations per cm (3 to 5 or 4 to 7), and petal length (2 mm or less, 3-4 mm, or 4-7 mm) Smith expressed no opinion on the status of M. ramiflorus subsp. oblongifolius (Cunn.) P. Green. © President and Fellows of Harvard College, 1985. Journal of the Arnold Arboretum 66: 491-502. October, 1985. 492 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Nv KT ir ne qi Figure 1. Melicytus base (Stauffer & Koroiveibau 5827): a, as Moe 1 stamen and 2 petals removed; b, s n, abaxial side, amen, adaxial side (stamens of other 3 ae virtually identical). CHARACTERS STUDIED AND THEIR DISTRIBUTIONS We examined material of Melicytus fasciger, M. ramiflorus subspecies ob- longifolius and ramiflorus, and M. samoensis collected throughout their ranges. All four are small trees with membranaceous, elliptic to ovate or obovate, glandular-toothed to subentire leaves. Stipules are triangular to lanceolate and caducous. Leaf scars show little variation in shape; there are always three vascular bundles. Leaf-venation pattern is similar throughout the genus: pin- nate and eucamptodromous, with the free endings of veinlets generally single but sometimes branched. Flowers are in axillary fascicles with pedicels 3-12 mm long that appear to elongate soon after anthesis in the pistillate plants. Petals and sepals are inserted at the edge of a somewhat expanded receptacle (see Ficures | and 2 for comparison of flowers of /. fasciger, a member of the study group, and M. /anceolatus, typical of the rest of the genus). The stamens, surprisingly uniform in these species, are free and have only a small appendage on the dorsal side (generally no more than half the length of the anther); the anthers are sessile or nearly so. 1985] KELLOGG & WEITZMAN, MELICYTUS 493 Ficure 2. Melicytus lanceolatus (Kirk s.n., A): a, flower with | stamen and 2 petals removed; b, stamen, abaxial side, note extended connective; c, stamen, adaxial side. In an attempt to find discrete, concordant differences among the species, we began by testing the characters that Smith had used, particularly leaf serrations and petal length. We counted the number of teeth per centimeter and per side of the leaf for five to ten leaves on each of 136 specimens. These data are displayed in Figures 3 and 4. There are clearly no breaks in the distribution of either character. Describing the leaf margins as serrate, subentire, or crenulate also requires subjective division of a continuum. Although certain tendencies are observable in some groups of specimens, they are insufficient to allow consistent distinction among groups. Stipules are generally glabrous, except in the New Zealand members of Mel- icytus ramiflorus, in which they are covered with stiff pubescence (as are the bud scales, and the pedicels and calyxes of pistillate flowers). Pubescence is present on all specimens of New Zealand M. ramiflorus examined, but it is absent from the Kermadec Islands specimens and from all other members of the genus, including the specimens from the Oceanian! islands. e measured petal length on 49 specimens; pistillate flowers were measured if they were open, whereas staminate flowers were measured only if they were 'As used here, Oceania does not include New Zealand or Australia. 494 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 a M. samoensis ae M. fasciger M. ramiflorus ae ssp ramitlorus Cc oO 18 a 14 J io) 10 4 _ 6 J ) a & 2 | poe | 4 Zz 2 4 6 8 Teeth per centimeter FiGure 3. Leaf margins: number of teeth per centimeter of margin. Each graphed value = median of counts on 10 leaves per specimen. (Melicytus ramiflorus subsp. oblongifolius (obscurely crenate rather than dentate) not illustrated.) past anthesis. (Smith (1978) noted that petals elongate rapidly prior to anthesis.) The measurements are graphed in FiGureE 5. Several conclusions are possible from these graphs. First, pistillate flowers appear to have smaller petals than staminate ones. Second, there is no break at 2 mm, as was suggested by Smith (1978); New Zealand and Oceanian specimens can therefore not be distin- guished on the basis of this character. Third, there is a conspicuous break between 3.5 and 4.8 mm for the Fyian plants. The plants with very long petals are all staminate ones collected from Viti Levu (Fiji), but there are short-petaled specimens from that island as well (discussed in more detail below). Petal shape varies from short and rounded to more or less triangular to long and lanceolate, with the shape correlating roughly with the length; however, the variation 1s not consistently correlated with any other characters that we have been able to find, nor can it be divided into discrete character states. Each flower is generally subtended by two bracteoles, but the position of these varies. They may be directly under the calyx, as in the long-petaled specimens from Fiji; about midway on the pedicel, as in Melicytus ramiflorus, at the base of the pedicel and indistinguishable from the bracts, as in the specimens from Samoa and Tonga; or variable in position, as in plants from Norfolk Island. Bracteole shape varies little. Pedicel length varies somewhat, but because elongation appears to occur soon after anthesis in the pistillate plants, this was a difficult character to use. The fruit is a berry with several seeds. Seeds are of two distinct types: small (less than 3 mm long) and purplish black, or large (greater than 3.5 mm) and tan. The small, dark seeds are found in both subspecies of Melicytus ramiflorus, while the larger, tan ones occur throughout the genus, including M. fasciger and . samoensis. Curiously, the large seeds are rarely filled with endosperm, whereas the smaller ones are nearly always filled with a white oily endosperm. The seeds of the Samoan specimens are substantially larger (all over 4 mm) than those of any other group of specimens, whereas the seeds of the other 1985] KELLOGG & WEITZMAN, MELICYTUS 495 M. samoensis plants o f M. fasciger - 4 cb) a 84 = 4 5 6, =< 4 4] ‘ M ramiflorus 2 4 ssp ramiflorus : T _T 10 20 30 40 50 Teeth per leaf side Ficure 4. Leaf margins: number of teeth per side of leaf. S planation under Fic- URE 3. those of M. ram The two basic seed types also have distinctive testa structures. The small seeds (FIGURE 6A) have a double or triple outer layer of large, open, irregular, thin-walled cells containing irregular bodies of dark-staining material that ma be tannins; inside this tissue is a single or double layer of thick-walled lignified cells with prominent plasmodesmata. The innermost layer of cells is again thin walled and small. In these seeds a vascular bundle with a sclerenchymatous sheath is always visible at the chalazal end. The large seeds (FiGurE 6B) have a thin outer layer of more or less collapsed and indistinct cells around a single or double layer of thick-walled cells similar to those in the small seeds. Although some vascular tissue is apparent in the funicular region of these seeds, it is never surrounded by a sclerenchymatous sheath. In specimens of Melicytus fasciger and M. samoensis, there is considerable variation in the thickness of the various cell layers in the testa, but there are too few specimens available to determine whether this is due to the age of the seed or to variation within a plant, or whether it might delimit taxonomic groups. Oceanian plants are intermediate in size between those of M. samoensis and miflorus. DISCUSSION AND CONCLUSIONS The data suggest that Melicytus ramiflorus from New Zealand can be dis- tinguished from the Oceanian members of the genus by 1) stiffly pubescent 496 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 oO 2 F — SAMOENSIS Cc Oo T T = / Q 4 2 ; - fasciger oO a T T / — ® 6 a E 4 = M. ramiflorus Zo». . ssp. ramiflorus [| T ii ai 3 T T T L' T 3 4 5 6 7 Petal length (mm) Figure 5. Petal length. Shaded bars = pistillate flowers (measured if open); open bars = staminate flowers (measured after anthesis). Flowers measured after rehydration. Each graphed value based on mean of 5 flowers per specimen, 5 petals per flower. Single flowering specimen seen of Melicytus ramiflorus subsp. oblongifolius was staminate, with petals 1.1—-1.2 mm. stipules and bud scales on all plants, and puberulent pedicels and sepals on