JOURNAL OF THE ARNOLD ARBORETUM Volume 56 HARVARD UNIVERSITY 1975 MissOUR! BoTANICAB GARDEN LiskARY Dates of Issue No. 1 (pp. 1-184) issued 16 April, 1975 No. 2 (pp. 185-264) issued 13 June, 1975 No. 3 (pp. 265-374) issued 2 September, 1975 No. 4 (pp. 375-478) issued 15 November, 1975 Contents of Volume 56 Lauraceae Hardy in ao North America. STEPHEN A. SPONG Systematic Anatomy of ‘hs Xylem and Comments on the Relationships of coarse: Reais B. MIL ; The Neotropical ee Tachia (Gentianaceae). BASSETT MAGUIRE and RICHARD E. WEAVER, JR. Species Versatility in Shore Habitats. HuGu M. Raup The Taxonomic Status o the Genus Bauerella (Rutaceae). THomaAS G. HARTLE What and Whence Was Miller s “Caryophyllus ; cotinifolius? ROGERS MCVAUGH . Kadsura heteroclita — Microsporangium and Pollen. . VISAYARAGHAVAN and UsHA DHA p Statement of Ownership Reproductive Adaptations in Prosopis (Leguminosae, Mimosoideae). OTTo T. SOLBRIG and PHILIP D. CANTINO . Cytotaxonomic Notes on Some Gentianaceae. RICHARD E. WEAVER, Jr. and LiLy RUDENBERG The Oxalidaceae in the Southeastern United States. KENNETH R. ROBERTSON : Gaultheria swartzii, nom. nov. and the Combinations in Raeuschel’s Nomenclat RICHARD A. ee ie Additional Notes on the Genus Flindersia (Rutaceae). T. G. HARTLEY and B. P. M. AND , The Mayacaceae in As Southeastern United States. JOHN W. THIER Development of the 1 Digitately Decompound Leaf in Cussonia spicata (Araliacea . F. REYNEKE and H. P. nae DER SCHIJFF Caroline K. Allen [notice]. The Genus Cladocolea (Loranthaceae). JosB KuIJT. : Pet Hybridization and Introgression i in Quercus alba. JAMES W. HARDIN ; The Genus Anetanthus ( Geinecinceae). RicHarp A. Howarp A New Species of Zanthoxylum ( Rutaceae) from ‘New Guinea. THOMAS G. HarT . The Genera of Si caacest in the Southeastern United States. LyMaN B. SMITH and CaRROLL E. Woon, Jr. . 1975 256 264 Isozyme Variation in Species of Prosopis (Leguminosae). OTTO T. SOLBRIG and KAMALJIT S. BAWA . The Balsaminaceae in the Southeastern United States. CaRROLL E. Woop, J F Studies in Schefflera je ae The Cephaloschefflera Complex. G. FRODIN Lindernia brucei, A New West Indian Species of the Asian Section Tittmannia. CHARD A. HOWARD The Podostemaceae in the Southeastern United States. S. A. GRAHAM and C. E. Woop, Jr. Index 398 427 449 456 466 SGURNAL oF ne ARNOLD ARBORETUM SISSN 0004-2625 es — cya eS a a cain mA eee Sateen ethene ate apm ne mt ea aa eg erate 2 on janet EE : pe a oe oe > ono meat aay Sotie Wheaees ni vee ons > 73 Sees Soap +m ods ae ee £255 el * Y my es i 2 S38 ve mu ater ale 7 may moe bro) inaiapiactyens Weeks sic Bieninccaazeen eres 2 i rane es iM Rae), ope 24s ba oo tees Stn 9 ect ee . me ie : Siemens alam 3 ce ii Nalin sam es ae pee iw ih ea mai ares ay ae eearclig at tig, Noe Ee Naps = aaron . aie a 2 i A onyemape Pein. Si Sra isle Lity May Perry On January 5, Dx. Lity May Perry observed her eightieth birthday. The staff of the Arnold Arboretum, with admiration, appreciation, and af- fection, dedicates this number of the Journal of the Arnold Arboretum to her. Miss Perry arrived at Harvard fifty years ago. With an absence of only five years, she served under two directors at the Gray Herbarium be- fore transferring to the Arnold Arboretum, where she has helped the three directors who succeeded Charles Sargent. Although Miss Perry officially retired in 1964, she has rarely missed a day of “work” since that time, completing her studies of the Myrtaceae of Papua New Guinea, revising a large manuscript on medicinal plants of Southeast Asia, participating in regular seminars, serving as unofficial historian of systematic botany at Harvard, and aiding anyone who asks her help. She obviously enjoys each day, and we join in wishing her a happy birthday and many more. JOURNAL OF THE ARNOLD ARBORETUM Vor. 56 JANUARY 1975 NUMBER 1 LAURACEAE HARDY IN TEMPERATE NORTH AMERICA STEPHEN A. SPONGBERG THE TREATMENT OF the five genera of Lauraceae presented below is an initial contribution towards a projected manual of cultivated ligneous plants, the preparation of which is a project of the Arnold Arboretum, and the purpose of which is to provide a modern, accurate account of woody plants encountered in cultivation in the cooler temperate regions of North America. It is planned that additional treatments of selected fam- ilies, groups of families, individual genera, or taxa of other ranks will be published as they are completed. This decision has been made for several reasons. Through publication the information assembled will be made available immediately. It is hoped that errors, omissions, and supplemental information, particularly concerning hardiness, will be brought to our at- tention; moreover, we will welcome constructive criticisms and suggestions from our colleagues and other interested individuals. In addition, nomen- clatural and taxonomic problems and proposals that would be inappro- priate in the manual can be presented and discussed more easily in the pages of a botanical journal. It is also hoped that the periodic appearance of these treatments will stimulate further interest in the taxonomy, en- courage continued investigations, result in additional collections, and pro- mote further ornamental use of a wider variety of cultivated woody plants. That there is a need for a modern manual of cultivated woody plants has become increasingly evident within tue last decade. While the indig- enous or spontaneous flora of most areas of North America is relatively well known and has been treated in numerous readily available regional and/or local manuals or floras, cultivated plants generally have not re- ceived equal attention. As a result, many of the species that comprise our cultivated flora are poorly known, and few manuals or guides that can be used to identify cultivated and exotic material are available. The ab- sence of a modern, standard reference treating cultivated plants consti- tutes a noticeable gap in our total floristic knowledge of North America, especially since ornamental cultivated plants are prominent in the en- vironment of our increasingly urbanized society. As a result of this prom- inence, not only has the American public become more interested in plants in general, but botanists, teachers, nurserymen, and professional and ama- © President and Fellows of Harvard College, 1975. 2 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 teur horticulturists, among others, have expressed need for an accurate and current reference dealing with the woody members of this large cosmopolitan group of plants. As with any taxonomic study, our work in compiling a manual treating cultivated woody plants will be partially original, but it must be based upon and must draw information from previous scientific investigations and publications; the most recent North American work of the type now en- visioned, and the model upon which our work will largely be based, was prepared by Alfred Rehder (1863-1949). Rehder’s monumental contribu- tions to our knowledge of the taxonomy of cultivated trees and shrubs are for the most part incorporated in his Manual of Cultivated Trees and Shrubs Hardy in North America, Exclusive of the Subtropical and Warmer Temperate Regions, which was written while Rehder was a member of the staff of the Arnold Arboretum, and in his Bibliography of Cultivated Trees and Shrubs Hardy in the Cooler Temperate Regions of the Northern Hemisphere. Since their publication, these two works have remained the standard references of their kind for the area.covered. The work presently under way will attempt to update and correct the information included in Rehder’s Manual. However, our current investigations will eventually result in a new manual, not a new, revised edition of Rehder’s work. The first edition of Rehder’s Manual appeared in 1927 and was followed by a second, revised and enlarged edition in 1940. Currently in its twelfth printing, the Manual is available only periodically and never in great enough quantity to satisfy the continued demand. As a result, it has been increasingly difficult to obtain. The Bibliography, which gives complete bibliographic citations and almost complete synonymy for the names ac- cepted in the second edition (including a few not in the Manual), was pre- pared at and published by the Arboretum during Rehder’s retirement and appeared just before his death in 1949. The supply of copies, however, has long been depleted. Since the publication of the second edition of the Manual and the Bibliography thirty-four and twenty-five years, respectively, have elapsed, and, as a consequence of numerous experimental and systematic studies published during these years, changes in the interpretations and under- standing of many of the taxa treated in Rehder’s works have resulted. Furthermore, the results of these studies have often necessitated nomen- clatural changes. Additional nomenclatural alterations are required under the provisions of the current (1972) edition of the International Code of Botanical Nomenclature (Regnum Vegetabile vol. 82), since Rehder pre- pared the second edition and the Bibliography following the 1935 edition of the International Code. Moreover, expanded provisions for the nomen- clature of cultivated plants, in particular, and the official adoption of the old concept but new term cultivar were incorporated in the 1953 edition of the International Code of Nomenclature of Cultivated Plants. The current edition of that code, which includes additional modifications, was adopted in 1969 (Regnum Vegetabile vol. 64). These nomenclatural considerations and the advance of our knowledge 1975] SPONGBERG, LAURACEAE 3 of many groups have often rendered Rehder’s treatments of these groups outmoded and inaccurate. Also, the continued introduction into cultivation of new plants that are not treated in the second edition of the Manual (e.g., Metasequoia) has further diminished the usefulness of that work. Our work, therefore, will be based on a complete re-examination of her- barium material and botanical and horticultural literature; living speci- mens will be studied whenever possible and herbarium specimens of cul- tivated plants will be studied and compared with specimens of the same taxa from their native areas. New information, such as chromosome num- bers and indications of plants known to be poisonous to man, will be in- corporated. Keys for identification will be strictly dichotomous through- out, and selected references to recent, as well as standard, taxonomic and horticultural publications will be included under families and genera to increase the usefulness and value of each treatment. Except when known for taxa new to cultivation, dates of introduction will not be included, nor will expanded references to illustrations, but it is hoped that the inclusion of drawings, at least for critical groups, will be possible. Continuity with Rehder’s works will be achieved, since it has been de- cided that all of the accepted taxa included in Rehder’s Bibliography will either be treated or accounted for in the new manual. Taxa treated in Rehder’s Manual and Bibliography for which no records in cultivation exist will be handled in one of two ways.! Either the name will be listed as undocumented in cultivation, or, if confusion exists between a taxon known in cultivation and an undocumented taxon, the undocumented taxon will be keyed and/or described in order to clarify its status and prevent continued confusion. Changes in taxonomic interpretation that result in the inclusion of taxa recognized by Rehder within the concepts of other taxa will be indicated by the addition of major synonymy. Documentation will be based on three sources but except in rare in- stances will not be included in the treatments. Herbarium specimens will constitute the primary evidence of a taxon’s occurrence in cultivation; yet literature reports (including selected nursery catalogs) and the published inventories of various botanical gardens and arboreta from within the range outlined below will also be accepted as valid. Several of the inven- tories to be consulted are available in computerized form from the Plant Records Center of the American Horticultural Society. It will be as- sumed that the published and inventory records are correct, and the names therein will be treated so that misidentifications, if they have occurred, can be corrected. In determining which newly cultivated taxa are to be added to those in- cluded in Rehder’s Bibliography, Rehder’s broad concept of woodiness, outlined in the Introduction to the first edition of his Manual, will be employed. Additionally, documentation will be required from within an arbitrary range that roughly coincides with the area outlined in the seventh and eighth editions of Gray’s Manual. Our area will include all 1 For the most part, these taxa comprise Rehder’s “related species” and those in- cluded in anticipation of their introduction and/or success in cultivation. 4 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 of northeastern North America west to the western boundaries of Minne- sota, Iowa, and Missouri, and south to the southern boundaries of Mis- souri, Kentucky, and Virginia. In Canada, the western boundary will be a hypothetical line extending northward to the Arctic Ocean from the northwestern corner of Minnesota. Although this area is arbitrary and artificial, it has been defined for the following reasons. The majority of North American botanical gardens and arboreta in the Temperate Zone are located within this area. Secondly, the greatest representation of culti- vated woody plants in the Arnold Arboretum herbarium is from the same region. Additionally, it will be feasible for us to visit major living col- lections within this area, and if new species of woody plants are in culti- vation in temperate North America, it is expected that the majority will occur here. Two problems, one of major concern to horticulturists and the second of interest and concern to both horticulturists and taxonomists, center around the potential range of species in cultivation and the treatment and concept of cultivar and ranks below the level of species. Both of these multifarious problems have received considerable attention and thought in the planning of the new manual and deserve mention here. Plant hardiness is the factor most often considered in discussions of the potential range of cultivated woody species, and the information usu- ally sought is the northern limit at which a particular species will tolerate the severity of winter climate. But when one considers northern species in cultivation, the question must also be asked from the reverse position, i.e., how far south will a northern species tolerate the changing, more southern environmental conditions. Additionally, a northern species grown primarily for its flowers may survive a southern Virginia winter, but the more south- ern climate and photoperiod may affect adversely or eliminate its ability to bloom and, therefore, also affect its ornamental value. The same circum- stances In reverse may prove true for a southern species at more northern latitudes. Only the repeated efforts of trial and error will determine with accuracy the possible ranges of species in cultivation, and the range of a particular species may require modification through the discovery of physiological and ecological variation within that species. As a consequence of such variation, nursery stock originating from seed collected from plants native to the Virginia Coastal Plain may not prove hardy in Boston, while plants of the same species grown from seed collected in the Mississippi Embayment peste Leet might flourish in the Arnold Arboretum. ith problems such as in mind, i : : clusion of zonal ae see : = non avian we . rf sable a LE yee e aa until publi- data will temporarily limit the usa a th a are — iw hoped thae ities oda’ dub can . oO e published treatments, it ° e accumulated and tabulated from scr janis offerings, and personal and communicated observations e final zonal designations in the manual will be more accurate 1975] SPONGBERG, LAURACEAE 5 and dependable than if given provisionally now. It is also intended that a notation will be developed to include information for at least some spe- cies on “reverse hardiness” as well as “useful range.” In our initial work towards these goals the Plant Hardiness Zone Map prepared by the United States Department of Agriculture (Miscellaneous Publ. No. 814. 1965) is being used for zonal designations. By allowing for more exacting designations due to zone subdivisions, this map has an advan- tage over previously published hardiness zone maps. The primary intent of this work is to provide modern taxonomic treat- ments in manual form that will facilitate the determination of the botanical entities and provide the correct names of the genera and species of ligneous plants cultivated within our area. Thus, the treatment of cultivars is not a primary concern. Moreover, it would be impossible within the scope of the work presently envisioned to treat all of the cultivars now being grown. Such a work would necessarily be encyclopedic in length, and its value questionable, inasmuch as new cultivars, many of which replace and eclipse the popularity of other cultivars, are constantly being named and introduced. Being without rank, cultivars may be selected from within a botanical taxon at any infraspecific rank, may comprise the entire ranked category, may cut across botanical categories of the same or a different rank, or may even cut across the limits of biological species, i.e., they may include elements of two distinct gene pools. When it can be ‘determined that a named cultivar is coextensive with an accepted botanical taxon, or that a taxon as it is known in cultivation is represented primarily by a particu- lar cultivar, we will attempt to list the correct alternative cultivar name. For some groups we will endeavor to indicate the characters that dis- tinguish widely grown cultivars, and whenever known, published com- pilations of cultivars will be included under generic references. In many instances horticulturally significant variations have been rec- ognized in a botanical context, usually at the rank of forma. In those instances where evidence suggests that the plants comprising these cate- gories are not worthy of taxonomic recognition, a cultivar name may be desirable so that the particular variants can be referred to in a horticul- tural context. In this respect, our concern with cultivars is primarily restricted, except as outlined above, to accounting for variants recognized by botanical combinations in Rehder’s Bibliography but no longer con- sidered worthy of taxonomic recognition. We have decided that in our treatments infraspecific taxa that are of dubious taxonomic status will be handled in a special manner. The correct botanical name will be given in a distinctive type face (SMALL CAPITALS), the presumed distinguishing characters will be stated, and the alternative cultivar name will be listed if one has been designated previously. The choice of name, either botanical or cultivar, is open and dependent upon the context in which the reader is working. If a cultivar name has not been proposed for the dubious tax- on, we will not designate one, If in the future there is need for a cultivar name, we hope that one will be given in accordance with the then cur- 6 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 rent provisions of the International Code of Nomenclature of Cultivated Plants. ACKNOWLEDGMENTS The entire professional staff of the Arnold Arboretum is due thanks for freely given time and knowledgeable suggestions during the initial planning of the manual project. The responsibility for the final decisions based on the variety of opinions and diversity of viewpoints expressed during these discussions, however, is mine. For their continued help, ad- vice, interest, and encouragement in the project, special thanks are extend- ed to Drs. R. A. Howard, B. G. Schubert, C. E. Wood, Jr., and R. E. Weaver, J and Mr. R. S. ‘Hebb and Miss M. Gilmore. I am also indebted to Dr. E. A. Shaw, with whom I have had several constructive discussions concerning cultivars, and to Miss K. Clagett for editorial assistance. Special thanks and gratitude are also extended to an anonymous donor whose generous gift to the Arnold Arboretum for this project has made and continues to make this work possible. LAURACEAE A. L. de Jussieu, Gen. Pl. 80. 1789, nom. cons. (LAUREL FAMILY) Evergreen or deciduous trees or shrubs, the leaves, bark, and wood usually containing aromatic oils. Leaves exstipulate, simple, mostly al- ternate, entire, unlobed or occasionally lobed; venation pinnate or 3- veined from the base. Inflorescences usually axillary, cymose, racemose, or reduced and umbelliform, sometimes subtended by a deciduous in- volucre. Flowers small, perfect or imperfect (and the plants dioecious or rarely polygamodioecious). Perianth of (4 or) 6 yellowish or greenish tepals in 2 similar whorls, the tepals free nearly to the base, forming a Very. shallow perianth tube below. Stamens in 4 whorls of 3 stamens each, inserted on the rim of the perianth tube, 1 or more whorls often absent . reduced to staminodia; functional stamens of the third whorl usually associated with stalked or sessile glands; anthers 2- or 4-locular, introrsely to extrorsely dehiscent by valvular flaps. Ovary superior or + adnate to the perianth tube, 1-locular, with a single pendulous, anatropous ovule; style and stigma 1. Fruit a fleshy or rarely dry, usually indehiscent, 1- seeded drupe, the perianth tube (if persistent) and the pedicel often thickened to form a cupule beneath the drupe; seeds lacking endosperm, the straight embryo with large, fleshy cotyledons. Type Genus: Laurus L. Between 2,000 and 2,500 species in 30 to 40 genera, primarily of tropical and warm-temperate regions, particularly of Central and South America and eastern Asia. Several species of this family are the sources of well- known spices and herbs. Notable among those not mentioned below is 1975] SPONGBERG, LAURACEAE i the cinnamon of commerce, the dried bark of Cinnamomum zeylanicum Nees and/or C. cassia Blume. REFERENCES: Hutcuinson, J. H. Lauraceae. Gen. Fl. Pls. 1: 125-243. 1964. KosTerMAns, A. J. G. H. Lauraceae. roca 4: 193-256. 1957. [Gen- eral review of all aspects of the fam . Bibliographia Lauracearum. xvi iia 450 pp. Bogor. 1964. [An alpha- betical listing of Lauraceous taxa with references to the literature in which they have been treated and cited. Liou, H. Lauracées de Chine et d’ Indochine: contribution a |’étude systéma- tique et phytogéographique. xii + 226 pp. Paris. 1934. [Originally pub- lished in 1932 as a thesis presented to the Faculty of Science, University of Paris. | Pax, F. Lauraceae. Nat. Pflanzenfam. III. 2: 106-126. 1891. ReEHDER, A. Man. Cult. Trees Shrubs. ed. 2. Pp. 257-260, 901. 1940. . Bibliogr. Cult. Trees Shrubs, pp. 187-189. 1949. Woop, C. E., Jr. The genera of woody Ranales in the southeastern United States. Jour. Arnold Arb. 39: 296-346. 1958. [Lauraceae, 326-346; in- cludes extensive bibliography as well as discussions of Persea, Lindera, and Sassafras. | Key To GENERA OF LAURACEAE IN CULTIVATION Inflorescence subtended and enclosed in bud by a deciduous involucre of bracts; flowers picks i pedunculate or subsessile (often appearing fascicu- late) umnbelliforns CIUIStCTS GHIA Vereen oth a ee aa aie ene 2. 2. Umbelliform flower pas distinctly pedunculate, the clusters subtended by an involucre of 5 or 6 caducous bracts; flowers perfect; s 4- Mie ee a a sian eg ee Re) ele es 1. Um bellularia. Umbelliform flower clusters subsessile (often appearing fasciculate) to distinctly pedunculate, the clusters subtended by an involucre of 4 ca- ducous bracts; flowers imperfect and the plants dioecious or occasionally polygamodioecious: SUreTe 2-0 hes et ee = & 3. Perianth of 4 bractlike tepals in 2 whor Is; staminate flowers with 12(—16) stamens, all associated with pairs of stipitate glands or rare- ly the outer 2 whorls eglandular. Oa cress) Paani ee . Laurus. 3. Perianth of 6 petaloid tepals in 2 whorls; staminate flowers with 9 stamens, the outer 2 whorls eglandular, the inner whorl associated girs oF stinitate PADS. <. 6.5 ied es : 3. Lindera. ; iio neither subtended nor enclosed in bud by : an - involucre of bracts; flowers sc in small racemes or pedunculate cymose or ae umbelliform ll bal siete oe wn 'e s 4. Plants deciduous; agua a small raceme; flowers imperfect and He plants dioecious ‘(or occasionally polygamodioecious); anthers 4-locular, Gebiscing thirorly. 2 a. See eee 4. Sassafras. Plants evergreen; inflorescence a pedunculate subumbel or cyme; flowers perfect; anthers 4-locular, the inner whorl dehiscing extrorsely, the outer MOE CRIA SIITOTIO oS 5 as 6 ice i es ek vist ee 5. Persea. — = _ > 8 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 1. Umbellularia (Nees) Nuttall, N. Am. Sylva 1: 87. 1842. Evergreen trees or shrubs with naked winter buds. Leaves strongly aromatic when bruised, short petiolate, alternate, involute in bud, pin- nately veined. Flowers perfect, 4-5 mm. long, arranged in pedunculate umbelliform clusters in the axils of upper leaves or appearing to be in short, bracteate, terminal, compound-racemose inflorescences; each flow- er cluster enclosed in bud by a caducous involucre of 5 or 6 bracts. Peri- anth of 6, pale yellow, bractlike tepals. Functional stamens 9, the inner 3 with stipitate orange glands on each side of the filaments at base, alter- nating with an inner whorl of 3 scalelike staminodia; anthers 4-locular, the inner 3 with extrorse dehiscence, the outer 6 dehiscing introrsely. Ovary subglobose, small, tapering into a slender style; stigma capitate. Fruits subglobose or ovoid purplish-brown drupes borne on slightly thick- ened pedicels. (Oreodaphne subg. Umbellularia Nees, Syst. Laurin. 462. 1836.) Type species: Tetranthera californica Hooker & Arnott = U. californica (Hooker & Arnott) Nuttall. (Name Latin, diminutive of um-- bella, a little umbel.) — CALIFORNIAN LAUREL, OREGON MYRTLE, PEPPER- WOOD. A monotypic genus native to the Pacific Coast of North America. REFERENCES: Hooker, W. J. Oreodaphne californica. Bot. Mag. 88: ¢. 5320. 1862. KAsAPLIcIL, B. Morphological and ontogenetic studies of Umbellularia califor- nica Nutt. and Laurus nobilis L. Univ. Calif. Publ. Bot. 25: 115-240. pls. 7-28. Si; SARGENT, C. S. Umbellularia californica. Silva N. Am. 7: 21, 22. pl. 306. 1905. STEIN, Ww. I. Silvical characteristics of California laurel (Umbellularia califor- ica). U. S. Forest Serv. Pacific NW Forest Range Exp. Sta. Silvical Ser. 2: 16 pp. ‘ Umbellularia (Nees) Nutt., California laurel. Pp. 835-839 in — : woody plants in the United States. viii + 883 pp. Agr. Handb. No. U.S.D.A. Washington, D.C. 1. U. californica (Hooker & Arnott) Nuttall, N. Am. Sylva 1: 87. 1842. Aromatic trees or shrubs of various habit to 45 m., the trees usually with a dense crown of erect, slender branches; bark greenish to reddish brown. Leaves oblong to oblong-lanceolate, 3- 8(— 10) cm. long, 1.5—3 cm. wide, with obtusely acuminate apices and cuneate to subrounded bases; surfaces of the blades finely reticulate, shining dark green above, paler green and dull beneath. Flower clusters 1.5-2 cm. in diameter, with 4-9 flowers; involucre of caducous bracts leaving conspicuous scars at the sum- mit of the peduncle. One, 2, or 3 subglobose or ovoid drupes developing per flower cluster, each drupe 2-2.5 cm. long, greenish, becoming brownish purple when mature. 2n = 24. Tetranthera ? californica Hooker & Arnott; Oreodaphne californica Nees.) 1975] SPONGBERG, LAURACEAE 9 Indigenous to the Pacific Coast of the United States from southwestern Oregon (Coos County) south to San Diego County, California, and oc- curring in both the Coast Ranges and the Sierra Nevada. Plants with the peduncles and lower surfaces of the leaves finely tomentulose have been recognized as var. fresnensis Eastwood (Leafl. West. Bot. 4: 166. 1945), while of the various growth forms, the trees with wide-spreading branches forming a crown broader than high and with slender pendulous branchlets have been designated as f. PENDULA Rehder (Jour. Arnold Arb. 1: 143. 1919), Often harvested and sold for flavoring in cooking as California bay leaf, the leaves of this species should not be confused with those of the true bay leaf, the foliage of Laurus nobilis. 2. Laurus Linnaeus, Sp. Pl. 1: 369. 1753; Gen. Pl. ed. 5. 173. 1754. Evergreen shrubs or small trees with glabrous or pubescent reddish- or purplish-brown branchlets. Leaves ovate or obovate to narrowly elliptic, alternate, with pinnate venation. Flowers imperfect and the plants dioecious; flowers small, 3-4 mm. long, short pedicellate in pedunculate umbelliform clusters, the clusters occurring singly, fascicled, or in race- mose inflorescences in the axils of leaves; each flower cluster subtended by an involucre of 4 deciduous bracts. Perianth of 4 yellowish, persistent. bractlike tepals in 2 whorls. Staminate flowers with 12 (rarely up to 16) stamens in 3 (or 4) whorls; filaments of all stamens associated with a pair of stipitate glands, or rarely the filaments of the first 2 whorls eglandular; anthers 2-locular, dehiscing introrsely. Carpellate flowers usually with 4 staminodia with sagittate filaments, often with small glands; ovary sub- globose with a short style. Drupes ovoid, black, borne on the persistent and slightly enlarged perianth tube and pedicel. Lectotype species: L. nobilis L.; typified by the removal of the other species attributed to Laurus by Linnaeus and their placement in other genera of Lauraceae. (Name an ancient one applied to the Laurel.) —- LAUREL, SWEET BAY. Two closely related species, Laurus azorica (Seub.) J. Franco (L. cana- riensis Webb & Berth.), 2n = 36, of the Canary Islands and the Azores, and L. nobilis L. of the Mediterranean region, which is occasionally culti- vated in our area. REFERENCES: Fercuson, D. K. On the taxonomy of recent and ap sare of Laurus (Lau- ra aceae). Bot. Jour. Linn. Soc. 68: 51-72. pls. GracosBE, A. Ricerche hos a x ecloih sul toe nobilis L. Arch. Bot. Forli 15: 33-82. pls. 1, Giacomini, V., & A. ZANIBONI. Osserazion sulla variabilita del — nobilis L. nel bacino del Lago di Garda. Arch. Bot. Forli 22: 1-16 KasaPLiciIL, B. Morphological and crucial: studies of iesbdlalatee cali- fornica Nutt. and Laurus nobilis L. Univ. Calif. Publ. Bot. 25: 115-240. pls. 7-28. 1951. MarkcrafF, f Lauraceae. Jn: G. Hect, Illus. Fl. Mittel-Europa. ed. 2. 4(1): 12-15. 10 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 1. L. nobilis Linnaeus, Sp. Pl. 1: 369. 1753. Evergreen shrubs or trees to 10 or rarely 20 m. with resinous winter buds, glabrous reddish-brown branchlets, and smooth brown or black bark. Petioles short, 3-6 mm. long, narrowly winged; leaf blades coria- ceous, ovate to obovate or elliptic, (3—)5—-10(—12) cm. long, (1.5—)2—4 cm. wide, with entire margins, acute to obtuse apices, and cuneate bases; both surfaces of the blades glabrous and finely reticulate, grayish green and shining above, pale and with the midvein elevated beneath. Flowers borne on finely pubescent pedicels in umbelliform cymose clusters, the clusters distinctly pedunculate, 1 to several in the axils of leaves or leaf scars. Drupes black and shining, ovoid to ellipsoid, 1-1.5 cm. long. 2” = 42.— GRECIAN LAUREL, SWEET BAY Native to and characteristic of the Mediterranean region from Asia Minor west to Spain and Portugal. Cultivated since ancient times, this species is the laurel of mythology, history, and poetry and the source of bay leaf commonly used in cooking for flavoring. Easily trimmed into various shapes, the pruned plants are often grown in tubs for formal orna- mental purposes. Aside from the typical form, f. angustifolia (Nees) Markgraf (in Hegi, Illus. Fl. Mittel-Europa ed. 2. 4(1): 15. 1958) (= cv. Angustifolia; var. salicifolia Hort.), with very narrow lanceolate leaves only 6-20 mm. wide, and f. crispa (Nees) Markgraf (loc. cit., 1958) (= cv. Tindclela, var. undulata Meisner), with margins of leaf blades con- spicuously wavy, may be encountered in cultivation. 3. Lindera Thunberg, Nov. Gen. Pl. 64. 1783, nom. cons. Aromatic, deciduous or evergreen trees and shrubs, the leaves of de- ciduous species sometimes persistent over winter; buds absent or with few to numerous imbricated scales. Leaves petiolate, alternate to subopposite, unlobed with pinnate venation or 3-lobed and 3-veined from the base. Flowers imperfect and the plants dioecious or occasionally polygamodioe- cious; flowers small, yellow, short pedicellate in subsessile or short-pedun- culate umbelliform clusters above the axils of leaves or of leaf scars; each flower cluster subtended by 4 deciduous bracts. Perianth of 6 or rarely more tepals in 2 whorls. Staminate flowers with 9 stamens in 3 whorls, the 3 innermost stamens with pairs of conspicuous stalked glands at the base of the filaments; anthers 2-locular. Carpellate flowers with stamens variously developed; ovary globose, with a short style. Fruits borne on slightly or obviously thickened pedicels, fleshy and indehiscent or dry and irregularly dehiscent. (Benzoin Schaeffer; including Daphnidium Nees, Aperula Blume, and Parabenzoin Nakai.) TyPE species: L. umbel- lata Thunberg. (Name commemorating John Linder, 1676-1723, an early Swedish botanist.) A genus of about 100 species of temperate and tropical areas of eastern Asia and two species indigenous to the eastern United States. Lindera 1975] SPONGBERG, LAURACEAE 11 triloba (Sieb. & Zucc.) Blume and L. cercidifolia Hemsley, both listed by Rehder, have been deleted from the present treatment since no documen- tation for their cultivation in our area has been found. REFERENCES: ALLEN, C. K. Studies in the Lauraceae, III. Some critical and new species of Asiatic Lindera, with occasional notes on Litsea. Jour. Arnold Arb, 22: 1-31. 1941. BRINKMAN, K. A., & H. M. Purpps. Lindera benzoin (L.) Blume, spicebush. Pp. 503, 504 im Seeds of woody plants in the “yaa ris viii + 883 pp. Agr. Rie Nasu, G. V. Benzoin aestivale. Addisonia 5: 15, ne a 168. 1920. SCHROEDER, E. M. Dormancy in seeds of Benzoin aestivale L. Contr. Boyce Thompson Inst. 7: 411-419. 1935. STEYERMARK, J. A. Lindera melissaefolia. Rhodora 51: 153-162. pl. 1151. 1949. KEY TO THE SPECIES OF LINDERA IN CULTIVATION 1. Flowers appearing in spring before the leaves; plants deciduous, the leaves (or most of them) not persistent over winter. ....................... 2. Pedicels and abaxial surfaces of the subtending bracts densely silky pubescent; leaf blades unlobed or 3-lobed, 3-veined from the base; drupes BU A oy ce a kh tg ee ae Like obtusiloba. Pedicels and abaxial surfaces of the subtending bracts finely pubescent or glabrous; leaf blades unlobed with pinnate venation; drupes subglobose or ellipsoid, red, reddish brown, or rarely yellowish........ ...... ‘. 3. Flower clusters subsessile, not noticeably Reiaciate at ‘anthesis, usu- ally 4 clusters per node; drupes indehiscent, red, reddish brown, or OEE GUNN i ar hae ee SST we go phy DF ee AE 4, 4. Winter buds glabrous or + villous; pedicels of staminate flowers glabrous, pedicels of carpellate flowers 1-1.5 mm. long; drupes borne on slender pedicels 3—4 mm. long, not conspicuously en- larged at summit; mature drupes 8-10 mm. long. .. 2. L. benzoin. Winter buds villous: pedicels of staminate iyo finely pubescent, pedicels of Eg amr flowers 2.5 mm. long; drupes borne on stout tang Si) m. long, a eueaaiad mee at summit; ma- ure drupes rere 5 mm ot ee Pee Pep! . L. melissifolia. Paes clusters distinctly sintked on peduncles Py mm. long at an- thesis, usually 2 clusters per node; drupes dehiscent into 5 or 6 ir- regu lar segments, yellowish. SL ree ae oe ee _ L. praecox. 1. Flowers appearing in spring with the current season’s leaves, the persistent foliage of the previous season, or the plants evergreen 2 5. Plants deciduous, the leaves dropping in fall or persistent over winter; terminal buds glabrous, with 3 or 4 imbricated scales. .._. 6. 6. Leaves chartaceous, elliptic, ehampe rad or oblanceolate, not per- sistent over winter; flower clusters distinctly pedunculate and umbel- liform, the peduncles and/or pedicels densely silky pubescent. . 7. Branchlets yellowish brown with sessile winter buds; peduncles at anthesis 3-5 mm. long, glabrous; pedicels pubescent, in fruit 10- ~ ~ - 12 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 17 som. Jone: Cree WHR, kk os ieee a es 5. L. erythrocarpa.* Branchlets dark green with stipitate winter buds; peduncles at an- thesis 4-8 mm. long, pubescent; in fruit, the pubescent pedicels 15-22 mm. long; drupes black. ................ _ L. umbellata. 6. Leaves subcoriaceous, narrowly lanceolate to oblong, ere over winter, falling in spring; flower clusters subsessile, often appearing fasciculate in the axils of the persistent leaves; sparingly MII G20) Gee Foe Paes eens . L. angustifolia. 5. Plants evergreen; terminal buds large with 8-10 iy pubescent imbricated er Ronee ean ate Gul x ae NS . L. megaphylla. ~I 1. L. obtusiloba Blume, Mus. Bot. Lugd.-Bat. 1: 325. 1851. Shrubs or small, slender trees to ca. 10 m.; winter buds glabrous with 3 or 4 outer scales, the young branchlets pale yellowish green, often with conspicuous lenticels. Petioles pubescent, 1-2 cm. long; leaf blades 6-12 cm. long, 3-12 cm. wide, variable in shape, usually broadly ovate or subcor- date with acute apices or 1—3-lobed, the lateral lobes short and obtuse, bases broadly cuneate or subcordate and 3-veined from the base; blades dark green and glabrescent above, pale bluish green and silky pubescent beneath, at least along the veins. Flowers borne on densely silky-pubes- cent pedicels in subsessile, umbelliform clusters, several clusters together in the axils of leaf scars from the previous season’s leaves. Drupes black, subglobose, 7~8 mm. in diameter on pubescent pedicels ca. 1 cm. long. 2” = 24. (Benzoin obtusilobum (Blume) Kuntze; Lindera triloba Hort., non (Sieb. & Zucc.) Blume.) Native to eastern Asia in China, Japan, and Korea. 2. L. benzoin (L.) Blume, Mus. Bot. Lugd.-Bat. 1: 324. 1851. Bushy, many-branched aromatic shrubs to 4.5 m. with small, glabrous, vegetative buds and larger, subglobose floral buds; young branchlets gray- ish black. Leaves short petiolate, the blades erect or ascending, becoming clear yellow in fall, oblong to obovate, 7-12 cm. long, 2—3.5 cm. wide, with acute or short-acuminate apices and cuneate bases; upper surfaces light green, pale green beneath. Flowers in dense, subsessile or sessile clusters, the clusters of staminate flowers ca. 5 mm. in diameter, larger than the clusters of carpellate flowers, usually several eee above the scars of the previous season’s leaves; carpellate flower clusters often single or paired at the nodes. Drupes scarlet, elliptic-oblong, 8-10 mm. long, 5-7 mm. wide, on slender pedicels 3-4 mm. long, not conspicuously enlarged at the summit, deciduous. 2n = 24. {Lawns benzoin L.; Benzoin aesti- vale Nees.) — SPIcE BUSH. “Considerable taxonomic and nomenclatural confusion centers around Lindera erythrocarpa, L. umbellata, and other eastern Asiatic species of this group. Plants of the complex are variable, and the species are difficult to delimit; the gore adopted here is pergens that of J. Ohwi, Fl. Japan, English ed., F. G. Meyer & E. H. WALKER, eds. 196 1975] SPONGBERG, LAURACEAE 13 Widespread in eastern North America from Maine to southern Michi- gan and Illinois, southward to North Carolina, Kentucky, Missouri, and Kansas. Plants with finely pubescent branchlets, petioles, lower leaf sur- faces (pubescent at least along the veins), and ciliate leaf margins have been recognized as var. pubescens (Palmer & Steyerm.) Rehder (Jour. Arnold Arb. 20: 412. 1939) (Benzoin aestivale var. pubescens Palmer & Steyerm.). More southern in distribution, var. pubescens extends into Florida and Texas. Lindera benzoin {. xanthocarpa (G. S. Torrey) Rehder (Jour. Arnold Arb. 20: 413. 1939) (Benzoin aestivale {. xanthocarpa G. S. Torrey), with yellow rather than red drupes, is known from wild popu- lations in Massachusetts and is occasionally cultivated. 3. L. melissifolia (Walter) Blume, Mus. Bot. Lugd.-Bat. 1: 324. 1851. Low deciduous shrubs to ca. 2 m., similar to the preceding but with vil- Jous winter buds and reddish brown branchlets. Petioles short, finely pubescent; leaf blades drooping, chartaceous, narrowly oblong, broadly lanceolate, or ovate, 5-15 cm. long, 1.5—6 cm. wide, with acute to acumi- nate apices, finely ciliate margins, and broadly cuneate, rounded, or obtuse bases; blades green, smooth and glabrous above, finely reticulate and pu- bescent, particularly along the elevated midvein, beneath. Flowers in dense, subsessile clusters, usually several clusters together above the leaf scars of the previous season’s leaves. Mature drupes red, elliptic-oblong, 10-11.5 mm. long, 7-8 mm. wide, borne on pedicels 9-12 mm. long, the pedicels conspicuously enlarged at the summit and persistent. (Laurus melissaefolia Walter.) One of the rarest native North American shrubs, known from a few scattered localities from Florida to Louisiana and northward to eastern North Carolina, Arkansas, and southern Missouri; known in cultivation at the Henry Foundation for Botanical Research, Gladwyne, Pennsylvania. See Steyermark (1949) for a valuable discussion and comparison of this species and its close ally, L. benzoin. 4. L. praecox (Siebold & Zuccarini) Blume, Mus. Bot. Lugd.-Bat. 1: 324. 1851. Deciduous shrubs or small trees of bushy habit to 8 m.; vegetative buds small, conical, with 3 or 4 scales, floral buds globose; branchlets dark brown or silvery brown with conspicuous white lenticels when young. Leaves chartaceous, with petioles 1-2 cm. long; leaf blades elliptic, ovate, or broadly ovate, 4-9 cm. long, 2—5 cm. wide, with acute apices and broadly cuneate to subrounded bases; blades green above, glaucescent, often with soft hairs along the veins beneath. Flowers borne on short finely pubescent pedicels in small umbelliform clusters, the clusters on peduncles 3-5 mm. long, 2 or 3 clusters per node. Fruits dry, subglobose, 1.5—2 cm. in di- ameter, yellowish or yellowish brown, borne on thickened pedicels ca. 1 cm. long and dehiscing into 5 or 6 irregular segments to expose the single 14 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 = 24. (Benzoin praecox Sieb. & Zucc.; Parabenzoin praecox (Sieb. & Zucc.) Nakai.) Indigenous to Japan where it is relatively common in mountainous re- gions. Along with a few other Asiatic species of Lindera, L. praecox has been segregated into the genus Parabenzoin by Nakai because of its dry fruits that dehisce into five or six irregular segments. Carpellate plants are rarely encountered in cultivation, probably because their flower clusters are smaller and less showy than those of staminate plants. 5. L. erythrocarpa Makino, Bot. Mag. Tokyo 11: 219. 1897. Large deciduous shrubs to ca. 6 m. (?) with yellowish brown branch- lets and sessile winter buds. Petioles 6-10 mm. long; leaf blades charta- ceous, oblanceolate to oblong, 6-13 cm. long, 1.5—2.5 cm. wide, with acute or + obtuse apices and cuneate bases; upper surfaces of the blades gla- brous, dark green, the lower surfaces glaucescent with sparse deciduous pubescence. Flowers borne on pubescent pedicels in pedunculate, umbelli- form clusters, the glabrous peduncles 3—5 mm. long. Drupes red, globose, 5—6 mm. in diameter, on pedicels 10-12 mm. long. Native to China, Korea, and Japan; reported in cultivation at Long- wood Gardens. 6. L. umbellata Thunberg, Nov. Gen. Pl. 64. tab. 1783. Erect deciduous shrubs or small trees to ca. 3 m. with dark green branch- lets and short stipitate winter buds. Leaves thinly chartaceous with slender petioles 10-15 mm. long; blades narrowly oblong to ovate-oblong, 5-9 cm. long, 1.5-3.5 cm. wide, with acute apices and cuneate bases; blades glabrous above, the lower surfaces whitish pubescent when young, becoming glabrous. Flowers borne on pubescent pedicels in pedunculate umbelliform clusters, the pubescent peduncles 4-8 mm. long. Drupes black, globose, ca. 6 mm. in diameter, on pedicels 15-22 mm. long. (In- cluding L. umbellata var. hypoplauce (Maxim.) Makino; L. hypoglauca Maxim.) Native to China and Japan. 7. L. angustifolia Cheng in C. P’ei, Contr. Biol. Lab. Sci. Soc. China, Bot. Ser. 8: 294. fig. 21. 1933. Deciduous shrubs to ca. 3 m. (?) with small conical vegetative buds and larger, subglobose floral buds; young branchlets reddish brown or reddish green. Leaves short petiolate, subcoriaceous, oblong to narrowly lanceolate, 5-10 cm. long, 1—2.5 cm. wide, with acute apices and cuneate bases; blades dark shining green above, pale green and glaucous below, turning pastel shades of orange and pink in fall; leaves persistent over winter and deciduous after anthesis in spring. Flowers on distinct, sparse- 1975] SPONGBERG, LAURACEAE 15 ly pubescent pedicels in subsessile umbelliform clusters, several clusters together in the axils of the persistent leaves. Drupes black at maturity, globose, 5-6 mm. in diameter, borne on persistent pedicels, 1—1.5 cm. long, terminated by small discs or cupules, the drupes often appearing fascicu- late on the branchlets. Native to Central China. This species, not previously recorded as culti- vated in our area, has promise as an ornamental plant, particularly since its foliage turns attractive pastel shades of pink and orange in fall and persists on the shrubs over winter. Specimens of this species (some mis- identified as Lindera umbellata var. hypoglauca, others unidentified) have been examined from the Barnes Arboretum, the Garden Center of Greater Cleveland, and the Cole Nursery Company, Inc.; it is apparently also grown at the Holden Arboretum. 8. L. megaphylla Hemsley, Jour. Linn. Soc. Bot. 26: 389. 1891. Evergreen shrubs or small trees to 20 m.; branchlets purplish brown or purplish black with scattered white lenticels and large terminal buds 1-2 cm. long with numerous, finely white-pubescent, imbricated scales. Petioles 1-2.5 cm. long; leaf blades coriaceous, oblong to oblanceolate, 6-20 cm. long, (1.5—)2.5-6 cm. wide, with acuminate apices and cuneate bases; upper surfaces dark green and lustrous, the midveins prominently ele- vated on the dull green, glaucous, and glabrous or finely pubescent lower surfaces. Flowers borne on densely silky-pubescent pedicels in pedunculate umbelliform clusters above the axils of the leaves or leaf scars. Drupes black, globose to ovoid, ca. 1.5 cm. long, on stout pedicels ca. 1 cm. long; the pedicels terminated by discs ca. 8 mm. in diameter. (Benzoin grandi- folium Rehder.) Native to Taiwan, southern and southwestern China. 4. Sassafras T. F. L. Nees & Ebermaier, Handb. Med.-Pharm. Bot. 2: 418. 1831. Dioecious deciduous trees with thick, furrowed bark; winter buds with several imbricated scales. Leaves petiolate, involute in bud; leaf blades ovate to elliptic in outline, unlobed or 1—3(—5)-lobed at apex, with a prominent midvein and 2 prominent lateral veins from near the base. Flowers appearing before the leaves and/or as the leaves expand in spring, imperfect (or occasionally appearing perfect, but functionally imperfect), arranged in lax, drooping, several-flowered racemes in the axils of the scales of terminal buds. Perianth yellowish green, 6-parted nearly to base. Staminate flowers with 9 stamens in 3 whorls, each stamen of the inner whorl with a pair of stalked glands at the base of the filament; anthers 4-locular (2-locular in one species not in cultivation) with introrse de- hiscence; staminodia and pistillodia variously present or absent. Carpel- 16 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 late flowers with a rudimentary androecium of 6 stamens or 9 stamens and 3 staminodia; ovary ovoid, the slender style terminated by a slightly ex- panded stigma. Fruit an ovoid, dark blue drupe borne on the club-shaped, enlarged, fleshy pedicel and perianth base. (Including Pseudosassafras Lecomte.) Type species: Laurus sassafras L. = S. albidum (Nuttall) Nees. (Name apparently a vernacular one used by early European set- tlers in Florida and later adopted by Trew.) — SASSAFRAS. Three species, of which two, Sassafras tzuma Hemsley of China and S. randaiense Rehder of Taiwan, are not known in cultivation, while the third, S. albidum, is widely distributed and sometimes cultivated in the eastern United States and southern Canada. REFERENCES: Bonner, F. T., & L. C. MAISENHELDER. Sassafras albidum (Nutt.) Nees, sas- safras. Pp. 761, 762 in Seeds of woody plants in the United States. villi + 883 pp. Agr. Handb. No. 450. U.S.D.A. Washington, D.C. 1974 FERNALD, M. L. Nuttall’s white sassafras. Rhodora 15: 14-18. 1913. . The nomenclature of Sassafras. Ibid. 38: 178, 179. 1936 Kenc, H. A taxonomic or of Sassafras (Lauraceae). Quart. Jour. Tai- wan Mus. 6: 78-85. REHDER, A. The American a Asiatic species of Sassafras. Jour. Arnold Arb. 1: 242-245. 19 SARGENT, C. S. os Silva N. Am. 7: 13-18. pls. 304, 305. 1905. 1. S. albidum (Nuttall) C. G. Nees, Syst. Laurin. 490. 1836. Trees to 20 m. or rarely to 38 m., often suckering from the roots and forming colonies; branchlets and buds glabrous and glaucous, the bark on young branchlets green or brownish; leaves and bark aromatic. Petioles 1.5-3 cm. long; leaf blades ovate to elliptic, 8-12(—18) cm. long, 2-8 cm. wide, cuneate at base, unlobed or usually 1-3-(rarely 4- or 5-)lobed, characteristically mitten-shaped, the lobes subacute or obtuse; upper sur- faces bright green, glabrous and glaucous beneath; foliage becoming bright orange or yellowish in fall; leaf scars with a single, linelike bundle scar. Flowers in small racemes 3—5 cm. long; staminate flowers with 9 stamens, the anthers 2-locular; staminodia and pistillodia absent; carpel- late flowers with 6 rudimentary stamens in 2 whorls. Drupes ovoid, ca. 1 cm. long, borne on bright red fleshy pedicels. 2n = 48. (Sassafras of- ficinale Nees & Eberm. var. albidum Blake. ) Widespread in eastern North America from southern Maine and south- ern Ontario to Iowa and southward to Florida and Texas. Plants with finely pubescent or puberulent branchlets and the mature leaves silky pubescent beneath have been recognized as var. molle Fernald (Rhodora 38: 179. 1936) (Sassafras officinale Nees & Eberm.; S. variifolium (Salisb.) Kuntze). This variety is generally of more southern distribu- 1975] SPONGBERG, LAURACEAE 17 tion than var. albidum. Recently, f. moldenkei Oswald (Phytologia 7: 321. 1961) (plants with leaves pubescent beneath and the branchlets bright red purple instead of green or brownish) has been described from Long Island, and if introduced into cultivation may become valuable as an ornamental. It should be noted, however, that S. albidum is a very difficult species to transplant. Filé, a powder prepared from the dried, young, mucilaginous leaves and pith, sometimes mixed with thyme, is used to thicken gumbo and as a condiment in the southern United States. Sassafras tea is brewed using the bark of the roots, while an oil used to flavor carbonated beverages (root beer) is obtained from the roots and bar 5. Persea Miller, Gard. Dict. Abr. ed. 4. 1754, nom. cons. Evergreen trees and shrubs with naked buds. Leaves petiolate, revolute in bud, chartaceous to coriaceous, pinnately veined, and usually pubescent. Flowers perfect, arranged in pedunculate, cymose or subumbelliform in- florescences in the axils of leaves. Perianth lobes 6, nearly free to the base, hairy, persistent in fruit. Androecium of 9 functional stamens and 3 inner staminodia, the first 2 whorls of functional anthers with introrse dehiscence, the third whorl with extrorse dehiscence; anthers 4-locular; filaments with paired stalked or basally sessile glands. Ovary subglobose, the style slender and often pubescent. Drupes baccate, small and sub- globose or globose or large and ellipsoid, sometimes fleshy, borne on the spreading, persistent perianth lobes. (Borbonia Miller; Tamala Raf.) TYPE species: P. americana Miller. (Name an ancient one used by Theo- phrastus for an oriental tree and later adopted by Linnaeus.) — SWEET BAY, Approximately 150 species primarily of tropical America but extending southward to Chile and northward to Delaware and Arkansas; one species in the Canary Islands. As accepted here, two species are infrequently cultivated in our area, while outside our region additional species are na- tive to the southeastern United States, and Persea americana Miller, the American avocado, and its var. drymifolia (Schlecht. & Cham.) Blake, the Mexican avocado, are cultivated in warmer regions of the United States and often grown as house plants. REFERENCES: FERNALD, M. L. Botanical specialties of the Seward Forest and adjacent areas of southeastern Virginia. Rhodora 47: 93-142, 149-182, 191-204. 1945. [Discussion of Persea borbonia and P. palustris, 149-151.] Kopp, L. E. A taxonomic peba of the genus Persea in the Western Hemis- phere (Perseae — Lauraceae). Mem. N. Y. Bot. Gard. 14(1): 1-117. 1966. SARGENT, C. S. Persea Borboaie and Persea pubescens. Silva N. Am. 7: 4-8. pls. 301, 302. 1905. 18 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Worrorp, B. E. A biosystematic study of the genus Persea (Lauraceae) in the southeastern United States. Diss. Abstr. 34(11): 5354-B. 1974. [Ph.D. dissertation, University of Tennessee. 1973. ] : systematic significance of flavonoids in Persea of the southeas- tern United States. Biochem. Syst. Ecol. 2: 89-91. 1974 KEY TO THE SPECIES OF PERSEA IN CULTIVATION 1. Peduncles shorter than the petioles of the mise subtending the inflorescences ; pubescence of branchlets and leaves appressed... ...... 1. P. borbonia. 1. Peduncles longer than the petioles of the ee subtending the Saar onines pubescence of branchlets and leaves crisped and erect. ...... . P. palustris. 1. P. borbonia (L.) Sprengel, Syst. 2: 268. 1825. Shrubs or small trees to ca. 12 m. with thick, deeply furrowed, aromatic bark; branchlets reddish brown with angular tips and sparse to dense ap- pressed pubescence. Petioles 1-3 cm. long, the leaf blades coriaceous, el- liptic to lanceolate, 4—-10(—13) cm. long, 1-4(—6.5) cm. wide, with acute to rounded apices, remotely revolute margins, and cuneate bases; both surfaces thinly pilose when young, bright green, lustrous, and becoming glabrous above, pale green, often appearing glabrous but sparsely ap- pressed pubescent with coppery-brown hairs, primarily along the veins, below. Flowers inconspicuous, 3-3.5 mm. long, in pedunculate, several- flowered cymes, the peduncles slender, 0.8-2.5 cm. long, shorter than the petiole of the subtending leaf. Drupes subglobose, 8-12 mm. in diameter, black, glaucous, borne on reddish pedicels. 2n = 24. (Excluding P. hu- milis Nash; including P. littoralis Small.) — RED BAY. Native to the Coastal Plain and Piedmont of the southeastern United States from North Carolina to Florida and westward into Texas. 2. P. palustris (Rafinesque) Sargent, Bot. Gaz. 67: 229. 1919. Shrubs or small trees to 15 m. with thin, fissured, gray bark; branchlets angular, reddish brown, densely to sparsely pubescent with crisped, erect, rusty-brown hairs. Petioles 0.8—2.5 cm. long, the leaf blades subcoriaceous to coriaceous, obovate, ovate, or lanceolate, (5—)6.5-18 cm. long, 1.5—5.5 cm. wide, with acute to slightly rounded apices, remotely revolute margins, and cuneate bases; upper surfaces glabrescent, lustrous green, lower sur- faces grayish white, finely pubescent with rusty-brown, crisped hairs, par- ticularly along the veins. Flowers small, 4.5-5 mm. long, in pedunculate, several-flowered cymes, the peduncles slender. 1-7.5 cm. long, usually longer than the petioles of the subtending legtee Drupes subglobose to ellipsoid, 7-8 mm. in diameter, black. 2n = 24. (P. borbonia {. pubescens (Pursh) Fern.; P. pubescens (Pursh) Sarg.; Laurus caroliniensis B pu- bescens Pursh: Tamala palustris Raf.) — SwEET BAY, RED BAY, SWAMP BAY. 1975] SPONGBERG, LAURACEAE 19 Native to the Coastal Plain from southeastern Virginia to southern Florida and west into Texas; also known from the Bahama Islands. ARNOLD ARBORETUM HARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 D AN JAMAICA PLAIN, MASSACHUSETTS 02130 20 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 SYSTEMATIC ANATOMY OF THE XYLEM AND COMMENTS ON THE RELATIONSHIPS OF FLACOURTIACEAE Recis B. MILLER SLEUMER (1954) HAS STATED that “. .. no single character exists wherewith to distinguish Flacourtiaceae from other families or to rec- ognize them in the field.” However, the combination of simple generally alternate leaves, numerous stamens, a unilocular ovary with parietal pla- centation, copious endosperm, and often a glandular receptacle unites this complex of genera into a loosely organized family. This loose or- ganization has resulted in a variety of taxonomic treatments. The wood anatomy of selected Flacourtiaceae has been studied previously, but a comprehensive investigation of the secondary xylem has never been under- taken. Therefore, in an effort to understand more completely the classifi- cation of the Flacourtiaceae, this anatomical study, focusing mainly upon tribal and generic relationships, was initiated. Hopefully it will lead to the definition of a more natural taxon. In addition, the validity of pre- viously proposed ordinal and familial alliances is examined to help clarify phylogenetic problems and evolutionary trends. Generic descriptions to- gether with an anatomical circumscription of the family presented in this work will be useful in the identification of unknown wood specimens, in the construction of keys, and in the classification of new taxa. TAXONOMIC HISTORY Early taxonomists, such as De Candolle (1824, 1825), Endlicher (1839), and Lindley (1853), treated many of the tribes of the modern Flacour- tiaceae as separate “orders,” which are equivalent to the modern rank of family. Gradually the genera of these families (orders) and other genera were united by taxonomists such as Clos (1855, 1857) and Ben- tham and Hooker (1862, 1867) until the all-inclusive Bixaceae of Baillon (1875) was erected. In 1894 Warburg proposed the segregation of the Bixa complex (i.e., those genera usually assigned to the modern concept of Bixaceae and Cochlospermaceae) from the rest of the flacourtiaceous genera. From Warburg to the present this segregation is generally fol- lowed. In 1925 Gilg revised Warburg’s Flacourtiaceae, suggesting the union of the tribe Erythrospermeae with the tribe Oncobeae and propos- ing the new tribe Trichostephaneae. In contemporary times three major phylogenetic systems have been proposed. Hutchinson (1967) saw the Flacourtiaceae as the largest and most dominant family in the Bixales, an order of only eight families. Some of Hutchinson’s proposed changes within the Flacourtiaceae in- clude the union of Gilg’s (1925) tribes Abatieae and Phyllobotryeae with 1975] MILLER, FLACOURTIACEAE 21 the tribes Casearieae and Scolopieae, respectively; the exclusion of Gilg’s tribe Trichostephaneae from the Flacourtiaceae; the removal of the tribe Paropsieae to the Passifloraceae; and the removal of the subtribe Prockiinae (tribe Scolopieae) to the Tiliaceae. Hutchinson saw the phy- letic position of the Flacourtiaceae as an intermediate group of plants be- tween orders Dilleniales and Tiliales. There seems to be little doubt that Hutchinson pictured the Flacourtiaceae (Bixales) not only as an intermediate group, but also as a primitive group giving rise to orders such as the Thymelaeales, Pittosporales, and Passiflorales. Cronquist (1968) and Takhtajan (1969) treated the Flacourtiaceae similarly. Takhtajan positioned the family at the base of his Violales, from which he derived the other families in the order. He proposed that members of the Violales were derived from dillenialean forebears and that they were closely related to the Theales. Takhtajan also derived order Passiflorales from the Flacourtiaceae through the Passifloraceae, the basal family of the former order. The tribe Paropsieae, included earlier by some botanists in the Flacourtiaceae, was transferred to the family Pas- sifloraceae. Cronquist also placed the Flacourtiaceae in order Violales; however, he did not consider the family to be a basal group as did Takhtajan. Cronquist believed that although the Flacourtiaceae was primitive in the order, other families in the Violales did not arise from it directly. In contrast to Takhtajan, Cronquist considered the Violales to be derived from order Theales. He circumscribed the Violales more broadly than Takhtajan and included 20 families to form a somewhat heterogeneous group. Nevertheless, Cronquist stated i these families still belong “to the same general givele of affinity. . ANATOMICAL REVIEW Several anatomical studies on segments of Flacourtiaceae have been directed toward clarifying relationships among the genera. In studying the Indonesian Flacourtiaceae Den Berger (1928) noted that the forma- tion of the segregate families Bixaceae and Samydaceae was not con- sistent with the wood anatomy. He also stated that Paropsia differs very strongly from the other genera of Flacourtiaceae, even at first glance. Other pertinent observations made by Den Berger suggest similarities between the Flacourtiaceae and certain Euphorbiaceae, the genus Siphono- don (Celastraceae), and the Elaeocarpaceae (Tiliaceae). He also main- tained that there is no special link between the Flacourtiaceae and Thea- ceae. Tupper (1934) concluded that the wood anatomy of Flacourtiaceae was “remarkably and strikingly constant and similar.” Taylor (1938) also suggested that the Flacourtiaceae formed a homogeneous unit. Like Den Berger, Taylor concluded that the tribe Paropsieae should be in- cluded in the Passifloraceae. In 1964 Ayensu and Stern studied the anatomy of the Passifloraceae and also concluded that the Paropsieae be- long in that family. 22 WARBURG Erythrospermeae GROUP I, 4 genera Pangieae Oncobeae GROUP I, 1 genus GROUP I, 1 Pat GROUP II, 1 gen GROUP II, hyo GROUP III, 4 ined GROUP III, 1 genus Paropsieae Abatieae Phyllobotryeae GROUP Itt Pa senso Paropsieae Abatieae Trichostephaneae Phyllobotryeae JOURNAL OF THE ARNOLD ARBORETUM [ VOL. peace Scolopieae GROUP I, 1 genus GROUP III, 1 genus GROUP VI, 5 genera on States Homalieae Flacourtieae GROUP VI, 3 genera GROUP VI, ee sacks Casearieae GROUP I, 1 genus GROUP V, 1 genus GROUP VI, 6 genera | Bembicieae Scolopieae GROUP I, 1 gen GROUP III, 1 i. GROUP VI, 5 genera Homalieae Flacourtieae GROUP II, 4 genera GROUP III, : genera GROUP V, enus GROUP VI, . genera GROUP VI, 3 genera Casearieae GROUP I, 1 genus GROUP V, 1 genus GROUP VI, 8 genera Bembicieae The phylogenetic ra rei of tribes of Flacourtiaceae as proposed th in FIGURE by Warburg (1894) and Gilg (19 each anatomical group is shown. 25). For each tribe e number of genera 1975] MILLER, FLACOURTIACEAE 23 According to James and Ingle (1956), Flacourtiaceae of the Southwest Pacific area can be divided into two distinct structural groups. One of the groups generally corresponds to Gilg’s Oncobeae and Pangieae, while the other corresponds to Gilg’s Scolopieae, Homalieae, Flacourtieae, and Casearieae. Major anatomical studies of families closely related to Flacourtiaceae include investigations of the Hypericaceae and Guttiferae by Vestal (1937), Dioncophyllaceae and Peridiscaceae by Metcalfe (1952, 1962), Bixaceae by Williams (1962), Cochlospermaceae by Keating (1968), and Violaceae by Taylor (1972). Many of these authors report some degree of relationship with Flacourtiaceae. Pertinent results of these studies will be discussed later. Other anatomical studies generally have included only rite anh : selected genera or are contained in general reference works. Thes clude studies by Record (1941), Record and Hess (1943), Melanin a Chalk (1950), Solereder (1908), Desch (1941), Reyes (1938), Bannan (1943), Miller (1966), and others. MATERIALS AND METHODS TABLE 1 lists the 241 wood specimens examined. These represent 153 species in 64 genera, approximately 61 per cent of the genera of Flacour- tiaceae. The scientific names that accompanied the wood specimens were generally used. Sources for name changes that resulted from synonymy are cited in TABLE Sectioning and staining techniques oi generally standard and have been described fully elsewhere (Miller 1973). Nomenclature and terminology generally conform to the recommenda- tions of the Committee on Nomenclature, International Association of Wood Anatomists (1957). Standard terms for size classification follow those of Chattaway (1932); the Committee on the Standardization of Terms of Cell Size, International Association of Wood Anatomists (1937, 1939); and Record and Chattaway (1939). Pore diameters were measured in the tangential direction, and the aver- age was based on 25 measurements. Only the larger pores were included. millimeter were determined by examining an area of “1, 2, 4, or 5 square millimeters, such that it [contained] about 50 to 100 vessels” (Rendle & Clark 1934). In this study, descriptions of radial multiples that exceeded 10 per cent of the total percentage of pores are referred to as “mostly” (e.g., radial multiples mostly 2 and 3). Descriptions of those radial multi- ples that are less than 10 per cent of the total percentage of pores are referred to as “occasionally” (e.g., occasionally to 5). Vessel-element lengths were measured from tip to tip. These and fiber (imperforate tracheary elements) lengths are based on 50 measurements. A ratio of the fiber length to vessel-element length (developed by Chatta- way, 1936) was computed for each specimen from the average. (This ra- 24 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 poeseeernarr-aaitoraetant sar * Pe ‘a a Figures 2-6: 2, radial section of Calantica cerasifolia showing prismatic crystals in upright ray cells; 3, same prismatic crystals under polarized light; , maceration showing the integuments left behind after acid to show vitreous silica; fringence of partially decomposed cells. 1975] MILLER, FLACOURTIACEAE 25 tio is hereinafter referred to as “fiber length to vessel length ratio,” F/V.) Chattaway’s ratio, which varies from 1.1 to 9.5 in woody dicots, theoretically shows the relative specialization of wood. The closer the value approaches 1.00, the less specialized the wood. This indicates that in primitive species, as a whole, there is little elongation of the cambial derivatives. The minimum and maximum size of intervascular and vessel- “ray pits is reported. Maximum size was determined by measuring the pits in the largest dimension. *Where the intervascular and vessel-ray pits are sim- ilar in size, the size classification for intervascular pits is given. Because of the long uniseriate extensions of the heterocellular rays and the vertical fusion of rays, total ray height varied considerably. Conse- quently, only the multiseriate portion was measured for 25 of the larger rays. The measurements of the 10 largest rays were then averaged. By this method an average ray height for each specimen is obtained which is more easily reproducible and more reliable for comparison and identifi- cation purposes than an average obtained by randomly measuring any size ray. The shape and size of ray cells of the multiseriate portion are of diagnostic value. The shape of these individual cells as observed on the radial surface was noted to be elongate, rectangular, or square. The height of individual cells from the multiseriate portion of rays was deter- mined from the tangential section by dividing the number of cells counted Over a given distance (at least 150 wm.) into that distance to give an average cell measurement. Only the minimum and maximum values for multiseriate ray-cell height are reported. The presence of prismatic or druse crystals, presumed to be a form of cal- cium oxalate (Al-Rais et al. 1971; Scurfield, Michell, and Silva 1973), was determined by observing the crystals with polarized light (Ficure 3). The cell types and the relative abundance in which crystals occurred were recorded for each specimen. In some cases crystals in the upright ray cells are in short chains of two to eight crystals (Ficures 2, 8, 22). This type of arrangement, in which two to eight crystals in an upright cell are separated from one another by a septum, is called “chambered.” An arrangement of two crystals in an upright cell is called two-cham- bered, three crystals three-chambered, and so forth. Specimens with prismatic crystals that were surrounded by a sheath or integument were also recorded. These integuments can be readily observed, since in macerated preparations the crystal decomposes, leaving the integument as a mold of the crystal (FicuRE 4). When no integuments were found in macerated material and yet crystals were observed in section, a radial free-hand section in which there were at least a few crystals was cut in order to verify the observation. Jeffrey’s macerating fluid was then drawn under the cover slip and the crystals were observed with and without polarized light. After 5 to 10 minutes, the crystals completely disappeared and the presence or absence of integuments was determined. When crystals were so infrequent that it could not be determined with TABLE 1. Wood specimens examined. — guiane mollis fii & Endl.) Tul nitida ‘Spruce ex Benth. regia Sandwith roigii P. Wils. vellozii Gardn. RIA fistulosa Mast. BARTHOLOMAEA sessiliflora = BENNETTIODENDRO leprosipes (C ay Merr. ipes ALANTIC cerasifolia Tul. ALONCOBA — (Stapf) Gilg brevite bee bre china (Oliv.) Gilg ec fagellifore ( Mildbr.) gilgiana (Sprague) Gilg LI. Williams 5321 P. Shank 124 LI. Williams 7031 LI. Williams 6986 Acosta- Solis 6934 H. S. Irwin 2121 Breteler 1404 Ortiz 109 SiBoeeca 3788 Koorders 2085 F. G. Meyer 9766 Carrington 508 Thouvenot 74 Cooper 89 Cooper 173 Cooper 331 Cooper 470 C. Vigne 2804 Cooper 122 Devred 1262 C. Vigne 2751 Peru Nicaragua Peru Peru Ecuador Cuba Brazil West Africa Guatemala Sumatra Java Chile COLLECTION HEr- SPECIES * COLLECTOR ” LOCALITY BARIUM ° XYLARIUM ° AHERNIA glandulosa Merr. CLPw Mus. Pl. 176 Philippines None ° SJRw‘ 2296 glandulosa R. Rosenblyth & Philippines US? CLPw 11674* F. Tamesis s.”