pistillate ones; 2) bracteoles about midway along the pedicel; 3) seeds less than 2.5 mm long; and 4) testa dark, minutely and irregularly tuberculate, with a distinctive structure in cross section. Of these characters, numbers | and 3 appear to be unique in the genus, while 4 is shared only with M. ramiflorus subsp. oblongifolius, from Norfolk Island. The seed characters also appear in Sykes 643 (L), from the Kermadec Islands, but the stipules on this plant are nearly glabrous. We conclude that the testa morphology serves as a unique character to unite the New Zealand, Kermadec Islands, and Norfolk Island plants as a single species. The Norfolk Island plants, Melicytus ramiflorus subsp. oblongifolius, have seeds 2.3-3 mm long, intermediate between seeds of M. fasciger and those of M. ramiflorus subsp. ramiflorus. Unlike the latter subspecies, M. ramiflorus subsp. oblongifolius has leaf margins that are only obscurely crenate, rather than toothed. It is also intermediate between M. fasciger and M. ramiflorus subsp. ramiflorus in bracteole position, which varies from midway up the pedicel to immediately subtending the calyx. The endosperm of M. ramiflorus subsp. oblongifolius is crisp and fills the seed but appears to be less oily than that of M. ramiflorus subsp. ramiflorus. Despite the lack of floral differences, the New Zealand, Kermadec Islands, and Norfolk Island plants should not be considered conspecific with those from the other Oceanian islands. The seed and stipule characters are sufficiently distinct and consistent to mark Melicytus ramiflorus as a strictly monophyletic taxon, separate from the other two species. 1985] KELLOGG & WEITZMAN, MELICYTUS 497 Tissd eb eeines. FiGuRE 6. Cross sections of testa near chalazal end of seed: A, Melicytus ramiflorus subsp. ramiflorus (Cooper 121932), B, M. fasciger (Bernardi 12944). Camera lucida drawings of paraffin-embedded material stained with safranin and fast green. Key: 0 = outer layer of thin-walled cells, many highly crushed in B; v = vascular tissue; s = sclerenchymatous sheath; t = inner layer of thick-walled cells; i = innermost layer of thin-walled cells; f = layer of crushed thin-walled cells present only in funicular region of seeds of Oceanian species. Scale = 0.01 mm. Among the Oceanian plants, the Samoan ones are distinctive in lacking bracteoles on the pedicels and in having pale brown seeds that are over 4 mm long. Although our material is insufficient to allow us to reach firm conclusions, it appears that representatives of Melicytus from Tonga are similar and should be included with the Samoan plants. Smith has applied the name M. samoensis to these plants. Melicytus fasciger occurs on Fiji (Viti Levu, Taveuni, and Ngau) and Va- nuatu; we have also seen one specimen from the Solomon Islands. These plants are distinguished from M. ramiflorus and M. samoensis in having brown seeds 3-4 mm long. Within this group of plants, there is a marked discontinuity in petal length of the mature staminate flowers. The average petal lengths in five collections (two from Vanuatu, two from Viti Levu, and one from Taveuni) are 1.4—2.6 mm; in another seven collections (all from Viti Levu), 4.8-6.6 mm We have seen two collections of flowering pistillate plants, one from Viti Levu and the other from the small island of Ngau. These had average petal lengths of 1.7 and 3.2 mm, respectively. As noted above, in all taxa examined pistillate flowers tended to have shorter petals than did staminate ones. Thus the pistillate plant from Viti Levu could be conspecific with either the long- or the short- petaled staminate forms, whereas ihe plant from Ngau may be associated with longer-petaled staminate plants. However, we have seen no staminate plants fi au. We have seen two fruiting specimens from Fiji—one from Viti Levu, with seeds ca. 3 mm long, and one from Taveuni with seeds up to 3.9 498 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 mm. Lack of flowering material from Taveuni prevents connection of these plants with either of the two staminate forms from Viti Levu. This evidence suggests that there may be two taxa in Fiji and Vanuatu—one relatively long-petaled one that may be endemic to Viti Levu, and a second, more widespread, short-petaled one. Only more collecting will determine whether this is the case or if petal length is simply very variable on Viti Levu. The type specimen of Melicytus fasciger (Parks 20645) is a long-petaled staminate plant from Viti Levu. If future I ecide that the short-petaled plants are indeed distinct, a new name will have to be provided. The four taxa discussed here appear to be unusual within Melicytus/Hy- menanthera because of their comparatively short, lanceolate to lance-ovate petals that are not at all imbricate at anthesis and their short stamen appendages. We think that they represent a monophyletic unit within the genus. Within this group, M. ramiflorus is also a monophyletic taxon based on the uniquely derived character of testa structure. Each of the other two taxa has unique characters, but we have found no character suggesting that M. fasciger and M. samoensis together constitute a monophyletic unit. This rules out the possibility of recognizing M. samoensis as a subspecies of M. fasciger to form a taxon distinct from M. ramiflorus. If the classification is to reflect the cladistic struc- ture of the group, then M. fasciger and M. samoensis must be given the same rank as M. ramiflorus. Whether this rank should be variety, subspecies, or species is arbitrary. We have chosen the rank of species because the several distinguishing seed characters, although not easily observed, are consistent within geographic units. TAXONOMIC TREATMENT Key TO THE OCEANIAN TAXA OF MELICYTUS 1. Bracteoles at base of pedicel; seeds => 4 mm long; plants of Samoa and Tonga. .... bug aiatiods geht jot gesste ao eects Rates os aa ny wees Pe ae 2 ln Be ee che 3. M. samoensis. 1. Bracteoles above base of pedicel; seeds < 4 mm lon . Leaves crenate; seeds 2.5-3 mm long; plants of Norfolk Island. ............... Powe ataeearaw es geese ees en ae wands 7 M. ramiflorus subsp. oblongifolius. 2. Leaves dentate; seeds < 2.5 or > 3 mm lon 3. Stipules stiff-pubescent (except on de Islands plants); bracteoles near middle of pedicel; seeds black, minutely and sparsely tuberculate, < 2.5 mm long; testa with vascular bundle with sclerenchymatous sheath; plants of New Zealand and Kermadec Islands. ....... 2a. M. ramiflorus subsp. alah alas 3. Stipules glabrous; iui: Marui located; seeds brown, smooth, mm long; testa without p vascular bundle; ‘ants of Fiji, Vanuatu, and Sion on aes Sapeiip ata de sucnerece dehtice detects M. fasciger. 1. Melicytus fasciger Gillespie, Bernice P. Bishop Mus. Bull. 91: 20. fig. 22. 1932. Melicytus ramiflorus J. R. & G. Forster subsp. fasciger (Gillespie) P. Green, Kew Bull. 969. Type: Viti Levu, Mba, Nandarivatu, May, June, July 1927, Parks 20645 (holotype, BISH; isotypes, a. SUVA, UC, US). 1985] KELLOGG & WEITZMAN, MELICYTUS 499 Shrubs or small trees to 10 m; bark whitish, smooth. Leaves with stipules deltate to lance-linear, 0.5-0.9 mm long, acute at apex, glabrous, caducous; petiole 5-13 mm long, adaxially bicarinate; blade elliptic, ovate, obovate, or oblanceolate, 8.5-17.5 x 3-6.7 cm, membranaceous, apex acuminate, base cuneate, margin serrate to dentate, with dentations | to 4 per cm and generally gland tipped. Inflorescences fascicles of 1 to 14 flowers. Pedicel 5-12 mm long in flower, becoming 8-21 mm in fruit; bracteoles variously located on pedicel, from below middle to just beneath calyx, ovate, erose; sepals deltate to ovate, 0.8-1.4 mm long, acute to obtuse at apex, |-nerved, erose, green; petals lan- ceolate to lance-ovate, unequal, averaging |.5—3 or 4.5-7 mm long in staminate flowers and 1.5-3.4 mm in pistillate, often apically thickened, white; anthers pare sessile, ovate, the connective a short abaxial triangular or ovate flap, < ' length of anther; stigma flaring, crateriform. Fruits subglobose, 4.5-5.5 x 4.5-6 mm, becoming dark at maturity; placentae 3 to 5; seeds 2 per placenta, 3 or 4 developing, 3-3.5 mm long, tan to dark, smooth, with endosperm oily, shrunken in all specimens seen; embryo straight with orbicular cotyledons and straight hypocotyl. SPECIMENS EXAMINED, Fiji. Vir1 Levu. Road to Mavai, alt. 2700 ft, Gibbs Rok alse BM). Mba, Nandarivatu: valley of Sigatoka, alt. 900 m, Gillespie 385] (sterile: BIsH, 2 sheets); Mt. eee alt. 2700-2900 ft, Koroiveibau 13946 (short-petaled ine BISH, BRI); Mt. Koroyanitu, alt. 3850 ft, Koroiveibau 14144 (short-petaled staminate: BISH), Parks Be (long-petaled staminate: p); Tavua, upper part of W ak s of Mt. Lomalagi, alt. 950 m, Stauffer & Koroiveibau 5827 (long-petaled staminate: A, BISH, BRI, K, P); by Ce oe s Seat,” Im Thurn s.n., 31 Jan. 1906 (short-petaled a k); Tavua , remnant woods on steep slopes at head of Savundamatau Creek, ca. 3 mi W of Nandarivatu, a 2900-3000 ft, Webster & Hildreth 14258 (in fruit: BisH, GH). Man- drongo, Nausori Highlands, rain forest on W slopes of Mt. Mandrongo, alt. ca. 2000 ft, Webster & Hildreth 14274 (short-petaled staminate: BIsH). Mt. Victoria: alt. 800 m, Lam 6856 (long-petaled staminate: 1); lower slopes of mtn., alt. 3000 ft, Vaughan 3415 ore petaled staminate: BM). Nandronga and Navosa [formerly Tholo West]: near Koroneya- lewa, alt. 1500 ft, on forest ridge, Parham 1467 (sterile: A); N portion of Rairaimatuku Plateau, between Nandrau and Rewasu, alt. 725-925 m, Smith 5647 (long-petaled sta- minate: A, BISH, K, US); alt. ca. 2700 ft, Vaturua, Nadrau, Ranamu FD 1187 (long-petaled staminate: BISH, BRI). TAVEUNI: vic. of Walyevo, stream banks, alt. 650 m, Gillespie 4723 1500 ft, Watinieie BSIP 1695 (short- petaled staminate: L). Vanuatu. ANEITYUM: in vicinioribus A semitam ad rivum Inwa Lelgey, alt. 10-180 m, Bernardi 12944 (k); fen ae Bay, Kajewski 84] (A, 2 sheets), Morrison s.n., 6 July 1896 (x). Espiritu SANTO. Mt. Tabwemasana: alt. 1460 m, Chew RSNH 217 (kx, L), alt. 5800 ft, Gillison & pee 3516 (Kk), alt. 1600-1800 m, McKee 24170 (k); entre les deux sommets, alt. 1800 m, Raynal RSNH 16342 (k, L, P). TANA: Mt. Tokosh Meru, alt. 600 m, Kajewski 166 (a). 2a. Melicytus ramiflorus J. R. & G. Forster, Char. Gen. Pl. 124. 1776. Type: [New Zealand], Forster 222 (holotype, BM!). Shrubs or small trees to 4 m; bark smooth, gray, lenticellate. Leaves with stipules broadly asymmetric, triangular, tapering to acuminate point, covered 500 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 with stiff erect trichomes, caducous; petiole 11-26 mm long, adaxially bicar- inate; blade ovate, oblong, or elliptic, 7-14.4 x 2.6-5.8 cm, membranaceous, apex acute to acuminate (rarely obtuse), base rounded to cuneate, margin dentate, with dentations | to 7 per cm and generally gland tipped. Inflorescences fascicles of 1 to 20 flowers. Pedicel 2-6(—16) mm long in flower, becoming 6—- 11 mm in fruit, puberulent in pistillate fl , glabrous in staminate; bracteoles usually near midpoint of pedicel, ovate, erose; sepals triangular, 0.6-1.2 mm long, acute to obtuse at apex, l-nerved, erose, green, puberulent in pistillate flowers, glabrous in staminate; petals ovate to lanceolate, unequal, averaging 1-2.9 mm long in staminate flowers and 0.6-1.1 mm in pistillate, white, apically thickened; anthers nearly sessile, ovate, the connective an abaxial flap, shorter than anther; stigma flaring, crateriform. Fruits subglobose, 3-5 x 3-5.2 mm, blue-violet; placentae 3 (to 5); seeds 2 or 3 per placenta, up to 9 or 10 developing, 1.8-2.4 mm long, dark, lustrous, minutely and sparsely tuberculate, with en- dosperm oily, filling seed; embryo straight with ovate cotyledons and straight hypocotyl. SPECIMENS EXAMINED. New Zealand. Without further locality, Anonymous s.n., BRI 247133 (Bri), Banks & Solander s.n., 1768-71 (us), Sind s.n. (Bri), Wilkes Expedition n., 1838-42 (GH). NorTH IsLAND: Woodhill State Forest, ca. 50 km NW of Auckland, alt. 50-100 m, Bernardi 12366 (us); Waiheke Is. in Hauraki Gulf, S coast at Rocky Bay, Broek & Broek-Groen 51 (tL, 2 sheets); Port Waikato, Cooper 121932 (a); Swanson Reserve near Auckland, Davis & Cooper s.n., 21 March 1950 (us); Urewera Natl. Park, Gisborned Distr., Aniwanewa, far E side of Lake Waikaremoana, just E of Waipai Swamp, Lake Ruapani track, Edwards 32 (A); Waitakere Range W of Auckland, S end of Scenic Drive, alt. 300-450 m, Fosberg 30255 (us); Orakei Basin, Auckland, Gardner 859 (L), Taranaki, Mt. Egmont, in bush at 3000 ft, Hunnewell 13534 (Gx); Woodcocks N of Auckland, Hynes s.n., 18 Oct. 1958 (us), Kirk s.n. (us), Auckland, Leland et al. 224 (Gu, 2 sheets; us); Manukau Co., ca. 10 km E-SE of Clevedon, Orchard 3282 (a); Whangarei Co., ca. 142 km SW of Oakura Bay settlement, alt. 60 m, Orchard 3684 (a); Coromandel Co., ca. 5 km E of Coromandel on road to Te Rerenga, alt. 340 m, Orchard 3949 (a); Auckland, Purewa Bush, Powell s.n., 29 Nov. 1949 (a); Auckland Prov., Cascade Park, Waitakere range, W-NW of Auckland, Walker 4246 (us); Wellington Prov., near The Spiral in Natl. Park near Raurimu, Walker 4315 (us); Wellington Prov., near Waikane, 37 mi N of Wellington, Walker 5168 (us); Auckland metropolitan area, Mt. Wellington lava fields, Wright 503 (L); Northland, Mangamuku Gorge, Zotov 84968 (a). SouTH IsLAND: Akaroa, Belligny s.n. (Gu); Nelson, Dall s.n., 1882 (Bri); Greymouth, Helms s.n (sri); Westland, Franz Josef Glacier, Hunnewell 13535 (Gu), Kirk s.n. (A); Wellington, Kirk 205 (Gu), Kirk 215 (us); Canterbury, Riccarton Bush, Lothian s.n., Jan. 1937 (Gu), Von Mueller s.n. (Bri); Canterbury, Pel Forest, Philipson 10111 (a); Christchurch, Rad- cliffe Valley, Stemmer s.n., 10 Dec. 1972 (L). KERMADEC IsLANDs. Raoul Is.: Low Flat, Sykes 643/K (tL), above Low Flat, Sykes 1084/K (bri). 2b. wea aa ramiflorus J. R. & G. Forster subsp. oblongifolius (Cunn.) P. Green, J. Arnold Arbor. 51: 220. 1970. Tyre: Norfolk Island, 1830, ee 127 (holotype, k!). Hymenanthera a Cunn. London J. Bot. 1: 124. 1842. Hymenanthera dentata R. Br. var. oblongifolia (Cunn.) Kirk, Trans. & Proc. New Zealand Inst. 28: 511. ae Shrubs or small trees to 8 m; bark whitish, smooth. Leaves with stipules lanceolate, deltate, or narrowly lanceolate, 0.5—0.8 mm long, acuminate at apex, 1985] KELLOGG & WEITZMAN, MELICYTUS 501 hyaline and erose at margin, glabrous, caducous; petiole 10-14 mm, adaxially bicarinate; blade elliptic to ovate, obovate, or oblanceolate, 5.5-9.5 x 2.1- 3.7 cm, membranaceous, apex acute, base cuneate, margin obscurely crenate with gland dots where veins meet margin, | to 4 gland dots per cm. Inflores- cences fascicles of 1 to 7 flowers. Pedicel 2-7 mm long in flower, becoming 6- 11 mm in fruit; bracteoles from near midpoint of pedicel to just beneath calyx, ovate, erose; sepals triangular, 1-1.8 mm long; petals ovate, 1.1-1.2 mm long in staminate flowers (pistillate flowers unknown), thickened on back; anthers nearly sessile, oblong to broadly deltate, the connective an abaxial flap, shorter than anther. Fruits subglobose, 4.2-4.7 x 2.8-3.7 mm, becoming mauve at maturity; placentae 3; seeds 2 per placenta, 3 to 6 developing, 2.3-3 mm long, pale to dark brown, smooth, with endosperm crisp and watery, filling seed; embryo straight with suborbicular cotyledons; hypocotyl pale greenish. SPECIMENS EXAMINED. Norfolk Island: saddle between Mt. Pitt and Mt. Bates, alt. ca. 800 ft, Hooglund 11361 («); Mt. Pitt Reserve, Lazarides 8073 (1), Prior s.n., 1903 (x); Ralston s.n., July 1969 (k); without further locality, Backhouse 641 (kK), Cunningham s.n. (Hb. Brown, kK); Cunningham 44 (k). 3. Melicytus samoensis (Christoph.) A. C. Smith, Allertonia 1: 370. 1978. Type: Samoa, Savaii, 8 Aug. 1931, Christophersen & Hume 2315 (ho- ne BISH!; isotypes, K!, US). Melicytus ramiflorus J. R. & G. Forster var. samoensis Christoph. Bernice P. Bishop Mus. Bull. 128: 149. fig. 27. 1935. Melicytus ramiflorus J. R. & G. Forster subsp. samoensis (Christoph.) P. Green, Kew Bull. 23: 346. 