. glandulosa Whitford 73w Philippines US? CLPw 12683* ANCISTROTHYRSUS tessmanii Harms A. Ducke 290 Brazil MAD * SJRw 33817 APHLOIA myrtiflora Galp. A. A. Pardy s.n. S. Rhodesia None USw 21257 — (Willd.) Benn. H. Browne 52-1897 East Africa None K- theiformi For. Dep. Mauritius None SJRw 15517 sbecneis For. Dep. Mauritius None SJRw 32941 ASTEROPEIA micraster Hallie CTFw 149 Madagascar None SJRw 29785 —— (Baker) Baill. R. Block 21 Madagascar None SJRw 10759 rho paloide CTFw 46 Madagascar None SJRw 33869 ZARA integrifolia R. & P. D. S. Bullock 70 Chile None USw 18895 microphylla Hook. f. M. Rothkugel & Argentina BAFC? SJRw 1768 H. Curran 597 serrata R. & P. F. G. Meyer 9635 Juan Fernandez US USw 34027 Is. serrata Chile None SJRw 34064 uruguayensis (Speg.) Sleum. W. Herter 1396d Uruguay MAD SJRw 34146 ANARA axilliflora Sleum. Krukoff 5175 Brazil F MADw 18988 guianensis Aubl. B. Maguire & Surinam NY MADw 11755 Stahel 22781 MADw 16421 SJRw 46910 MADw 23635 MADw 16424 MADw 23705 SJRw 26541 SJRw 53071 UW 9321 (i) USw 28357 SJRw 30093 USw 34057 TERVw’ 24319 MADw 25421 USw 4518 USw 4811 SJRw 15237 SJRw 15329 FHOw 8466 SJRw 13772 (k) FHOw 7935 92 WOLAYOdUY GIONUV AHL AO TVNUNOL 9$ “I0A] [S261 AVAQVILYNOOVTA ‘WATIIN TABLE 1. Wood specimens examined (continued). COLLECTION HEr- SPEcIEs * CoLLEcTor ” LOCALITY BARIU XYLARIUM “ pe CALONCOBA (con’d) glauca (P. Beauv.) Gilg Escherich 340 Cameroon B Bw glauca FHI 7718 Nigeria FHI? PRFw 23105 schweinfurthii Gilg Uganda For. Dep. Uganda ENT FHOw 8245 207; Herb. 1152 a schweinfurthit Gilg Uganda For. Dep. Uganda ENT FHOw 13889 pa 168; Herb. 11 ze ose (Oliv.) Gilg Sargos 827 ongo P? PRFw 15281 Z ee sch Zenker 783 Cameroon B? USw 31300 a AMPTOS 3 Calan (Oliv. ) Gilg Zenker 1637 Cameroon B? Bw 4 mannii (Oliv.) Gilg Dechamps 36; Congo BR TERVw ce} wood 522 ms mannii Zenker 2860 Cameroon B? Bw 5 CARPOTROCHE 2 brasiliensis Endl, Tatto 35 Brazil MAD SJRw 40639 = platyptera Pittier Cooper T. 11 Costa Rica MAD SJRw 10473 o platypter Cooper 377 Panama MAD SJRw 11970 > platyptera Terrill 187 Nicaragua MAD SJRw 12436 - CARRIEREA Ss) calycina Franch. Cheng 46 China ? BWCw 10731 — calycina Chow s.n. China None SJRw 42572 a CASEARIA | 2 DasyLepis (Sleumer 1972e) brevipedicellata Chipp C. Vigne 2750 Ghana K SJRw 23989 Dovyatis (Sleumer 1972b) na caffra (Hook. f. & Harv.) s Hook. f. Opdyke 589 Ohio (Cult.) None MADw 12235 r caffra Ferreira s.n. S. Africa None USw 20714 4 ELEUTHERANDRA S pes-cervi Sloot. For. Dep. of Indonesia L? SJRw 15445 a Java 3499 pes-cervi For. Dep. of Indonesia L? SJRw 15446 Java 4115 ERYTHROSPERMUM (Smith 1936 acuminatissimum (A. Gray) A.C. ae Gillespie 4667 Fiji BISH SJRw 25976 acuminatissim A. C. Smith 1470 Fiji MAD SJRw 28238 <4 candidum Sees. ) Bece. FPAw 20250 New Guinea L USw 24084 5 FLACOURTIA i cataphracta Roxb. ex od Willd. W. L. Stern & Dominica MAD USw 35472 ~ Wasshausen 2421 Lm indica (Burm. f.) Merr. A. J. Fors 310 Cuba SV? MAD 13915 Q indica Schlieben 5464; Tanzania M SJRw 13915 co wood 437 a indica Schlieben 5416; Tanzania MAD SJRw 33954 S wood 4 QO rukam Zoll. and Mor. Krukoff 306 Sumatra F USw 31377 A rukam Kanehira 352; Micronesia FU? SJRw 20339 = wood A1816 rukam Kanehira 1294; Micronesia FU? SJRw 26782 wood A2053 subintegra A. C. Smith A. C. Smith 1700 Fiji MAD SJRw 28328 subintegra A. C. Smith 1939 Fiji MAD SJRw 28426 age strep (Wilson 1930) _ (Griseb,) P. Wils. A. J. Fors 70 Cuba MAD MADw 13780 ‘- prae Rose 8 Venezuela US SJRw 2663 - longifolium Benth. pallidum A. C. Smith racemosum Jacq. racemosum racemosum smythei Hutch. & Dalz. smythei steno phyllum Merr. tomentosum (Vent.) Benth. Blake trichostemon Hypnocarpus (Sleumer gracilis (Sloot.) Sleum. gracilis heterophylla Blume kunstleri (King) Warb. kunstleri macrocarpus (Bedd.) Warb. pus macrocar Saigonensis Pierre sumatrana (Miq.) Koord. sumatrana venenata Gaertn. yatesii Merr. ESIA polycarpa Maxim. KEPw 1289: KEP 4734 RPPRw Tree No. 48 Cooper 324 Cooper 469 Sun Yat Sen U. 7 ee beg 834 Col. LL Pa a Krukoff 4164 For. Dep. of Koorders 1269a KEP 46109 Col. No. 2913 CLPw 433 Koorders 1253c Broadway s.n. Krukoff 4165 K. Ogata s.n. Malaya Cuba Puerto Rico Liberia Liberia China Burma Mexico Sumatra Indonesia Java Indonesia Malaya Sumatra Japan (Cult.) TABLE 1. Wood specimens examined (continued). COLLECTION HEr- SPECIES “* COLLECTOR ” LOCALITY BARIUM ° XYLARIUM ° GYNOCARDIA odorata R. Br. DD 39643 E. Pakistan DD DDw 6177 odorata G. Gillett 1866 Hawaii BISH MADw 25466 (Cult.) HASSELTIA floribunda H.B.K. nO 122 Panama US MADw 5747 floribunda Engles Nicaragua MAD SJRw 12427 cf. guatemalensis Warb. Little MAD MADw 10338 lateriflora Rusby Espina & Giacometto Colombia MAD SJRw 20891 A116 lateriflora Espina & Giacometto Colombia MAD SFRw 20924 A149 —— ig ) Eichl. Ll. Williams 588 Peru F MADw 15062 HECATOST Pita nici oe (H.B.K.) Sleum. LI. Williams 9943 Venezuela F MADw 23752 HoMALIUM foetidum (Roxb.) Benth. BZFw 6929 Java p SJRw 8182 grandiflorum Benth. For. Dep. of Indonesia L SJRw 22357 Java 3498 grandifiorum Benth. var. javanicum (Koord. & Valet.) Sleum Koorders 1131c Java BZF? SJRw 30985 guianensis (Aubl.) Warb. Stahel 372 Surinam MAD MADw 19878 hainanense Gagnep. McClure 18345; China LU? SJRw 26708 wood 11 letestui Pellegr. Cooper 229 Liberia MAD SJRw 15155 SJRw 28970 SJRw 28136 MADw 12297 MADw 14451 MADw 17485 SJRw 15231 SJRw 15328 SJRw 29563 SJRw 13178 MADw 9877 MADw 25423 SJRw 15442 SJRw 30098 SJRw 22353 SJRw 38716 SJRw 12705 SJRw 13111 SJRw 13182 MADw 22588 SJRw 30097 SJRw 10940 MAD 25422 TWTw 155 o¢ WOLAYOdUV GIONUV AHL AO TYWNUAOL 9S “I0A] AVAOVILANOOVTA ‘MATIIN [S61 Te TABLE 1. Wood specimens examined (continued). SPECIES * COLLECTOR ” IDESIA (con’d) polycarpa H. H. Hu 46 polycarpa Fan nape Inst. of Biol. 1 polycarpa Fan Mem Inst of IToa stapfit (Koord.) Sleum. Stap fii KIGGELARIA africana L. flavo-velutina Sleum. TIA apetala Jacq. apetala calophylla Eichl. cupulata Spruce ex Benth. micrantha A. Robyns micrantha procera (Poepp.) Eichl. procera Endl procera suaveolens (Poepp. & .) Benth. ternstroemioides Griseb. ternstroemioides thamnia L. LETHEDON (= Microsemma le-ratii (Guill.) Kosterm. setosa — T. White) stig LInDAC dentat Oliv.) Gilg dent. latifolia Benth. ooh Pr val ynensis pahads sa ( hog ) png paraensis Kuhlm Lunia (Sleumer 1972a) mauritiana Gmelin a ag Capuron & Sleu LUNANIA cubensis Turcz. cubensis parviflora Spruce ex Benth. parviflora MACROHASSELTIA & L. Wms.) L. Wms. macroterantha Biol. 3 Schram (B. hig 7779) For. Dep. o Java ye PFPw 5410 Schlieben 3528 (Type) ; wood 179 Capucho 466 LI. Williams 14194 Stern et al. 206 Stern et al. 513 Type) Stahel 124 Maguire 48294 Maguire 51753 LI. Williams 8035 Bucher 20 J. G. Jack 5878 Madera del Trop., Tree No. 49 McKee 4329 L. S. Smith 3368 Zenker 879 C. Vigne 2468 LI. Williams 14896 H. Pittier 5228 A. Ducke 190 Capuron SF 27114 M. G. Cours 2768 Bucher 132 Bucher 257 LI. Williams 1895 Krukoff 5275 Barbour 1016 Dayton 3125 COLLECTION LOCALITY China China China New Guinea Indonesia S. Africa Tanzania Brazil B Venezuela Panama Panama Surinam Brazil Brazil Peru Cuba Cuba Yucatan New Caledonia Australia Cameroon BARIUM ‘° PE? PE PE =] > XYLARIUM ° SJRw 21462 SJRw 21739 SJRw 21863 MADw 2569 SJRw 15447 SJRw 50377 SJRw 27529 MADw 23725 SJRw 21437 MADw 23669 MADw 23726 SJRw 54698 SJRw 54946 MADw 19646 MADw 20267 MADw 21447 MADw 16436 SJRw 14737 SJRw 16706 MADw 14988 FPAw 14222 FPAw 11038 SJRw 23251 MADw 23727 MADw 5778 MADw 12330 MADw 23677 SJRw 23652 (i) (i) SJRw 16841 SJRw 21428 MADw 15244 MADw 19018 MADw 10286 MADw 10305 cy WOLAXOdAVY GIONUV AHL AO IVNUNOL 9S “I0A] [S61 AVAOVILANOOV TA ‘WATTIIN TABLE 1. Wood specimens examined (continued). COLLECTION SPECIES * CoLLectTor ” LOCALITY AYNA amazonica (Mart.) Macbr. Krukoff 9001 Brazil echinata Spruce & Triana LI. Williams 4892 Peru grandifolia (Karst.) Warb. Dugand, 1014; Colombia wood 468 longicuspis (Standl.) Cooper & Slater Panama Stand. 234 (Type) longicus pis Cooper 638 Panama longifolia Poepp. & Endl. LI. Williams 2711 Peru odorata Aubl. Krukoff 4629 razil pacifica Cuatr. Cuatrecasas 16562 Colombia zuliana (Pittier) A. Robyns Stern e¢ al. 908 Panama NEOPTYCHOCARPUS (Buchheim 1959) apodanthus (Kuhlm.) uchheim A. Ducke 416 Brazil cctin hi Pires & Silva 11239 Brazil OLMEDI betacrion (Goepp. ) Loe Salas s.n. Guatemala ONCOBA spinosa Forsk. Schlieben 4133; Tanzania wood 236 OPHIOBOTRYS zenkeri Gilg Ghana For. Dep. Ghana 2056 OSMELIA grandistipulata Sloot. Indonesia grandistipulata grandistipulata i (Turcz.) Benth. lippina edule Reinw. edule PAROPSIA SS aecae 1970) braunii Gilg guineensis Oliv. madagascariensis ( Baill.) _ Perr. vareciformis (Griff.) Mast. ISCUS lucidus Benth. PIN EDA weberbaueri Irmscher For. Dep. of For. Dep. of Java 6190 For. Dep. of Java 5528 SiBoeeca 6752 Bartlett 7272 Krukoff 4003 CLPw 315 For. Dep. of Java 3315 Schlieben 5442; wood 429 Zenker 727 TEFw 716.R.182 KEP No. 32695 A. Ducke 113 Iltis & Ugent 539 Record & Kuylen H.43 Kew Gardens ican pee aS ee Indonesia Indonesia Sumatra Sumatra Sumatra Philippines Indonesia Tanzania Cameroon Madagascar alaya Brazil HEr- BARIUM ° MADw 9 MADw 10991 MADw 11004 MADw 11255 SJRw 9989 XYLARIUM 4 MADw 23681 MADw 16445 SJRw 33759 SJRw 10587 SJRw 12271 SJRw 17987 MADw 23685 MADw 23738 SJRw 55120 SJRw 44330 IANw SJRw 22081 RBHw 1671 SJRw 20025 SJRw 16046 SJRw 16047 SJRw 16048 USw 28880 USw 29390 SJRw 34299 MADw 18439 SJRw 15443 RBHw 1830 Bw USw 27402 PRFw 9008 SJRw 22573 MADw 193 MADw 9855 869 K-Jw ve WOLAYOdUV GIONYV AHL AO TVNUANOL “I0A | [SL6I AVAOVILANOOVTA “MATIIN TABLE 1. Wood specimens examined (continued). ScoLopia (Sleumer 1972c) luzonensis (Presl.) Warb. mundii (Nees) Warb. spinosa (Roxb.) Warb. spinosa spinosa spinosa spinosa thouvenotii H. Perrier zeyheri (Nees) Harve SCOTTELLIA (Sleumer 1972d) j Pierr laineana laine klaineana Pierre var. mimfiensis (Gilg) Pellegrin SOYAUXIA (Brenan 1953) grandifolia Gilg & Stapf STREPTOTHAMNUS moorei F. Muell. TETRATHYLACIUM johansenii Standl. macrophyllum Poepp. Bartlett 13492 PFPw 5414 SiBoeeca 4830 SiBoeeca 5077 PRFw 5050 Zenker 3018 PRFw 7193 Cooper 292 Cooper 369 Cooper 420 C. Vigne 2502 Cooper 233 Webb & Tracey 10267 Curran 329 LI. Williams 2713 W. H. Wetmore 9 CLPw 10065% Philippines . Africa Indonesia Indonesia Java Madagascar S. Africa Cameroon Australia Colombia Peru Philippines ilippines US? US? COLLECTION HEr- SPECIES * COLLECTOR ” LOCALITY BARIUM ° XYLARIUM ° PROCKIA crucis P. Br. ex L. Reitz & Klein 7559 Brazil WIS MADw 21831 crucis H. Pittier 11936 Venezuela MAD SJRw 8400 RAWSONL ulugurensis Sleum. Schlieben 3948 ; East Africa B Bw wood 221 Ryania (Monachino 1949) angustifolia (Turcz.) i Froes 12528 Brazil NY MADw 21104 angustifolia Krukoff 7643 Brazil F SJRw 34111 angustifolia Froes 15386 Brazil NY SJRw 40678 pyrifera (L. C. Rich.) Uitt. & Sleum. Krukoff 15402 Trinidad NY MADw 21105 speciosa Vahl var. chocoensis (Triana & Planch.) Monachino Cuatrecasas 15716 Colombia US MADw 17541 RYPAROSA javanica (Blume) Kurz ex ord. & Val. Koorders 30291B; Java BZF? SJRw 30100 wood 1339c kunstleri King For. Dep. of Indonesia L? SJRw 15444 Java 4167 kunstleri Krukoff 4155 Sumatra F SJRw 34374 dodecandra Jacq. G. S. Miller 1676 Puerto Rico US? USw 6101 macrantha P. Wils. J. G. Jack 5893 MAD SJRw 16707 SCAPHOCALYX Spathacea Ridl. Selvaraj s.n. Malaya KEP KEPw 11179 USw 29824 SJRw 50380 USw 28616 USw 28688 SJRw 22356 SJRw 22888 SJRw 30086 MADw 25424 USw 11945 Bw MADw 16827 SJRw 15204 SJRw 15261 SJRw 15284 SJRw 23261 USw 4843 (m) MADw 10684 MADw 16447 MADw 5270 SJRw 2298 9¢ WOLANOTUVY GIONUV AHL AO TYNuNOf gg “10A] [$261 AVAOVILANOOVTA ‘WATIIN TABLE 1. Wood specimens examined (continued). COLLECTION HEr- SPECIES * CoLLectTor ” LOCALITY BARIUM ‘ XYLARIUM ° TRIMERIA tropica Burkill Schlieben 5072; Tanzania MAD SJRw 2945 wood 345 TRIPHYOPHYLLUM (Shaw 1952) peltatum (Hutch. & Dalz.) Shaw Cooper 303 Liberia MAD SJRw 15213 XYLOSMA benthamii Griseb. LI. Williams 12509 Venezuela F MADw 23696 congestum Merr. Fan Mem. Inst. of China PE SJRw 20046 Biol. 283 flexuosa (H.B.K.) Hemsl. Madera del Trop., Yucatan F MADw 15706 Tree No. 58 flexuosa Record BH. 38 Br. Honduras MAD SJRw 8806 longifolium Clos Col. No. C3690 urma DD? SJRw 12530 nelsonii Merr. Kanehira 3630; Mariana Is. FU? SJRw 33238 wood A2259 panamensis Turcz. Cooper 548 Panama MAD MADw 23697 pilosum Macbr. LI. Williams 4977 Peru SJRw 18640 (Type) prunifolium Griseb. R. Espina 49 Colombia MAD SJRw 20498 prunifolium Dugand 233; Colombia MAD SJRw 22522 wood 70 salzmanni (Clos) Eichl. LI. Williams 4487 Peru F MADw 23744 salzmanni Hoehne 28203; Brazil MAD SJRw 23792 venosum N. E. Brown ZUELANIA guidonia (Sw.) Britt. & Millsp. guidonia guidonia “Names cited are those that initially accompanied the specimens, except for names based upon recent taxonomic re- f the genera. Authorities vd wood 47 Col. No. 59 H. Pittier 2710 Type LI]. Williams 8777 LI. Williams 9164 LI. Williams 8651 J. G. Jack 5659 Argentina visions. When there are appropriate generic monographs, author and date follow other synonymies are as follows: Blake (1919), Dale and Greenway (1961), ee (1967), Hutchinson and Dalzie (1954), Kao (1959), Kuhlmann (1928), Macbride (1941), Pellegrin Soe (1934, 1938, 1950, 1953, 1954), Williams (1961), and _— and Sillans > Usually refers to the collector and his number, but in * Abbreviations follow those recommended by Lanjouw a Stafleu (1964) i “ Abbreviations follow those recommended by Stern and Chambers ae and gia (1967) in the Index Xylariorum. * Refers to specimens collected without accompanying herbarium m Number refers to former Philippine Bureau of Forestry; abbreviate a B.F. * yer refers to the herba Forestry ( i } Unofficial abbreviation Specimen from herbarium sheet. of Musée Royal de Sr Centrale, Service d’Anatomie des Bois Tropicaux de la Section d'Economie Agricole et Forestiére at Tervuren, Be “Slide from . Sleumer at piksiarbarints, Leiden, Netherlands. Genus examined for Master’s Thesis (Miller 19 Baas and Dr. ™ Specimen obtained through Dr. S. arium maintained at the U. S. Forest Products Laborat , whi the pre-existent U. S. Forest Products Laboratory herbarium with the herbarium formerly at Yale University School of names (1968), Shultes (1945), ee SJRw 15015 MADw 5771 MADw 9882 MADw 9883 MADw 15688 SJRw 16644 me cases refers on the catalog number of an institution. n the Index Herbariorum. Record Memorial Wood niece forest cited as Yw and = at Yale Uni- aboratory, Madison, Wisc tory, Madison, Wisc., which combines L. Everist, Botanic Museum and Herbarium, Brisbane, Queensland, Australia. 8e WOLAYOdaV GIONAV AHL AO TVNUNOL are < S mS uL an AVAOVILMAOOVITA ‘MATIN [SL61 6¢ 40 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 certainty whether integuments were absent, the notation “no integu- ments observed” is applied. Silica deposits, which are chemically unconfirmed in situ, occur in the form of dark amorphous granules or glassy casts (vitreous silica). The granular type of silica was observed in maceration (Ficure 5). The vitreous silica was observed by treating dried macerated material with concentrated sulfuric acid. This process removes most cellulosic and lignin material, leaving the silica casts which appear as a glassy replica of the decomposed cell. Confusion between a silica cast and a partly de- composed cell may be dispelled by observation with polarized light. The silica cast is nonbirefringent, whereas the cellulose cell is birefringent (Ficure 6). Other deposits are not quantified or qualified and are only classified according to color and relative abundance. ANATOMICAL DESCRIPTIONS APPENDIX I lists the more important secondary xylem characters for each genus and may be used as a key to the woods of Flacourtiaceae. The genera in ApPpENDIx I and in the generic descriptions are arranged in ac- cordance with the scheme of Hutchinson (1967). The tribe Prockieae, which is in Hutchinson’s Tiliaceae, follows the tribe Casearieae. After the Prockieae, there is a group labeled “Anomalous Genera” which includes many taxa previously incorporated in Flacourtiaceae. FAMILY DESCRIPTION The secondary xylem of Flacourtiaceae is somewhat variable, yet some characters are common to most genera, The wood is diffuse porous with poorly defined to rarely distinct growth rings. Pores are generally rounded or circular in cross-sectional outline, but in Azara, Bennettio- dendron, Berberidopsis, Buchnerodendron, Camptostylus, Carpotroche, Erythrospermum, Hydnocarpus, Idesia, Mayna, Osmelia, Ryania, and Scaphocalyx the pores are angular. The overall average pore diameter (ie. the average of individual specimen averages) varies from 34 pm. in Neoptychocarpus to 212 ym. in Streptothamnus; however, pore diameters are mostly moderately small (50-100 um.). Generally pores are 50-80 per cent solitary. Berberidopsis and Streptothamnus have pores that are essentially 100 per cent solitary, Radial multiples consist mostly of two to four pores. Although the overall average number of pores per square millimeter varies from 6 in Pangium to over 100 in some species of Azara, in most genera the overall average number of pores per square millimeter 1s numerous to very numerous (20 to over 40) (Ficures 11, 12, 13). Vessel elements are usually ligulate and vessel walls are 1-8 pm. thick. The overall average length of vessel elements varies from 478 pm. in Poliothyrsis to 1794 pm. in Hydnocarpus. Spiral thickenings occur throughout the vessels in all species of Berberidopsis, Kiggelaria, Olme- diella, Poliothyrsis, and Carrierea (Ficure 18). Also, some species of Appendix I --Summary of anatomical features in Flacourtiaceae and other selected genera NOTE: peer she enclosed by parentheses are either rare for the genus or characteristic of only some species of the genus. Refer to generic descriptions re complete detail. LEGEND: End wall: Simp. = Exclusively simple perforation plat + = Character present Crystals: P = Prismatic Scal. = res lusively scalariform perforation “plates - = Character absent ee rekon S&S = Simple and scalariform sa ec aetan plat A= al parenchyma Fibers: T = Tracheid M = naltis abies be! cell Intervessel pitting: Opp. = Opposite intervessel pittin F= wenab-ernebebl U = Upright ray cell t. = Alternate intervessel pitting L = Libriform fiber | Fibrous pepo O-A = Opposite to alternate intervessel pitting ys: L = Over 1 cam. Silica: G = arma Spirals: +Vessel = Spirals present throughout ve M = 1,000-10,000,= Vv = Vitr +Tails = Spirals present only in ce ee tails S = 500-1,000.m M= tiltiserinte ray cell VS = Up to 500\m U = Upright r cell F/V ratio: F/V = Fibrous element length to vessel element length ratio Ht. - Heterogeneous | , 4, (1935) F = Fibrous Ho. = Homogeneou: cave V = Vessel element Genera :Group: Vessel elements ‘ F/V ‘ Fibers : Ray :Axial : Crystals Silica ; : : ratio : 2 :paren-: : End Pitting :Pores: Spirals : :Type:Sep- :Height: ee : Type :chyma : Type :Loca-: In :Integu-:Type:Loca- wall : :per- : : : ttate : : : : : ition :cham-:mented : :tion : Intervessel :Vessel-:cent : : 3 $ 3 : pitta : : : : :bered: Ioomee ea -=---: ora :soli-: : $ 3 Hy : $ : up- : Opp. : Size : --:tary : : : : : : : : : right 2 -Alew : (Gm) : : : : 3 } : : : 2 ray : O-A : H : : ‘ 8 : : : 3 H : cells BERBER IDOPS IDEAE reptothamnus I Scal. : O-A : 8-10: 0: 100: - (ie Se,” et i aa ee oe ee & 3-5 :Ht.-I : - 3: (P) M = - * 5 Berberidopsis I Scal. : Opp. 820 : 10-30 : 99 : #Vessel : 1.37 :T : - : L : 15-25 sHe.-I : = : - ~ - - - = Erythrospermum a Scal 0-A 7-24 : 834: 77: - 2 20350 t- 8 oes ON : 2-6 :Ht.-I 2: - : M&U - + = = ptostylus II S68" + Ale. 8-10 : 836: 79 :(+Tails) : 1.79 :F&éL : + : M : 2-5 :Ht.-I: - :P&(D) : M&U : (+) = = = ernia :. EIT sSimp, -2-Alt,: 8-10. 's> 8-30 +372 - pl.ee oP eo ee 8 e266 Be -I ee: an pee ape ee | + + = sylep east | Scal. : Alt. 8-20 : 10-22 : 84: - ge e. © Wes es ee ere, eee a | : 4-6 <:Ht.-I: = ee M ers - oie! Scottellia Toe Seale 2 alts 2655 O90 &. 63 eR R le (601 Gk te ee eS) eRe Wk f= M&U : ci 9) °) ed a oni LL 4Sceal.—s Alt, 9-26 : 8-25: 50: - fasts oF es ss cok? ht. =) t= : (RP) :M&(0) - + eee ad ONCOBEAE Carpotroche ut Seal. : O-A : 7236 : 830: 72: - ¢: 1.55 sF6L 3+ 4 ok : 2-5 «:Ht.-I : <= ae 4 M&U - - :- - tit) (S&S) : 3 : : : : : $ H : $ : : Mayna pyle: i Simp.,: A : 7-34 : 826: 69 :(4+Vessel): 1.56 :F&L: + : M : 3-5 :Ht.-I: - ie : M60 : - : - :(G) : M&U $33, 865,58: : 2 : :(#Tails) : : : Hy 3 $ : : . : : € i 2 4 Scal. =: : H : : $ : : : 3 ¢ : : t : ELT Simp. < Alt. 2 7-8 : G25 t OT = - [Toe et Se ee ee UL eS SHt.=5-2 = ? ie ieee ace ieee + to = gyn cae eae S&S -: Alt. 8-10 : 10-36 : 61: - : 2.07 <:FéL : + : M ¢ 2=f sHt.-I : = P M+: = - - - Sthdechar ti PASE Simp. < Alt. 6-10 : 7-32 : 49 :(#Tails) : 1.70 :F&L: + : M ¢ 2-7 ‘Ht.-I : = :P&(D) M : (+) + :(G) M&U (II) (S&S) ¢ H 2 H ‘ : 3 $ : : : Buchnerodendron II S&S : Alt. : 8&9 : &13 : 66: = P63 Poe oe ee 6 tee 2 = P&(D) : M6U : - - sisi - SCOLOPIEAE Scolopia : VI imp. : Alt. : 4-6 : 4-6 : $9 : $Tatls : 1.84 :L : @ : VS-S : 2-5 sHt.-: 2=3 ‘:Ht.-I : = P :U&(M): + ~ - - Homalium ¢ VI. 3: Simp. : Bae BG i hah oe AS - + 1.70: - 3 ¥6L: > ¢ VS8-S =: 2-5 :Ht.-I : - 2 :U&(M) + + - - ¢ (WW) : ($68): £8). 3) (8) cs : : 3 3 8 H :&(F) PANGIEAE Hydnocarpus I Seal. O-A 8-10 : 8-44: 6 :(4Tails) : 1.56 :F : + : M : 2-3 :Ht.-I - P M&U - - :(V) V&F Fc Clay 6 : : : 3 : $ : : Eleutherandra III Sap, Alt. 6-8 : 838: 36: - ew Pe i Wests "Feat Sai ut amy : 1-3 :Ht.-I P M&U + - - Gynocardia oe & Simp. : Alt 10-14 : tra 3 has 2 ae ~ ¢-1.70 Pot ee 2 VSS) 3 T=? -2ht.-I - (P) M&U - - - - - : - y UE e: Gim. ALG So Ze oe Jak gS te - 35.68 SPRL 8 Oe Bee sHt.-I : = BO :M&(U): - + ee oops ae Neoptychocarpus : IV : Scal. : Alt. : 2=4 : 2-6 : 58: - aie eed a Pa eat SA SO. aimee peer Maier | oe eae ae “ a J a ec ap coe ee fe * Ab Neg es i 4 =) = } eo *T. s 1248: Diit-Sh pate “8°: : : ; 2e Oe re Bi kat eH Gat eae fakin ~_ ~\ ) seh ae 7 x, (cee ; + Ses Ria tie Sats f ° + A a, apa Me ~ Oo : . ei ee v3 Seciss=c ae “8. eg i | + o 5 a3 Hh a7 See Qube te ‘@. TASS et ey. Fatah 6 ites bam aesa"Gs SG: aR eB 176 88 Me SGe.: ‘= Cob etet Qe ears dete ieee. s a @' 4 Ww Teel Pte ti a > . Lind wa gee i te + re A ‘6 aig es Kf dete SH Sie $f a « a ee aus et Hun ' FF © s 7 eget << L % ry ay . 4 or : Ee ARS ER AE PO eRe ao Bi ees A hei J ea a: 753@:\086. ive eee 4: ar se a ths ta f fy ae S ee Shovet. ‘ nee oP it Ty : e wae ’ tg OT Gti ae oe. oe ; “4 ‘ Sage ait ts a8 Pe tes 3:2 Wee eee te Battie Jats Sach ‘e etiee os: ae $ ae. 7S UME eee) Se CS aT Pers 7! a: i} 3 wages. : s. i} wate v< Te J aT i t ness : : eet Ld é Te fete Bad Aiea tg Boh igor BA RS aig Os: Zee eee: @yi-b : ttt eo ean te "é: ae . Ae e = ez < = oe ‘e-: St TJ Leer eel Aeeks Hog meetee aan = ot S e “ hy i os ie D : bate 1 a ark cist Ores by WEY aoe: sgt ath : ieee teeth AA Ss i mests, Se A ares ih ge sto ec. Behe 3 ‘ AR PS Kiet Te eae wine ae ? ve i Se8 ets Mar ar ae eer" ‘* lee wey ratty oe 2B. sux) bets” Ube. 7, ‘ ¥, ‘J 3 wag el & *.. od pet é. * Ste, : a" a4 ote ae! 4ik@: +-12 nll) ae fags ‘ €¢ ‘= 8 CHE 3 . iF Seat Siritiet abe Ne ©’ cle ee a> Sige 1@ ok 4 Shier a a Bey . - iets 4” Fete ¢ et 28s chee oS 5S aye As oh@ f freget alc et, cam loest. © 6 ‘ AG) yt hee : reir. a cake: oP. : Seat: cog eth uae ta @Ueiey ae * ‘os: rate gence «S aOR EG Chet gigs: 22's ay te or @.:: Bry fae be ETHERS TEES Rt “ig ates na iE tg oR bad EO se Ocigg ms ex . a HON Se sil Cy tay 32 oe S ‘ pet re 1] +, 2 ere a e> ‘itech? Gees att So eeg 28 ga ee. ae te A ee ae aS Fe ce he oe ce cae Hit ‘\ \ FIGURES 11-14: 11, transverse section of Ryania angustifolia showing poorly defined growth rings, little or no axial parenchyma, angular pores, very nu- merous pores per square millimeter, and an average pore diameter of less than 50 pm.; 12 Lindackeria latifolia, typical transverse section of Flacourtiaceae with poorly defined growth rings, little or no axial parenchyma, rounded pores. 1975] MILLER, FLACOURTIACEAE 49 ally opposite; pits circular to linear; medium-sized to very large, 7-34 pm. Vessel-ray pits circular to linear; medium to coarse, 8-26 ym. Height of multiseriate portion of rays averages 3622 um., range 2535-4307 pm.; width 3 to 5 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 20-40 ym. Simply perforated ray cells in M. amazonica, M. echinata, M. longicuspis (SJRw 10587), M. pacifica, and M. zuliana. Fiber-tracheids and libriform fibers medium-sized to moderately long (1263-1990 um.; average 1517 pm.) usually with thin to very thin walls, 2—6 um., thick to very thick, 5-8 pm., in M. amazonica; septate. F/V ratio averages 1.56, range 1.51—1.66. Prismatic crystals ‘abundant to occasional in ray cells of multiseriate por- tion and frequent to rare in upright ray cells; absent in M. amazonica; not integumented; not in chambered cells. Large silica bodies (10—16 pm.) abundant in ray cells of M. amazonica. Reddish-brown deposits abundant to occasional in ray cells and fibrous elements. Oncoba Forskall. Ze to 40 species from tropical Africa and South Africa. One specim Pore diameter ce moderately small (72-104 »m.; average 85 pm.) ; pores average 49 per cent solitary; radial multiples mostly 2 and 3, oc- casionally to 5; pores per square millimeter numerous (31 pores/mm.”). Vessel elements medium-sized to moderately long (518-1128 pm.; aver- age 855 »m.); perforation plates exclusively simple; end-wall angles 30° to 45°. Intervascular pitting alternate; pits circular to oval; medium- sized, 7-8 wm. Vessel-ray pits circular to linear; fine to coarse, 6-25 pm. Height of multiseriate portion of rays averages 345 pm.; maximum 416 vm.; width mostly 2 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 13-16 pm. Simply perforated ray cells present. Fiber-tracheids medium-sized to moderately long (1159-1800 ym.; average 1435 pm.) with mostly thin walls, 4-6 ym.; septate. F/V ratio 1.68. Prismatic crystals frequent in upright ray cells and absent in ray cells of multiseriate portion; integu- mented; mostly in 2-, occasionally in 4-chambered upright ray cells. Reddish- brown deposits occasional in ray cells. Caloncoba Gilg. Fifteen to 20 species from tropical Africa. Thirteen specimens representing seven species. Pore diameter moderately small to medium-sized (52-122 pm.; aver- age 90 um.); pores average 61 per cent solitary, range 47 to 84 per cent; radial multiples mostly 2, occasionally to 5; pores per square millimeter numerous pores per square millimeter, and an average pore diameter of 78 ym.; 13, transverse section of Laetia procera showing no growth rings, little or no axial parenchyma, rounded pores, moderately few pores per square meter, an average oe ao er of more tha 4, Pleuranthodendron mexicana, ma thickenings in “the vessel-element tails showing spira (ligules) ; Shireen sahil partially crossed nicols. 50 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 moderately numerous to very numerous (11-85 pores/mm.*; average 29 pores/mm.”). Vessel elements mostly moderately long to very long (797— 1269 um.; average 1056 »m.); perforation plates mostly simple and oc- casionally scalariform with 1 to 10 bars which are 1-4 pm. thick and 4— 14 pm. apart; end-wall angles 30° to 45°. Intervascular pitting alternate; pits circular to oval; mostly medium-sized, 8-10 wm. Vessel-ray pits cir- cular to linear; mostly coarse, 10-36 »m. Height of multiseriate portion of rays averages 1387 pm., range 941-3065 pm.; width mostly 2 to 3 cells, but 3 to 5 cells in C. echinata (FHOw 8466) and C. glauca (PRFw 23105) and 4 to 7 cells in C. welwitschii (PRFw 15281). Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; elongate in C. flagelliflora; cell height 23-40 »m. Simply and scalariformly perforated ray cells are usually present; absent in C. brevipes and C. welwitschii (PRFw 15281). Fiber-tracheids and libriform fibers moderately long to very long (1692-2655 ym.; average 2174 ym.) with very thin to very thick walls, 3-9 pm. F/V ratio averages 2.07, range 1.60— 2.30. Prismatic crystals generally more abundant in ray cells of multiseriate portion than in upright ray cells; not integumented; not in chambered cells. Reddish-brown or yellowish deposits abundant to absent in ray cells and fibrous elements. Lindackeria Presl. Eighteen to 25 species from tropical America and tropical Africa. Seven specimens representing six species. Pore diameter moderately small (54-89 ym.; average 71 »m.); pores average 49 per cent solitary, range 36 to 61 per cent; radial multiples mostly 2 and 3, occasionally to 9; pores per square millimeter numerous to very numerous (20-47 pores/mm.”; average 33 pores/mm."). Vessel elements medium-sized to mostly moderately long (705-1182 pm.; aver- age 940 uwm.); perforation plates exclusively simple; in L. dentata (Bw) perforation plates are mostly simply and rarely scalariform (up to 3 bars); end-wall angles 30° to 50°. Tyloses are occasionally present in all speci- mens of Lindackeria except L. dentata (Bw), in which tyloses are absent. Fine spiral thickenings occasionally occur in vessel tails of L. dentata (Bw). Intervascular pitting alternate; pits circular to oval; mostly medium- sized, 6-10 pm. Vessel-ray pits circular to linear; medium to coarse, 7— 32 wm. Height of multiseriate portion of rays averages 2106 pm., range 1621-3183 wm.; width 2 to 7 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 20-40 wm. Simply perforated ray cells in L. maynensis. Fiber-tracheids and libriform fibers medium-sized to moderately long (1297-1990 pm.; average 1588 ym.) with thin to thick walls, 3-8 um.; septate. F/V ratio averages 1.70, range 1.42—1.84. Prismatic crystals abundant to rare in ray cells of multiseriate portion and mostly rare to absent in upright ray cells; integumented; not in chambered cells. In L. dentata (Bw) druse crystals occasionally occur in 2-, 3-, or 4-chambered ray cells. Silica bodies abundant in both types of ray cells of L. laurina. Reddish-brown deposits abundant to occasional in ray cells and fibrous elements. 1975] MILLER, FLACOURTIACEAE 51 radial section of Buchnerodendron speciosum showing 2 n showing _Ficures 15-18: 15 simple and scalariform perforation plates; note spiral thickenings in yore ele- ment; 17, radial section of neds grencouse candidum showing sca ere perforation plates with many bars; angential section of Carrierea calycina showing spiral thickenings in vessel elemen 52 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Buchnerodendron Giirke. Five or six species from tropical Africa. One specimen. Pore diameter mostly moderately small (48-64 »m.; average 57 pm.) ; pores average 66 per cent solitary; radial multiples mostly 2, occasionally to 11; pores per square millimeter very numerous (57 pores/mm.”). Ves- sel elements medium-sized to mostly moderately long (629-1199 um.; average 942 pum.); perforation plates mostly simple and occasionally scalariform (up to 5 bars); end-wall angles 20° to 40°. Tyloses oc- casionally present. Intervascular pitting alternate; pits circular to polyg- onal; medium-sized, 8-9 ym. Vessel-ray pits circular to linear; medium to coarse, 8-13 »m. Height of multiseriate portion of rays averages 1632 pm., maximum 2160 pm.; width 3 to 6 cells. Individual ray cells of multi- seriate portion as observed on the radial surface are mostly square; cell height 25-35 um. Simply and scalariformly perforated ray cells common. Fiber-tracheids medium-sized to moderately long (1081-1945 wm.; aver- age 1536 pm.) with very thin to thin walls, 3-4 pm.; septate. F/V ratio averages 1.63. Prismatic crystals frequent to occasional in ray cells of multiseriate portion and in upright ray cells; not integumented; not in chambered cells. Druse crystals present in ray cells of suspected wounded area. Tribe Scolopieae Scolopia Schreber. Forty-five to 55 species from the Old World tropics and subtropics. Nine specimens representing five species. Pore diameter mostly moderately small (54-105 »m.; average 76 um.) ; pores average 59 per cent solitary, range 47 to 71 per cent; radial mul- tiples mostly 2, occasionally to 6; pores per square millimeter numerous to very numerous (20-44 pores/mm.?; average 31 pores/mm.”). Vessel elements medium-sized to very long (617-1279 pm.; average 881 pm.); perforation plates exclusively simple except in S. zeyheri, which has per- foration plates that are mostly simple and rarely scalariform; end-wall angles 20° to 45°. Spiral thickenings generally present in the vessel tails; occasional to rare throughout the vessel elements; absent in S. zeyheri. Intervascular and vessel-ray pitting alternate; pits circular to polygonal; small, 4-6 ym. Height of multiseriate portion of rays averages 476 pm., range 226-722 wm.; width 2 to 5 cells. Individual ray cells of multi- seriate portion as observed on the radial surface are elongate; cell height 12-23 wm. Simply perforated ray cells occur in S. luzonensis, S. zeyheri, and S. spinosa (SJRw 22356 and SJRw 30086). Libriform fibers medium- sized to moderately long (1278-2090 pm.; average 1582 »m.) with thin to very thick walls, 3-8 um.; septate. F/V ratio averages 1.84, range 1.62—2.10. Prismatic crystals abundant in upright ray cells and rare to absent in ray cells of multiseriate portion; in S. zeyheri crystals are oc- casional in both types of ray cells; integumented; mostly in 2- to 4-cham- bered upright ray cells, occasionally in 6- to 8-chambered cells. Prismatic crystals occasionally in the fibrous elements of S. spinosa (USw 28688). 1975] MILLER, FLACOURTIACEAE 53 Dark reddish-brown deposits abundant in the ray cells and occasionally in the fibrous elements. Bartholomaea Standley & Steyermark. Two species from Central America. One specimen from a herbarium sheet. Pore structure not examined since the twig specimen was very small. Vessel elements medium-sized to moderately long (580-1037 pm.; aver- age 785 wm.); perforation plates mostly simple and rarely scalariform, up to 5 bars which are 2 um. thick and 4 pm. apart; end-wall angles 20° to 35°. Intervascular and vessel-ray pitting alternate; pits circular, small, ray cells; integumented; mostly in 2- or 4-chambered upright ray cells. Tribe Banareae Banara Aublet. Thirty-five to 50 species from the West Indies and Central America to southern Brazil and Paraguay. Nine specimens rep- resenting seven species. Pore diameter very small to medium-sized (42-139 ym.; average 93 pm.); pores average 46 per cent solitary, range 11 to 65 per cent; radial multiples mostly 2 and 3, occasionally to 9; pores per square millimeter moderately numerous to very numerous (14-97 pores/mm.”; average 37 pores/mm.”). Vessel elements medium-sized to moderately long (553- 026 »m.; average 766 um.); perforation plates exclusively simple; end- wall angles 25° to 60°. Spiral thickenings are rare to occasional in the vessel tails of B. guianensis (MADw 11755), B. roigii, and B. vellozit. Intervascular and vessel-ray pitting alternate; pits circular to polygonal ; small, 4-7 pm.; in B. axilliflora very small, 2-4 um. Height of the multi- seriate portion of rays averages 276 pm., range 199-349 um.