1969. Shrubs or small trees to 7 m; bark smooth. Leaves with stipules lanceolate to deltate, 1-1.5 mm long, acute at apex, glabrous, caducous; petiole 8-20 mm, adaxially bicarinate; blade elliptic, ovate, or obovate, the largest 10.5-18 x 3.8-7.5 cm, membranaceous, apex acuminate, base cuneate, margin crenate to minutely dentate, dentations < | to 3 per cm and generally with dark apical gland. Inflorescences fascicles of 1 to 13 flowers. Pedicel 3—9(-12) mm long in flower, becoming 7-12 mm in fruit; bracteoles generally basal, not clearly distinguishable from bracts; sepals deltate to ovate, 0.8—1.2 mm long, acute to obtuse at apex, 1-nerved, erose, green; petals lanceolate, lance-ovate, or ovate, unequal, 1.5-4.5 mm long in staminate flowers, averaging 2.4 mm in single pistillate plant seen, white, thickened apically, spreading at anthesis; anthers nearly sessile, ovate, the connective a short abaxial triangular flap, ca. '/2 length of anther; stigma flaring, crateriform. Fruits irregular, 5.5-8 x 4.5-8 mm, thin walled, smooth; placentae generally 3; seeds 2 per placenta, usually 6 devel- oping, = 4 mm long, tan, smooth, with endosperm shrunken in all specimens seen; embryo straight, with orbicular cotyledons and straight hypocotyl. SPECIMENS EXAMINED. Tonga, Eva: Powell Plantation, Parks 16006 (isu, K), Parks 16307 s Fuai plantation, near center . 80 Christophersen 3094 (bisH); forest at Olo, oe Safotu, 700-800 m, Christophersen & Hume 2315 (isu, P); Olo, alt. + 700 m, Christophersen & Hume 2519 (usu, K); Aopo- 502 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Gagamalae, alt. 1000-1110 m, Christophersen & Hume 3437 (BisH, US); Maungalsa, Vaupel 201 (x, L); in forest W of Mt. Silisili, alt. 1600 m, Whistler W2523 (pis); 1n forest between Mauga Mu and Mauga Afi, alt. 1S00 m, Whistler W262] (A, BISH, k). Upo tu: E of main road near Tiavi, alt. 700 m, Whistler W1064 (pis, Us); near Mt. Le Pu’e, alt. 750 m, Whistler W1189 (bisy, us). ACKNOWLEDGMENTS We would like to thank P. F. Stevens for suggesting this project and for his comments throughout. We also thank R. A. Howard for his comments on the manuscript, and A. Cronquist and P. S. Green for their reviews. LITERATURE CITED BeEUZENBERG, E. J. 1961. Observations on sex differentiation and cytotaxonomy of the Zealand species of the Hymenantherinae (Violaceae). New Zealand Jour. Sci. 4: 337-349. Green, P.S. 1970. Notes relating to the flora of Norfolk and Lord Howe islands. I. J. Arnold Arbor. 51: 204-220. Jacoss, M. 1966. Rinorea (Alsodeia) (Violaceae). Pp. 430-442 in Identification lists of Malaysian specimens. Foundation Flora Malesiana, % Rijksherbarium, Leyden Holland. & D. M. Moore. 1971. Violaceae. Flora Malesiana, I. 7: 179-212. Smitu, A. C. 1978. A precursor to a new flora of Fiji. Allertonia 1: 331-414. —. 1981. Violaceae. /n: Flora Vitiensis Nova 2: 655-662. SreeNis C.G.G. J. vAn. 1975. Miscellaneous botanical notes XXIII. Blumea 22: 168, 69. HARVARD late: rene 22 Divinity AVEN CAMBRIDGE, yore 02138 1985] HOWARD, TRIPLARIS SCANDENS 503 THE “TRIPLARIS SCANDENS (VELL. CONC.) COCUCCI” COMPLEX (POLYGONACEAE) RICHARD A. HOWARD Cocucci (1957a) published the combination Triplaris scandens (Vell. Conc.) Cocucci based on Magonia scandens Vell. Conc. (1829). Magonia Vell. Conc. is illegitimate, being a later homonym of Magonia A. St. Hil. (Sapindaceae). As synonyms of his 7riplaris scandens, Cocucci listed T. laurifolia Cham. & Schldl. (1828), 7. macrocalix Casar. (1845), Ruprechtia lundii Meisner (1855), R. obidensis Huber (1909), R. macrocalix Huber (1909), and R. scandens Rusby (1927). He later (1965) added to the synonymy R. zernyi (Standley) Howard, which I had transferred from the genus Coccoloba. A reexamination of the original descriptions, authentic specimens as available, and more recent col- lections indicates that this is a heterogeneous assemblage. I suggest that four species— Ruprechtia crenata (Casar.) Howard, R. /aurifolia (Cham. & Schldl.) Meyer, R. /undii, and R. obidensis—be recognized within “Triplaris scandens (Vell. Conc.) Cocucci.” Cocucci’s publications on species of Ruprechtia (1957a, 1957b, 1961, 1965) have established the vegetative characters of a hollow pith and persistent ocreae for distinguishing Triplaris from Ruprechtia, which has solid internodes and caducous ocreae. Brandbyge (1982), in an unpublished thesis I have been privileged to study, found that these characters are not exclusive. He described some species of Trip/aris with solid stem internodes and some with nonper- sistent ocreae. He also altered Cocucci’s proposed interpretation of the inflo- rescence, as well as his emphasis on the narrowed hypanthium base in Ru- prechtia. In general, the species of Ruprechtia are small trees or bushes of dry areas, while 7viplaris is represented by larger trees with much larger leaves and is generally found in wetter areas. Although one can easily distinguish specimens of Triplaris from specimens of Ruprechtia by general appearance, assigning unambiguous key characters to separate the two genera is difficult. Relating the staminate and pistillate plants of a species is also difficult in both genera. Some species are represented in herbaria primarily by staminate specimens, others by pistillate specimens or fruiting material. Although perianth characters of pistillate plants and achene characters seem reliable, size and shape of the mature fruiting perianth have not been determined for all species. Cocucci’s “Triplaris scandens complex’’ presents additional problems. Some plants are described as lianas or vines, a growth form not previously recognized in either 7riplaris or Ruprechtia. These may have either solid or hollow stems, and the ocreae are either persistent or caducous. In the specimens available for study, the leaves on the main stems are commonly larger than those on the © President and Fellows of Harvard College, | Journal of the Arnold Arboretum 66: 503-508. oe 1985. 504 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 terminal portions of the stem or on the axillary branches. The majority of staminate plants have the inflorescences on the main stem, which rarely has axillary branches. The specimens with pistillate flowers or fruits seem to rep- resent either terminal portions of a main branch or axillary branches. Staminate inflorescences are branched from the base as fascicles of racemes or are panicu- late. Pistillate inflorescences are infrequently paired and rarely branched above. The fruiting perianth is accrescent in both the hypanthium and the lobes. Fully mature fruiting perianths are not known for all species. Brandbyge (1982) did not accept Triplaris scandens in his monographic treatment of Triplaris; in fact, he suggested that its proper position was in Ruprechtia and that more than one taxon was involved. I agree with Brandbyge that the component species involved in the circumscription of 7riplaris scan- dens sensu Cocucci are better accommodated in Ruprechtia. Neither Cocucci or Brandbyge nor I have seen all of the types to establish beyond doubt the correct names for some of the more difficult taxa. None of us has assembled material from the many herbaria in Brazil; we hope our colleagues there will examine these conclusions and seek the necessary mature collections in future field work. Ruprechtia crenata (Casar.) Howard, comb. nov. Triplaris crenata Casar. Nov. Stirp. Brasil. Dec. 9: 80 Ruprechtia carpinoides Meisner in Martius, Fl. Brasil. a oe 1855. Casaretto based Trip/aris crenata on an unnumbered Riedel collection from Rio de Janeiro. It is not clear whether the holotype is in Turin, Genoa, or elsewhere. Correspondence on this problem has not been answered. Meisner based Ruprechtia carpinoides on a staminate specimen in the De Candolle herbarium and suggested that it may be Triplaris crenata Casar. Cocucci (1961) placed it in the synonymy of 7. crenata, stating that he had not the slightest doubt they were one and the same species, but he did not state whether he saw the material of Casaretto. A Field Museum photograph (neg. #7413, Gu) of the “type” in the Delessert Herbarium shows a staminate plant that was collected “R. Jan. Jan. 1838, Brezil’’; however, the name ““Lund”’ as collector is crossed out and “Riedel” is written in. A Riedel specimen without number (Ny) was collected in “Rio de Janeiro Jan. 1883 [sic] and is probably a true isotype. Two Glaziou collections from Rio, /2//5 (kK) and 1976/ (xk), can be assigned here. In his unpublished manuscript Brandbyge (1982, p. 70) concluded that 77rip- laris crenata ‘“‘must belong to Ruprechtia.” Descriptions refer to the plants as trees ‘‘40 pedalis ex Riedel’ and to specimens of R. carpinoides as “‘a very high tree.”’ Clearly this is not comparable to Triplaris scandens sensu Cocucci. Ruprechtia laurifolia (Cham. & Schldl.) Meyer, Mém. Acad. Imp. Sci. Saint- Pétersbourg, Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6(2): 150. 1840. Triplaris laurifolia Cham. & Schldl. Linnaea 3: 55. 1828. Triplaris macrocalyx Casar. Nov. Stirp. Brasil. Dec. 9: 79. 1845. 1985] HOWARD, TRIPLARIS SCANDENS B14) For Triplaris laurifolia, Chamisso and Schlechtendal cited a collection made and sent by Sellow (s.n., s./.). A collection of a staminate plant from Brasilia aequinoctialis, Sellow 1395 (B), may be the holotype. The type of Triplaris macrocalyx was described without location or collector and is therefore presumably a specimen collected by Casaretto from ““Taypt” in the province of Rio de Janeiro. Brandbyge (1982) excluded both names from Triplaris. Several collections by Riedel and by Riedel and Luschnatt bear a herbarium name honoring Riedel by ‘“‘Hauk” as “‘spec. nov. with affinities to R. /aurifolia det. E. Hassler.’’ Neither ““Hauk” nor any reference to a publication by Hassler can be traced. ADDITIONAL SPECIMENS SEEN. Brazil. Without further locality, Clausen s.n. (us). Epo. Rio DE JANEIRO: without further locality, Gardner 5593 (BM, kK), Glaziou 6703 (Kk), 8905 (x), 12116 (k), 13.134 (us, a collection of 2 sheets with different localities: on one “Province of Goyas”’ is printed and Goyas is crossed out; on the other “Province of” is printed, “Rio-Janeiro” is stamped on, and above this is written ““Minas’’), Mrs. Graham s.n. (k), Martius 67 (kK), Miers 3753 (x), Riedel 672 (A, GH), S.n. (K), Riedel & Luschnatt 672 (ny, us), 1374 (us), Sello 631 (BM, K), 5.1. (BM, K), . i ire 104 (Ny), 109 (K, Ny), Tweedie 110 (kx), Weddell 479 (a); Jacarépagud, Vidal s. Ruprechtia lundii Meisner in Martius, Fl. Brasil. 5(1): 53. 1855. Lund 578, photographed by Macbride among the types in the Delessert Herbarium (Field Mus. neg. #7416, GH), appears to consist of a leafless branch with staminate inflorescences, a leafless branch with large mature fruits, and a separate cluster of four leaves. One label states only “Bresil’”’ as the location but bears the number 578 and the date 1839. A second label, without number, states, “R. Jan. Sept. 33”’ and “‘Bresil, ms Lund 1839.” Two specimens at Ny are possible isotypes: Lund 578 was collected “in monte prope Brioca (Rio de Jan.),” and Lund N 576 at “Vende Grande, prope Rio Janeiro 9/1833.” Meisner did not indicate a type but cited several collections in w, pc, and mM. Cocucci (1957a, p. 362) stated he saw “‘el isocétipo ScHotr 4562” but did not indicate the herbarium or any label details, nor did he select a lectotype. Ruprechtia lundii Meisner forma minor Meisner (in Martius, ibid.), with the type Blanchet s.n., is based only on isolated fruits. The large fruit of Ruprechtia lundii exemplified by Lund 578 is matched by the recent collection Prance & Ramos 6991 (A, US) made along the Pérto Velho to Cuiaba highway, Territory of Rondénia, Brazil. A second collection, Cor- deiro 603 (A) from Estrada Belmonte, Terr. de Ronddénia, appears to be the same, with younger pistillate flowers. The leaves of these collections are com- parable to those of Lund 578 (Field Mus. neg. #7416); they differ from those of the specimens I cite of R. /aurifolia and R. obidensis. Rio de Janeiro and Territorio RondGénia are admittedly widely separated. Ruprechtia obidensis Huber, Bol. Mus. Paraense Hist. Nat. 5: 344. 1909. Magonia scandens Vell. Conc. Fl. Flumin. 165. 1825 [1829], Icones 4: p/. 60. 1827 [1831]. 506 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Triplaris eter Conc.) Cocucci, Rev. Fac. Ci. Exact. Fis. Nat. Univ. Nac. 957. Ruprechtia see 7 var. sprucel Meisner in DC. Prodr. Syst. Nat. Regni Veg. 14: 182. 1857. Ruprechtia scandens Rusby, Mem. New York Bot. Gard. 7: 237, 238. 1927. Ruprechtia macrocalyx Huber, Bol. Mus. Paraense Hist. Nat. 5: 345. 1909. Coccoloba zernyi Standley, Publ. Field Mus. Hist. Nat., Bot. Ser. 22: 18. 1940. Ruprechtia zernyi (Standley) Howard, J. Arnold Arbor. 41: 357-390. 1960. Vellozo’s name Magonia scandens cannot be transferred to Ruprechtia be- cause of Ruprechtia scandens. | do not know ifa voucher specimen for Magonia scandens exists. Vellozo’s plate with the dissection may typify the taxon. The plant was collected ‘“‘Reg. Praedii S. Crucis.’’ Cocucci expressed no doubt in transferring the specific name to 7rip/aris. Brandbyge thought that Cocucci’s concept of 7rip/aris was in error and so excluded the Vellozo name from his treatment of 7riplaris. The first available name for this species is Ruprechtia obidensis (1909) based on Ducke 2899 (staminate) and Ducke 2901 (pistillate) from Obidos, Edo. Para, Brazil. Presumably a specimen exists in the herbarium of Museu Goeldi, and the pistillate/fruiting plant should be chosen as the lectotype. The original description clearly describes immature fruits, and Field Museum negative no. 8492 (GH) of an isotype in the Delessert Herbarium shows a pistillate plant without evident fruit. Huber compared this species with Ruprechtia laurifolia, stating it differed in the long, acute leaves. Cocucci (1957a) concluded that the differences were not of taxonomic value and placed the species in the synonymy of his 7riplaris scandens. Ducke accepted the name Ruprechtia obidensis and indicated that a synonym was R. macrocalyx. Huber described R. macrocalyx at the same time as R. obidensis and cited Ducke 8540 (pistillate) and Ducke 8539 (staminate) from Faro, Edo. Para, Brazil. His description emphasizes the large fruiting calyx. The specific name ‘‘macrocalyx”’ would have been a preferable choice, had Ducke carefully considered the original descriptions. Loose specimens of Ducke 8540 and 8539 in the Delessert Herbarium have been combined in one pho- tograph (Field Mus. neg. #8493, Gu), but the young fruits pictured are not the same size as those described by Huber. A lectotype for R. macrocalyx must be sought elsewhere. Spruce 639, from Santarém, Edo. Para, was described as Ruprechtia apetala Wedd. var. sprucei by Meisner. The specimen in the Delessert Herbarium (Field Mus. neg. #7414, Gu) is staminate Ruprechtia scandens is based on material from head of Beni River, Edo. La Paz, Bolivia, 18 Aug. 1921, cited as Rusby & White 972. The holotype (Ny) has a Rusby field label with ““Rusby” crossed out and ‘“‘White” written in. Among his observations, White noted that the stems were hollow but no ants were present in twelve staminate vines examined. An isotype (GH) collected on 18 August 1921 has a few young pistillate flowers just past the receptive stage and is credited to Rusby and White. A second sheet, with a larger quantity of mature fruits, was credited to O. E. White as number 972, collected 17 August 1921. Rusby admitted that he was sick most of the trip and that White 1985] HOWARD, TRIPLARIS SCANDENS 507 did a large part of the collecting. It cannot be determined if these two collections are from the same t. Ruprechtia zernyi was originally described as a species of Coccoloba and is known from a single staminate collection that has very small leaves. It was made at Taperinha, near Santarém, Para, Brazil. Comparable small leaves are found on many other specimens. ADDITIONAL SPECIMENS SEEN. Bolivia. Epo. LA Paz: Prov. S. Yungas, Basin Rio Bopi San Bartolomé (near Calisaya), Krukoff 10126 (A, us). Brazil. Epo. PARA: Municipio de Oriximina, estrada Oriximina-Obidos, Cid, Ramos, Mota, & Rosas 2493 (a); Rio Trom- betas, Oriximina, M. Silva 1.702 (a); Obidos, Ducke 19542 (ws), cae Spruce 903 (k); Belterra, Baldwin 2751 (us). Evo. AMAzonas: Urucara, Sao Sebastiao, M. Silva 1820 (us), 1824 (A); Mandos, Estrada do Aleixo, Ducke 738 (Ny, US), Guédes 38 (us); Serra near Namorado Novo watershed between Rio Curuqueté & Rio Madeira at Abuna, Prance et al. 14709 (a, K); Manaus, Ducke 25.627 (us); Terr. Acre, near mouth of Rio Macauhan (tributary of Rio Yaco), Krukoff 5791 (A, BM, K, M, NY, US); Rio Acre, Ule 9350 (k); Rond6nia, ie from W bank of Rio Madeira, 3 km ee mouth of Rio Abun§a, Prance et al. 6043 (A, GH, K, NY, US). Colombia. Evo. MAGDALENA: Santa Marta, Rio Frio, Quebrada Rodriguez, F. Walker 1212 (us); Poponte, C. Allen 929 (k). Peru: Rio Acre, Seriugal Auristella, Ue 9350 (us). Venezuela. Dpto. TRUJILLO: Quebrada Seca bridge & R. Motatan, Pittier 13299 (a, us), 13302 (A, M, US). UNPLACED COLLECTIONS Two collections from Venezuela have not been adequately placed. Wurdack & Monachino 41230 (a, us), from Edo. Bolivar, northernmost slopes of Cerro Baraguan, and Bunting & Aristeguieta 6111 (A), from Edo. Zulia, carretera Maracaibo—Carora, are both staminate plants described as small trees to 6 m or less. Neither collection fits any known species of Ruprechtia, and each may represent a new species. I prefer to delay applying any names to this material until fruiting material is known. REFERENCES BRANDBYGE, J. 1982. A revision of the genus 7riplaris Loefling (Polygonaceae) with ments on the generic delimitation between Trip/aris and Ruprechtia C. A. Meyer. 