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the ra- dial surface are mostly elongate; cell height 10-23 pm. Fiber-tracheids and libriform fibers medium-sized to moderately long (1025-2000 pm. ; average 1414 »m.) with thin to very thick walls, 2-8 »m.; septate. F/V ratio averages 1.84, range 1.47—2.15. Prismatic crystals abundant to rare in upright ray cells, usually absent or rare in ray cells of multiseriate por- tion; integumented; mostly in 2- to occasionally 4-chambered upright ray cells; in B. nitida and B. roigii the cells are mostly 4- to 8-chambered. Druse crystals occasionally in upright ray cells of B. mollis and B. regia. Prismatic crystals occasionally in the fibrous elements of B. nitida, B. re- gia, and B. roigii. Pineda Ruiz & Pavon. One to two species from Peru. One specimen. Pore diameter very small to moderately small (40-56 pm.; average 45 um.); pores average 49 per cent solitary; radial multiples mostly 2 and 54 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 3, occasionally to 10; pores per square millimeter very numerous (86 pores/mm. 2). Vessel elements medium-sized to moderately long (400- 2 wm.; average 659 uwm.); perforation plates exclusively simple; end- wall angles 20° to 45°. Intervascular pitting alternate; pits circular or oval to polygonal; small to mostly medium-sized, 6-9 pm. Vessel-ray pits mostly circular to oval, occasionally oblong to linear; fine to coarse, 6-20 ym. Height of multiseriate portion of rays averages 223 wm. or 10 cells, maximum 320 pm. or 16 cells; width 2 cells. Individual ray cells of mul- tiseriate portion as observed on the radial surface are square to rectangu- lar; cell height 18-23 ym. Simply perforated ray cells present. Fiber- tracheids medium-sized (932-1498 um.; average 1203 um.) with thin to thick walls, 3-6 »m.; septate. F/V ratio averages 1.83. Prismatic crys- tals abundant in upright ray cells and occasional in ray cells of multi- seriate portion; integumented; mostly in 2- to occasionally 4-chambered upright ray cells. Trimeria Harvey. Five to eight species from tropical and South Africa. One specimen. Pore diameter very small (32-50 »m.; average 39 um.); pores average 57 per cent solitary; radial multiples mostly 2 and 3, occasionally to 9; pores per square millimeter very numerous (69 pores/mm.”). Vessel ele- ments medium-sized to moderately long (518-1067 wm.; average 816 ym.) ; perforation plates exclusively simple; end-wall angles 25° to 35°. Inter- vascular and vessel-ray pitting alternate; pits circular or oval; small to medium-sized, 6-8 wm. Height of multiseriate portion of rays averages 582 pm., maximum 760 um.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 14-18 ym. Simply perforated ray cells present. Libriform fibers mostly medium-sized (1067-1647 um.; average 1415 pm.) with thin walls, 4—6 pm.; septate in normal fibers, but nonseptate in gelatinous fibers. F/V ratio averages 1.73. Prismatic crystals abundant in upright ray cells and occasional in ray cells of multiseriate portion; integumented; mostly in 2- to occasionally 4-chambered upright ray cells. Tribe Homalieae Calantica Jaubert ex Tul. Five species from tropical East Africa and Madagascar. One specimen. Pore diameter mostly moderately small (72-104 um.; average 83 pm.) ; pores average 42 per cent solitary; radial multiples mostly 2, occasionally to 4; pores per square millimeter moderately numerous (14 pores/mm.”). Vessel elements mostly moderately long to very long (762-1555 pm.; average 1165 »m.); perforation plates exclusively simple; end-wall angles 25° to 35°. Intervascular and vessel-ray pitting alternate; pits circular to polygonal; small, 3-5 pm. Height of multiseriate portion of rays averages 452 um., maximum 680 um.; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are rec- tangular to elongate; cell height 20-30 wm. Fiber-tracheids and libriform 1975] MILLER, FLACOURTIACEAE 55 fibers moderately long to very long (1860-2592 um.; average 2245 pm.) with very thick walls, 8-11 um.; septate. F/V ratio averages 1.93. Pris- matic crystals abundant in upright ray cells and occasional in ray cells of multiseriate portion; integumented; mostly in 2-, occasionally in 3- or 4-chambered upright ray cells. Reddish-brown deposits frequent in ray cells. Homalium Jacquin. Over 200 species from the tropics and subtropics. Sixteen specimens representing 12 species Pore diameter moderately small to medium-sized (77-146 pm.; aver- age 97 um.); pores average 45 per cent solitary, range 22 to 80 per cent; radial multiples mostly 2 and 3, occasionally to 7; pores per square mil- limiter moderately few to numerous (8-38 pores/mm.?; average 22 pores/mm.”). Vessel elements medium-sized to very long (560-1362 um.; average 1056 »m.); perforation plates exclusively simple in most species; in H. longifolium and H. pallidum perforation plates are mostly simple and occasionally scalariform with few or vestigial bars; end-wall angles 15° to 60°. Intervascular and vessel-ray pitting alternate: pits circular to polygonal; small, mostly 4-6 um., occasionally 6-8 wm. Height of multi- seriate portion of rays averages 524 um., range 350-973 ywm.; width 2 to 5 cells. Individual ray cells of multiseriate portion as observed on the radial surface are elongate; cell height mostly 13-23 pm.; in H. grandi- florum cell height 18-27 ym. Fiber-tracheids and libriform fibers medium- sized to moderately long (1115-2247 wm.; average 1776 wm.) with mostly thick to very thick walls, 4-11 pm.; septate. F/V ratio averages 1.70, range 1.27-2.00. Prismatic crystals abundant in upright ray cells, but rare to occasional in H. stenophyllum; mostly occasional to absent in ray cells of multiseriate portion, but abundant in H. longifolium, H. pallidum, and H. racemosum (MADw 14451); integumented; mostly in 2- to 4- chambered upright ray cells or cells appearing to be chambered, and fre- quently more than 1 crystal per chamber; not in chambered cells in H. letes- tui. Prismatic crystals occasionally in scanty paratracheal parenchyma and in the fibrous elements of H. foetidum, H. pallidum, and H. racemosum (MADw 14451). Reddish-brown deposits abundant in the ray cells and fibrous elements of H. grandiflorum var. javanicum, H. hainanense, and H. trichostemon; absent in the ray cells of H. letestui, H. smythei, and H. tomentosum; sporadic in the ray cells of the remaining specimens. Tribe Pangieae Hydnocarpus Gaertner. Thirty to 40 species from India, Malay Archi- pelago, and Indo-China. Twelve specimens representing eight species, in- cluding the species of Asteriastigma and Taraktogenos. Pore diameter moderately small to medium-sized (55-146 pm.; aver- age 86 um.); pores average 76 per cent solitary, range 45 to 93 per cent; radial multiples mostly of 2, occasionally to 4; pores per square millimeter moderately numerous to very numerous (13-72 pores/mm.*; average 38 pores/mm.”). Vessel elements very long to extremely long (1296-2361 56 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 pm.; average 1794 um.); perforation plates exclusively scalariform, mostly over 15 bars which are 1-6 pm. thick and 4-16 pm. apart; end-wall angles 10° to 25°. Tyloses occasional to rare in H. gracilis (MADw 25423), H. kunstleri (SJRw 22353), H. sumatrana (MADw 22588), and H. yatesii. Spiral thickenings occur in the vessel tails and occasionally throughout vessel elements of H. kunstleri (SJRw 38716). Intervascular pitting opposite to alternate; pits circular to oval; medium-sized, mostly 8-10 pm. in H. gracilis (MADw 25423), H. macrocarpus, H. sumatrana, and H. venenata; large, mostly 10-14 wm. in the remaining specimens. Vessel-ray pits circular to linear; medium to coarse, 8-44 pm. Height of multiseriate portion of rays averages 1218 pm., range 348-3273 pm.; width 2 to 3 cells. Individual ray cells of multiseriate portion as ob- served on the radial surface are square to elongate; cell height 23-53 pm. Simply perforated ray cells in H. kunstleri (SJRw 38716). Fiber-tracheids moderately long to extremely long (1982-3628 pm.; average 2793 pm.) with thin to very thick walls, 3-15 »m.; septate. F/V ratio averages 1.56, range 1.46—1.81. Prismatic crystals abundant to occasional in both types of ray cells, usually more prevalent in ray cells of multiseriate portion, absent in H. kunstleri (SJRw 22353), H. macrocarpus, H. saigonensis, and H. yatesii; not integumented; not in chambered cells. Vitreous silica in the vessel elements and occasionally fibrous elements of all species ex- cept H. sumatrana. Reddish-brown or brownish-orange deposits in the ray cells of H. macrocarpus and H. sumatrana. Eleutherandra Van Slooten. One or two ia from Sumatra and Borneo. Two specimens representing one spec Pore diameter medium-sized (119-126 pm.; ow 122 pm.); pores average 36 per cent solitary, range 24 to 48 per cent; radial multiples mostly 2 and 3, occasionally to 7; pores per square millimeter moderately few (7-8 pores/mm.?; average 8 pores/mm.”). Vessel elements very long (1103-1252 mm.; average 1177 pm.); perforation plates exclusively simple; end-wall angles 20° to 35°. Sclerotic tyloses occur occasionally in E. pes-cervi (SJRw 15445). Intervascular pitting alternate; pits circu- lar to polygonal; small to medium-sized, 6-8 wm. Vessel-ray pits circular to linear; medium to coarse, 8-38 »m. Height of multiseriate portion of rays averages 1640 pm., range 1630-1650 »m.; width 1 to 3 cells. Indi- vidual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 28-40 um. Fiber-tracheids and oc- casionally libriform fibers are very long (2306-2736 pm.; average 2521 pm.) with very thick walls, 10-16 um.; septate. F/V ratio averages 2.13, range 2.09-2.16. Prismatic crystals abundant i in both types of ray cells; integumented; not in chambered cells Gynocardia R. Brown. Monotypic genus from India and Burma. Two specimens Pore diameter moderately small to medium-sized (64-117 mm.; aver- age 91 »~m.); pores average 63 per cent solitary, range 60 to 65 per cent; MILLER, FLACOURTIACEAE Ficures 19-23: 19, radial section of Buchnerodendron speciosum showing simply perfo rated ray cell; 20, radial section of Carpotroche brasiliensis showing modi poe scalariformly perf rated ray cel shov i druse cna si ing prism cells; iweitial ponte of Erythrosprmum candidum showing opposite and eed Sc intervascular pitting 58 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 radial multiples mostly 2, occasionally to 3; pores per square millimeter moderately numerous (13-19 pores/mm.?; average 16 pores/mm.*). Ves- sel elements moderately long (1086-1096 wm.; average 1091 p»m.); per- foration plates mostly simple and occasionally to rarely scalariform with vestigial and few bars, up to 5 bars which are 2 pm. thick and 6 wm. apart; end-wall angles 30° to 45°. Intervascular pitting alternate; pits circular to polygonal; large, 10-14 wm. Vessel-ray pits circular to linear; coarse, 10-40 »m. Height of multiseriate portion of rays averages 560 pm. or 11 cells, maximum 800 pm. or 15 cells; width 1 to 2 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 40-80 um. Scalariformly perforated ray cells present. Fiber-tracheids moderately long (1782-1934 mm.; average 1858 pm.) with thin to very thin walls, 3-6 um.; septate. F/V ratio averages 1.70, range 1.64—1.76. Prismatic crystals occasional in either upright ray cells or ray cells of multiseriate portion; no integuments observed; not in chambered cells. Pangium Reinwardt. One to three species from Malay Archipelago, Philippine Islands, a Islands, and New Guinea. Two specimens representing one spec Pore diameter nee aay sized (139-148 pm.; average 143 um.); pores average 56 per cent solitary, range 54 to 58 per cent; radial multiples mostly 2, occasionally to 3; pores per square millimeter moderately few (6 pores/mm.”). Vessel elements moderately long (930-1000 pm.; aver- age 965 »m.); perforation plates exclusively simple; end-wall angles 25° to 60°. Intervascular pitting alternate; pits circular to polygonal; medium- sized, 8-10 pm. Vessel-ray pits circular to linear; coarse, 10-56 pm. Height of multiseriate portion of rays averages 2482 pm., range 1952- 3212 wm.; width 3 to 5 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 30— 50 wm. Fiber-tracheids moderately long to very long (2037-2713 pm.; average 2375 wm.) with thin to thick walls, 5-8 ym.; septate. F/V ratio averages 2.40, range 2.19-2.71. Prismatic crystals abundant to frequent in both types ‘of ray cells; integumented; not in chambered cells. Trichadenia Thwaites. One to two species from Ceylon, Philippine Islands, New Guinea, and Melanesia. Two specimens representing one species. Pore diameter medium-sized (149-170 wm.; average 160 »m.); pores average 40 per cent solitary, range 34 to 46 per cent; radial multiples mostly of 2 and 3, occasionally to 4; pores per square millimeter mod- erately few (8-9 pores/mm.?; average 8 pores/mm.”). Vessel elements very long (1194-1196 um.; average 1195 wm.); perforation plates ex- clusively simple; end-wall angles 30° to 50°. Intervascular pitting alter- nate; pits circular to polygonal; mostly medium-sized, 8-11 ym. Vessel- ray pits circular to linear; mostly coarse, 10-45 ym. Height of multi- 1975] MILLER, FLACOURTIACEAE 59 seriate portion of rays averages 2316 wm., range 2006-2625 pum.; width 2 to 5 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to rectangular; cell height 26-55 pm. Fiber- tracheids and occasionally libriform fibers are very long to extremely long (2635-3112 wm.; average 2874 ym.) with thick to very thick walls; 6— 15 pm.; septate. F/V ratio averages 2.41, range 2.21—2.60. Prismatic crystals abundant to occasional in both types of ray cells; integumented; not in chambered cells. Scaphocalyx Ridley. Two species from the Malay Peninsula. One specimen Pore diameter moderately small (72-88 um.; average 78 »m.); pores average 78 per cent solitary, radial multiples mostly 2, occasionally to 4; pores per square millimeter numerous (38 pores/mm.”). Vessel elements moderately long to very long (915-1708 um.; average 1324 um.) per- foration plates exclusively simple; end-wall angles 15° to 25°. Inter- vascular pitting alternate; pits circular to linear; medium-sized to very large, 8-25 pm. Vessel-ray pits circular to linear; medium to coarse, 7-35 ym. Height of multiseriate portion of rays averages 1847 »m., max- imum 2299 um.; width mostly 2 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 28-38 wm. Simply perforated ray cells present. Fiber-tracheids and libriform fibers moderately long to very long (1708-2776 um.; average 2385 pm.) with mostly thick walls, 6-8 »m.; septate. F/V ratio averages 1.80. Prismatic crystals abundant to frequent in ray cells of multiseriate portion and occasional in the upright ray cells; not integumented; not in chambered cells. Ryparosa Blume. Eighteen to 25 species from Andamans, Indo-China, Malay, and New Guinea. Three specimens representing two species. Pore diameter medium-sized (108-154 pm.; average 130 »m.); pores average 58 per cent solitary, range 33 to 74 per cent; radial multiples mostly 2, occasionally to 5; pores per square millimeter moderately few to moderately numerous (7-17 pores/mm.?; average 13 pores/mm.”). Vessel elements very long (1445-1678 wm.; average 1592 um.); perfora- tion plates mostly simple and occasionally scalariform with vestigial and up to 15 or more bars which are 1 pm. thick and 2-4 pm. apart; end- wall angles 15° to 25°. Intervascular pitting alternate; pits mostly cir- cular; large, 10-14 pm. Vessel-ray pits circular to linear: coarse, 12—50 um. Height of multiseriate portion of rays averages 3423 pm., range 1955— 4197 »m.; width 3 to 8 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square to occasionally elon- gate; cell height 25-40 um. Simply perforated ray cells in R. kunstleri (SJRw 15444). Fiber-tracheids and libriform fibers very long to extreme- ly long (2762-3246 pm.; average 3075 wm.) with thick to very thick walls, 7-17 um.; septate. F/V ratio averages 1.93, range 1.91-1.94. 60 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Prismatic crystals frequent to occasional in ray cells of multiseriate por- tion and occasional to absent in upright ray cells; not integumented; not in chambered cells. Kiggelaria Linnaeus. One to four species from tropical Africa and South Africa. Two specimens representing two species. Pore diameter moderately small (72-96 »m.; average 83 wm.); pores average 52 per cent solitary; radial multiples mostly 2 and 3, occasionally to 4; pores per square millimeter numerous (22-37 pores/mm.”; aver- age 30 pores/mm.”). Vessel elements medium-sized (642—797 mm.; aver- age 720 um.); perforation plates exclusively simple; end-wall angles 20° to 45°. Spiral thickenings occur throughout the vessel elements. Inter- vascular pitting alternate; pits circular to polygonal; medium-sized, 8—10 pm. Vessel-ray pits circular to linear; medium to coarse, 7-26 wm. Height of multiseriate portion of rays averages 1008 pm., range 872-1145 pm.; width 3 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 23-35 um. Fiber- tracheids and libriform fibers medium-sized (1291-1583 pm.; average 1437 wm.) with mostly thin walls, 3-6 wm.; septate. F/V ratio averages 2.00, range 1.99-2.01. Prismatic crystals rare in ray cells of multiseriate portion and absent in upright ray cells; no integuments observed; not in chambered cells. Tribe Flacourtieae Olmediella Baillon. Monotypic genus known only in cultivation, gen- erally from Mexico and Honduras. One specimen. Pore diameter moderately small (64-120 um.; average 94 um.); pores average 61 per cent solitary; radial multiples mostly 2 and 3, occasionally to 6; pores per square millimeter numerous (36 pores/mm.”). Vessel ele- ments moderately long (549-1189 wm.; average 844 um.); perforation plates mostly simple and rarely scalariform; end-wall angles 20° to 35°. Coarse spiral thickenings common throughout the vessels. Inter- vascular pitting alternate; pits circular to linear; large to very large, 10-34 wm. Vessel-ray pits circular to linear; coarse, 10-32 wm. Height of multiseriate portion of rays averages 1606 pm., maximum 2161 pm.; width 4 to 6 cells. Individual ray cells of multiseriate portion as observed on the radial surface are very elongate; cell height 20-35 pm. Simply perforated ray cells. Fiber-tracheids and libriform fibers moderately long (1828-1951 um.; average 1890 um.) with thin to very thick walls, 4-10 vm.; mostly septate, some nonseptate fibrous elements. F/V ratio 2.23. Prismatic crystals abundant in both types of ray cells; integumented; not in chambered cells; occasionally many small crystals in one cell. Bennettiodendron Merrill. Three species from India, southern China, and Malay Archipelago. Two specimens representing one species. 1975] MILLER, FLACOURTIACEAE 61 Pore diameter mostly moderately small (47-67 um.; average 58 pm.) ; pores average 70 per cent solitary; radial multiples mostly 2 and 3, oc- casionally to 6; pores per square millimeter very numerous (61-94 pores/ mm.”; average 76 pores/mm.2). Vessel elements moderately long (847- 1094 »m.; average 970 »m.); perforation plates mostly simple and oc- casionally to rarely scalariform with up to 5 bars; end-wall angles 10° to 20°. Fine spiral thickenings occasionally throughout the vessel elements or more commonly in vessel tails. Intervascular pitting alternate; pits circular to occasionally linear; mostly medium-sized to large, 8-14 pm.; occasionally very large, up to 25 ym. Vessel-ray pits circular to linear; medium to coarse, 8-25 um. Height of multiseriate portion of rays aver- ages 308 wm., range 263-354 »m.; width 2 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elon- gate; cell height 18-30 »m. Fiber-tracheids and libriform fibers medium- sized to moderately long (1092-1780 pm.; average 1436 ym.) with thin walls, 2-4 »m.; septate. F/V ratio averages 1.46, range 1.30—1.63. Prismatic crystals abundant in upright ray cells and occasional in ray cells of multi- seriate portion; integumented; mostly in 2-, occasionally in 3- or 4- chambered upright ray cells. Yellowish-brown deposits common in rays. Flacourtia Commerson ex L’Héritier. Fifteen to 60 species from tropical Africa, Southeast Asia, Malaysia, and Fiji Islands. Nine specimens rep- resenting four species. Pore diameter mostly moderately small (48-77 ym.; average 66 pm.) ; pores average 41 per cent solitary, range 28 to 66 per cent; radial multi- ples mostly 2 and 3, occasionally to 7; pores per square millimeter mod- erately numerous to numerous (17-32 pores/mm.?; average 23 pores/ mm.”*). Vessel elements medium-sized to very long (616-1201 HM. ; average 876 um.); perforation plates exclusively simple; however, in f. subintegra (SJRw 28328), a few vestigial bars occur; end-wall angles 25 to 55°. Spiral thickenings throughout vessel elements or in the vessel tails of F. indica (MADw 13915). Intervascular and vessel-ray pitting alter- nate; pits circular to polygonal; small, 4-6 wm. Height of multiseriate portion of the rays averages 350 wm., range 256-408 pm.; width mostly 2 to 3 cells, occasionally 6. Individual ray cells of multiseriate portion as observed on the radial surface are rectangular to elongate; cell height mostly 13-23 ym.; in F. subintegra (SJRw 28426) cell height 16-26 pm. Simply perforated ray cells common; absent in F. indica (MADw 13915 and SJRw 33954) and F. rukam (USw 31377). Fiber-tracheids and libri- form fibers medium-sized to moderately long (1018-2194 pm.; average 1545 ym.) with thin to very thick walls, 3-11 pm.; septate. F/V ratio averages 1.78, range 1.60—2.00. Prismatic crystals abundant to occasional in upright ray cells and rare to absent in ray cells of multiseriate portion; in F. indica (MADw 13915) and F. subintegra crystals are abundant in types of ray cells; integumented; mostly in 2- to 4-chambered up- right ray cells. Reddish-brown deposits common in the rays and fibrous elements. 62 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Dovyalis E. Meyer ex Arnott. Twenty to 30 species from tropical Africa and South Africa, Ceylon, and New Guinea. Two specimens repre- senting one species. Pore diameter very small (36-49 um.; average 43 pwm.); pores aver- age 63 per cent solitary, range 60 to 65 per cent; radial multiples mostly and 3, occasionally to 6; pores per square millimeter very numerous (46-51 pores/mm.”; average 49 pores/mm.”). Vessel elements medium- sized (485-508 um.; average 496 pm.); perforation plates mostly simple and occasionally scalariform with vestigial and up to 8 bars which are 2-3 pm. thick; end-wall angles 15° to 45°. Intervascular and vessel-ray pit- ting alternate; pits circular to polygonal; small, 4-6 »m. Height of mul- tiseriate portion of the rays averages 373 wm., range 326-420 um.; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 15-23 wm. Simply perforated ray cells in D. caffra (USw 20714). Fiber-tracheids medium- sized (945-983 wm.; average 964 wm.) with mostly thin walls, 2-4 pm.; septate. F/V ratio averages 1.95, range 1.86-2.03. Prismatic crystals abundant in both types of ray cells; integumented; not in chambered cells. Azara Ruiz & Pavon. Eleven to 28 species from western Argentina, Chile, and Juan Fernandez Islands. Five specimens representing four species. Pore diameter very small to moderately small (37-96 »m.; average 58 pm.); pores average 45 per cent solitary, range 28 to 70 per cent; radial multiples mostly 2 and 3, occasionally to 16; pores per square millimeter very numerous (56-121 pores/mm.?; average 83 pores/mm.?). Vessel elements medium-sized (404-704 pm.; average 526 pm.); perforation plates mostly simple and occasionally scalariform with up to 4 bars; in A. serrata (USw 34027) perforation plates are exclusively scalariform with 6 to 15 bars which are 2—3 pm. thick and 4—6 pm. apart; end-wall angles 10° to 30°. Very coarse spiral thickenings common throughout the ves- sels of A. microphylla. Intervascular pitting alternate to occasionally op- posite; pits circular to oval; medium-sized to large, 8-12 pm.; in A. ser- rata (USw 34027) intervascular pitting is opposite; pits circular to linear and large to very large, 10-44 ym. Vessel-ray pits circular to linear; me- dium to coarse, 8-28 wm. Height of multiseriate portion of rays averages 257 wm., range 229-277 »m.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elon- gate; cell height 15-25 wm., in A. serrata (USw 34027) cell height is 20- 35 wm. Fiber-tracheids moderately short to medium-sized (687-1029 um.; average 901 ym.) with thin walls, 2-5 »m.; septate. F/V ratio averages 1.73, range 1.46-1.88. Prismatic crystals frequent to occasional in both types of ray cells; absent in A. serrata (USw 34027); integumented; mostly not in chambered cells, occasionally in 2-chambered cells in A. integrifolia. Reddish-brown deposits common in rays. 1975] MILLER, FLACOURTIACEAE 63 Ludia Commerson ex Jussieu. Six or seven species from East Africa, Madagascar, and Mascarene Islands. Two specimens, both from her- barium sheets, representing two species. Pore structure not examined since the twig specimens were very small. Vessel elements medium-sized (373-712 mm.; average 543 pm.); per- ey PASE va Q al a yy Vae A ah i 0 4 f j i. hd ref ry oo’ o%, vo 0 8 r a” a ? + : ars ove * @ 4 * ’ Py ) o* 4° e ® a 9” 0 4* s + Vey ae | a5 i) r) one PTY TT y , ’ ’ 7 hy, + as ot hy a6 4% » eee svar ete ve a7 ' ‘ ‘ ete Ficures 24-27: 24, tangential section of Ahernia glandulosa showing medium- sized intervascular pits; 25, radial section of A. glan ulosa showing coarse vessel- ray pits; 26, tangential section of Calantica cerasifolia showing small inter- vascular pits; 27, radial section of C. cerasifolia showing fine vessel-ray pits and unilaterally compound pitting. 64 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 foration plates mostly simple, occasionally scalariform with a few bars or with vestigial bars; end-wall angles 10° to 45°. Fine spiral thickenings occasionally present throughout the vessels of L. scolopioides. Intervascu- lar and vessel-ray pitting alternate; pits circular to oval; small, 4-5 pm. Height of multiseriate portion of rays averages 452 pm., range 224-680 pm.; width mostly 2 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square; cell height 16-23 wm. Simply and scalariformly perforated ray cells present. Fiber-tracheids moderately short to medium-sized (627-1088 pm.; average 858 ym.) with mostly thin walls, 2-5 wm.; septate. F/V ratio averages 1.61, range 1.53-1.68. Pris- matic crystals abundant in upright ray cells, occasional in ray cells of multiseriate portion; integumented; mostly in 2- to 4-chambered upright ray cells. Xylosma G. Forster. About 100 species from the American and Asian tropics and warm temperate regions, absent in Africa. Thirteen specimens representing 10 species. Pore diameter very small to medium-sized (37-111 pm.; average 76 pm.); pores average 52 per cent solitary, range 31 to 74 per cent; radial multiples mostly 2 and 3, occasionally to 21; pores per square millimeter moderately numerous to very numerous (17-103 pores/mm.?; average 37 pores/mm.*). Vessel elements medium-sized to moderately long (633- 3 wm.; average 851 um.); perforation plates exclusively simple; end- wall angles 40° to 50°. Fine spiral thickenings common throughout the vessels of X. benthamii, X. congestum, X. flexuosa (SJRw 8806), X. longi- folium, X. pilosum, X. salzmanni, and X. venosum. Intervascular pitting alternate; pits circular to polygonal and small, 4-6 pm., in X. flexuosa (SJRw 8806), X. longifolium, X. nelsonii, X. panamensis, X. pilosum, and X. prunifolium; pits small to medium-sized, 6-8 pm., in X. benthamii, X. congestum, X. flexuosa (MADw 15706), X. salzmanni, and X. venosum. Vessel-ray pits circular to oval; similar in size to their respective inter- vascular pits. Height of multiseriate portion of rays averages 581 pm., range 318-1270 »m.; width 2 to 5 cells. Individual ray cells of multi- serlate portion as observed on the radial surface are mostly elongate and the cell height is 13-20 wm. in X. benthamii, X. congestum, X. longifo- lium, X. pilosum, X. prunifolium, and X. salzmanni (MADw 23744); the ray cell type is square to elongate and the cell height is 20-35 wm. in X. flexuosa, X. nelsonii, X. panamensis, X. salzmanni (SJRw 23792), and X. venosum. Simply perforated ray cells occur in X. flexuosa (SJRw 8806), X. longifolium, X. prunifolium (SJRw 22522) and X. salzmanni (SJRw 23792). Fiber-tracheids and libriform fibers medium-sized to moderately long (1128-1802 pm.; average 1457 pm.) with mostly thin to very thin, occasionally thick, walls, 2-6 »m.; septate. F/V ratio aver- ages 1.73, range 1.50-2.37. Prismatic crystals abundant to frequent in upright ray cells, mostly occasional to rare in ray cells of multiseriate por- tion; in X. flexuosa (MADw 15706) crystals are abundant in both types of ray cells; integumented; generally in 2-chambered upright ray cells, not in chambered cells in X. congestum and X. flexuosa (MADw 15706). 1975] MILLER, FLACOURTIACEAE 65 Reddish-brown deposits generally common in rays and fibrous elements; absent in X. congestum, X. panamensis, and X. salzmanni (SJRw 23792). Poliothyrsis Oliver. One to three species from China and Celebes. One specimen. Pore diameter very small to moderately small (40-56 pm.; average 46 vm.) ; pores average 50 per cent solitary; radial multiples mostly 2 and 3, occasionally to 11; pore clusters common; pores per square millimeter very numerous (79 pores/mm.”). Vessel elements moderately short to medium-sized (278-695 pm.; average 478 um.); perforation plates ex- clusively simple; end-wall angles 15° to 30°. Fine spiral thickenings fre- quent throughout vessel. Intervascular pitting alternate; pits circular to oval; medium-sized to large, 8-11 ym. Vessel-ray pits circular to linear; medium to coarse, 8-16 »m. Height of multiseriate portion of rays aver- ages 213 um. or 14 cells, maximum 227 um. or 17 cells; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial sur- face are mostly elongate; cell height 12—18 »m. Fiber-tracheids moderate- ly short to medium-sized (669-1086 »m.; average 874 ym.) with mostly very thin walls, 2-3 ym.; septate. F/V ratio averages 1.83. Prismatic crystals absent. Carrierea Franchet. Three or four species from southern and western China and Indo-China. Two specimens representing one species. Pore diameter moderately small (63-68 »m.; average 66 pm.); pores average 54 per cent solitary, range 51 to 56 per cent; radial multiples mostly 2 and 3, occasionally to 5; pores per square millimeter mostly very numerous (39-49 pores/mm.?; average 44 pores/mm.”). Vessel ele- ments medium-sized (705-730 ym.; average 718 wm.); perforation plates mostly simple and occasionally scalariform with vestigial and up to 3 bars which are 2 pm. thick; end-wall angles 15° to 40°. Very coarse spiral thickenings common throughout the vessel. Intervascular pitting alternate; pits mostly circular, occasionally to linear; mostly large, 10-14 pm.; OC- casionally very large, up to 16 pm. Vessel-ray pits circular to linear; medium to mostly coarse, 8-20 »m. Height of multiseriate portion of the rays averages 164 pm. or 8.5 cells, range 110 pm. (5 cells) to 217 pm. (12 cells); width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 15-20 um. Fiber-tracheids and libriform fibers medium-sized (1291-1354 pm. ; average 1322 ym.) with mostly very thin walls, 2—3 pm. ; only septate in nongelatinous and latewood fibrous elements. F/V ratio averages 1.84, range 1.83—1.84. Prismatic and druse crystals occasional to rare in both types of ray cells; integumented; not in chambered cells, but druse crystals generally occur in “paired” upright ray cells. Itoa Hemsley. Two species from eastern Asia and New Guinea. Two specimens representing one species. Pore diameter medium-sized (171-186 pm.; average 178 pm.) ; pores average 39 per cent solitary, range 30 to 48 per cent; radial multiples 66 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 mostly 2, occasionally to 4; pores per square millimeter moderately few (6-8 pores/mm.?; average 7 pores/mm.”). Vessel elements moderately long (847-887 pm.; average 867 »m.); perforation plates exclusively simple; end-wall angles 60° to 80°. Intervascular pitting alternate; pits mostly circular to polygonal; mostly large, 10-15 pm.; occasionally linear and very large (up to 120 wm.) in J. stapfii (MADw 2569). Vessel-ray pits circular to linear; coarse, 10-36 pm. Height of multiseriate portion of rays averages 462 ym., range 454-470 pm.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are elongate; cell height 18-23 ym. Fiber-tracheids and libriform fibers moderately long (1770-1836 pm.; average 1803 ym.) with thin to very thin walls, 2—4 »m.; septate in normal wood, but nonseptate in gelatinous fibers. F/V ratio averages 2.08, range 2.07—2.08. Prismatic crystals abundant in upright ray cells, rare or absent in ray cells of multiseriate portion; integumented; not in chambered cells. Idesia Maximowicz. Monotypic genus from China and Japan. Four specimens. Pore diameter moderately small (65-82 wm.; average 74 wm.); pores average 55 per cent solitary, range 46 to 61 per cent; radial multiples mostly 2 and 3, occasionally to 8; pores per square millimeter very nu- merous (44-61 pores/mm.?; average 55 pores/mm.”). Vessel elements medium-sized to moderately long (764-930 pm.; average 870 um.); per- foration plates mostly exclusively simple; in J. polycarpa (TWTw 155) mostly simple and rarely scalariform with up to 5 bars which are 2 pm. thick; end-wall angles 15° to 50°. Occasional tyloses in /. polycarpa (TWTw 155). Intervascular pitting alternate; pits circular, large, 10— 12 wm. Vessel-ray pits circular to oval, medium to coarse, 8-12 pm. Height of multiseriate portion of the rays averages 447 pm., range 383— 543 wm.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are elongate; cell height 18-25 pm. Fiber-tracheids medium-sized (1246-1626 pm.; average 1466 pm.) with thin to very thin walls, 2-4 um.; nonseptate. F/V ratio averages 1.68, range 1.62—1.75. Prismatic crystals frequent to rare in upright ray cells, absent in ray cells of multiseriate portion; completely absent in J. poly- carpa (SJRw 21863); integumented; not in chambered cells. Tribe Casearieae Casearia Jacquin. About 160 to 250 species from both the New and Old World tropics and subtropics. Eighty-six specimens representing 27 species from the New World. Description condensed from unpublished Master’s thesis, entitled “Systematic wood anatomy of the American Casearia Jacq.” (Miller 1966). Pore diameter mostly moderately small (46-108 »m.; average 75 um.) ; pores average 46 per cent solitary, range 22 to 78 per cent; radial multi- ples mostly 2, occasionally to 6; pores per square millimeter moderately 1975] MILLER, FLACOURTIACEAE 67 numerous to very numerous (10-96 pores/mm.?; average 31 pores/mm.?). Vessel elements medium-sized to very long (550~1350 pm.; average 937 vm.) ; perforation plates exclusively simple; end-wall angles 15° to 70°. Intervascular and vessel-ray pitting alternate, pits circular to polygonal ; mostly very small, 2~4 wm.; occasionally 5-6 »m. Height of multiseriate portion of rays variable, approximate range 300-2000 pm. and as high as 3000-7000 pm. in C. javitensis and C. iquitosensis; width mostly 2 to 3 cells and as wide as 12 cells in C. javitensis and C. iquitosensis. Indi- vidual ray cells of multiseriate portion as observed on the radial surface are square in some species and elongate in others; cell height less than 20 vm. in some species and more than 20 um. in others. Simply perforated ray cells present in some species. Fiber-tracheids and libriform fibers mod- erately short to moderately long (882-1960 »m.; average 1444 ym.) with mostly thin to thick walls; septate. F/V ratio averages 1.54. Prismatic crystals common in ray cells of most species, but variable in frequency and location; integumented; not in chambered cells. Reddish-brown deposits common in some species. Gossypiospermum Urban. Two to three species from Cuba and tropical South America. Two specimens representing one species. Pore diameter very small (35-48 um.; average 42 wm.); pores average 53 per cent solitary, range 50 to 56 per cent; radial multiples mostly 2 and 3, occasionally to 7; pores per square millimeter very numerous (70— 77 pores/mm.?; average 74 pores/mm.”). Vessel elements medium-sized (546-698 ym.; average 622 pm.); perforation plates exclusively simple; end-wall angles 30° to 50°. Intervascular and vessel-ray pitting alternate; pits circular to polygonal; very small, 3-4 pm. Height of multiseriate portion of rays averages 634 ym., range 451-818 pm.; width mostly 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 11-16 wm. Libriform fibers me- dium-sized (1031-1097 pm.; average 1064 pm.) with thick to very thick walls, 4-6 »m.; septate. F/V ratio averages 1.73, range 1.57-1.89. Pris- matic crystals in G. praecox (MADw 13780) abundant in both types of ray cells, in G. praecox (SJRw 2663) crystals abundant in upright ray cells and occasionally in ray cells of multiseriate portion; both have in- tegumented crystals and both do not have crystals in chambered cells. Laetia Loefling ex Linnaeus. Ten to 20 species from West Indies and Mexico to tropical South America. Thirteen specimens representing eight species. Pore diameter very small to moderately small (45-98 ym.; average 73 vm.); in L. procera medium-sized to moderately large (112-217 pm.; average 175 wm.); pores average 50 per cent solitary, range 28 to 84 per- cent; radial multiples mostly 2 and 3, occasionally to 9; pores per ae millimeter moderately numerous to very numerous (16-92 pores/mm.*; average 40 pores/mm.?); in L. procera, mostly moderately few (6-11 pores/mm,?; average 8 pores/mm.”). Vessel elements medium-sized to 68 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 very long (729-1400 p»m.; average 1007 wm.); perforation plates ex- clusively simple in all Laetia except L. calophylla, which has perforation plates that are mostly simple and occasionally scalariform with up to 15 or more bars which are 2 pm. thick and 4 wm. apart; end-wall angles 15° to 65°. Intervascular and vessel-ray pitting alternate; pits circular to polygonal; mostly very small, 2—5 »m.; in L. calophylla and L. procera small, 5-7 pm. Height of multiseriate portion of rays averages 1771 pm., range 878-4647 pm.; in L. cupulata rays are over 5 cm. high. Ray width 2 to 7 cells; in L. cupulata up to 15 cells or 240 pm. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 16-40 »m.; in L. micrantha very elongate and 11- 16 wm. in height. Simply perforated ray cells in L. apetala (SJRw 21437), L. calophylla, L. micrantha (SJRw 54698), L. suaveolens, and L. tern- stroemioides (SJRw 16706). Fiber-tracheids and libriform fibers medium- sized to very long (1262-2522 wm.; average 1727 wm.) with mostly thick to very thick walls, 3-14 »m.; septate. F/V ratio averages 1.72, range 1.53-2.09. Prismatic crystals abundant to frequent in both types of ray cells; in L. micrantha and L. procera crystals frequent in upright ray cells and rare in ray cells of multiseriate portion; crystals absent in L. calophylla and L. cupulata; integumented and not in chambered cells in all Laetia. Stalked and stalkless druse crystals in “paired’’ upright ray cells of L. procera (MADw 19646, MADw 21447). Reddish-brown de- posits abundant to frequent in ray cells and occasionally in fibrous ele- ments of L. cupulata, L. micrantha, and L. suaveolens. Hecatostemon Blake. Monotypic genus from Venezuela. One specimen. Pore diameter moderately small (56-80 »m.; average 60 wm.); pores average 53 per cent solitary; radial multiples mostly 2, occasionally to 3; pores per square millimeter numerous (25 pores/mm.?). Vessel ele- ments medium-sized to very long (397-1220 ym.; average 838 y»m.); per- foration plates exclusively simple; end-wall angles 35° to 45°. Inter- vascular and vessel-ray pitting alternate; pits circular to polygonal; very small, 3-4 wm. Height of multiseriate portion of rays averages 328 pm., maximum 368 wm.; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 13-18 ym. Simply perforated ray cells observed. Fiber-tracheids and libriform fibers medium-sized to moderately long (1250-1891 mm.; aver- age 1512 pm.) with mostly thin walls, 3-5 uwm.; septate. F/V ratio averages 1.80. Prismatic crystals frequent in upright ray cells and rare in ray cells of multiseriate portion; integumented; rarely in chambered upright ray cells Ryania Vahl. Eight to 14 species from northern tropical South America and Trinidad. Five specimens representing three species. Pore diameter very small to moderately small (39-75 ym.; average 54 pm.) ; pores average 70 per cent solitary, range 56 to 84 per cent; radial multiples mostly 2, occasionally to 7; pores per square millimeter very 1975] MILLER, FLACOURTIACEAE 69 numerous (47-98 pores/mm.”; average 72 pores/mm.2). Vessel elements mostly moderately long (864-1155 pm.; average 987 pm.); perforation plates exclusively simple in R. pyrifera and R. speciosa var. chocoensis ; mostly simple and rarely scalariform with vestigial or few bars in R. angus- tifolia; end-wall angles 20° to 40°. Intervascular and vessel-ray pitting alternate; pits circular to oval; small, 4-6 »m. Height of multiseriate por- tion of rays averages 5878 »m., range 5157-6817 pm.; width mostly 5 to 10 cells, up to 20 cells wide in R. pyrifera. Individual ray cells of multi- seriate portion as observed on the radial surface are square to elongate; cell height 17-40 um. Simply perforated ray cells in R. angustifolia (S}Rw 34111). Fiber-tracheids and libriform fibers moderately long (1320-1836 vm.; average 1578 wm.) with very thin to thick walls, 3-7 »m.; septate. F/V ratio averages 1.60, range 1.42-1.82. Prismatic crystals occasional to absent in both types of ray cells; no integuments observed; not in chambered cells. Reddish-brown deposits common in rays and fibrous ele- ments Zuelania A. Richard. Four or five species from Central America, West Indies, and Venezuela. Five specimens representing one species. Pore diameter moderately small (64-91 »m.; average 78 pm.); pores average 50 per cent solitary, range 31 to 62 per cent; radial multiples mostly 2, occasionally to 9; pores per square millimeter mostly numerous to very numerous (19-54 pores/mm.?; average 29 pores/mm.”). Vessel elements medium-sized to moderately long (770-1088 pm.; average 964 vm.); perforation plates exclusively simple; end-wall angles 20° to 45°. Intervascular and vessel-ray pitting alternate; pits circular to polygonal; small, 4-5 ym. Height of multiseriate portion of rays averages 1276 um., range 537-1637 »m.; width mostly 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elon- gate; cell height 20-35 yum. Simply perforated ray cells in Z. guidonia (MADw 5771, MADw 9882, and SJRw 16644). Fiber-tracheids and libri- form fibers medium-sized to moderately long (1168-1790 pm.; average 1569 um.) with mostly thin to thick walls, 3-7 wm.; septate. F/V ratio averages 1.62, range 1.52-1.73. Prismatic crystals usually abundant in both types of ray cells; integumented; not in chambered cells. Osmelia Thwaites. Four to 12 species from Ceylon, Malay Peninsula and Archipelago, Philippine Islands, and New Guinea. Six specimens rep- resenting two species. Pore diameter mostly moderately small (56-105 wm.; average 79 pm.) ; pores average 58 per cent solitary, range 32 to 82 per cent; radial multi- ples mostly 2, occasionally to 6; pores per square millimeter moderately numerous to mostly numerous (17—42 pores/mm.”; average 28 pores/ mm.?). Vessel elements very long to extremely long (1249-2029 pm. ; average 1607 p»m.); perforation plates mostly simple and rarely scalari- form with up to 15 or more bars; end-wall angles 10° to 65°. Inter- vascular and vessel-ray pitting alternate; pits circular to polygonal; very 70 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 small to small, 3-5 »m. Height of multiseriate portion of rays averages 1415 pm., range 971-2293 wm.; width 1 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 17-40 ym. Simply and scalariformly perforated ray cells in O. grandistipulata (SJRw 16046 and SJRw 16048) and O. philip- pina (USw 29390). Fiber-tracheids and libriform fibers very long (2317- 2991 um.; average 2583 um.) with thin to thick walls, 4-8 »m.; septate. F/V ratio averages 1.62, range 1.47-1.86. Prismatic crystals usually abundant or frequent in ray cells of multiseriate portion and occasional or absent in upright ray cells; not integumented; not in chambered cells. Ophiobotrys Gilg. Monotypic genus from tropical West Africa. One specimen, Pore diameter moderately small (64-88 »m.; average 74 »m.); pores average 65 per cent solitary; radial multiples mostly 2, occasionally to 3; pores per square millimeter numerous (21 pores/mm.”). Vessel elements moderately long to extremely long (854-2257 pm.; average 1462 pum.); perforation plates exclusively simple; end-wall angle 20° to 35°. Inter- vascular and vessel-ray pitting alternate; pits circular to polygonal; very small, 2-4 um. Height of multiseriate portion of rays averages 802 pm., maximum 1160 »m.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 17-24 ym. Libriform fibers moderately long to very long (1830-2745 pm.; average 2231 wm.) with mostly very thick walls, 6-9 pm.; septate. F/V ratio averages 1.53. Prismatic crystals abundant in upright ray cells and frequent to occasional in ray cells of multiseriate portion; integumented; not in chambered cells. Lunania Hooker. Eighteen to 20 species from West Indies, Central America, and tropical South America. Four specimens representing two species. Pore diameter moderately small (54-97 »m.; average 70 pm.); pores average 55 per cent solitary, range 44 to 77 per cent; radial multiples mostly 2 and 3, occasionally to 6; pores per square millimeter numerous to very numerous (35-42 pores/mm.?; average 38 pores/mm.?). Vessel elements moderately long to very long (1034-1388 um.; average 1207 um.) ; perforation plates exclusively simple; end-wall angles 30° to 45°. Inter- vascular and vessel-ray pitting alternate; pits circular to polygonal; very small to small, 3-6 um. Height of multiseriate portion of rays averages 1386 wm., range 758-2124 wm.; width 2 to 4 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to rectangular; cell height 20-35 um. Fiber-tracheids and libriform fibers moderately long (1715-2111 pm.; average 1889 ym.) with thin to very thick walls, 3-7 ym.; septate. F/V ratio averages 1.57, range 1.50-1.75. Prismatic crystals abundant or frequent in both types of ray cells; inte- gumented; not in chambered cells. 1975] MILLER, FLACOURTIACEAE 71 Tetrathylacium Poeppig & Endlicher. Four to five species from Central America and west tropical South America. Two specimens representing two species. Pore diameter moderately small (64-84 um.; average 74 p»m.); pores average 58 per cent solitary, range 43 to 72 per cent; radial multiples mostly 2, occasionally to 6; pores per square millimeter numerous (24-38 pores/mm.*; average 31 pores/mm.”). Vessel elements very long (1278- 1334 wm.; average 1251 um.); perforation plates exclusively scalariform with up to 15 or more bars which are 2—4 pm. thick and 4-16 pm. apart; end-wall angles 10° to 25°. Occasional tyloses occur in T. johansenii. Intervascular pitting alternate; pits circular to polygonal, occasionally oblong; mostly medium-sized, 8 10 »m.; occasionally very large, up to 18 pm. in T. macrophyllum. Vessel- -ray pits circular to linear; medium to coarse, 8-26 wm. Height of multiseriate portion of rays averages 1432 pm., range 1077-1787 »m.; width 2 to 5 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 20-35 ym. Fiber-tracheids and libriform fibers mod- erately long (2010-2158 »m.; average 2084 pm.) with very thin to thin walls, 3-6 um.; septate. F/V ratio averages 1.67, range 1.56-1.76. In T. johansenii prismatic crystals abundant in both types of ray cells; integ- umented; occasionally in 2-chambered upright ray cells. In T. macro- phylium, prismatic crystals abundant in upright ray cells and occasional in ray cells of multiseriate portion; integumented; not in chambered cells. Samyda Jacquin. Sixteen to 30 species from Mexico and West Indies. Two specimens representing two species Pore diameter very small (29-38 um.; average 34 »m.); pores average 65 per cent solitary, range 56 to 74 per cent; radial multiples mostly 2, occasionally to 6; pores per square millimeter very numerous ( 72-120 pores/mm.”; average 96 pores/mm.”). Vessel elements medium-sized (548-649 um.; average 599 um.); perforation plates exclusively simple; end-wall angles 20° to 45°. Intervascular and vessel-ray pitting alternate; pits circular to polygonal; very small, 24 pm. Height of multiseriate por- tion of rays averages 601pm., range 633-669 pm.; width 2 cells. Indi- vidual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 20-28 pm. Fiber-tracheids and libriform fibers mostly medium-sized (874-1161 »m.; average 1013 »m.) with thin to thick walls, 3-5 um.; septate. F/V ratio averages 1.69, range 1.58— 1.79. Prismatic crystals frequent in ray cells of multiseriate portion and occasional to rare in upright ray cells; integumented; not in chambered cells. Neoptychocarpus Buchheim. Two species from tropical South Ameri- ca. Two specimens representing one species Pore diameter very small (31-38 pm.; averdse 34 pwm.); pores average 58 per cent solitary; radial multiples mostly 2; occasionally to 7; pores per square millimeter very numerous (73-81 pores/mm.”; average 76 72 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 pores/mm.”). Vessel elements moderately long to very long (966-1327 pm.; average 1146 um.); perforation plates exclusively scalariform with up to 15 or more bars which are 2 pm. thick and 3—5 wm. apart; end-wall angles 10° to 20°. Intervascular and vessel-ray pitting alternate to sometimes opposite; pits circular to oval; very small, 2-4 um. Height of multiseriate portion of rays averages 1882 pm., range 1128-2635 pm.; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 28-40 wm. Libriform fibers moderately long (1669-1953 pm.; average 1811 um.) with thick walls, 10-14 »m.; septate. F/V ratio averages 1.60, range 1.47-1.73. Prismatic crystals abundant in ray cells of multiseriate portion and oc- casional to absent in upright ray cells; integumented; not in chambered cells. Reddish-brown deposits abundant in ray cells. Tribe Prockieae (Tiliaceae) Prockia P. Browne ex Linnaeus. Three to 18 species from the West Indies, tropical America, and Argentina. Two specimens representing one species. Pore diameter very small to moderately small (42-56 pm.; average 49 pm.); pores 38 per cent solitary, range 23 to 53 per cent; radial multiples and/or radial pore chains mostly 2, 3, and 4, occasionally to 14; pores per square millimeter very numerous (42-92 pores/mm.?; average 67 pores/mm.”). Vessel elements medium-sized (695—740 um.; average 718 wm.); perforation plates exclusively simple; end-wall angles 15° to 45°. Intervascular and vessel-ray pits alternate; circular to polygonal; small, 4-7 wm. Height of multiseriate portion of rays averages 310 pm., range 270-350 pm.; width 2 to 3 cells. Individual ray cells of multiseriate por- tion as observed on the radial surface are mostly elongate; cell height 12-16 wm. Fiber-tracheids and libriform fibers medium-sized (1102-1282 pm.; average 1192 ym.) with mostly thin walls, 3-5 ~m.; septate. F/V ratio averages 1.66, range 1.59-1.73. Prismatic crystals abundant to fre- quent in upright ray cells and occasional to absent in ray cells of multi- seriate portion; integumented; mostly in 2-chambered to rarely 4-cham- bered upright ray cells. Reddish-orange deposits abundant in rays of P. crucis (MADw 21831). Hasseltia H.B.K. Ten to 12 species from Mexico, Central America, and tropical South America. Six specimens representing four species. Pore diameter moderately small (51-95 »m.; average 63 pm.); pores average 60 per cent solitary, range 38 to 71 per cent; radial multiples mostly 2, occasionally to 5; pores per square millimeter numerous to very numerous (32-110 pores/mm.”; average 54 pores/mm.”). Vessel elements moderately long to very long (832-1250 pm.; average 1073 pm.); per- foration plates in H. floribunda mostly simple and occasionally scalariform with vestigial and up to 6 bars; exclusively simple in all other specimens of Hasseltia; end-wall angles 20° to 35°. Tyloses occur occasionally in 1975] MILLER, FLACOURTIACEAE 73 H. floribunda (MADw 12427), H. lateriflora (SJRw 20891), and H. laxi- flora. Fine spiral thickenings rarely occur in the vessel tails of H. flori- bunda (SJRw 12427), H. lateriflora, and H. cf. guatemalensis. Inter- vascular pitting alternate; pits circular to polygonal; small, 4—7 wm. Ves- sel-ray pits circular to linear; fine to coarse, 4-30 pm. Height of multi- seriate portion of rays averages 544 pm., range 298-765 um.; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 15-27 pm. Simply per- forated ray cells in H. floribunda (SJRw 12427), H. lateriflora, and H. laxiflora. Fiber-tracheids and libriform fibers medium-sized to moderately long (1416-2014 um.; average 1821 ym.) with very thin to thin walls, 3- 6 wm.; septate. F/V ratio averages 1.70, range 1.43-1.91. Prismatic crystals usually abundant to frequent in upright ray cells and occasional to rare in ray cells of multiseriate portion; in H. laxiflora crystals are abundant in both types of ray cells; in H. cf. guatemalensis crystals are rare in upright ray cells and absent in ray cells of multiseriate portion; all specimens of Hasseltia have prismatic crystals that are integumented and mostly in 2- to occasionally 4-chambered upright ray cells. Druse crystals rarely to occasionally in procumbent and 4-chambered up- right ray cells of H. floribunda (MADw 5747). Reddish-yellow de- posits frequent in ray cells of H. laxiflora. Pleuranthodendron L. O. Williams. One to four species from Mexico, Central America, and tropical South America. Six specimens represent- ing one species. Pore diameter moderately small (52-84 »m.; average 70 pm.) ; pores average 49 per cent solitary, range 30 to 74 per cent; radial multiples mostly 2 and 3, occasionally to 8; pores per square millimeter numerous to very numerous (32—68 pores/mm.?; average 44 pores/mm.*). Vessel elements medium-sized to moderately long (739-1067 pym.; average 971 um.); perforation plates simple and scalariform with up to 7 bars which are 2—4 wm. thick and 4—20 pm. apart; end-wall angles 20° to 50°. Fine spiral thickenings occur in the vessel tails. Intervascular pitting alternate; pits circular, occasionally linear; mostly medium-sized, 8-10 wm., Oc- casionally very large, up to 40 pm. Vessel-ray pits circular to linear; medium to coarse, 8-32 ym. Height of multiseriate portion of rays aver- ages 585 um., range 301-838 »m.; width 2 to 5 cells. Individual ray cells of multiseriate portion as observed on the radial surface are square to elongate; cell height 13-23 pm.; in P. mexicana (MADWwW 11004) cell height 18-28 pm. Scalariformly perforated ray cells common. Fiber- tracheids and libriform fibers medium-sized to moderately long (1436- 1907 um.; average 1684 ym.) with thin to thick walls, 3-6 pm.; septate. F/V ratio averages 1.74, range 1.57-1.94. Prismatic crystals more abun- dant in upright ray cells than in ray cells of multiseriate portion; integ- umented; mostly in 2-chambered upright ray cells, not in chambered cells in P. mexicana (MADw 11004). Reddish-brown deposits common in ray cells. 74 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Macrohasseltia L. O. Williams. Monotypic genus from Central Ameri- ca. Two specimens. Pore diameter moderately small (86-90 um.; average 88 »m.); pores average 48 per cent solitary, range 36 to 60 per cent; radial multiples mostly 2 and 3, occasionally to 6; pores per square millimeter moderately numerous (17—20 pores/mm.?; average 18 pores/mm.”). Vessel elements moderately long (816-1121 ym.; average 968 wm.); perforation plates mostly simple and occasionally scalariform with vestigial and up to 6 bars; end-wall angles 25° to 50°. Tyloses frequent in M. macroterantha (MADw 10286). Fine spiral thickenings occur in the vessel tails and occasionally throughout the vessel elements. Intervascular pitting alter- nate; pits circular to occasionally linear; mostly large, 10-14 pm., oc- casionally very large, up to 40 um. Vessel-ray pits circular to linear; coarse, 10-22 ym. Height of multiseriate portion of rays averages 223 pm. or 10 cells, range 220-226 um.; width 2 to 3 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly elongate; cell height 17-28 »m. Simply perforated ray cells in M. macro- terantha (MADw 10286). Fiber-tracheids and libriform fibers medium- sized to moderately long (1491-1877 wm.; average 1684 wm.) with thin walls, 3-5 pm.; septate. F/V ratio averages 1.75, range 1.67—-1.83. Pris- matic crystals abundant to occasional in upright ray cells and absent in ray cells of multiseriate portion; integumented; mostly in 2-chambered upright ray cells. Reddish-brown deposits abundant in ray cells of M. macroterantha (MADw 10305). Anomalous Genera The genera described in this category were once placed in the Flacour- tiaceae, but now are not considered by most taxonomists as belonging to this family. The following descriptions are complete descriptions and no characters are deleted. Ancistrothyrsus Harms secon Monotypic genus from west- ern tropical America. One specim Growth rings poorly defined Ps somevdiat distinct. Pores mostly cir- cular in outline; tangential diameter medium-sized to moderately large (174-260 pm.; average 228 wm.); pores average 89 per cent solitary; radial multiples mostly 2; pores per square millimeter moderately few (6 pores/mm.”). Vessel elements medium-sized to moderately long (366— 7 pm.; average 728 wm.); perforation plates mostly simple and occa- sionally scalariform with a few vestigial bars; end-wall angles 30° to 90°. Vessel-wall thickness 6 ym. Tyloses present, occasionally sclerotic; sometimes prismatic crystals in tyloses. Intervascular pitting alternate; pits mostly circular; medium-sized, 8-10 ym. Vessel-ray pits circular to somewhat oblong; medium to coarse, 8-14 ym. Rays of two types, uni- seriate homocellular rays composed entirely of upright ray cells and multi- seriate heterocellular rays with long uniseriate extensions (Heterogeneous 1975] MILLER, FLACOURTIACEAE fg Types I and IIA, Kribs 1935). Height of multiseriate portion of rays averages 2157 wm., maximum 5185 ym.; width 3 to 7 cells. Individual ray cells of multiseriate portion as observed on the radial surface are mostly square; cell height 30-40 »m. Imperforate tracheary elements are tracheids; medium-sized to moderately long (1037-1738 pm.; average 1418 nm.) with thin to thick walls, 5-7 um.; nonseptate. F/V ratio 1.95. Axial parenchyma abundant; vasicentric to somewhat aliform and apo- tracheal diffuse. Prismatic crystals occasional in axial parenchyma; fre- quent in ray cells of multiseriate portion and rare in upright ray cells; not integumented; not in chambered cells. Brown to reddish-brown de- posits frequent to occasional in axial and ray parenchyma. Barteria Hooker f. (Passifloraceae). Five to seven species from tropical Africa. One specimen. Growth rings poorly defined. Pores circular to oval in outline; tangen- tial diameter medium-sized (144-192 um.; average 164 ym.); pores aver- age 34 per cent solitary; radial multiples mostly 2, 3, and 4, occasionally to 6; pores per square millimeter moderately few (6 pores/mm.”). Ves- sel denients moderately long to very long (793-1708 »m.; average 1190 »um.); perforation plates mostly simple and occasionally scalariform with vestigial and up to 12 bars which are 2—4 um. thick and 4—10 pm. apart; end-wall angles 35° to 50°. Vessel-wall thickness 2-6 pm. Intervascular and vessel-ray pitting alternate; pits circular to oval; small to medium- sized, 5-8 um. Rays of two types, uniseriate homocellular rays composed entirely of upright ray cells and multiseriate heterocellular rays with long uniseriate extensions (Heterogeneous Type I, Kribs 1935). a. of multiseriate portion of rays averages 624 p»m., maximum 840 p» width 1 to 3 cells. Individual ray cells of pailtiievints portion as eevee on the radial surface are square to elongate; cell height 35-55 pm. Im- perforate tracheary elements are libriform fibers; moderately long to ex- tremely long (1860-3263 ym.; average 2511 pm.) with very thick walls, 9-12 pm.; nonseptate. F/V ratio 2.11. Axial parenchyma abundant; vasicentric and apotracheal in short tangential lines (reticulate). Pris- matic crystals absent. Reddish to yellowish-brown deposits abundant in rays. Paropsia Noronha ex Thouars (Passifloraceae). Thirteen to 20 species from tropical Africa, Madagascar, Sumatra, and the Malay Peninsula. Four specimens representing four species Growth rings poorly defined to absent. Pores circular to oval in out- line; tangential diameter moderately small to medium-sized (79-138 um.; average 111 »m.); pores average 52 per cent solitary, range 37 to 70 per cent; radial multiples mostly 2 and 3, occasionally to 10; pores per square millimeter few to moderately numerous (4-18 pores/mm.°; average 12 pores/mm.”). Vessel elements medium-sized to very long (655-1735 pm.; average 966 pm.); perforation plates exclusively simple; end-wall angles 30° to 50°. Vessel-wall thickness 4-6 »m. Intervascular and vessel-ray 76 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 pitting alternate; pits circular to oval; very small to small, 3-5 or in P. braunii and P. guineensis and small to medium-sized, 6—8 madagascariensis and P. vareciformis. Rays variable; mostly ieee homocellular rays or occasionally heterocellular rays with short uniseriate extensions (Heterogeneous Types I and IIA or Homogeneous Type I, Kribs 1935). Height of multiseriate portion of rays averages 2077 pm., range 979-3327 y»m.; width 2 to 5 cells. Individual ray cells of multi- seriate portion as observed on the radial surface are square to occasionally elongate; cell height 23-55 um. Simply perforated ray cells in P. braunii. Imperforate tracheary elements fiber-tracheids and libriform fibers; mostly very long to extremely long (2115-3884 p»m.; average 2570 pm.) with very thick walls, 5-14 »m.; nonseptate. F/V ratio averages 2.82, range 2.24-3.23. Axial parenchyma abundant, apotracheal in short tangential lines (reticulate). Large prismatic cryatals (~ 40 pm.) occur occasional- ly in axial parenchyma of P. braunii and P. vareci eas mis. Prismatic crystals generally more frequent in ray cells of multiseriate portion than in up- right ray cells; no integuments observed; not in chambered cells. Red- dish-brown deposits abundant in the axial and ray parenchyma of P. guineensis and P. vareciformis. Soyauxia Oliver (Medusandraceae or Passifloraceae). One to seven species from tropical West Africa. One specimen. Growth rings poorly defined. Pores angular in outline; tangential diameter moderately small (64-80 »m.; average 72 wm.); pores average 100 per cent solitary; pores per square millimeter numerous (21 pores/ mm.”). Vessel elements very long to mostly extremely long (1769-2653 pm.; average 2168 pm.); perforation plates exclusively scalariform, mostly over 15 bars which are 2-3 pm. thick and 6-10 pm. apart; end-wall angles 10° to 25°. Vessel-wall thickness 3-4 ym. Intervascular pits absent ex- cept on overlapping vessel-element ligules; no definite arrangement ne served; medium-sized, 6—10 wm. Vessel-ray pits circular to linear; dium to mostly coarse; 8-36 wm. Rays uniseriate and Scpppscl tees (Heterogeneous Type III, Kribs 1935); height averages 471 pm. or 17 cells, maximum 720 pm. or 27 cells. Individual ray cells as observed on the radial ec are square toward the middle of the rays and upright toward the end of the rays; square cell height 25-35 ym. Imperforate tracheary elements are tracheids; very long to extremely long (2318-2660 pm.; average 2912 »m.) with mostly very thick walls, 7-10 »m.; non- septate. F/V ratio 1.34. Axial parenchyma apotracheal in short tangential lines (reticulate) and diffuse. Prismatic crystals absent. Silica bodies abundant in square ray cells and occasionally in upright ray cells; 10-14 pm. in diameter. Reddish-brown deposits abundant in rays and fibrous elements. Peridiscus Bentham (Peridiscaceae). Monotypic genus from Venezuela and Brazil. One specimen. Growth rings absent. Pores circular to somewhat angular in outline; 1975] MILLER, FLACOURTIACEAE 77 tangential diameter mostly medium-sized (96~120 pm.; average 109 pm.); pores 45 per cent solitary; radial multiples mostly 2 and 3, occasionally to 5; pores per square millimeter moderately numerous (14 pores/mm.’). Vessel elements very long to extremely long (1550-2978 pm.; average 2218 p»m.); perforation plates exclusively scalariform, up to 15 or more bars which are 4-6 pm. thick and 8-12 pm. apart; end-wall angles 15° to 30°. Vessel-wall thickness 4-6 wm. Tyloses abundant to frequent. In- tervascular pitting opposite; pits circular to oval; large to mostly very large, 14-18 wm. Vessel-ray pits circular to linear; coarse, 10-20 um. Rays of two types: uniseriate homocellular rays composed entirely of upright cells and multiseriate heterocellular rays with long uniseriate ex- tensions (Heterogeneous Type I, Kribs 1935). Height of multiseriate portion of rays averages 1707 um., maximum 2947 »m.; width 1 to 2 cells. Individual ray cells of multiseriate portion as observed on the radial sur- face are mostly square; cell height 33-53 um. Imperforate tracheary ele- ments libriform fibers; very long to extremely long (2448-3794 um.; average 3134 um.) with very thick walls, 9-15 »m.; septate in part. F/V ratio 1.41. Axial parenchyma abundant; apotracheal in short tangential lines (reticulate) and diffuse. Prismatic crystals absent. White deposits occasionally occur in vessels and reddish-brown deposits are frequent in rays. Aphloia (DC.) Bennett (= Neumannia, Neumanniaceae). Four to six species from tropical East Africa, Madagascar, Seychelles Islands, and Mascarene Islands. Four specimens representing two species. Growth rings poorly defined. Pores circular to angular in outline; tan- gential diameter moderately small to medium-sized (78-120 pm.; aver- age 94 wm.); pores average 97 per cent solitary; radial multiples occa- sionally to 2; pores per square millimeter numerous to very numerous (32-61 pores/mm.?; average 43 pores/mm.*). Vessel elements mostly very long to extremely long (1051-2416 pum.; average 1452 pm.); per- foration plates exclusively scalariform; in A. theiformis (SJRw 32941) mostly scalariform and occasionally simple, mostly over 15 bars which are 2—4 um. thick and 2-8 pm. apart; end-wall angles 15° to 25°. Vessel- wall thickness 2—4 »m. Fine spiral thickenings present in vessel-element tails; occasionally to rarely throughout the vessel elements. Intervascular pitting alternate; pits circular to oval; small, 6-7 wm. Vessel-ray pits circular to occasionally linear; medium to coarse, 4-20 pm. Rays of two types: uniseriate homocellular rays composed entirely of upright cells (Heterogeneous Type I, Kribs 1935). Height of multiseriate portion of rays averages 3666 um., range 2711-4795 pm.; width 4 to 30 cells or 96- 520 wm. (mostly 191-349 pm.). Individual ray cells of multiseriate por- tion as observed on the radial surface are mostly elongate; cell height 19-32 pm. Scalariformly perforated ray cells occur in A. theiformis (SJRw 32941). Imperforate tracheary elements fiber-tracheids ; medium- sized to moderately long (1329-2214 »m.; average 1860 »m.) with mostly 78 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 thin to thick walls, 5-8 um.; in A. theiformis (SJRw 32914), thick to very thick, 11-13 pm.; septate. F/V ratio averages 1.80, range 1.72—1.85. Axial parenchyma rare to frequent; vasicentric and apotracheal diffuse. Prismatic crystals absent. Reddish-brown deposits abundant in rays. Asteropeia Thouars (Theaceae or Asteropeiaceae). Six to seven species from Madagascar. Three specimens representing two species. Growth rings absent. Pores circular to oval in outline; tangential di- ameter moderately small to mostly medium-sized (91-190 pm.; average 156 wm.); pores average 97 per cent solitary; range 93 to 100 per cent; radial multiples occasionally to 2; pores per square millimeter in A. rhopaloides moderately few (5-7 pores/mm.*); in A. micraster numerous (24 pores/mm.*). Vessel elements medium-sized (556-670 pm.; aver- age 627 wm.); perforation plates exclusively simple; end-wall angles 60° to 70°. Vessel-wail thickness 4-6 ym. Intervascular pits essentially ab- sent except on the vessel-element ligules; alternate; very small, 2—4 pm. Vessel-ray pits circular to oval; fine, 2-4 wm. Rays mostly uniseriate, rarely biseriate, and homocellular (Homogeneous Type III, Kribs 1935) ; height averages 194 um. or 7 cells, range 122-241 pm. or 6 to 9 cells. In- dividual procumbent cells as observed on the radial surface are elongate; cell height 12-25 wm. Imperforate tracheary elements fiber-tracheids; very short to medium-sized (828-1146 um.; average 1015 pm.) with very thick walls, 4-10 »m.; nonseptate. F/V ratio averages 1.61, range 1.49- 1.71. Axial parenchyma abundant; aliform to confluent. Prismatic crys- tals absent. Yellowish deposits abundant to occasional in vessels; in A. micraster and A. rhopaloides (SJRw 33869) deposits occur in axial and ray parenchyma. Lethedon Sprengel (= Microsemma Labillardiére Thymelaeaceae). Eleven species from New Caledonia and Queensland, Australia. Two specimens representing two species. Growth rings poorly defined. Pores circular to oval in outline; tan- gential diameter moderately small to medium-sized (72-121 pm.; aver- age 96 wm.); pores average 56 per cent solitary, range 33 to 79 per cent; radial multiples mostly 2, occasionally to 8; pores per square millimeter moderately numerous to numerous (13—22 pores/mm.2; average 18 pores/ mm.