1 pp. Specialerapport 1. Botanisk Institut, Aarhus Universitet. (Unpublished.) Cocucci, A. E. 1957a. Una nueva combinacién en el género Triplaris aoe ery Rev. Fac. Ci. Exact. Fis. Nat. Univ. Nac. Cérdoba 19: 361-363. (Also in Trab. Mus Bot. nee Nac. Cérdoba 2: 361-363. 1958.) ———. . Elgénero Ruprechtia Wee genes en Argentina, Paraguay y Uruguay. Ibid es (Also in Trab. Mus. Bot. Univ. Nac. Cordoba 2: 559-618. 1958.) 1961. Revision del género Ruprechtia (Polygonaceae). Kurtziana 1: 217-269. 1965. El nombre correcto de Ruprechtia zernyi (Polygonaceae). Ibid. 2: 222, 223. Ducxe, A. 1930. Plantes nouvelles ou peu connues de la région amazonienne. Arch. Jard. Bot. Rio de Janeiro 5: 104. Meisner, C. F. 1855. Polygonaceae. Jn: C. F. P. von Martius, Fl. Brasil. 5(1): 1-59. —. 1856. Polygonaceae. In: A. DE CANDOLLE, Prodr. Syst. Nat. Regni Veg. 14: I- 508 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Mever,C. A. 1840. Eini ueber di he Familie der Polygonaceae. Mém. Acad. Imp. Sci Saint- sane Sér. 6, Sci. Math., Seconde Pt. Sci. Nat. 6(2): 135-151. ARNOLD ARBORETUM 22 Diviniry AVENUE CAMBRIDGE, MASSACHUSETTS 02138 1985] INDEX 509 INDEX Abelia, 422, 423 — spathulata, ae 441, 458 Acanthaceae, er, Aceraceae, 8 ec hatseaepacene) 4 Achatocarpus, 4 Adoxa, 422, 423, 441, 442, 444-447, 450- 453, - asian ae 422, 434, 439, 457 — omeie hee "422, 434, 437 6 16 Agapetes (Ericaceae) in Southeast Asia, otes on Vaccinium and, 471-490 Agapetes, 471-473, 483, 489 — subg. Agapetes, 471-474 — ser. Robustae subser. Chartacea, 471, 474, 476, 478 — subg. Paphia, 471, 473 — ser. Longifiles, 475 — ser. Robustae subser. Coriacea, 479, 484 — dulongensis, 476, 477 — forrestii, 472 — glandulosissimum, 475 — inopinata, 475, 476 — leptantha, 475, 478, 481 — mannii, 472 _ miniata, 474, 483 , 480 — rubropedicellata, 472, 474, 478, 479 Agastac ee 2, 37 Agdestis, 2, 3, 11, 35-37 r 5 Agrosinapis, 313 Agrostidaceae, 127 Agrostis, — hiemalis, 158 Aira, 157 — brevifolia, 234 Airopsis brevifolia, 234 Aizoaceae, AL-SHEHBAZ, IHSAN A. Raphanus boissieri (Cruciferae), a New Species from t Middle East, 275-278 At-SHEHBAZ, IHSAN A. The Genera of Brassiceae (Cruciferae; Brassicaceae) in the Southeastern United St AL-SHEHBAZ, IHSAN A. The G Thelypodieae (Cruciferae; Brassicaceae) in the Southeastern United States, 95- 111 Alangiaceae, 250 Alangium, 248-250, 259, 264 Alfaroa, 249 Alismataceae, 250 Amaranthaceae, 3, 5 Ammannia (Lythraceae) in the Western Hemisphere, A Revision of, 395-420 2 420 — ulata, 396- ver 400-405, 410, 411, 4G. "417, 420 — — var. arenaria, 403, 405, 420 ———f. brasiliensis, 403, 405, 420 — — x Ammannia robusta — baccifera, 395, 396, 402- 407, 420 — — subsp. aegyptiaca, 407 — — var. prasilicncis: 416 510 Ammannia coccinea, 396-405, 407-411, 413-417, 420 — — subsp. longifolia, 408, 420 — — subsp. purpurea, 408, 420 — hyrcanica, 417, 420 — koehnei, 411, 413, 420 var. eur cula. 412, 420 — latifolia, 395-403, 405, 411 —414, 417, = 420 — — var. octandra, 408, 420 — linearifolia, 417, 420 _— mexicana, 417, 420 — multicaulis, 417, 420 — multiflora, 396 — nuttallii, yee 420 _ crear 417, 420 r. pygmaea, 417, 420 _ octandra, 397, 407, 408, 416, 420 _ racemosa, 403, 417, a — ramosior, 402, 407, 416 420 — robusta, 396-398, 400, yea ae 410, 411, 414-417, 420 — sagittata, 411, — — var. seers 407, 420 — sanguinolenta, 407, 417, 420 — — subsp. longifolia, 408, 420 — — subsp. purpurea, 408, 420 — — subsp. robusta, 414, 420 — senegalensis, 396 — — var. peas 403, 420 — stylosa, 407, 420 — teres, 407, 410, 413, 420 — — var. exauriculata, 412, 414, 420 - bane ee 420 414 _ ete 396, 400, 407 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Ammannia wormskioldii, 417, 420 0 Amphibromus, 158 — scabrivalvis, 158 corlacea var. pe oetal ea. 2 isehae: ae, 259 Anomochloa, 136 Aucmochloaceae. 127 nae 262 Antenor ead. 173 Anthephora, 173 oe 157 Apio ee Aquillapollenites, 76, 87 Arabis, 82 Araceae, 80, 83 at nar The Genus Meryta in Samoa, 113-12 ee 80, 83, 113 Aristida, 149-152 — longispica, 164 Arnold Arboretum, Journal of the, Index to Authors and Titles, Volumes 51-65 39, 146 — gigantea, 132, 146, 149 — variegata, 135 Arundinellaceae, 127 Arundo, 150, 152 — donax, 149, 152 Ascyrum, 81 Asia, Eastern, and Eastern North America, Perspectives on the Origin of the Floris- tic Similarity between, 73-94 Asimina, 259 Asteraceae, 123 Asthenatherum, 153 Astilbe, 81 Atcopis californica, 234 1985] Atropis canbyi, 235 — laevis, — — var. stenophylla, 236 Atroxima, 353, 378, we - 386, 390 — afzeliana, 356, 377, — liberica, 356, 378 Aucuba japonica Authors and Titles, Index to, Journal of the Arnold Arboretum, Volumes 51-65 72 Axonopus, 173 Baby pepper, 27 Bambusa, 145, 146 ei ie 127 Barbeu oe : Barnhartia Berberidaceae 2 84 Betula, 76, 2 aR eh 81 Biosystematic Study of the Poa secunda Complex, A, 201-242 165 Boykiana humilis, 416 Brachiaria, 175 Brachyelytrum, 139, 175, 176 — erectum, 158, 175 Brassica, 280, 282, 283, 288-306, 310, 314, 2 — sect. Br: | o Q — sect. — sec — sect. — sect. — sect. Pseudobrassica, 291 INDEX Brassica sect. Rapa, 289 — sect. Sinapoides, 289 — alba, 313, 314 — campestris, 281, 290 — elongata, 291 — eruca, 324 — erucastrum, 309 — fruticulosa, 292 _ eT 289, 292 — intogifolia, 290 _ ae 95 — ar. crispifolia, 290 _— ieiten — muralis, 32 — rapa, 290-292, 2 . amplexicaulis, 294 . campestris, 290 . chinensis, 294 . rapa, 290 sinapistrum, 313 Brassiceae (Cruciferae: Brassicaceae) in the Southeastern United States, The Genera ; —351 Brassicella, 309 — erucastrum, 310 512 Bredemeyera, 354, 363, 364, 383-385, 387, — collettioides, 387 — densiflora, 356, 363, 364 — floribunda, 356, 359, 364, 365, 387 — lucida, 356, 359, 363, 365, 387 — microphylla, 387 — papuana, 356, 359, 364, 365, 390 Bunias cakile, 340, 343 — cochlearioides, 338 — edentula, 341 Buxaceae, 80 Cakile, 280, 282, 283, 287, 321, 340-348 — subg. Eremocakile, 341 — sect. Eremocakile, 341 — aequalis, 341 — americana, 341 — californica, 341 — chapmanil, 342 _ consti 3a, 343 s, 341 — — subsp. harperi, 341, 342, 344 - seorar 343 — harp ] _ han 341, 343 — — subsp. alacranensis, 343 a 1 — — var. peniculata, 343 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 ase ae 157 Calamovilfa, 165 Caldesia. 250 Calepina, 280, 282, 287, 338, 339 _ eee ee 338 — corvinii, 338 — Pee 281, 338, 339 Callicarpa, ae et lin 59 CAMPBELL, CunistonEEn S. The Subfam- ilies and Tribes of Gramineae (Poaceae) in the Southeastern United States, 123- 199 Campsis, 81 Capparaceae subfam. Cleomoideae, 97 Caprifoliaceae Sensu Lato, Pollen Diver- sity and Exine Evolution in Viburnum and the, 421-469 Caprifoliaceae, 80, 422, 423, 434, 437, 440- 442, 449-453 — subfam. Caprifolioideae, 422, 434 — — tribe Caprifolieae, 422, 434, 450, 457, 45 — — tribe Diervilleae, 422, 423, 435, 450, 452, 45 — — tribe Linnaeeae, 422, 436, 450, 452, 457, 458 — — tribe Triosteae, 422, 435, 450, 458 — subfam. Sambucoideae, 434 — tribe Sambuceae, 423 — tribe Viburneae, 423 Cardamine, 82 Carex, 80 Carpinus, 243 Carpolobia, 354, 374, 376, 383, 385, 386, 90, 391 — alba, 356, 376, 377 — gossweileri, 356, 368, 374-377 — lutea, 356, 368, 374, 376 Cartiera, 104 Carya, 80, 105 Caryophyllaceae, 3-5 Catalpa, 81 Catapodium, 160 Caulanthus, 97, 104, 106 — gracillimus, 174 Centosteca, 153 Centotheca, 153 1985] Ceratocnemum, 336 — rapistroides, 282 Ceratostemma angulatum, 476 — vacciniacea, Cercidiphyllum, 76 Chrysopogon, 169 Cinna, | Cladrastis, 80 Cleomaceae, 259 Cleome, 97 ee 100 a, 250 Cbccaloba. 