*). Vessel elements medium-sized (447-625 pm.; average 536 pm.); perforation plates exclusively simple; end-wall angles 25° to 70°. Vessel- wall thickness 4-6 pm. Intervascular and vessel-ray pitting alternate; pits circular to oval; small, 4-7 um. Rays uni- or biseriate and homo- cellular or heterocellular with 1 to 3 rows of upright cells (Heterogeneous Type IIA and Homogeneous Type I, Kribs 1935). Excluding upright ray cells, ray height averages 928 um., range 734-1122 pm.; individual ray cells as observed on the radial surface are square to elongate; cell height 26-40 wm. Imperforate tracheary elements tracheids; medium- sized (1175-1420 wm.; average 1298 ym.) with thin to thick walls, 5-8 vm.; nonseptate. F/V ratio averages 2.44, range 2.27—2.62. Axial paren- 1975] MILLER, FLACOURTIACEAE 79 chyma frequent; aliform to confluent. Prismatic crystals rare in upright ray cells and occasional to frequent in other ray cells; no integuments ob- served; not in chambered cells. Crystals absent in L. setosa. Triphyophyllum Airy Shaw (= Dioncophyllum, Dioncophyllaceae). Monotypic genus from Sierra Leone, Liberia, and Ivory Coast. Descrip- tion based on work by Metcalfe (1952) and one specimen. Growth rings absent. Pores mostly circular in outline; tangential diameter medium-sized to very large (165-350 ym.; average 300 pm.); pores mostly solitary; radial multiples occasionally to 2; pores per square millimeter very few to few (about 2 pores/mm.2). Vessel elements mod- erately short to medium-sized (286-530 wm.; average 412 p»m.); perfora- tion plates exclusively simple; end-wall angles slightly oblique to trans- verse. Vessel-wall thickness 12-16 pm. Intervascular pits rare and similar to vessel-ray pits; mostly alternate; circular to oval; medium-sized to large, 8-12 »m.; often with coalescent apertures. Rays uniseriate and homocellular, entirely composed of square or upright cells (Homogeneous Type III, Kribs 1935); height short to moderately high. Imperforate tracheary elements fiber-tracheids; very short to medium-sized (653-1102 pm.; average 861 wm.) with thin to thick walls; nonseptate. F/V ratio 2.09. Axial parenchyma frequent; vasicentric and apotracheal diffuse. Prismatic crystals absent. DISCUSSION COMPARATIVE ANATOMY OF THE SECONDARY XYLEM WITHIN FLACOURTIACEAE The xylem anatomy of Flacourtiaceae supports Dr. Hermann Sleumer’s contention (personal communication) that the ‘Flacourtiaceae as a fam- ily is a fiction; only the tribes are homogeneous.” Morphologically and anatomically, only a combination of characters can be used to circum- scribe and define Flacourtiaceae. Features of the wood common to most genera include the absence of axial parenchyma, presence of septate fi- brous elements, heterocellular rays with long uniseriate extensions, mod- erately small to medium-sized pore diameters, medium-sized to very long vessel and fibrous elements, a fibrous-element length to vessel-element length ratio of less than two, and prismatic crystals in the ray cells. Two of the more conspicuous features which vary are the vessel pits and per- foration plates. By combining these two variable features, I have been able to define six anatomical categories or groups into which the genera of Flacourtiaceae can be placed. Genera in groups I, IJ, and III have medium-sized to very large (7— over 15 »m.) intervascular pits and medium to coarse (7~ over 10 pm.) vessel-ray pits. In addition, the intervascular and vessel-ray pits do not have similar shapes. These combinations of pit- ting are called large vessel pitting throughout the remainder of the text (Ficures 24, 25). Genera in group I have exclusively scalariform perfora- tion plates; genera in group II have simple and scalariform perforation 80 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 plates; and genera in group III have exclusively simple perforation plates. Groups IV, V, and VI have intervascular pits that are similar in size and shape to the vessel-ray pits. Since the intervascular and vessel-ray pits are generally very small or small (< 8 yum.), this pitting is called small vessel pitting throughout the remainder of the text (FicurEsS 26, 27). Genera of Group IV have exclusively scalariform perforation plates; gen- era of group V have simple and scalariform perforation plates; and gen- era of group VI have exclusively simple perforation plates. In APPENDIX I each genus of the Flacourtiaceae is assigned to one or two of the six groups just described. For the most part, the two different pit sizes are specific for the tribes of Flacourtiaceae. The tribes Berberidopsideae, Pangieae, and Oncobeae contain genera with large vessel pits (groups I, II, and III); whereas the tribes Scolopieae, Homalieae, Banareae, and Casearieae (except Tetra- thylacium) have genera with small vessel pits (groups IV, V, VI). The tribe Flacourtieae has seven genera with large vessel pits and four with small vessel pits. Although there are other features in the sec- ondary xylem which further separate these genera, no single taxonomic character or combination of characters suggests that the genera of tribe Flacourtieae with large vessel pitting should be separated from those genera with small vessel pitting. Thus, anatomically the Flacourtieae appears to be a transitional group linking the tribes with large vessel pits to the tribes with small vessel pits. Since there appears to be a continuum, the Flacourtiaceae must be considered as a large heterogeneous family. However, future investigations in chemotaxonomy, morphology, palynol- ogy, and other fields may help to define more precisely the subfamilial or familial rankings of the tribes comprising the Flacourtiaceae. EVOLUTIONARY TRENDS WITHIN FLACOURTIACEAE For the most part, the secondary xylem supports the phylogenetic se- quences of tribes of Flacourtiaceae that were proposed by Warburg (1894) and Gilg (1925). Since the six anatomical groups generally con- form to the tribes of Flacourtiaceae, I attempted to determine the phylog- eny of the anatomical groups independently of the sequences of Warburg and Gilg. The only assumption which guided my comparisons is that the family Flacourtiaceae is monophyletic in origin. Bailey and Tupper (1918) established conclusively that within a given taxon simple perforation plates were more specialized than scalariform perforation plates. Consequently, genera of group I which have many ars, or genera of group IV which have small vessel pits and exclusively scalariform perforation plates with many bars appear to be the most primitive. When the floral characteristics and other features of the sec- ondary xylem (APPENDIX I) are examined in the genera of group I (most- ly in the Berberidopsideae), characters such as spirally arranged flower parts, numerous sepals and stamens, occasionally opposite intervascular pitting, and generally very long vessel elements are found to be present. 1975] MILLER, FLACOURTIACEAE 81 In contrast, Neoptychocarpus (tribe Casearieae), the only genus of group IV, has more specialized structures, such as whorled flower parts, four sepals and no petals, eight stamens, and moderately long vessel elements. Therefore, group I is potentially the most primitive of the six anatomical roups. Frost (1930b) demonstrated evolutionary trends from exclusively scalar- iform perforation plates with many bars to exclusively scalariform per- foration plates with fewer bars, to simple and scalariform perforation plates, to exclusively simple perforation plates. Thus group I, which has exclusively scalariform perforation plates, may have given rise to group II, which has simple and scalariform perforation plates. Also, group III, which has exclusively simple perforation plates, is more specialized than either groups I or II. Groups with small vessel pits also could have evolved in a like manner, but Neoptychocarpus, the only genus of group IV, is morphologically rather specialized for the Flacourtiaceae. In addi- tion, the wood anatomy of Neoptychocarpus appears to show affinities with the family Lacistemaceae, which is discussed later. It seems that unless Neoptychocarpus is derived from some nonflacourtiaceous group, it probably evolved from the genera in group I, since the genera of both these groups have exclusively scalariform perforation plates. Whether the genera of groups V and VI evolved from Neoptychocarpus or directly from group I or II cannot be determined with certainty. However, assuming a monophyletic origin for Flacourtiaceae, genera with large vessel pits ap- pear to have given rise to genera with small vessel pits. If we compare the generic composition of the six anatomical groups to the flacourtiaceous tribes of Gilg (1925), Warburg (1894), and Hutch- inson (1967), many similarities are noted. In Ficure 1 the phylogenetic sequence of Gilg’s tribes is shown along with the number of genera rep- resented by each anatomical group. Basing his conclusions primarily on gross morphology, Gilg considered the tribe Oncobeae to be the most primitive. Anatomically, Gilg’s Oncobeae has several genera with ex- clusively scalariform perforation plates and large vessel pits (group I). Thus the wood anatomy substantiates the primitive position of Oncobeae. Warburg (1894) and Hutchinson (1967) considered the genera of Gilg’s Oncobeae to constitute the base for two separate tribes. Warburg called his tribes Erythrospermeae and Oncobeae and considered the Erythrosper- meae to be the most primitive (Ficure 1). Hutchinson’s two tribes are the Oncobeae and Berberidopsideae, the latter of which he considered the most primitive. The genera of Berberidopsideae or Erythrospermeae be- long mainly to group I, while the genera of Oncobeae belong mainly to group II (ApPENprIx I). Consequently, the wood anatomy not only sup- ports the splitting of Gilg’s tribe Oncobeae into two separate tribes, but it also supports the phylogenetic specialization from group I (Warburg’s Erythrospermeae) to group II (Warburg’s Oncobeae) (Ficure 1). As shown in Ficure 1, the tribe Pangieae is more specialized than either of its possible ancestors, the Erythrospermeae or Oncobeae. Both these primitive tribes are characterized by genera in group I, but tribe 82 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Pangieae is characterized by genera mostly in groups II and III. As pro- posed, genera of group I probably gave rise to genera in groups IT and III. Thus, the wood structure confirms this part of the sequences. The tribe Scolopieae is derived from the tribe Oncobeae. The genera of Gilg’s Scolopieae belong to groups I, II, III, V, and VI; however, Hutchinson (1967) placed most of these genera elsewhere. Genera in Hutchinson’s Scolopieae and Banareae (formed from genera in Gilg’s Scolopieae) are in groups V and VI. As proposed, group VI is the most specialized group, since genera with small vessel pits are derived from genera with large vessel pits and group VI has exclusively simple per- foration plates. Thus, the xylem anatomy cannot negate the evolution of the Scolopieae (genera with small vessel pits) from the Oncobeae (genera with large vessel pits). The tribe Homalieae is derived from the Scolopieae. Since the genera of Homalieae belong mostly to group VI, the secondary xylem cannot ne- gate the derivation of tribe Homalieae from the Scolopieae. As discussed later, the wood of Homalieae, Banareae, and Scolopieae suggest a close alliance. As previously mentioned, the Flacourtieae is the only tribe in which some genera have large vessel pits and some have small vessel pits. The phylogenies of Warburg (1894) and Gilg (1925) show tribe Scolopieae as the origin of the Flacourtieae. If Hutchinson’s Scolopieae and Banareae replace the Scolopieae of Warburg and Gilg, then the derivation of tribe Flacourtieae from the Scolopieae suggests an interruption in the con- tinuum from large to small vessel pits. Tribe Oncobeae is characterized by large vessel pits; Hutchinson’s Scolopieae and Banareae are character- ized by small vessel pits; and tribe Flacourtieae is characterized by both large and small vessel pits. Thus, the secondary xylem indicates need for a change from the phylogenies of Warburg and Gilg. The anatomy sug- gests the derivation of both the Flacourtieae and Scolopieae from tribe Oncobeae. The Flacourtieae would then occupy a transitional position between the tribes characterized by large vessel pits and the tribe Ca- searieae, which generally has small vessel pits and exclusively simple per- foration plates. The xylem anatomy does not negate this derivation of the Casearieae from tribe Flacourtieae. TRIBAL AND GENERIC ANATOMY The generic composition of Hutchinson’s (1967) Flacourtiaceae gen- erally agrees with evidence from the secondary xylem. Hutchinson’s transfer of Paropsia and other genera to the Passifloraceae and the re- organization of the genera in Gilg’s Scolopieae to form tribes Scolopieae, Banareae, and Prockieae (Tiliaceae) are supported or at least are not ne- gated by the xylem anatomy. The relationships of the tribes of Flacour- tiaceae together with their respective genera and a group of “Anomalous Genera” are discussed in detail below. Tribe Berberidopsideae. The tribe Berberidopsideae is anatomically and 1975] MILLER, FLACOURTIACEAE 83 taxonomically the most primitive tribe of the Flacourtiaceae. The woods of genera in this tribe are homogeneous with the exception of Ahernia, Berberidopsis, and Streptothamnus. Of the eight genera examined, only Ahernia has the combination of exclusively simple perforation plates and large vessel pits (group III). Akernia also has many other distinctive fea- tures (APPENDIX I). These characteristics indicate affinities to certain genera in Flacourtiaceae; however, Sh Oe ate characters do not con- form these supposed affinities to Akernia Berberidopsis and Streptothamnus are “the two most primitive genera in the Flacourtiaceae. Anatomically both genera have nonseptate tracheids (FicurE 7), approximately 100 per cent solitary pores, and very high rays (over 1.5 cm.). These three characters, coupled with evidence from the floral morphology (Hutchinson 1967), not only ally these two genera, but also seem to put them somewhere between the Flacourtiaceae and Dil- leniaceae. Perhaps a new family could be established to contain them. This Dilleniaceae-Flacourtiaceae relationship will be discussed further under FAMILY RELATIONSHIPS Tribe Oncobeae. The genera in the tribe Oncobeae as formulated by Warburg (1894) or Hutchinson (1967) are scarcely distinguishable ana- tomically (APPENDIX I) and are related to the genera of the Erythrosper- meae (Warburg) or Berberidopsideae (Hutchinson). Evidence which supports the close relationship of tribes Erythrospermeae (Berberidopsi- deae) and Oncobeae is the occasional retention of opposite intervascular pitting and exclusively scalariform perforation plates in some species of Mayna and Carpotroche (Oncobeae). After the generic description of Buchnerodendron, Hutchinson (1967) stated that it is “‘an interesting genus providing a definite link with Tilia- ceae and resembling a Sparrmania [sic|.” The wood of Buchnerodendron is similar to that in other genera of Oncobeae. An examination of a specimen of Sparmannia africana L. f. (SJRw 33838) from South Africa revealed many differences which militate against any close alliance between Buchner- odendron and Sparmannia. Tribe Pangieae. Although the wood anatomy of the genera of Pangieae (excluding Goethalsia) is somewhat homogeneous, Hydnocarpus (sensu lato) seems to be distinct. Hutchinson (1967) considers Hydnocarpus and Taraktogenos to be separate but related genera; however Warburg (1894), Gilg (1925), and Sleumer (1938, 1954) consider these two gen- era, together with Asteriastigma, as one genus — Hydnocarpus. In addi- tion, Schaeffer’s (1972) study of pollen morphology supports Sleumer and others. All species of Hydnocar pus (sensu lato) have exclusively scalariform perforation plates and all species, except H. sumatrana (Miq.) Koord., contain vitreous silica (FIcuRE 6). Since no anatomical feature could be found to support the segregation of Hydnocarpus (sensu lato), the xylem anatomy favors the submersion of Taraktogenos and Asteriastig- ma in Hydnoc arpus. Hydnocarpus is distinctive and primitive in that it is the only genus of 84 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 the Pangieae with exclusively scalariform perforation plates and opposite or opposite to alternate intervascular pitting. In addition, Hydnocarpus has the lowest fiber length to vessel length ratio (1.56) of the Pangieae, some of the longest vessel and fibrous elements of the Flacourtiaceae, and is the only genus of the Flacourtiaceae producing vitreous silica. Thus, Hydnocarpus is undoubtedly the most primitive genus in tribe Pangieae. Based on the structure of the wood, a more likely placement of Hydnocar- pus would be in either the tribe Berberidopsideae or the Oncobeae. The floral morphology, however, does not suggest any such transfer, although the pollen morphology does support the view that Hydnocarpus is some- what isolated. Schaeffer (1972) concluded that only Chlorocarpa (no wood available) and Neoptychocarpus have pollen that is similar to that of Hyd- nocarpus. Although Neoptychocarpus is in a different and more advanced tribe (the Casearieae), the wood of Neoptychocarpus is not only primitive but is also similar to the wood of Lacistema. Hydnocarpus, Neoptycho- carpus, and Lacistema do not appear to be closely related florally, but there do seem to be some common bonds which need further examination. Evidence from chemotaxonomy suggests a link betwen tribe Oncobeae and Hydnocarpus. Of the genera of tribe Pangieae, only species of Hydno- carpus produce chaulmoogra oil (i.e. cyclopentene fatty acids). Pangium and Gynocardia were once thought to contain chaulmoogra oil, but they are now known to contain the cyanogenetic heteroside, gynocardoside (Alston & Turner 1963). Other genera in the plant world known to contain chaulmoogra oil are Carpotroche, Mayna, Lindackeria, Oncoba, and Caloncoba, all of which belong to the tribe Oncobeae. Supposedly Roig and Rodriguez (1944) isolated chaulmoogra oil from some genera in the tribe Casearieae, but Gibbs (1945) stated that only genera in the tribes Pangieae and Oncobeae contain chaulmoogra oil. With corrobora- tive evidence from chemotaxonomy, pollen morphology, and wood anat- omy, it appears that the genus Hydnocarpus is somewhat isolated. Also, Hydnocarpus has retained some primitive genetic structure of the ancient gene pool from which the tribes Pangieae and Oncobeae and possibly the genera Neoptychocarpus and Lacistema may have evolved. Tribe Scolopieae. As formulated by Hutchinson (1967), the tribe Sco- lopieae consists of Scolopia, Pseudoscolopia, and Dioncophyllum of Gilg’s Scolopieae, the genera of Gilg’s tribe Phyllobotryeae, and a few genera described since 1925. Of these nine genera only Scolopia, Bartholomaea, and Dioncophyllum (including Triphyophyllum) were available for study. Since Triphyophyllum is considered by most taxonomists as an aberrant genus in the Flacourtiaceae, it is discussed later under the heading “Anomalous Genera.” Of the other two genera, only Scolopia is repre- sented in my study by an ample number of wood specimens. From ana- tomical features summarized in APPENDIX I, the secondary xylem of Sco- lopia and Bartholomaea can be compared. Although a few features are inconsistent, there is enough similarity to conclude that Scolopia and Bartholomaea are allied and belong in the same tribe. 1975] MILLER, FLACOURTIACEAE 85 Tribes Banareae and Homalieae. Banara and Pineda of Gilg’s tribe Scolopieae, together with Trimeria of Gilg’s tribe Homalieae and the anomalous genus Asteropeia, form Hutchinson’s new tribe Banareae. Since Asteropeia is anomalous, it is considered under “Anomalous Gen- era.” In their xylem anatomy, Banara, Pineda, and Trimeria are so sim- ilar that they are scarcely separable on this basis. Of the seven genera of Homalieae only Homalium and Calantica were available for study. These two genera have very similar secondary xylem, and in some cases species of Calantica cannot be distinguished from some species of Homalium From the summary of anatomical features in APPENDIX I, a comparison can be made of the xylem anatomy in genera of the Scolopieae, Banareae, and Homalieae. It is apparent that the genera in these three tribes are allied and practically indistinguishable on anatomical grounds. Thus, whether the genera of tribes Banareae and Scolopieae constitute one tribe and two subtribes or two separate tribes or whether the genus 7rimeria is in the Homalieae or Banareae is strictly a matter for taxonomic judg- ment. Tribe Prockieae (Tiliaceae). The placement and relationships of the genera of the Prockieae are not fully understood. Within the Prockieae, Prockia, Hasseltia, Pleuranthodendron (= Hasseltiopsis), and Macro- hasseltia (included here by Williams 1961) were examined (APPENDIX I). Prockia belongs in the anatomical group VI and the other three genera Prockia differs from these genera in that it has long radial multiples and/ or radial pore chains, no spiral thickenings in the vessels, no perforated ray cells, exclusively simple perforation plates, and small vessel pitting (group VI). Other features such as ray height and width and crystal type and arrangement tend to unite Prockia with the other genera of tribe Prockieae; however, the woods of Prockia, Banara, Scolopia, and Homa- lium are so similar that it is difficult to distinguish among some species of these genera. Although the secondary xylem of Prockia suggests a close alliance with the Scolopieae, Banareae, and Homalieae, Prockia and the other genera of the Prockieae are united florally by their common pos- session of axile placentation. Thus, Prockia should remain united with the other genera of the Prockieae. Gilg (1925) placed the genera of the Prockieae in subtribe Prockiinae of tribe Scolopieae (including the Banareae). The wood anatomy can support Gilg’s arrangement since all the genera of the Prockieae are grouped together in the subtribe Prockiinae and a relationship to the genera Scolopia and Banara is implied by the inclusion of all these genera in the tribe Scolopieae. The xylem anatomy could also support the placement of tribe Prockieae in the family Elaeocarpaceae. On the basis of the axile placentation and valvate calyx, Hutchinson (1967) established the tribe Prockieae in the 86 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Tiliaceae (including the Elaeocarpaceae). For the same reasons, Bentham and Hooker (1862) included the known Prockieae as a separate tribe in their Series B Heteropetalae, a taxon equivalent to the Elaeocarpaceae. A comparison of Kukachka and Rees’ (1943) description of the xylem anatomy of Tiliaceae and Elaeocarpaceae with the secondary xylem of tribe Prockieae suggests a close alliance between tribe Prockieae and the Elaeocarpaceae. Keating (1973) notes that the Scolopieae, Banareae, Homalieae, Fla- courtieae, and Prockieae all have similar pollen morphology. He also notes a similarity between the pollen of tribe Homalieae (and presumably the Prockieae) and the family Elaeocarpaceae. The evidence from pollen morphology and wood anatomy appears then to suggest that tribe Prockieae is closely allied to both the Flacour- tiaceae and the Elaeocarpaceae. Thus the correct placement of the Prockieae is still somewhat in doubt. Evidence from the wood structure also reveals a reduction series in the Prockieae. The intervascular pits are large (10-14 pm.) in Macrohasel- tia, medium-sized (8-10 um.) in Pleuranthodendron, and small (4-7 pm.) in Hasseltia. In addition, the vessel-ray pitting is coarse (over 10 pm.) in these three genera, but Prockia has vessel-ray and intervascular pits that are not only the same size but also small (4-7 um.). Since Prockia has exclusively simple perforation plates and the other three genera be the most specialized of these four genera. Thus, a reduction in the size of the vessel pitting from Macrohasseltia to Prockia seems plausible. Whether there are any evolutionary trends related to this reduction series, however, cannot be determined at this time. Tribe Flacourtieae. The xylem anatomy in the Flacourtieae (excluding Aphloia) is rather diverse. The anatomical groups represented in the tribe are as follows: group II — Bennettiodendron, Azara (rarely group 1), Carrierea, and Olmediella; group III — Poliothyrsis, Itoa, and Idesia (rarely group II); group V— Dovyalis; group VI — Xylosma and Fla- courtia (rarely group V). It is apparent that two groups of genera are present in the Flacourtieae. One group has large vessel pitting and the other group has small vessel pitting. These two groups are rather distinct and except for characters present in most genera of the Flacourtiaceae, the only feature which these two groups have in common is the presence of integumented prismatic crystals usually more abundant in the upright ray cells than in the ray cells of the multiseriate portion of the ray. The seven genera with large vessel pits can be separated into two groups based on the size of the intervascular pits. One group has inter- vascular pits over 10 »m. in diameter and the other group has some inter- vascular pits under 10 pm. in diameter. The four genera with intervascular pits over 10 wm. do not have prismatic crystals in chambered ray cells and some of their fibrous elements are nonseptate. Of these genera, Carrierea and Olmediella have coarse spiral thickenings throughout the 1975] MILLER, FLACOURTIACEAE 87 vessels (FIGURES 16, 18). This seems to indicate that these two genera are more closely allied to each other than to Jdesia and Jtoa. The three genera with large vessel pitting and some intervascular pits under 10 pm. have septate fibrous elements. Thus, based on the wood structure, Poliothyrsis, Bennettiodendron, and Azara appear to be more closely related to each other than to the other four genera with large vessel pitting. Of the four genera with small vessel pits, only Dovyalis has a slightly different wood structure. Dovyalis lacks spiral thickenings in the vessels and also does not have prismatic crystals in chambered upright ray cells. Recently, Sleumer (1972a) stated that Ludia is morphologically very similar to Scolopia (tribe Scolopieae). As might be expected, this morpho- logical similarity extends into the secondary xylem. In addition, species of Ludia, Flacourtia, and Xylosma of the Flacourtieae, Scolopia and Bar- tholomaea of the Scolopieae, Homalium and Calantica of the Homalieae, Banara, Pineda, and Trimeria of the Banareae, and Prockia of the Prock- ieae (Tiliaceae), as previously mentioned, are for the most part indistin- guishable anatomically (APPENpIx I). Keating (1973) has found that the pollen morphologies of these genera are also scarcely distinguishable from each other. Tribe Casearieae. For the most part, the wood structure of tribe Casearieae is homogeneous (APPENDIX I). Tetrathylacium and Neoptychocarpus are exceptions to this homogeneous structure. Tetrathylacium is the only genus in Casearieae which has exclusively scalariform perforation plates and large vessel pitting (group I). The floral morphology of Tetrathylacium is similar to that of other genera in the Casearieae, and its position in the tribe has not been questioned by taxonomists. Although the structure of the wood is primitive, Tetrathy- lacium has a specialized floral structure. Apparently, Tetrathylacium has retained some primitive features of the xylem while the floral morphology evolved. Thus, the xylem anatomy of Tetrathylacium suggests that the forebears of the genera of Casearieae evolved from some ancient group which had exclusively scalariform perforation plates and large vessel pits (i.e. genera of group I). The data in APPENDIX I suggest that the tribe Berberidopsideae contains the ancestral stock of the Casearieae. This proposed line of evolution also agrees with the phylogenetic sequences of Warburg (1894) and Gilg (1925) (Ficure 1). Neoptychocarpus is the only genus in the Flacourtiaceae which has ex- clusively scalariform perforation plates and small vessel pitting (group IV); otherwise, the secondary xylem is similar to that of other genera of Casearieae (APPENDIX I). On the other hand, the intervascular pit- ting sometimes tends to be opposite, although it is not clear whether the pits are opposite because of genetic influences or opposite through crowd- ing. Monachino (1948), however, considered that Neoptychocarpus was unquestionably correctly placed in the Flacourtiaceae. Whether the pres- ence of exclusively scalariform perforation plates is the retention of a primitive flacourtiaceous feature or whether features of Neoptychocarpus 88 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 and the other genera of Casearieae are similar because of convergent or parallel evolution is difficult to ascertain. If Neoptychocarpus belongs in the Casearieae, then it probably evolved along the same lines as Tetrathylacium. Like Tetrathylacium, Neoptycho- carpus has retained the primitive scalariform perforation plates which are typical of the Berberidopsideae. However, in contrast to Tetrathy- lacitum, Neoptychocarpus developed small vessel pitting. Another possible line of evolution is through the genus Lacistema (Lacis- temaceae). Assuming that opposite intervascular pits in Neoptychocar- physical or mechanical adjustments, then the secondary xylem of Lacis- tema is similar to that of Neoptychocarpus. On the basis of floral morphol- ogy, Chirtoiu (1918) suggested that Lacistema is more closely related to the Flacourtiaceae than to any other family. Krause (1925) specifically suggested Prockia (Flacourtiaceae) as the closest genus to Lacistema. Hutchinson (1967) implied some relationship, since he placed the Lacis- temaceae and Flacourtiaceae in the order Bixales. Although the floral structure of Neoptychocarpus is not closely similar to that of Lacistema, the wood anatomy does imply an alliance. However, until more evidence is found to support a closer relationship between Neoptychocarpus and Lacistema, Neoptychocarpus should remain in the Casearieae. As mentioned before, Hydnocarpus and Neoptychocarpus have similar pollen, representing a rare type in the Flacourtiaceae (Schaeffer 1972). The similarity in secondary xylem between these two genera is no greater, however, than that between Neoptychocarpus and any other genus belong- ing to group I (ApPpENDIx I). Neoptychocarpus has small vessel pitting and integumented prismatic crystals, whereas Hydnocarpus has large ves- sel pitting and nonintegumented prismatic crystals. Also, Hydnocarpus has spiral thickenings in the vessel-element tails of some species and vitreous silica in the vessels of most species. Perhaps Hydnocarpus, as well as Lacistema, is closely allied to Neoptychocarpus; however, these relation- ships are not clear. Anomalous Genera Paropsia, Barteria, and Ancistrothyrsus (Passifloraceae). Hutchinson (1967), Sleumer (1970), and others consider the tribe Paropsieae of Gilg’s Flacourtiaceae as a member of the Passifloraceae. In their study of the systematic anatomy of the Passifloraceae, Ayensu and Stern (1964) concluded that Paropsia and related genera are anatomically more similar to Passifloraceae than to Flacourtiaceae. The wood structure of Paropsia, Barteria, and Ancistrothyrsus, differs greatly from that in the Flacourtia- ceae. With anatomical evidence and with corroborating observations pre- sented by Ayensu and Stern (1964), Den Berger (1928), Tupper (1934), Sleumer (1970), De Wilde (1971), and Hutchinson (1967), I concur that Paropsia, Barteria, and Ancistrothyrsus are members of the Passi- floraceae and not of the Flacourtiaceae. 1975] MILLER, FLACOURTIACEAE 89 Soyauxia (Passifloraceae? Medusandraceae?). Soyauxia of Gilg’s Parop- sieae seems out of place in either the Passifloraceae or the Flacourtiaceae. The features of Soyauxia (APPENDIX I) suggest a relationship with a primitive group of plants, but probably not the primitive Berberidopsis and Streptothamnus of the Flacourtiaceae; at least no close relationship is evident. Soyauxia, Berberidopsis, and Streptothamneus have some fea- tures in common, such as solitary pores, long vessel and tracheid ele- ments, and exclusively scalariform perforation plates; however, the struc- ture of the rays and the axial parenchyma differs in each genus. Soyauxia has uniseriate rays and an abundance of parenchyma and silica in the ray cells, whereas Berberidopsis and Streptothamnus have large rays and lack axial parenchyma and silica. On the basis of a central column in the ovary, Brenan (1953) placed Soyauxia in Medusandraceae. Studying the anatomy of Soyauxia, Met- calfe (1962) stated, “. . . although there are points of similarity in the structure of these two genera, Medusandra differs from Soyauxia in pos- sessing a well developed system of secretory canals.” Metcalfe argued that this anatomical difference together with morphological differences supports the view that Soyauxia and Medusandra are not closely related. Using the anatomy of Peridiscus (Peridiscaceae) as supporting evidence, Metcalfe also contended that Soyauxia is more closely allied to the Fla- courtiaceae than to the Passifloraceae. The xylem anatomy does not sug- | gest the placement of Soyauxia in the Flacourtiaceae, Passifloraceae, or Peridiscaceae, and until more evidence is available, the placement of Soy- auxia must remain uncertain. Peridiscus (Peridiscaceae). Both Warburg (1894) and Gilg (1925) indi- cated that Peridiscus is questionably a member of the Flacourtiaceae. In 1959, Hutchinson accepted the Peridiscaceae and placed it in his Tiliales. Later, in 1967, Hutchinson placed the Peridiscaceae in his Bixales and near the Flacourtiaceae. Sandwith (1962) added the genus Whittonia to the Peridiscaceae, and in a sequel to his paper, Metcalfe (1962) dis- cussed the systematic anatomy of the Peridiscaceae. Metcalfe concluded that, ‘‘Peridiscaceae may quite well be allied to the Flacourtiaceae.” In some respects the wood anatomy of Peridiscus is similar to that of some primitive genera of Flacourtiaceae, such as Erythrospermum. Both these genera have exclusively scalariform perforation plates, opposite intervas- cular pitting, and large vessel pitting. In addition, the ray structure, fiber length to vessel length ratio, and vessel and fibrous-element length are similar (ApPENDIx I). The major differences between Peridiscus and most Flacourtiaceae are the absence of prismatic crystals, the presence of many nonseptate fibrous elements, and the abundance of either diffuse or reticulate (in short tangential lines) apotracheal parenchyma. Therefore, I agree with Metcalfe (1962), who believes that Peridiscus is definitely not a member of the Flacourtiaceae; yet the secondary xylem does sug- gest that Peridiscus is allied to the family. Aphloia (= Neumannia, Neumanniaceae). Although the floral morphol- | 90 JOURNAL OF THE ARNOLD ARBORETUM [ VoL. 56 ogy is somewhat specialized, Aphloia shows a primitive xylem anatomy. Hutchinson (1967) placed Aphloia in the tribe Flacourtieae. Under the name Neumannia, Warburg (1894) and Gilg (1925) also placed Aphloia in the Flacourtieae. According to Willis (1966), Van Tieghem proposed Neumannia as the basis of the monotypic family Neumanniaceae, which showed uncertain affinities to the Flacourtiaceae. The woods of Aphloia and the primitive genera Berberidopsis and Streptothamnus are similar. In APPENDIX I the anatomy of these genera can be compared. For the most part, the floral morphology of Aphloia seems to resemble the genera of tribe Flacourtieae. However, Willis (1966) notes that there is “per- haps some justification for maintaining the family Neumanniaceae dis- tinct.” It is possible that ApAloia retained the primitive wood structure of the ancestral stock of tribe Flacourtieae while the floral structure evolved along the same line as the other genera of the Flacourtieae. How- ever, I believe that Aphloia evolved from the same forebears as the genera of the Flacourtieae, but deviated sufficiently from the evolutionary line of the Flacourtiaceae to produce a combination of characters which could justify consideration of placement in a separate family. Asteropeia (Asteropeiaceae). Hutchinson (1967) included Asteropeia in his tribe Banareae, but most taxonomists assign this genus elsewhere, gen- erally to the Theaceae. According to Willis (1966), Takhtajan proposed the monotypic family Asteropeiaceae, showing possible affinities with the Linaceae, Tetrameristaceae, or Flacourtiaceae. Based on the wood anatomy (APPENDIx I), Asteropeia is not a member of the Flacourtiaceae and there does not seem to be any indication of close affinities with this family. According to Record (1942), the wood of Asteropeia is not related to that of the Theaceae. Thus, it seems that Takhtajan’s monotypic fam- ily Asteropeiaceae is the best position for Asteropeia, at least until more information is available to indicate its affinity elsewhere. Goethalsia (Tiliaceae). The floral and wood structure of Goethalsia is not flacourtiaceous. Generally Goethalsia is placed in the Tiliaceae, but following the recommendation of Gleason (1934), Hutchinson (1967) placed Goethalsia in the tribe Pangieae (Flacourtiaceae). In 1934, Rec- ord stated that “. . . the pith, bark and wood of Goethalsia all suggest Tiliaceae and not Flacourtiaceae.”’ Burret (1934), a specialist in Tiliaceae, agreed with Record (1934) and noted that Gleason (1934) misinterpreted the flower structure of Goethalsia. When Kukachka and Rees (1943) studied the wood anatomy of the Tiliaceae, they found no evidence to support Gleason’s transfer of Goethalsia to the Flacourtiaceae. Features found in Goethalsia and not in genera of the Flacourtiaceae include an abundance of axial parenchyma and nonseptate fibrous elements. Thus, I concur with Record (1934), Burret (1934), and Kukachka and Rees (1943) that Goethalsia is tiliaceous, not flacourtiaceous. Triphyophylium (Dioncophyllaceae). The xylem anatomy of Triphyophyl- lum (APPENDIX I) is definitely unusual for Flacourtiaceae. Hutchinson 1975] MILLER, FLACOURTIACEAE 91 (1967) submerged Triphyophylium in Dioncophyllum and placed it in the tribe Scolopieae. Both Warburg (1894) and Gilg (1925) also in- cluded Dioncophyllum in their Scolopieae. In 1952, Airy Shaw proposed the family Dioncophyllaceae. He stated that ‘“Dioncophyllum had nothing whatever to do with the Flacourtiaceae.” In an anatomical study, Metcalfe (1952) supported Airy Shaw and suggested that “. . . there may well be affinities between the Dioncophyllaceae and the Nepentha- ceae and between the Dioncophyllaceae and Droseraceae.” From personal observation, the wood anatomy supports the assertions of both Airy Shaw (1952) and Metcalfe (1952). Lethedon (Thymelaeaceae or Aquilariaceae). Warburg (1894) placed Lethedon (= Microsemma) in a questionable group of Flacourtiaceae. Gilg (1925) excluded Lethedon from the Flacourtiaceae and placed it in the Thymelaeaceae. Hutchinson (1967) placed Lethedon in the Aquilaria- ceae, a segregate of Gilg’s Thymelaeaceae. The secondary xylem of Lethedon (APPENDIX I) is definitely not flacourtiaceous, and from the morphology it seems likely that Lethedon is related to the Thymelaeaceae or Aquilariaceae. FAMILY RELATIONSHIPS Ancestral stock. Judging from the primitive wood structure in some branches of the extant Flacourtiaceae, immediate progenitors of the plants we recognize today as Flacourtiaceae must have been relatively unspe- cialized. According to Hutchinson (1967), the family Flacourtiaceae is a somewhat indeterminate and intermediate group of plants, somewhere between the Dilleniaceae (Dilleniales) and the order Tiliales. Takhtajan (1969) also suggests a Dillenialean ancestry, but Cronquist (1968) pro- poses a Thealian one Many characters in the Dilleniaceae and in the two primitive genera of Flacourtiaceae are parallel. Features of the wood which occur in the Dilleniaceae but do not appear in Berberidopsis and Streptothamnus in- clude larger and fewer pores, more axial parenchyma, and raphide crystals. There are free carpels and distinct sepals and petals in the Dilleniaceae but not in Berberidopsis and Streptothamnus. The secondary xylem of the Dilleniaceae is also similar to that of the Theaceae, and Dickison (1967) suggests that the similarity of wood structure supports the taxo- nomic alliance between the Dilleniaceae and Theaceae. As might be ex- pected, the woods of Berberidopsis and Streptothamnus resemble the woods of the Theaceae. Features not found in Berberidopsis, Streptothamnus, or the Dilleniaceae, but which do occur in the Theaceae, include shorter and narrower rays, a 3—5-locular ovary, scanty endosperm, and axile placen- tation. Since there appears to be more similarity among Berberidopsis and Streptothamnus and the Dilleniaceae, the ancestral stock of the Fla- courtiaceae would appear to lie in the Dilleniaceae as opposed to the Theaceae. 92 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Cronquist derives the family Flacourtiaceae (Violales) from the Theales and through a different line of evolution also derives the Elaeocarpaceae (Malvales) from the Theales. He notes a similarity between Flacourtia- ceae and Elaeocarpaceae, but concludes that their similarity is a product of common ancestry. Because of similar secondary xylem and pollen morphology of the Flacourtiaceae and Elaeocarpaceae, I would expect a more direct line of evolution from the Dilleniales through the Flacourtiaceae to the Tiliales or Malvales, as proposed by Takhtajan (1969) and Hutch- inson (1967). Additional evidence supporting the evolution of the Tiliales or Mal- vales from the Flacourtiaceae is shown in data from chemotaxonomy. According to Alston and Turner (1963), certain Malvales, especially Sterculiaceae, contain the fatty acid, sterculic acid, which has a three- membered ring. In some Flacourtiaceae, fatty acids with five-membered rings (chaulmoogric and hydnocarpic) are present. Fatty acids with ring structures are not only rare in the plant world, they are also very specific for genera, families, and possibly even for orders. It is easy to imagine then that plants producing cyclic fatty acids with a three-membered ring could have evolved directly from taxa having fatty acids with a five- membered ring. Intraordinal relationships. The xylem anatomy cannot negate the sup- posed alliance among the families generally placed in the same order as the Flacourtiaceae. Williams (1962) and Keating (1968) studied the comparative morphology of the Bixaceae and Cochlospermaceae respec- tively. They found that these two families are more closely related to each other than to any other family. Comparing the Cochlospermaceae and Flacourtiaceae, Keating states, “further, Flacourtiaceae . . . better overlap the range found in Cochlospermaceae than in any other parietalian families named.”’ In a subsequent paper, Keating (1973) noted that the pollen of both the Bixaceae and the Cochlospermaceae lies within the range of the Flacourtiaceae. My work also supports Keating’s findings. Another family similar to the Bixaceae and Cochlospermaceae is the Cistaceae. The anatomy of these small families resembles that of some- what selected groups of Flacourtiaceae. In addition, the Flacourtiaceae is more primitive than any of these three families. Vestal (1937) proposed a phylogeny of these four families based primarily on wood anatomy. He concluded that the Flacourtiaceae gave rise to the Bixaceae and Cochlo- spermaceae and that the Bixaceae gave rise to the Cistaceae. This phylo- genetic sequence cannot be negated from the evidence gathered from the secondary xylem, but neither can it be strongly substantiated or a close alliance established. According to Metcalfe and Chalk (1950) and Taylor (1938, 1972), the wood anatomy in the Violaceae is similar to that in the Flacourtiaceae. Taylor (1972) contends that anatomical information “. . . reinforces the suggestion of kinship between the Violaceae and F lacourtiaceae.” Takh- tajan (1969) states that the family Violaceae is closely allied to the Fla- 1975] MILLER, FLACOURTIACEAE 93 courtiaceae through the primitive tribe Rinoreae (Violaceae). Hutchin- son (1969) places the Violaceae in its own monotypic order somewhat distant from the Flacourtiaceae and the rest of the Bixales. The anatomical resemblance, coupled with taxonomic evidence, seems to outweigh Hutch- inson’s arguments for placing the Violaceae in an order by itself. The relationship of the Peridiscaceae and Lacistemaceae has previously been discussed. The xylem anatomy of Peridiscus (Peridiscaceae) indi- cates a close alliance to the primitive taxa of Flacourtiaceae. Neoptycho- carpus, of the tribe Casearieae (Flacourtiaceae), and Lacistema (Laciste- maceae) have similar wood structure. In addition, the pollen morphology also supports a close alliance (Keating 1973). Order Passiflorales. According to Hutchinson (1969), “. . . Passiflorales, . probably derived from Bixales, show close relationships with Fla- courtiaceae.” In addition, Takhtajan (1969) states that “it is very dif- ficult to draw a clear taxonomic boundary between the two most primitive families — Passifloraceae and Flacourtiaceae.”’ Species of Pas- siflora (Passifloraceae) and Hydnocarpus and Rawsonia (Flacourtiaceae) show a positive reaction to antifungal activity tests (Nicolls 1970). The chemical causing antifungal activity is not known, but it is thought to be the same in both the Flacourtiaceae and Passifloraceae, thus supporting a close family relationship. The secondary xylem of each of these families has many distinguishing features and they are easily separated anatomical- ly. Although differences exist, in no way does the wood anatomy negate the possibility that the Passifloraceae is derived from the Flacourtiaceae. Order Euphorbiales. The secondary xylem of the Euphorbiaceae (Euphor- biales) is diverse, and some selected genera of the Euphorbiaceae are very similar to selected genera of the Flacourtiaceae. Cronquist (1968) places the order Euphorbiales in his subclass V, Rosidae, which is phylo- genetically distant from the Flacourtiaceae (subclass IV, Dilleniidae). Takhtajan (1969), Hutchinson (1967), and Sleumer (1954) all suggest somewhat of an alliance between the Euphorbiaceae and Flacourtiaceae. Takhtajan aligns the Euphorbiales close to the Malvales. He states that “one may therefore presume that the Euphorbiales arose from some ancient group intermediate between the Flacourtiaceae and Malvales.” Hutchinson (1967) and Sleumer (1954) point out the resemblance of some Flacourtiaceae, particularly those with unisexual flowers and no petals, to some genera of Euphorbiaceae. Hutchinson proposes that “per- haps a small part of Euphorbiaceae has arisen from the same stock as the Flacourtiaceae’’; he also cites Kiggelaria (Flacourtiaceae) as a genus possessing characters of a few Euphorbiaceae. According to Metcalfe and Chalk (1950), the wood of Antidesma, Bischoffia, and Phyllanthus of the Euphorbiaceae is very similar to the wood of Caloncoba, Erythrospermum, and Kiggelaria of the Flacourtiaceae. Furthermore, the genera Acalypha, Aporosella, Glochidion, and Hymenocardia of the Euphorbiaceae suggest an alliance with the genera of the tribes Casearieae, Homalieae, and Fla- courtieae (in part). These morphological and anatomical similarities 94 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 may be due to convergent evolution, as envisioned by Cronquist (1968) ; however, since a moderate number of both morphological and anatomical similarities are noted, it seems probable that some Euphorbiaceae and some Flacourtiaceae are allied, if not directly, then through common an- cestry. Order Salicales. According to Takhtajan (1969) and Cronquist (1968), the Salicales is derived from the Violales (including the Flacourtiaceae). Generally, this order is thought to be isolated and not closely related to any particular group, although it is often associated with taxa of the ‘“‘Amentiferae.”” Hutchinson (1969) derived the Salicales from the Hama- melidales; however, Takhtajan and Cronquist claim that the gynoecium of Salicales is anomalous to that found in the subclass Hamamelidae. In an investigation of nectary structure, similarities were noted between the Violales and Salicales. In addition, similarities exist between pollen of some Flacourtiaceae and Salicaceae, although the pollen of Salicaceae is also similar to that of other unrelated families (Cronquist 1968; Keating 1973). However, investigations of the secondary phloem, chemistry, and hair structure suggests that the Flacourtiaceae and Salicaceae are not al- lied (Metcalfe & Chalk 1950). According to Takhtajan (1969), who cited an unpublished thesis by Gzyrian (1952) which I did not see, the wood anatomy of Salicaceae is closer to the wood anatomy of Flacourtiaceae than to that of any other family. Takhtajan states that “both in external morphology and in wood anatomy the greatest similarity to the Salicaceae is observed in the sub- tribe Idesiinae of the Flacourtiaceae.” If the wood of Salix and Populus (Salicaceae) and IJdesia and Jtoa (Idesiinae, Flacourtiaceae) are com- pared, many similarities, such as intervascular and vessel-ray pitting, type of perforation plate, and absence of axial parenchyma, are found to exist among these genera. In the Salicaceae, the more obvious differences in- clude shorter and narrower rays, homocellular or heterocellular rays with only a few rows of upright cells, and no prismatic crystals or septate fibrous elements. Although these differences are distinct, the xylem anat- omy does not reveal any features which would negate the evolution of the Salicaceae from Flacourtiaceae. In addition, it is possible to construct a reduction series from Jdesia and Itoa to Populus and Salix. The rays of Idesia and Itoa are 2- to 4-seriate and heterocellular with long uniseriate extensions. A reduction in the width of the rays and in the number of rows of upright ray cells, coupled with the complete loss of septate fibrous elements and prismatic crystals, would produce a wood structure resembling that of Salix. With the elimina- tion of upright ray cells in Salix, secondary xylem resembling that of Populus would be evident. Carlquist’s (1961) trends in the evolution of ray types in dicotyledons would support this possibility. Stern and Brizicky (1958) have pointed out that it is necessary to be aware of the potentially erroneous conclusions inherent in selecting gen- era from a large heterogeneous family, such as the Flacourtiaceae, for 1975] MILLER, FLACOURTIACEAE 95 comparison with homogeneous families of a few genera. However, I be- lieve that enough evidence has been gathered from the floral and wood structure to favor the evolution of the Salicales from Violales (including the Flacourtiaceae). Conclusive evidence supporting or negating this evo- lutionary trend must come from other independent fields of inquiry. Orders Tamaricales and Capparales. Since the woods of Tamaricaceae and Capparaceae are relatively specialized and the woods of Flacourtia- ceae are more primitive, the xylem anatomy cannot negate the possibility that Tamaricaceae (Tamaricales) and Capparaceae (Capparales) are de- rived from Flacourtiaceae (Violales or Bixales), but the numerous dis- similarities in the secondary xylem do not support such a derivation. SUMMARY AND CONCLUSIONS Anatomically, the Flacourtiaceae is composed of homogeneous tribes loosely united into a family. Based on the types of perforation plates and vessel pits, six anatomical groups are defined. The phylogeny of these groups is determined assuming a monophyletic origin for the Flacourtia- ceae. Small vessel pitting in Flacourtiaceae is apparently a more spe- cialized feature than large vessel pitting. In comparing the phylogeny of tribes of Flacourtiaceae, as proposed by Warburg and Gilg, to the phylogeny of the anatomical groups, a strong correlation is suggested. In addition, the wood anatomy supports Hutchinson’s definition of the tribes Berberidopsideae and Oncobeae formerly included in Gilg’s tribe Onco- beae. For the most part, the wood anatomy supports the generic and tribal composition of Hutchinson’s Flacourtiaceae. The transfer of Gilg’s tribe Paropsieae from Flacourtiaceae to Passifloraceae is confirmed. On the basis of axile placentation and valvate calyx, Hutchinson transfers Gilg’s subtribe Prockiinae (tribe Scolopieae) from the Flacourtiaceae to the tribe Prockieae in the Tiliaceae (including the Elaeocarpaceae). The sec- ondary xylem in genera of tribe Prockieae is flacourtiaceous; however, the wood anatomy in the Prockieae is similar to that in the Elaeocarpaceae. Consequently, if tribe Prockieae is to be transferred on a morphologic- taxonomic basis, the evidence from the wood anatomy endorses the place- ment of the Prockieae in the Elaeocarpaceae. Berberidopsis and Streptothamnus have distinctive wood anatomy for Flacourtiaceae. They have very long tracheids, solitary pores, very long vessel elements, and scalariform perforation plates which suggest a very primitive condition. Perhaps a new family should be defined to con- tain these two aberrant genera. Hydnocarpus apparently has retained some of the primitive xylem fea- tures of the common ancestral stock of the Pangieae and Oncobeae. The long vessel and fibrous elements, opposite intervascular pitting, and scalariform perforation plates suggest the placement of Hydnocarpus in the primitive tribe Berberidopsideae, but the floral structure negates such a 96 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 suggestion. Chemotaxonomy indicates an alliance with the Oncobeae since only species of Hydnocarpus and some genera in Oncobeae contain chaul- moogra oil. In addition, the wood anatomy favors the submersion of Taraktogenos and Asteriastigma in Hydnocarpus. The secondary xylem in the genera of the Scolopieae, Banareae, and Homalieae and in the genus Prockia of the Prockieae (Tiliaceae) is so similar that many genera among these tribes are not easily distinguishable anatomically. Thus, the xylem anatomy can neither support nor negate Hutchinson’s formation of the new tribe Banareae and his transfer of Trimeria from tribe Homalieae to the Banareae. However, since Prockia is distinctive florally, it should remain united with the other genera of the Prockieae. In addition, a reduction series of vessel pitting is pro- posed for the genera of the Prockieae. Tribe Flacourtieae has two major groups of genera, one of which has small vessel pitting and the other large vessel pitting. Furthermore, two subgroups exist within the group possessing large vessel pits Tetrathylacium and Neoptychocarpus of the specialized tribe Casearieae have exclusively scalariform perforation plates. Since Tetrathylacium has large vessel pitting (group I) and florally fits well in the Casearieae, it appears to have retained the primitive xylem structure from its ancestral stock, probably among the Berberidopsideae. In contrast, Neoptychocar- pus has scalariform perforation plates and small vessel pitting; otherwise, it is similar to any other genus of the Casearieae. In many respects the secondary xylem of Lacistema (Lacistemaceae) is similar to that of Neoptychocarpus; thus, Lacistema and Neoptychocarpus might have evolved from the same forebears that gave rise to the Flacourtiaceae. However, more evidence is needed to support a close alliance between Neop- tychocarpus and Lacistema. Hutchinson’s placement of the genera Aphloia, Asteropeia, Dioncophyl- lum, and Goethalsia in the Flacourtiaceae is negated on the basis of the xylem anatomy. Aphloia is anomalous as a member of the tribe Flacour- tieae, for it has a primitive and unusual wood structure which to some extent resembles that of Berberidopsis and Streptothamnus. Therefore, the character of the xylem anatomy supports the proposed monotypic family Neumanniaceae, which has affinities with the Flacourtiaceae. The wood of Asteropeia is certainly not flacourtiaceous. Since Record (1942) and others rule out the Theaceae, the proposed monotypic Asteropeia- ceae may be justified. Airy Shaw’s (1952) statement that “Dioncophyl- lum [has] nothing whatever to do with the Flacourtiaceae” agrees with the evidence from the xylem. The secondary xylem and floral morphology sug- gest that Goethalsia is tiliaceous, not flacourtiaceous. Other genera some- times associated with the Flacourtiaceae, but having nonflacourtiaceous wood structure, include Peridiscus (Peridiscaceae), Soyauxia (possibly Me- dusandraceae or Passifloraceae), and Lethedon (= Microsemma, Thy- melaeaceae or Aquilariaceae). The stock from which the Flacourtiaceae arose appears to be repre- sented in the forebears of the Dilleniales. According to Cronquist, Fla- 1975] MILLER, FLACOURTIACEAE 97 courtiaceae (Violales) is derived from Dilleniales through the Theales. The secondary xylem of Berberidopsis and Streptothamnus is primitive and seems to indicate affinities with the Dilleniaceae. Thealean ray struc- ture, axile placentae, and scanty endosperm are not suggestive of a fla- courtiaceous ancestry. The other families placed in the same order as Flacourtiaceae are for the most part more specialized than Flacourtiaceae. The wood anatomy the wood structure of families in other orders is more similar to that of the Flacourtiaceae than the wood structure of families within the same order. e xylem anatomy supports the derivation of order Passiflorales from the Flacourtiaceae through the tribe Paropsieae. Also, based upon ana- tomical structure, the Malvales or the Tiliales could be derived from the Flacourtiaceae through tribe Prockieae (Tiliaceae). In both cases chemo- taxonomic evidence supports such derivations. Selected genera of Flacourtiaceae and Euphorbiaceae have similar wood structure, lending support to the proposed evolution of order Euphorbiales from the Flacourtiaceae. /desia and Jtoa of the Flacourtiaceae and Popu- lus and Salix of the Salicales have similar secondary xylem in some re- spects, and no features were found which would negate the evolution of order Salicales from the Flacourtiaceae. It has also been suggested that the Tamaricales and Capparales are derived from the Flacourtiaceae. Al- though the xylem anatomy does not negate the derivation of these orders from the Flacourtiaceae, support for such phylogenies is lacking. ACKNOWLEDGMENTS I wish to express my sincere gratitude to Dr. William Louis Stern, who guided my research, and to Dr. B. Francis Kukachka, who initially pro- posed this study. To those kind and generous scientists and institutions who provided me with wood specimens, I am extremely grateful. The foremost among these institutions is the U.S. Forest Products Laboratory in Madison, Wisc., which houses both the Samuel James Record Me- morial Wood Collection (SJRw) and the U. S. Forest Products Laboratory Wood Collection (MADw). Other contributors are as follows: National Museum of Natural History, Washington (USw); Rijksherbarium, Lei- den; Forest Research Institute, Kepong (KEPw); Forest Products Re- search Laboratory, Princes Risborough (PRFw); Koninklijk Museum voor Midden Afrika, Tervuren (TERVw); Botanic Museum and Her- barium, Brisbane; Field Museum of Natural History, Chicago (wood collection now located at the U. S. Forest Products Laboratory); Insti- . tut fiir Holzbiologie und Holzschutz, Hamburg (RBHw); Harold L. Lyon Arboretum, Honolulu; Commonwealth Forestry Institute, Oxford (FHOw); CSIRO, Melbourne (FPAw); Instituut voor Systematische Plantkunde, Utrecht (Uw); Royal Botanic Gardens, Kew (K—Jw); For- 98 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 est Products Research and Industrial Development Commission, College, Laguna (CLPw); Instituto Agronomico del Norte, Belém (IANw); For- est Research Institute, Dehra Dun, (DDw); Government Forest Experi- ment Station, Tokyo (TWTw); Botanisches Garten und Museum Berlin- a ASG (Bw); and New York State College of Forestry, Syracuse (BW I ae also like to thank Dr. H. Sleumer, Dr. R. Kiger, and all my contemporaries who posed many thought-provoking questions and ex- pressed a deep and earnest concern. LITERATURE CITED At-Rats, A. H., A. Myers, & L. Watson. 1971. The isolation and properties of oxalate crystals from plants. Ann. Bot. (London) 35: 1213-1218 Auston, R. E., & B. L. TuRNER. 1963. 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[English sum- Soon} K. 1925. Lacistemaceae. Jn: A. ENGLER & K. Prantt, Die natiirlichen = Ed. 2. Vol. 21. iv + 660 pp. Wilhelm Englemann, Fin D. We 1935. Salient lines of structural specialization in the wood rays of dicotyledons. Bot. Gaz. (Crawfordsville) 96: 547- KuuHiMann, J. G. 1928. Monograph on the Brazilian species of the genera of the Oncobeae tribe: Carpotroche, Mayna, and Lindackeria (Flacourtia- ceae), whose seeds contain an oil analogous to that obtained from chaul- moogra seeds. Mem. Inst. Oswaldo Cruz 21: 403-416 KuKacuka, B. F., & L. W. Rees. 1943. Systematic anatomy of the woods of the Tiliaceae. Minnesota Agric. Exp. Sta. Tech. Bull. 158: 1-70. Lanjouw, J., & F. A. STaFLev. 1964. Index herbariorum. Ed. 5. Regnum . 31: 1-251. Linptey, J. 1853. The vegetable kingdom. Ed. 3. Ixviii + 908 pp. Bradbury & Evans, London MacprripE, J. F. 1941. Flacourtiacea. In: Flora of Peru. Field Mus. Nat. Hist., Bot. Ser. 13. 4(1): Metcatre, C. R. 1952. ae anatomical structure of the Dioncophyllaceae in relation to taxonomic affinities of the family. Kew Bull. 1951(3): 351-368. . Notes on the systematic anatomy of Whittonia and Peridiscus. Ibid. 15: 472-475. H 1950. Anatomy of the dicotyledons. lxiv + 1500 pp. Clarendon Press, Oxfor MItter, R. B. 1966. Systematic wood anatomy of the American Casearia Jacq. Master’s Thesis. University of Wisconsin. Madison, Wisconsin. [Un- published. } ——.. 1973. Systematic anatomy of the xylem and relationships of Flacourtia- ceae. Doctoral Thesis. University of Maryland. College Park, Maryland. — J. 1948. A new species of Ptychocarpus from Peru. Phytologia : se 433. : . A revision of Ryania (Flacourtiaceae). Lloydia 12: 1-29. aear A s 1970. Antifungal activity in Passiflora species. Ann. Bot. (Lon- don) 34: 229-237. PELLEGRIN, F. 1952. Les Flacourtiacées du Gabon. Bull. Soc. Bot. France 1952: 0 E21: REcorD, S. J. 1934. Note on the classification of Goethalsia. Trop. Woods 40: 18 ———. 1941. American woods of the family Flacourtiaceae. [bid. 68: 40-57. ———. 1942. American woods of the family Theaceae. Jbid. 70: 23-33. & M. M. Cuattaway. 1939. List of vee ero ene used in clas- sifying — Pee Trop. Woods 57: 11-1 & R. W . Timbers of the New a xv + 640 pp. Yale Univ. Press, 6 bond RENDLE, B. J., & S. H. CLarK. 1934. The diagnostic value of measurements in wood anatomy. Trop. Woods 40: 27-40. 1975] MILLER, FLACOURTIACEAE 101 Reyes, L. J. 1938. Flacourtiaceae. Jn: Philippine woods. Techn. Bull. Dept. Agric. Philippine Islands 7: 336-340 Rosyns, A. 1968. Family 128. Flacourtiaceae, In: R. E. Woopson & R. W. SCHERY, rane of Panama. Ann. Missouri Bot. Gard. 55: 93-144. Roic, J. T., & J. M. Ropricuez. 1944. Los aceites de las Flacurciaceas: Sus propiedades. Aceites de las Flacurciaceas Cubanas. Rev. Leprol. Dermatol. Sifilogr. 1: 256-266. SANDWITH, N. Y. 1962. Contributions to the flora nig America: LXIX. A new genus of Peridiscaceae. Kew Bull. 15: SCHAEFFER, J. 1972. Pollen morphology of the sed Hydnocarpu (Flacour- tiaceae) with notes on related genera. Blumea 20: 65-8 SCHULTES, R. E. 1945. Plantae austro-americanae. IV. cdi 3: 439-444. SCURFIELD, G., A. J. MIcHELL, & S. R. Smtva. 1973. Crystals in woody stems. Bot. Jour. Linn. Soc. 66: 277-289 SHAw, H. K. Atry. 1952. On the Dioncophyllaceae, a remarkable new family of flowering plants. Kew Bull. 1951(3): 327-347. SLEUMER, H. 1934. Beitrage zur Kenntnis der Flacourtiaceen Siidamerikas. II. Notizb Bot. Gart. Berlin-Dahlem 12: 56. —. 1938. Monographie der Gattung Hydnocarpus Gaertner nebst Bes chreibung und Anatomie der Friichte und Samen Pig Pharmakognostisch wichtigen Arten (Chaulmugra). Bot. Jahrb. Syst. 69: 1950. Algunas Flacourtiaceae sudamericanas. ie = 247-251. . 1953. Las Flacourtiaceae Argentinas. /bid. 26: 5-56. 1954. Flacourtiaceae. Jn: C. G. G. J. VAN SrTeENIs, Fl. Malesiana Bull. I. 5: 1-106. . 1970. Le genre Paropsia Noronha ex Thouars (Passifloraceae). Bull. Jard. Bot. Nat. Belg. 40: 49-75. ——., 1972a. anagem du genre Ludia Comm. ex Juss. (Flacourtiacées). Adansonia 12: 79-10 a A ee revision of the genus Dovyalis E. Mey. ex Arn. (Flacourtiacese). Bot. Jahrb. Syst. 92: 64-89, 972c. taxonomic Po yage of the genus Scolopia Schreb. (Fla- tetas Blumea 20: 1972d. A scabies revision of the genus Scottellia Oliv. (Flacour- taceae) Ibid. 275-281. 972e. A taxonomic revision of the genus Dasylepis Oliv. (Flacour- paatiall Bot. Jahrb. Syst. 92: 554-561. SmitH, A.C. 1936. SP gana In: Fijian Plant Studies. Bernice P. Bishop Mus. Bull. 141: 98, SOLEREDER, H. 1908. Destin anatomy of the dicotyledons (Translated by L. A. Boopte & F, E. Fritscu; revised by D. H. Scott). xii + 1182 pp. Clarendon Press, Oxford. STERN, W. L. 1967. Index xylariorum. Regnum Veg. 49: & G. K. Brizicky. 1958. The go aa ae pie taxonomy of mes cons Bull. Torrey Bot. Club 85: -123. & K. L. CHAmsers, 1960. The aohdoe o wood specimens and her- barium vouchers in anatomical research. Taxon 9: 7-13. 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The systematic position of tribe Paropsieae, in particular the genus Ancistrothyrsus, and a key to the genera of Passiflora- ceae. Blumea 19: 99-104. Wittiams, L. O. 1961. Tropical American plants. II. Fieldiana Bot. 29: 345- WILtIaMs, B..<.:. 3962...the comparative anatomy and morphology of the Bixaceac. Master’s Thesis. University of Cincinnati. Cincinnati, Ohio. [ Unpublished. ] Wi.us, J. C. 1966. A dictionary of the flowering plants and ferns. Ed. 7. (Revised by H. K. Airy SHAw.) University Press, Cambridge Witson, P. 1930. Notes on Flacourtiaceae I. Torreya 30: 72, 73. CENTER FOR Woop ANATOMY RESEARCH U.S. D. A. Forest ServIce P. O. Box 5130 Mapison, WISCONSIN 53705 1975] MAGUIRE & WEAVER, TACHIA 103 THE NEOTROPICAL GENUS TACHIA (GENTIANACEAE) BASSETT MAGUIRE AND RICHARD E. WEAVER, JR. THE GENUS Tachia Aublet, consisting of nine species as here recognized, is characteristic of the rain forest lowlands and midlands of the Hylaea. It is unusual among the genera of the Gentianaceae in that characters separat- ing it from others are well marked and constant. All species are semiherbaceous or soft-stemmed perennials that usually develop a single stem. Sometimes they assume small treelike aspects. The essentially sessile flowers, arising in succession from a “cushion” or broad short shoot in the axils of the leaves, and the ovary mounted on a short, persistent, fibrous peg are unique in the family. Some species seem to be imperfectly delineated, possibly because of the scarcity of collected ma- terial. Such taxa here recognized may in the future, in the light of more adequate observation, require re-evaluation. MORPHOLOGY — ANATOMY Habit. As noted above, all members of the genus are perennial with subligneous, commonly subvirgate and little branched, quite characteristi- cally greenish or bright yellow stems. This yellow coloration, present also in the calyces and often in the corollas, makes the plants conspicuous in their forest habitats. Leaves. The leaves are entire and petiolate. Species of section TACHIA develop penniveined, coriaceous or chartaceous, seldom membranaceous blades. Those of section SCHOMBURGKIANA are invariably tri- or quintuple- veined and somewhat membranaceous. Flowers. The calyx provides excellent and cera criteria for the distinction of species in its degree of division, i.e., in the relative length of tube and lobes. The development or absence of calyx reihly is consistent. In Tachia schomburgkiana the keel becomes a prominent wing which is extended and oriented beyond and at right angles to the plane of the calyx tube as a prominent lobe. The corolla is tubular, often somewhat ventricose or expanded, with lobes commonly considerably shorter than the tube. In Tachia parviflora the tubes and lobes are essentially equal in length. The five stamens are commonly exserted; their filiform filaments are adnate to the corolla tube, the point of attachment being a dependable character in the separation of species. Anthers are introrse, oblong, caudate and basifixed, with connective not produced, although the region of transi- tion may sometimes be at an angle with the plane of the anther. Dehiscence is longitudinal and ventral. The gynoecium is surmounted on a short but obvious glandular-lobed 104 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 gynobase, and is 2-carpellary. The ovary is unilocular, but the lateral su- tures are deeply intruded, and placentation, therefore, is sometimes sub- pseudoaxillary. Styles exceed the ovary but are sometimes deciduous. The stigma is bilamellate. Seeds are small, usually coarsely papillate, subprismatic, and commonly 0.4—0.6 mm. in longest axis. Pollen. The pollen grains are sphaeroidal or rarely ellipsoidal, tricol- porate, and usually 30-40 pm. along the longest axis. The exine is typical- ly reticulate, but the width of the lumina, and therefore the coarseness of the reticulum, vary enormously from species to species. In Tachia guianensis, T. grandifolia, and T. schomburgkiana the lumina are large and the reticulum is relatively fine. In T. parviflora, however, the lumina are greatly reduced and the exine appears merely punctate. Finally, in T. occidentalis the exine appears completely smooth except for the presence of a few, irregularly spaced globules. Unfortunately, as Nilsson (1967, 1968, 1970) has found to be the case with many Gentianaceae, the variation in pollen grain morphology is not correlated with gross morphological variation. Therefore, although it does provide specific characters, pollen morphology is of little phyletic significance in this genus. PHYLOGENY AND GEOGRAPHY Distribution patterns of the species of Tachia show a checkerboard con- figuration (Map 1). From the material now available, no two species seem to be sympatric except T. occidentalis and T. parviflora, and these in only a small part of their assumed overlying ranges. For six species the ranges are, comparatively, “eastern”? and local. Three species are “western”: the range of T. occidentalis is the largest, albeit somewhat dis- junct; that of T. loretensis is local; and that of T. parviflora is limited, but greatly disjunct. There seems to be no significant geographic or ecologic correlation with presumptive systematic relationships within the genus. Indeed, if the mem- bers of section SCHOMBURGKIANA, so delimited largely because of the pli- nerved leaves, are considered the more primitive group, then its members have achieved the more extended distribution, with the distinctive Tachia schomburgkiana occupying a compact range on the eastern periphery of the Roraima sandstone sediments of Guyana and contiguous Venezuela, and the disjunct T. parviflora a range of eastern middle altitudes in central Peru and of similar habitat in Amazonian Bolivia. The indefinite locality for the original collection of T. gracilis, and the scanty collections from the pediments of Cerro Marahuaca of Roraima sediments in Territorio Ama- zonas of Venezuela, offer remote intermediate geographic connection. Distribution of the six members of section Tacuta, characterized by penniveined leaves, similarly does not present any persuasive indication of progressive distribution as related to morphologic modification. Tachia would fit into the Tachiinae of the Gentianeae as ordered by 1975] MAGUIRE & WEAVER, TACHIA 105 | , Section Tachia OT. grandifolia @T. guianensis AT. occidentalis AT. smithii @T. loretensis XT. parviflora APO : ie et 4 i Oe 3 Map 1. Distribution of species of Tachia. Gilg (1895) and thus be aligned in our area with Macrocarpaea (Griseb.) Gilg and the later described Chorisepalum Gleason & Wodehouse, which is endemic to the Guayana Highland. Palynologically, Tachia is similar to these two genera. ACKNOWLEDGMENTS This work was carried out in part with assistance from the National Science Foundation Grant GB-35908. The authors are grateful to the curators of the following herbaria for the loan of material: a, F, GH, K, MO, NY, Us. Distribution of duplicate specimens, not necessarily indicated, has been made to the Royal Botanic Gardens, Kew; the Instituto Botanico, Caracas; the Swedish Museum of Natural History, Stockholm; the Insti- 106 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 sy ne Seas és ar “a Ficure 1. A-H, Tachia occidentalis. A, flower, X 1; B, opened Pee x1; Cc. sepal, cross-section diagram, X 6; D, anther, ventral view, X 6; E anther, dorsal — , X 6; F, stigma, pe Vigo 1047, 22.G; pistil, — Vigo -'H, capsu ule, cross-section diagram, Wolfe 12229. J-Q, Tachia grandi- ai, al irom Silva & Brazéo 60842. J, habit, x 1/2: K, flower, ~ 1; ‘a ge: flower, X 1; M, sepal, cross-section, X 6; N, anther, ventral view, X 6; anther dorsal view, X 6; P, stigma, Xx Be Q, pistil, X 2. 