503, 507 — zemyi, Coelorachis, 169 a, 30 — dicueathos. 309 Coix, 16 — lacryma-jobi, 170 Cole, 289 Comesperma, 353, 354, 358, 364, 365, 383, 384, 388-390 — calymega, 356, 365, 366 — confertum, 356, 366 9 —_ planisiliqua, 349, 350 Cordylocarpus, 336 — muricatus, 282, 336 Coridochloa, 175 Cornaceae, 80, 444, 445 rnus, 80 Cortaderia, 152 — selloana, 152 Cossonia, 328 Cox, PAUL ALAN. The Genus Meryta (Ara- liaceae) in Samoa, 113-121 Crambe, 282, 283, 321, 339, 344 — corvinii, 338 — gordjaginii, 282 — maritima, 28 Crassulaceae, 82 Crenea, 39 Cruciferae; pone iares The Genera of Brassiceae in the Southeastern United States, ee Cruciferae; Brassicaceae: The Genera of Thelypodieae in the Southeastern United States, 95-111 Cruciferae: Raphanus boissieri, A New Species from the Middle East, 275-278 Cruciferae, 82, 96, 97, 101, 108, 280, 282, 294, 325, 344, 385 — tribe Brassiceae, 279-351 — — subtribe Brassicinae, 282, 320, 329 — — subtribe Cakilinae, 280 — — subtribe Moricandiinae, 282, 349 — subtribe Raphaninae, 282, 336, 339 — tribe Romanschulzieae, 96 — tribe Stanleyeae, 95 — tribe Streptantheae, 96 — tribe Thelypodieae, 95-111 — tribe Velleae, 280 — tribe Zilleae, 280 eee 165, 166 Cynos 160 ee 80, 83, 137, 259 Dactylis, 160 Dactyloctenium, 166 Danthonia, 134, 151-153 — spicata, 149 514 Decodon, 259, 398 Ss) & io) = 3 jet) es Eas Dichanthelium clandestinum, 172 Diclidanthera, 355, 382-387, 390, 391 — bolivarensis, 356, 382, 383 — elliptica, 356, 379, 384 Didiplis diandra, 417 Diervilla, 80, 422, 441, 450 — lonicera, 435, 438, 458 aie 422 — e, 166 Diplotaxis, 282, 283, 288, 291, 310, 318- 325 ct. Anocarpum, 319 | = i) 4 = — muralis, 281, 7b) 32 x Diplotaxis in 321 — nepalensis, 319 — xschweinfurthii, 321 — tenuifolia, 319-321 — viminea, 321 Dipsacaceae, 442, 450, 451 Donoeuue; MicHaceL J. Pollen Diversity and Exine Evolution in Viburnum and the Caprifoliaceae Sensu Lato, 421-469 Dulichium, 259 Durandea, 328 Ebenaceae, 80 Echinochloa, 175 Eleusine, 166 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Elionurus, 169 Emblingia, 355 Enarthrocarpus, 280, 329 — tragicerus, 277 Engelhardtia, 248-250 Eocene North Atlantic Land Bridge, The: Its Importance in Tertiary and Modern Phytogeography of the Northern Hemi- jee 243-273 Epigae Epieyniam leucobotrys, 4 Epirixanthes, 353, 354, ie a 388, 389, 391 — cylindrica, 356, 370, 390 — elongata, 356, 367-370, 390 a, Eriandra, 355, 378, 383, 385, 387 — fragrans, 356, 378, 379, 381 Erianthus, 169 Ericaceae: Notes on Vaccinium and Aga- petes in Southeast Asia, 471-490 Ericaceae, 80, 474 — tribe Vaccinieae, 472-474 Eriochloa, 17 Eruca, 283, 288, 324-327 Beye 324, 325 — sativ ees 324, 325 — subsp. Erucaria, 280, 282, 310, 344 — cakiloidea, 282 Erucastrum, 282, 288, 291, 305-308, 310, 321 — abyssinicum, 306, 307 — arabicum, 306, 307 — cardaminoides, 307 — elatum, 307 — gallicum, 306, 307 — littoreum, 307 1985] Erucastrum meruense, 307 — nasturtiifolium, 306, 307 — ochroleucum, 306 — pachypodum, 307 — pollichii, 306 — rifanum, 307 — virgatum, 306, 307 — vulgare, Sas 104, 106 Euklis — ay nth ie 105 Euodia, 250, 259, 264 , 165 Euzomodendron, 282, 283 Euzomum, 32 Exine Evolution in d the Cap- rifoliaceae Sensu Lato, Pollen Diversity and, 421-469 Vih Vv Fabaceae, 123 — patagonica, 235 — spaniantha, 235 Festucaceae, 127 Ficus, 248 Flagellariaceae, 137 Floristic Similarity between Eastern Asia and Eastern North America, Perspec- tives on the Origin of the, 73-94 Fothergilla, 259 Galium, 81 Gallesia, 5 Garcinia, 386 Gaylussacia serrata, 485 Gelsemium, 81 Genera of Brassiceae (Cruciferae; Brassi- caceae) in the Southeastern United States, The, 279-351 Genera of Phytolaccaceae in the South- eastern United States, The, 1-37 Genera of Thelypodieae (Cruciferae; Bras- Si e) in the heastern United States, The, 95-11 Genus Meryta ee in Samoa, The, 113-121 Gisekia, 5 INDEX 515 Gisekia pharnacioides, 2,11 yi, 235 — septentrionalis, 158 — strata, 15 Glyptostrobus, 249, 250 4 GRAHAM, SHIRLEY A. A Revision of Am- mannia (Lythraceae) in the Western Hemisphere, 395-420 Graminaceae, 127 Gramineae (Poaceae) in the Southeastern United States, The Subfamilies and Tribes of, 123-199 Gramineae, 123-199 bfam. Andropogonoideae, 167 — subfam. Aristidoideae, 150 — subfam. Arundinoideae, 128, 131, 133, 134, 138, 144, 148, 150, 151, 153, 154, 163, 167, 176, 177, 189-196 — — tribe Aristideae, 134, 144, 151, 152, 164, 177, 189-196 — — tribe Arundineae, 134, 143, 144, 149, 151-154, 189-196 — — tribe Centotheceae, 134, 144, 149, 151, 153, 154, 189-196 - tribe Danthonieae, 151-153 1 | | =f o oO m a; = i-7 p a — subfam. Bambusoideae, 128, 129, 131, 132, 134, 135, 138, 142, 145, 146, 148, 149, 175-177, 189-196 — — tribe Ae ace ae. 132, 135, 142, 145-147, 149, 189-196 — — tribe Oryzeae, 142, 145, 189-196 --- subtribe Luziolinae, 147 Jl 147-149, — — tribe Phareae, 134, 149, 150, 189-196 = subfam. Centostecoideae, 150 — subfam. Centothecoideae, 134, 150 — subfam. Chloridineae, — subfam. Chloridoideac: 128, 131, 132, 134, 135, 138, 144, 153, 154, 163, 164, 166, 167, 189-196 — — tribe Aeluropodeae, 144, 163-165, 189-196 142, 143, 145, tribe Cynodonteae, 132, 145, 152, 163, 165-167, 189-196 516 Gramineae subfam. Chloridoideae tribe Unioleae, 144, 154, 165, 166, 189-196 — — — subtribe Uniolinae, 166 — — tribe Zoysieae, 135, 145, 167, 189- 196 — subfam. Eragrostoideae, 163, 176 5 — subfam. Panicoideae, 128, 131-135, 138, 144, 151, 153, 163, 167-170, 172, 174, 189-196 — — tribe Boe arya 132, 135, 144, 167- 171.173, -196 = subtribe i sacreaspitee 169 — — — subtribe Sorghinae, 169 -- — subtribe Tripsacinae, 169 — — tribe Paniceae, 139, 144, 152, 163, 167, 171-175, 189-196 --- subtribe Brachiariinae, 173, 175 ww — — ser, Pecticiormes 4 — — ser. Phragmitiformes, 129, 134 — subfam. Pooideae, 128, 129, 131-135, 138, 139, 143, 154, 156-158, 161, 162, 175, 176, 189-196 — — supertribe Poanae, 143, 156, 160 — — — tribe Agrostideae, 135, 143, 144, 156-158, 160, 175, 189-196 — — tribe Aveneae, 143, 144, 153, 156- 158, 160, 189-196 — — — tribe Meliceae, 143, 156, 158, 160, pane ribe Poeae, 143, 154, 156-158, ~ 160, aL. 176, 189-196 eves supertribe Triticanae, 143, 156, 160 — tribe Brachypodieae, 156 ipa SR 143, 156, 160, 161, 176, 189-196 tribe a 132, 140, 143, 156, 158, ee 163, -196 — subfam. Sit ie 134 — subfam. Saccharoideae, 167 — tribe Andropogineae, | — tribe Anthephoreae, 167, 171, 173 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Gramineae tribe Anthoxantheae, 157 — tribe Arthropogoneae, 17 — tribe Arundinaceae, 152 — tribe Arundinelleae, 171, 173 — tribe Avenaceae, 157 — tribe Brachyelytreae, 134, 143, 156, 158, 175, 176, 189-196 — tribe Brachypodieae, 161 — tribe Bromaceae, 160 — tribe Chlorideae, 163, 165 — tribe Coiceae, 169 — tribe un nee 152 — tribe Cynodoneae, 165 — tribe ss ee enn 134, 143, 156, 176, ibe Diarrheninae, 188 - tribe Elytrophoreae, 152 — een Euchlaeneae, 1 9. 3 — tribe Maydeae, 167, 169 — tribe Melicaceae, 158 — tribe Melinideae, 153, 167, 171, 173 — tribe Saccharineac, 169 — tribe Secaleae, 161 — tribe Spartineae, 165, 166 — tribe Sporoboleae, a 165, 166 — tribe Stipaceae, 17 — tribe Stipeae, 134, a: 143, 151, 156, 158, 159, 176, 177, 189-196 Grass Family, 124 Guenthera, 289 Guinea-hen weed, 32 dus, 80 Gymnopogon, 139, 166 Gyrostemonaceae, 4 Hackelochloa, 169 1985] Halesia, 81 bialoragidnces ae, 259 Hamamelidaceae, 80, 259 Hamamelis, 80 Hare’s-ear mustard, 349 Heimia myrtifolia, 418 Hemarthia, 169 Henicrambe. 283, 329 Heptacodium, 422, 441 — jasminoides, 436, 457 WARD, RICHARD A. The ie scandens (Vell. Conc.) Cocucci’? Com plex (Polygonaceae), 503-508 Hutera, 288, 291, 293, 308-312, 314, 315, 321 — cheiranthos, 309-311, 320 l Hydrochloa caroliniensis, 147 Hymenachne Hymenanthera 491, 498 — chathamica, 491 — dentata var. oblongifolia, 500 — latifolia, 491 — oblongifolia, 491, 500 Hyparrhenia, 169 Hystrix, 161, 162 — patula, 132, 162 Icacinaceae, 79, 243, 248 106 — hyacinthoides, 105 Ilex, 80 INDEX 517 Imperata, 169 Index to Authors and Titles, Journal of the Arnold Arboretum, Volumes 51-65 (1970-1984), 39-72 Isnardia subhastata, 411, 420 Jeffersonia, 82, 84 er, 104 ame 137 Journal of the Arnold Arboretum Index to hen rs and Titles, Wolumes 51-65 . 37 J ussiaea a. 411, 420 Justicia, 81 Kaliphora madagascarensis, 445 KELLOGG, ELIzABETH A., and ANNA L. WeitzMANn. A Note on the Oceanic Species of Melicytus (Violaceae), 491- 502 KELLOGG, ELIZABETH ANNE. A Biosystem- atic Study of the Poa secunda Complex, — amabilis, 436, 458 Labiatae, 81 Lafoensia, 398 Laguncularia, 25 eae — gracilis, 434, 458 Liliaceae, 81, 83, 106 — tribe Helonieae, 81 Limeum, | 518 Limnodea, 157 0 — sempervirens, 435 — tatarica, 435 Lophiocarpus, 2, 4, 5 Ludwigia hastata, 411, 420 — scabriuscula, 418, 420 Luziola, 147 Lycoperdon, 259 Lygeum, 151, 176 Lyonia, 80 Lysimachia, 81 Lythraceae: A Revision of Ammannia in the Western Hemisphere, 395-420 Lythraceae, 250, 259, 395, 397, 400 Lythrum, 397 — apetalum, 418, 420 Macropodium, 96, 97 Magnolia, — waltonii, 250 apa eee 80, 88, 250 Magonia, — scandens, 503, 505, 506 Mahonia, 84 ammea, 386 Manisuris, 169 — rugosa Megalophylla, 445 Melanosinapis, 289 gee = eae ees A Note on the ceanic Species of, 491-502 3 — ramiflorus, “491, 493-495, 497-500 — — subsp. fasciger, 49 — — subsp. oblongifolius, 491, 492, 494, 496, 498, 500, 501 — — subsp. ramiflorus, 491, 492, 494-498 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 oensis, — samoensis, 491,492, 494-498, 501, 502 oe ramiflorus subsp. samoensis, 501 . sam 0 73 Menispermaceae, 36, 81, 259 Menispermum Meryta (Araliacee) in Samoa, The Genus, 113-12 Meryta, ne 121 — capitata, 113-116 — macrophylla, 113-117 — malietoa, 114-118 — mauluulu, 114-117, 119, 120 — tenuifolia, 113, 120 Mesoreanthus, 104 Microdiptera parva, 250, 259 Microsemia, 104, 108 Microstegium, 169 Microtea, Middle East, Raphanus boissieri (Crucif- rae), a New Species from the, 275-278 Miliaceae, 127 165 Monnina, 354, 358, 370, 372, 383, 390, 1 — ciliolata, 356, 370-373 — wrightii, 356, 370, 372 — xalapensis, 356, 370, 373 Monococcus, 2, 32 Monocotyledoneae, 83 Moricandia, 282, 320, 349 Moutabea, 355, 380, 383, 385-387 — guianensis, 356, 379-381, 386 Muhlenbergia, 139, 165, 166 — schreberi, 16 Muraltia, 354, 366, 383, 384, 388, 389 — heisteria, 356, 359, 366 Muricaria, ie Mustard, 289, Myagrum en 335 — irregulare, 33 spermum minus, 338 Myricaceae, 259 Nardostachys, 450 1985] Nardostachys jatamansii, 437, 458 d 76 usia, 80 Neyraudia, 144, 150-153 — reynaudiana, 152 North America, Eastern, Perspectives on the Ongin of the Floristic Similarity be- tween Eastern Asia and, 73-94 Phytogeography of the Northern Hemi- sphere, 243-273 Northern Hemisphere, The Eocene North Atlantic Land Bridge: Its Importance in Tertiary and Modern Phytogeography of the, 243-273 Note on the Oceanic Species of Melicytus (Violaceae), A, 491-502 Notes on Vaccinium and Agapetes (Eri- caceae) : Sane Asia, 471-490 Nyctaginac Nveneta: 354, 368, 383, 388, 389, 391 spinosa, 356, 359, 367, 368 Ross. 79, 243, 248-250, 259 Nyssa, 80 — brandoniana, 250 — javanica, 250 Nyssaceae, 80 Oceanic Species of Melicytus (Violaceae), A Note on the, 491-502 9 Origin of the Floristic Similarity between Eastern Asia and Eastern North Amer- ica, Perspectives on the, 73-94 Dprl 1 Ovules and Seeds of the F 353- 94 Pachysandra, 80 Palaeowetherellia, 249 Palmae, 137, 259 INDEX 519 Panax, 80 Seen sandbergii, 235 Panicaceae, 127 Panicularia nuttaliana, 234 5 Panicum, 167, 171-173, 175 — subg. Dichanthelium, 175 — subg. Panicum, 173 — anceps, 173 — capillare, 175 — clandestinum, 172 Papaveraceae, 84 Pariana, 140 Penthorum, Perspectives on the Ongin of the Floristic Similarity between Eastern Asia and Phellodendron, 250, 259 Phleum, 157 Phragmites, os a 152 — australis, — communis, cos Phyllostachys, 146 Physorrhynchus, 280 Phytolacca, 2-4, 11-23, 82 520 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 66 Phytolacca subg. Phytolacca sect. Phyto- Poa subg. Pistillata, 203 03 acca, — subg. Poa, — subg. Pircunia, 13 — — sect. Abbreviatae, 203 — sect. Pircunia, 13 — — sect. Bolbophorum, 203 — sect. Pircuniastrum, 13 — — sect. Cenisia, 203 — sect. Pircuniopsis, 13 — — sect. Coenopoa, 203 — sect. Pseudolacca, 13 — — sect. Homalopoa, 203 — acinosa, 13, 15 — — sect. Leptophyllae, 203 — americana, 2, 11-17 — — sect. Macropoa, 203 — brachystachys, 13 — — sect. Nanopoa, 203 — decandra, 13 — — sect. Ochlopoa, 203 — dioica, 11, 13, 15 — — sect. Oreinos, 203 — dodecandra, 13, 16 — — sect. Poa, 203 — esculenta, 13, 15 — — sect. Stenopoa, 203 — heterotepala, 13 — — sect. Tichopoa, 203 — icosandra, 13 — subg. Poidium, 203 — meziana, | | — subg. Pseudopoa, 203 — octandra, 13 — subg. Secundae, 203 — purpurascens, 13 — sect. Alpinae, 203, 204 — rigida, 13, — sect. Annuae, 203, 204 — evinoides: 14 — sect. Epiles, 203, 204 — rugosa, 14 — sect. Homalopoae, 203, 204 — weberbaueri, |1 — sect. Nevadenses, 203, 205, 213 Phytolaccaceae in the Southeastern United — sect. Palustres, 203, 204 States, The Genera of, 1-37 — sect. Pratenses, 203, 204 Phytolaccaceae, 1-37, 82 — sect. Scabrellae, 203, 205 — subfam. Agdestidoideae, 2, 4, 35, 36 — acutiglumis, 236 _ bem Barbeuioideae, 2, 4 — alcea, 236 — subfam. Microteoideae, 2, 4 _ dipins. 229 — subfam. Phytolaccoideae, |-3, 11 — ampla, 212, 213, 221, 224, 230, 231, — subfam. Rivinoideae, 2, 3, 23 236 — — tribe Rivineae, 3, 23, 32 — andina, 234 — — tribe Seguierieae, — — var. major, 234 — subfam. Stegnospermatoideae, 2,4 — — var. spicata, 234 — tribe Agdestideae, 36 — arctica, 229 Phytolaceae, | — autumnalis, 204 ee 80 — bolanderi, 236 Pinus, 105 — brachyglossa, 236 Piptochaetium, 177 — brevifolia, 234 — avenac , 159, 177 — buckleyana, 234 ade. 177 — — var. elongata, 234 Pircunia, 13 — — var. sandbergii, 235 — sect. Pircuniastrum, 13 — — var. stenophylla, 236 — sect. Pseudolacca, 13 — californica, 234 Platycarya, 248, 249, 255 — canbyi, 207, 221, 231, 235 Pleiocardia, 104 — capillaris, 236 Poa secunda Complex, A Biosystematic — confusa, 236 Study of the, 201-242 — cottonii, 238 Poa, 127, 141, 154, 156, 160, 201-205, — curtifolia, 202, 206, 209, 210, 212, 213, 213, 229, 233 219, 221-226, 228-234, 240 — subg. Dioecia, 203 — cusickii, 204, 238 — subg. Dioicopoa, 203 — english, 237 — subg. Eupoa, 203 — epilis, — subg. Leucopoa, 203 — fendleriana var. juncifolia, 236 1985] Poa fibrata, 238 gracillima, 213, 215, 221, 230, 231, 235 var. m ilimonine. 23 — — var. saxatilis, 236 — helleri, 236 _ iGurvae 212, 231, 236 — interior, 238 — invaginata, 236 — juncifolia, 212, 213, 221, 236 — — subsp. porteri, 237 —_ nemoralis, 204 a, 235 — Bie 154, 229 — reflexa, 21 _ fae a 201, 205, 212, 221, 231, 235 — saxatilis, — seabrella, 213, 215, 221, 231, 235 01-242 — secunda, — sylvestris, 204 _ tenerrima, 236 — truncata, 236 wyomingensis, 236 Peacenk The Subfamilies and Tribes of ramineae in the Southeastern United Pokeweed Family, | Polanisia, 83, 259 Bolcmvoniaceas: 442 INDEX 521 Pollen sea ase) and Exine Evolution in ee the Caprifoliaceae Sensu Lato, "21 469 Polygala, 107, 353, 354, 358, 360, 383, 85, -391 — sect. Acanthocladus, 356, 361, 387, 388 — sect. Chamaebuxus, — sect. Hebecarpa, 357, 358, 387, 388, 391 — sect. Hebeclada, 357, 362 — sect. Ligustrina, 357, a6, 388, 389, 391 — sect. Polygala, 357, 362, 3 6 — conferta, 357, 6G. 388 — durandii, 357-361, 387 — floribunda, 357, 362 — glochidiata, 388 — jamaicensis, 357, 359-361, 387 61 , 357, 361 femme a: 357, 359-361, 388, 391 — microspora, 357, 360, 362, 388 — semialata, 357, 363, 388 — venenosa subsp. pulchra, 353, 389 — vergrandis, 357, 360, 362, 363, 388 2 Polygalaceae, Ovules and Seeds of the, 353- 394 Polygalaceae, 353-394 — tribe Moutabeae, 355, 385 — tribe Polygaleae, 353 — tribe Xanthophylleae, 355 Polygonaceae: The ‘“‘Triplaris scandens (Vell. Conc.) Cocucci’? Complex, 503- 08 5 Polygonaceae, 80, 83 seudofortuynia, 280 Pseudosasa, 146 Ptelea Picrocatyas 248-250 Puccinellia, 160, 217 ee _ nevadensis; 235 — scabrella, 235 522 Punica granatum, 386 Pyrularia, 81 Quercus, 100, 105 Quidproquo, 275, 328 — confusum, 27 Radish, 328 Raffenaldia, 328 Pe nmnediaocae 81, 83 Ranunculus, 8 Rapa, 289 x Raphanobrassica, 282, 293, 329, 330 Raphanus, 275, 282, 283, 287, 293, 327- 334 — sect. See una 275, 328 — sect. Raphanistrum, — sect. seni 328 — aucheri, 275 _ iced, 275-278, 328 — cau . tus — eru a, 324 a ee ee 341 — xmicranthus, 329 - phen, 281, 283, 309, 328-331 — — subsp. landra, 330 ao on — — subsp. 330 — — subsp. raphanistrum, 330, 331 — subsp. rostratus, 330 — sativus, 281, 328-331 — — var. sero 331 — — var. i, ger, 331 x pe eats 282