1975] MAGUIRE & WEAVER, TACHIA 107 _———— ——— a | & 20m F 4ym IGURE 2. Tachia grandifolia, Maguire et al. 37496, SEM soy aap aie Pol- len grains — 1, 3-colporate, exine str sie ‘asap te. A, general field, X 500; s and pore, csr view, X 1500; C, polar view, X 1500; D, intersulci, equatorial view, 1500: £, Setaecllien: ee 5000; F, portion of pore and sulcus, * 5000. 108 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 tuto Agronomico do Norte, Belem; the Jardim Botanico, Rio de Janeiro; and others. We gratefully acknowledge the contributions made by Mr. Charles C. Clare, Jr., the artist, and Mr. Yung-chau Huang, the electron-microscope technician. SYSTEMATIC TREATMENT Tachia Aublet, Pl. Guiane 1: 75. 1775. Flowers 5-merous, solitary, rarely binary, sessile or subsessile on an axillary “cushion” or broad short shoot, thereupon often appearing sea- sonally and successively; calyx tubular, sometimes 5-carinate or alate, the lobes exceeding the tube or subequal, the interior at the base beset with a 5-lobed ring of upwardly directed squamellae; corolla infundibuliform, slightly ventricose, rarely short salverform, the tube much exceeding the apiculate lobes (except in Tachia parviflora); stamens 5, exserted, the filaments attached below the middle of the corolla tube or at the juncture of the tube and lobes, the anthers introrse, linear-oblong, caudate, basi- fixed, 4-celled; pollen grains simple, 3-colporate, sphaeroidal or rarely ellipsoidal, 33-45 ym. in diameter, the polar axis somewhat the longer, the exine clearly and sharply reticulate (psilate and globulate in T. parviflora), or punctate; the ovary borne on a short, persistent, glandular gynobase, 1-locular, the placentae deeply intruded, shortly inflexed, the ovules nu- merous; styles marcescent, exceeding the corolla; the stigmas strongly bilamellate: seeds numerous, small, prismatic, tuberculate. Subligneous or soft- stemmed shrubby perennials, commonly simple- stemmed, often of small treelike aspect. Type: Tachia guianensis Aublet. This small genus may be divided into two groups, each reflecting close infrarelationships, one with pinnately veined leaves (6 species) and the other with quintuple-veined leaves (3 species). The most sharply dis- tinctive species is Tachia schomburgkiana, with thin pli-veined leaves and a prominently winged calyx. I. Section Tacnta. Blades of the leaves pinnately nerved. Tachia guianensis (type species), T. grandifolia, T. occidentalis, T. smithi, T. loretensis, and T. grandiflora. II. Section Schomburgkiana Maguire & Weaver, sect. nov. Laminae foliorum quintuplinervatae. Tachia schomburgkiana (type species), T. gracilis, T. parviflora. KEY TO THE SPECIES OF TACHIA A. Leaves epee ai, penninerved (sect. TAcHtA). . Calyx divided to pita the middle; leaf blades thick and somewhat pir to 28 cm. long; corolla 4 cm. long - less; pollen grains sphaeroidal, exine reticulate. ne ene Beg achia grandifolia. 1975] MAGUIRE & WEAVER, TACHIA 109 B. Calyx divided to the middle or above; leaf blades chartaceous, not more than 20 cm. long; corolla 5 cm. long or longer. C. Corolla lobes coiled laterally at anthesis; calyx (2/5-) re as long as the corolla tube; pollen grains ellipsoidal, sae ee aa ce oe ede BOE Ved LES ee ere ae achia pons C. Corolla lobes plane at a calyx a third as hee as the corolla re rarely nearly half a D. Calyx narrowly 5- sista divided 1/3 of its length; pollen grains subsphaeroidal, exine smooth, sparingly beset with globules. .... ee eee eS cas pans Reg ein istry ete 3. Tachia occidentalis. D. Calyx not alate, at most 5-carinate, divided to ca. the midd E. Corolla narrowly cubular-Funnelforn, the tube not expanded ae filaments conspicuously recurved or hook-shaped at the ee ae ee Tachia smithii. E. Corolla funnelform, the tube conspicuously expanded above; filaments straight or upcurved at the very tip. F, chine less than 6 cm. long; lateral veins of the leaves rming an acute angle (45°-60°) with the midvein and Se toward the tip of the leaf; pollen grains sphaeroidal, exine reticulate, 6 ieee 5. Tachia loretensis. Corolla 7 cm. long or longer; lateral veins of the leaves forming nearly a right angle with the midvein and spreading d the margins of the leaf. ... 6. Tachia grandiflora. A. Leaves distinctly 3—-5-nerved (sect. SCHOMBURGKIANA). G. Corolla more than 5 cm. long, the tube conspicuously surpassing the calyx. H. Calyx strongly 5-alate, 2.5-4.0 cm. long, the lobes 1.1—-2.8 cm. long; pollen grains sphaeroidal, exine reticulate. ......... BSN ar rar Wag) GP oe he men hese en igen Tachia schomburghiana. H. Calyx not alate, less ‘then 2 cm. long, the lobes less than 1 cm. long. ge ey Oe Su SE etiam ei Satis desu Gulag Festa | . Tachia gracilis. G. Corolla less than 2.5 cm. long, the tube barely surpassing the calyx; pol- len grains sphaeroidal, non-reticulate, smooth, minutely punctate. ...... Tachia parviflora. ae, 1. Tachia grandifolia Maguire & Weaver, sp. nov. TypE: Brazil. Amazonas: in catinga forest between Missao Salesiana and Serra Pirapucu [Neblina], Rio Maturaca, Rio Cauaburi-Negro, 400-800 m., Silva & Brazdo 60824 (holotype, NY; isotypes, IAN, RB, US, K). Ficures 1, J-Q; 2; 3. Herbae perennes saepe basibus lignosis; caulibus vulgo 2-4 m. altis crassis viridibus ca. 12-15 mm. diametro glabris, internodiis vulgo 12-14 cm. longis; foliis oppositis, petiolis 2-4 cm. longis triangularibus, laminis ovalibus vel oblongo-ovalibus vel aliquando late oblanceolatis 22—28 cm. longis 10-14 cm. latis firme subsucculentis, basibus acutis, apicibus ob- tusis, abrupte apiculatis vel abrupte brevi-acuminatis, costis prominenti- bus, inconspicue pinnivenatis; floribus axillaribus vulgo solitariis aliquan- do pluribus subsessilibus; calyce 10-12 mm. longo cylindrico non-alato valde 5-carinato glabro in sicco valde 5-angulari, tubo crasso intus glabro, lobis 5 oblongis obtusis 5—6 mm. longis cucullatis anguste scariomarginatis; 110 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 20um FicurRE 3. Tachia grandifolia, Maguire et al. 37496. Light microscope micro- graphs, < 1500. A-—C, polar views. 5 r focus vite B, lower — — C, median focus level. D-F, equatorial vi WS. er ie us level, sul- cus and pore; E, median focus level; F, ee fant level, note eps sre sulci. corollis infundibuliformibus ventricosis 4.5-5.0 cm. longis, tubo 1.82.0 ongo, limbo 2.8-3.0 cm. longo, lobis 8-9 mm. longis acutiusculis; staminibus 5, filamentis Ave mm. longis, juncto tubo et limbo affixis, an- theris oblongis ca. 3 mm. longis 1 mm. caudatis; pollinibus sphaeroideis 3- colporatis 42-45 wm. diametro sporodermate reticulato muris tenuibus; ovario uniloculari bivalvulo valvulis breviter inflexis, placentationibus valde inflexis subparietalibus, ovulis numerosis, gynobase glandulosa 2-3 mm. alta, stylis 26-28 mm. longis, stigmatibus bilamellatis ovatis obtusis ca. 2 mm. longis; capsulis 15-17 mm. longis; seminibus brunneis prismati- cis echinulatis 0.40.5 mm. longis. DisTRIBUTION. Low-altitude catinga or sometimes flooded forests or ad- jacent terra firma, approaches to Cerro de la Neblina. SPECIMENS EXAMINED. Venezuela. Territorio Amazonas: Rio Yatua, Rio Pacimoni, occasional at 110 m., Piedra Arauicaua, Maguire, Wurdack & Bunt- ing 37477 (ny, 2 sheets, VEN, Us); Piedra Tururumeri, 110 m., Maguire, Wur- dack, & Bunting 37496 (Ny, 2 sheets, VEN, US); woodland at base of Cerro Arauicaua, 125-250 m., Steyermark & Bunting 102534 (us). Brazil. Amazonas: Cucuhy, Rio Negro, 120 m., Holt & Gehriger 355 (us). la. Tachia grandifolia Maguire & Weaver var. orientalis Maguire & Weaver var. nov. Type: Brazil. Territorio Roraima: vicinity of 1975] MAGUIRE & WEAVER, TACHIA 111 Posto Surucucus Mission, forest on terra firme, Serra dos Surucu- cus, 2° 42-47’N, 63° 33-36’W, Prance et al. 10084 (holotype, Ny; isotypes, F, GH, US). Ficure 4. Tachia guianensis, Maguire 24611. Pollen grains — 3-colpo- rate, strongly reticulate. SEM micrographs. A, po f ; B, equa- torial intersulci view, 1500; C, i geroag view, sulcus, X 500° D, retic- ulum, < 5000; E, reticulum, sulcus, >< 500 112 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Varietati grandifoliae similis sed foliis parvioribus, petiolis tenuibus, 12- 26 mm. longis, laminis elliptico-acuminatis, minus coriaceis, vulgo 10-15 cm. longis, frequenter acuminatis. DIstTRIBUTION. Treelet of median altitudes in Roraima Formation for- ests, drainages of the Uraricoera, Brazil, and the Alto Paragua and Alto Caroni, Venezuela. SPECIMENS EXAMINED. Brazil. Territorio Roraima: 4-6 km. south of Auaris, 800 m. 4°3’N, 64°22’W, Prance et al. 9823 (F, GH, NY, US); in upland forest 20um FicurRE 5. Tachia guianensis, Maguire 24611. Light microscope micrographs, x Ps polar views. A, upper i s level: B, median focus level; ower focus le i D-F. equatorial vi at successive focal levels, grain oriented with sulcus uppermost. G, H. & J, equa —s tan at sgecciaiee fo- cal levels, grain | cane with intersulci area upperm 1975] MAGUIRE & WEAVER, TACHIA 113 at 1800 m. alt., plateau of Serra dos Surucucus 2°42-47’N, 63°33-36’W, Prance et al. 9962 (F, INPA, NY, US). Venezuela. Bolivar: exposed rocky slopes of quebrada on southwestern-facing portion of Chimanta-tepui (Torono-tepui), 1410 m., Steyermark 75407 (F, NY, 2 sheets); at base of sandstone bluff, Sierra Ichun, tributary of Rio Paragua, 500-625 m., Steyermark 90420 (ny, Us). The variety orientalis is obviously a smaller-leaved variant of Tachia grandifolia, but, as the name indicates, it is the more eastern segregate. The form and structure of the scanty and ill-preserved flowers and fruit of both varieties obviously demonstrate close consanguinity, but vegeta- tively var. orientalis is readily distinguishable by its smaller, thinner, and acuminate leaves. Specimens of var. orientalis came to our attention after the completion of the main study, and accordingly its description and citations were later inserted into the typescript. The description of Tachia grandifolia was drawn wholly from specimens of var. grandifolia 2. Tachia guianensis Aublet, Pl. Guiane 1: 75. ¢. 29. 1775. Type: an Aublet specimen, presiimably of French Guiana (P) (IDC 6213.11: E72). Ficures 4, 5. Shrubs or small trees to 4 m. tall; branches subterete, yellow; leaves thin-membranaceous, elliptic (sometimes broadly so) to oblong-elliptic, caudate, cuneate to somewhat rounded at the base, 8.8-19.0 cm. long, and 3.4—9.0 cm. broad, the petiole 5-21 mm. long; calyx exalate, 2.7- 3.5 cm. long, (2/5—)1/2 the length of the corolla tube, 2—3 times as long as the petioles, divided ca. 1/3 of its length (or less) into lanceolate, acute or acuminate, erosulate lobes; corolla yellow, narrowly tubular- funnelform, 6.0-7.7 cm. long, the lobes spreading, coiled laterally at an- thesis, oblong-lanceolate, abruptly acuminate, 11-16 mm. long and 4-7 mm. broad, 1/4 as long as the tube; stamens inserted in the lower third of the corolla tube, well below the apex of the calyx; filaments straight or slightly upturned at the apex, 4.0—5.2 cm. long, conspicuously surpassing the co- rolla tube, the anthers oblong, ca. 3 mm. long; pollen grains sphaeroidal, exine prominently reticulate; style 5.0-5.8 cm. long, finally surpassing the corolla lobes, stigma lobes spathulate to suborbicular, 2-3 mm. long; capsule fusiform, to 4 cm. long, projecting from the persistent calyx. DISTRIBUTION. Small trees or shrubs with subherbaceous stems, com- monly at low or middle altitudes in rain forests of the Guianas SPECIMENS EXAMINED. Guyana. Kalakoon, Mazaruni River, Jenman 2406 (NY); dense upland forest, Tumatumari, Gleason 56 (GH, NY, US); Tacoubea Creek, Kurupung River, Altson 316 (Ny); 400 ft. ca. 83 miles, Bartica-Potaro Road, Tutin 303 (us); near Makreba Falls, Kurupung River, upper Mazaruni re- gion, Pinkus 291 (GH, NY, US); wallaba forest near 14th milepost, Bartica-Potaro Road, Sandwith 1111 (¥, Ny); Kaieteur Savannas, Maguire & Fanshawe 23382 (K, Ny, US); forest slope, Mount Ayanganna, 1000-1500 m.; Maguire, Bagshaw, & Maguire 40599 (x, Ny); frequent in mixed evergreen forest on laterite, below JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 C 20um F 4um ee 6. Tachia occidentalis, SEM micrographs. he grain aie triangular, 3-colporate, exine finely subverrucose, sublaevate. A, general field, Schultes 12476, X 500; B, polar view, Killip & Smit th 26163, 1500; C, polar Ma Beige ‘12476, x 1500: D, equatorial view, Schultes 12476, x 1500; E, sulcus, Killip & Smith 26163, X 5000; F, portion of polar view, Schultes 12476, x 5000, note heavily bordered sulcus. 1975] MAGUIRE & WEAVER, TACHIA 115 talus of cliffs along NE side of Mount Ayanganna, elev. below 762 m., Tillett, Boyan, & Tillett 45024 (ny, US). Suriname. Tafelberg: vicinity Base Camp, Tafelberg Creek, Maguire 24098 (Ny, 2 sheets, v); infrequent in high mixed forest, rocky slopes, Arrowhead Basin, 625 m., Maguire 24611 (Ny, 2 sheets, U); in savanna forest between Tafelberg and source of Saramacca River, on Roraima sand, Wessels Boer 1540 (A, Ny, U) 3. Tachia occidentalis Maguire & Weaver, sp. nov. Type: Colombia. Vaupés: Rio Apaporis, Cachivera de Jirijimo y alrededores, ca. 250 m., Schultes & Cabrera 12476 (holotype, GH). Ficures 1, A-H; 6. Frutex vel arbor parva perennis subherbacea saepe basi lignosa; cauli- bus ad 8 m. altis quadrangularibus vel subteretibus; foliis oppositis la- minibus tenuiter membranaceis indistincte pinnivenatis ellipticis vel ob- longo-ellipticis abrupte vel graduate ad basim contractis 7-20 cm. longis 2.7—7.7 cm. latis, petiolis 6-17 mm. longis; flore solitario axillari; calyce 14-25 mm. longo petiolis excedentibus anguste 5-alato, lobis ca. 1/3 longitudine tubi; corollis tubulari-infundibuliformibus 6.4—7.7 cm. longis viridibus vel luteo-viridibus aliquantum arcuatis, lobis patentibus vel re- flexis oblongo-ovatis abrupte brevi-acuminatis vel apiculatis erosulatis 10- 15 mm. longis 5—8 mm. latis; staminibus 5, filamentis circa basin tubi af- fixis 4.0-4.7 mm. longis tubo vix exserto, antheris anguste oblongis ca. 5 mm. longis; pollinibus subsphaeroideis 3-colporatis ca. 40 wm. diametro sporodermate laevi sparse minute globulifero; stylis aliquantum exsertis, lobis stigmatum ca. 3 mm. longis suborbicularibus; capsulis non vidis. REPRESENTATIVE SPECIMENS. Colombia. Amazonas: trocha entre El Encano y La Chorrera, ca. 180 m., Schultes 3876 (¥, GH, US); Rio Popeyaca (tributary of Apaporis between Rio Piraparana and Raudal Yayacopi), near mouth, ca. 700 ft., Schultes & Cabrera 15571 (us). Vaupés: Raudal de Jirijimo, Rio Apa- poris, Schultes & Cabrera 14670 (cH); Rio Apaporis, entre los rios Kana- nari y Pacoa, 250 m., Garcia-Barriga 13932 (NY, US); Rio Apaporis, Soratama, Schultes & Cabrera 16144 (us); Macu-Parana, Allen 3084 (mo); headwaters of Cano Teemeefia, Lobo Igarapé, Schultes & Cabrera 17334 (us). Brazil. Amazonas: Sao Paulo de Olivenca, Ducke 1115 (mo, Ny, Us); Macubeta on Rio Marié, Frées (Krukoff) 12439/183 (a, Ny); Rio Negro, Taracua, Rodrigues & Pires 141 (us); Rio Negro, Ilha das flores, foz do Rio Uapés, Pires 394 (ny); Tonantins, Ducke 22389 (us). Brasiliae borealis: prope San Gabriel da Ca- choeira, R. Spruce 2190 (¥F). Peru. Huanuco: southwest slope of the Rio Llulla- pichis watershed, on the ascent of Cerros del Sira, ca. 860 m., Wolfe 12229 iN Agua Blanca (Camino a Monzén), 700-800 m., Sc hunke-Vi igo 1047 (ny) Junin: Pichis Trail, Santa Rosa, 625-690 m., Killip & Smith 26163 (®, NY, us). Loreto: Aguaytia, 300 m., Woytkowski 5348 (F, MO); Santa Ana on the Upper Rio Nanay, Williams 1243 (F); Florida, Rio oo at mouth of Rio Zu- bineta, 180 m., Klug 2123 (A, F, GH, MO, NY, US) The most widespread and most frequently collected of the species, Tachia occidentalis has for the most part passed as T. guianensis. It differs from that species, however, in its shorter, narrowly alate calyx, and its pollen 116 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 grains that are characterized by having a smooth rather than a reticulate exine. - Tachia loretensis, Klug 1563. SEM micrographs. Pollen grains sphaeroidal, 3- Rap exine re ints -corrugate. A, general field, X 500; », a view, 1500; C, portion of polar view showing corrugate sculpture, X 000; D, equatorial view, X 1500: E, portion of pore and sulcus, X 5000. 1975] MAGUIRE & WEAVER, TACHIA 117 4, Tachia smithii Maguire & Weaver, sp. nov. Type: Brazil. Para: in dense forest on southern slopes of the Akarai Mountains, in drain- age of Rio Mapuera (Trombetas tributary), 500-700 m., A. C. Smith 2931 (holotype, Ny; isotypes, A, F, MO, US). Frutex simplex ad 4 m. altus; foliis oppositis, laminibus tenuiter mem- branaceis ellipticis caudatis cuneato-attenuatis 10.0-17.2 cm. longis 4-8 cm. latis, venis lateralibus inconspicuis cum costa angulo 90° formantibus, petiolo 1-2 cm. longo; flore vulgo solitario axillari; calyce 1.8—2.5 cm. longo ecarinato, lobis oblongis obtusis vel acutiusculis longitudinaliter tubo aequalibus; corollis albis infundibuliformibus 6.5—7.3 cm. longis, lobis recurvatis ovatis abrupte acuminatis erosulatis ca. 15 mm. longis 8-11 mm. latis; staminibus 5, filamentis 3.9-4.5 cm. longis infra medium tubi affixis, fllamentis circa apices recurvis, antheris sagittatis ca. 3 mm. longis introrsis; stylo 5.0-5.2 cm. longo, lobis stigmatum ovatis vel ellipticis, 4—6 mm. longis; capsulis non visis. DIsTRIBUTION. Known only from the type locality, this plant is similar to Tachia guianensis, with which it may be sympatric. It differs from that species, however, in its generally shorter calyx, its white corolla, its plane corolla lobes, and its conspicuously recurved or hooklike filaments. 5. Tachia loretensis Maguire & Weaver, sp. nov. Type: Peru. Lo- reto: in dense forest, ca. 100 m. alt. Mishuyacu, near Iquitos, Kil- lip & Smith 29925 (holotype, us; isotypes, F, NY). FIGURE 7. Frutex ad 1 m. altus; ramis subteretibus; foliis oppositis, laminis tenui- membranaceis ellipticis brevi-caudatis cuneato-attenuatis 10.0—-16.5 cm. longis 3.0—6.5 cm. latis, venis lateralibus inconspicuis pinnatis, formantibus angulo acuto cum costa versus apicem recurvatis, petiolis 1.0-2.5 cm. longis; calyce 1.4—2.0 cm. longis minus 1/2 longitudine corollae lobis et tubo longitudine aequalibus ecarinatis, lobis oblongis, obtusis vel rotunda- tis erosulatis; corollis albis 5—5.9 cm. longis late tubuliformibus, tubo in- fra cylindricum supra expansum, lobis late ovatis vel oblongo-ovatis abrupte acuminatis erosulatis 10-13 mm. longis 5-8 mm. latis; staminibus 5 ali- quantum exsertis, filamentis 1.6-2.3 cm. longis medio tubi affixis; granis pollinis sphaeroideis ca. 40 pm. diametro sporodermate reticulato; lobis stigmatum spathulatis; capsulis maturis ca. 13 mm. longis. DIsTRIBUTION. Known only from the vicinity of Iquitos, Peru. SPECIMENS EXAMINED. Peru. spa forest, Klug 1277 (Ny, US); forest near Iquitos, 100 m. alt., Klug 1563 (F, u 6. Tachia grandiflora Maguire & Weaver, sp. nov. Type: Brazil. as: Serra da Lua, Rio Urubu, between Cachoeira Iracema and Natal, Prance et al. 5042 (holotype, F; isotypes, GH, INPA, NY, US). 118 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Ficure 8. A~G, Tachia parviflora ses 143 : 1. A, flower, X 2; B, opened corolla, & 2° <<, sepal, cross-section diagr m, X 3; D, ovary, style, and stigma, u 2. ~*~ . *, stigm, ? pc ‘ , ca) x # Tachia schomburgkiana. H, habit, M apuire, Steyermark, & Maguire 46914 and 3, = 1: KB 8 Pinkas 227; % 1: Ay sepal, cross-section ‘dia agram, Maguire 46794, x 3; M, anther, ventral view, Pinkus 3 3, X 4; N, anther, dorsal view, Pinkus 3, X 4; QO, ; gm. vary, oo diagram, Maguire, pa ang k, & M 7 R. ca ae Pinkus 3, X 2; S, seed, Pinkus 3, X 2 aguire 46 80; , cap- 1975] MAGUIRE & WEAVER, TACHIA 119 Frutex cum ramis scandentibus; ramis subteretibus vel angulosis ob- scuris; foliis oppositis, laminis tenui-membranaceis ellipticis caudatis cu- neato-attenuatis 9.5-15.5 cm. longis 4.0-6.6 cm. latis, petiolis 9-14 mm. longis; calyce exalato, 21-22 mm. longo tubo et lobis plus minusve aequali- bus, lobis obtusis vel acutiusculis erosulatis; corollis tubuliformibus ali- quantum late, tubo infra expansum 7.0—-7.7 cm. longo, lobis imbricatis ovatis abrupte acuminatis ca. 16 mm. longis 11-12 mm. latis; stylis et an- theris aliquantum exsertis, antheris ca. 4 mm. longis; lobis stigmatum sub- orbicularibus ca. 3 mm. longis. DIsTRIBUTION. Known only from two collections, the type and the fol- lowing: Brazil. Para: sousbois de la forét, Jurupa, Ducke 16168 (us). 7. Tachia schomburgkiana Bentham, Jour. Bot. Kew Misc. 2: 204. 1854. Type: Guyana. On the mountains covered with thick forest between Roraima and the Cuyuni, at an elevation of 3000—4000 ft., Richard Schomburgk 1546 (holotype, K, not seen). Ficures 8, H—-S; 10; 11; 12. Shrubs to 2 m. tall, branches quadrangular; leaves thin-membrana- ceous, distinctly 5-nerved, the upper lateral pair closely paralleling the midvein into the apex, elliptic to ovate or ovate-lanceolate, caudate, -+ abruptly constricted to the petiole and the base therefore rounded, 8.8—17.0 cm. long and 4.0-8.5 cm. broad, the petiole winged to the base, 1.0-1.5 cm. long; calyx yellowish, 2.6—4.0 cm. long, 1/2 to nearly 3/4 as long as the corolla tube, much exceeding the petioles, the tube strongly 5-alate and the lobes formed by an extension of the 3 mm. broad wings, the lobes long acuminate, 1.1—2.8 cm. long, as long as to nearly half again longer than the tube, auriculate at the base (this probably representing the junc- ture of the lobes proper with the greatly extended wing), the auricles ero- sulate; corolla yellow or yellow-green, tubular-funnelform, 6.5—7.4 cm. long, the tube constricted in the lower half, then expanding and cylindric or widening slightly to the apéx, the lobes oblong-lanceolate, abruptly short- acuminate, erosulate, apparently recurved, 11-14 mm. long and 5-6 mm. broad, ca. 1/6 the total length of the corolla; stamens 5, the filaments in- serted near the base of the corolla tube, below the apex of the calyx tube; filaments well surpassing the corolla tube, 4.2—5.2 cm. long, the anthers oblong, obtuse, 3-4 mm. long; pollen grains sphaeroidal, ca. 40 pm. in diameter, the exine reticulate; style equaling the corolla lobes, 5.0-5.5 cm. long; lobes of the stigma ovate; capsule including the beak 2—2.5 cm. long, the apex barely protruding from the persistent calyx; seeds strongly papillose. SPECIMENS EXAMINED. Venezuela. Bolivar: frequent in montane woodland, 400 m. alt., La Escalera, Rio Uiri-yuk, Alto Rio Cuyuni, Maguire, Steyermark, & Maguire 46780 (Ny, VEN); occasional in mixed montane forest below La Escalera, 600-800 m., Rio Uiri-yuk, Alto Rio Cuyuni, Maguire, Steyermark, & Maguire 46914 (Ny, VEN); km. 119 south of El Dorado, 1030 m. alt., Steyer- 120 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 ., 20um FicureE 9. Tachia parviflora, Dudley 13072. SEM micrographs. Pollen grains sphaeroidal, ie colporate, exine puncti-laevate. A, general field, X 500; B, polar view, X 1500; C, oblique equatorial view, X 1500; D, pitted exine, seed irregular puncti or perforations, X 5000; E, portion of spore and sulcus, 5 mark, Dunsterville, & Dunsterville 93044 (NY, Us, vEN). Guyana: Kamakusa, upper Mazaruni River, Leng 331 (Ny); Makreba Falls, inace River, Alison 355 (NY, 2 sheets); near Makreba Falls, Kurupung River, rocky soil on hillside, 1975] MAGUIRE & WEAVER, TACHIA 121 Pinkus 3 (NY, US); Membaru gies pita Mazaruni River, Pinkus 227 (ny, us); frequent i in Cunuria _ 000 elev., Maguire & Fanshawe 32345 (ny, 2 sheets, US); in mixed ev ape along line to E end of Karowtipu, 500 m. alt., Kako hel Tillett 2 “Tillett 45447 (Ny). 4 i aum |E Ficure 10, Tachia schomburgkiana, Tillett & Tillett 45447. SEM micrographs. Pollen aie —. 3-co st strongly ret ticulate. A, general field, < 500; B, polar view, X 1500; C, equatorial view, 1500; D, reticulum, 5000; E, portion of pore and Sa x a. 122 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 8. Tachia gracilis Bentham, Jour. Bot. Kew Misc. 6: 203. 1854. Type: Guyana (Brazil ?): “Serra Mey,” Schomburgk 145.5 (holotype, K; photograph, Ny). A shrub reputedly to 3 m. tall; leaves thin-membranaceous, distinctly 5-nerved, narrowly ovate to elliptic, caudate, abruptly constricted to the petiole, 5.5-10.5 cm. long and 2—4.3 cm. broad, the petiole 6—17 mm. long; calyx yellow, 14-20 mm. long, longer than the petiole, 2/5-1/2 as long as the corolla tube, weakly carinate, divided halfway to the base into ob- long, acutish lobes; corolla tubular or tubular-funnelform, yellow, 5—6 cm. long, the lobes recurved, oblong-lanceolate, abruptly acuminate, 9-11 mm. 20um FicurE 11. Tachia —— Tillett @ Tillett 45447. — agg aa. D- micrographs, X 1 , polar views at successive — lev: torial views at successive focal levels, ea uppermost; G—J, kaa at i at successive focal levels, intersulci area uppermos o 1975] MAGUIRE & WEAVER, TACHIA 123 long and 5—6 mm. broad, ca. 1/5 the total length of the corolla; filaments inserted near the base of the corolla tube, 3.5—4.5 cm. long, well surpassing the corolla tube; anthers oblong, obtuse, ca. 3 mm. long; style 3.7—4.8 cm. long; stigma lobes ovate; capsule ca. 2 cm. long. SPECIMENS EXAMINED. Venezuela. Territorio Amazonas: Cerro Marahuaca, 1000 m., Maguire & Maguire, Jr. 29207 (ny); Sierra Parima, frontera #8, 1300 m., Steyermark, Pantchenko, & Dilarmando Mendes 107570-A (a); Sierra Pa- rima, a lo largo de la frontera Venezolana-Brasilera, a unos 45 km. al Noroeste des las cabeceras del Rio Orinoco, 1300 m.. Steyermark 106081 (vEN); Cerro Duida, a lo largo del Orinoco, 1000 m., Farinas, Velasquez, & Medina 391 (vEN). The Schomburgk collection, upon which this name rests, was cited from British Guiana without a collector’s number. However, the original ticket bears the number “145.S,” the “S” indicating that the collection was rep- resented by a single specimen only. Reference to the lists of Schomburgk collections, deposited at Kew in the Bentham files, shows the number “145.S” to occur in a list of unicate collections without regard to chronology or geography. ‘‘Serra Mey,” the cited locality, as suggested by the Por- tuguese geographic name, is probably in Brazil and probably in the Rio Uraricuera (Araricuara), the Alto Rio Orinoco or Rio Negro area. A similar disposition has been made for the range designation of Sipapoa vestita (Benth.) Maguire of the Malpighiaceae. 9. Tachia parviflora Maguire & Weaver, sp. nov. Type: Colombia. Caqueta: Bosques entre 1000 y 1300 m. alt., vertiente oriental, Sucre, Cordillera Oriental, Cuatrecasas 9059 (holotype, F; isotype, Us). Ficures 8, A-G; 9. ?T. pavonii Gilg in Engler & Prantl, Nat. Pflanzenfam. 4(2): 93. 1895 (nomen nudum). Frutex vel arbor parva, ad 6 m. alta, aliquantum scandens; ramis sub- teretibus; foliis oppositis, laminis tenui-membranaceis 5-nervatis jugo pri- mario interdum indistincto, petiolis 1.0—2.5 cm. longis; floribus frequenter pluribus; calyce 1.0-1.5 cm. longo, tubo brevissimo, lobis ad 1.4 mm. longis ecarinatis lanceolatis obtusis vel acutiusculis scario-marginatis ero- sulatis; corollis chloritici-albis brevi-hypocrateriformibus 1.4—2.4 cm. longis ‘tubo vix calyce longiore, lobis oblongis abrupte brevi-acuminatis erosulatis ad apicem reflexis 6—9 mm. longis 3-5 mm. latis; staminibus 5, exsertis, filamentis subulatis ad summum tubi affixis ad basim expansis, antheris oblongis ca. 2 mm. longis; granis pollinis sphaeroideis, ca. 40 pm. diametro non reticulatis laevibus minute punctatis; stylis brevibus ca. 8 mm. longis, lobis stigmatum obovatis; capsulis immaturis longioribus calyce rostro prominento. DistrisuTIon. Rather widely distributed at median altitudes from Co- lombia to Bolivia. 124 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 SPECIMENS EXAMINED. Peru. Huanuco: SW slopes of Rio Llullapichis water- shed, on ascent of Cerros del Sira, ca. 1400 m. alt., Dudley 13072 (¥); SW 0.1 mm OS gs A- gkiana. SEM micrographs. Seed strongl papil- fe gly l .. Pinkus * Bo 100; B, 12 0; ‘el grap D, x 100; E and F, « 300. x x 300. D- F, Maguir Té 46794. 1975] MAGUIRE & WEAVER, TACHIA 125 slope of Rio Llullapichis watershed, on ascent of Cerros del Sira, 860 m., Wolfe 12228 (F), 12249 (F). Bolivia. Larecaja: Mapiri Region, San Carlos, 850 m., Buchtien 1431 (¥, NY, Us); Dept. of La Paz, Copacabana (ca. o km. ‘south of Mapiri), 850-950 m. alt., Krukoff 11004, 11091 (a, F, MO, NY, ; This species is unique in the genus because of its small flowers with salverform corollas. Therefore, it is possibly the species which Gilg (1895) had in mind when he mentioned “7. Pavonii Gilg, mit ziemlich kleinen Bl. (iiten).” The name “7. Pavonii,” being a nomen nudum, is illegitimate, however. LITERATURE CITED Gitc, E. 1895. rete In: A. ENGLER & K. PRANTL, Die Natiirlichen Pflanzenfamilien 4(2): 50-108. Nizsson, S. 1967. Pollen morphological studies in the Gentianaceae — Gen- tianinae. Grana Palyn. 7: 46-145. . 1968. Pollen bling in the genus Macrocarpaea (Gentianaceae) and its taxonomical significance. Sv. Bot. Tidskr. 62: 338-364. . Pollen morphological contributions to the taxonomy of Lisianthus L. s. lat. (Gentianaceae). /bid. 64: 1-43. B. M. R. E. W THE NEw York BoTANICAL GARDEN ARNOLD ARBORETUM Bronx, NEw York 10458 HARVARD rected JAMAICA siisiieelabines 02130 126 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 SPECIES VERSATILITY IN SHORE HABITATS HucHu M. Raup MATERIALS FOR THE present paper are derived from notes and plant collections made during seven field seasons in the years 1926-30, 1932, and 1935, in the Athabaska-Great Slave Lake region of northwestern Canada. In the course of this work shoreline vegetation was described at approximately 130 places. Seventy-nine of these were on the shores of sloughs, ponds, and small lakes, while the remaining 51 were on the shores of the larger lakes (Athabaska and Great Slave) or on river banks and deltas. The following discussion deals primarily with the vascular flora, though reference is made on occasion to lichens and mosses. A part of the material was published in the author’s “Botanical inves- tigations in Wood Buffalo Park” (1935). Itineraries of the seven expedi- tions will be found in this paper and in others dealing with the vascular flora and its distribution (Raup, 1930b, 1936, 1941). A brief account of the vegetation of Shelter Point, Lake Athabaska, was published in 1928, and a paper on the shore vegetation at Fort Reliance, Great Slave Lake, in 1930(a). The most complete sets of supporting plant collections are at the National Herbarium of Canada in Ottawa, and at the Harvard Uni- versity Herbaria in Cambridge, Massachusetts. Most of the vegetational data for the present study were gathered along transects selected because they showed differences or similarities when compared in the field with other transects. The differences were recorded first in terms of species’ presence or absence, and second in terms of primary and secondary species. In common ecological parlance the primary species in an assemblage would be termed “dominants.” They are the ones that give a specific form, color, or other characteristic to an assemblage of plants by which the latter is readily distinguished visually from those adjoining it. All other species in the assemblage are regarded as secondary. Usually the primary species are those that predominate in numbers of individuals, but in sparse vegetative cover or in tree or shrub vegetations the popula- tions of primary species may be smaller than those of secondary species. The selection of primary species was done by eye. A general view of the shore floras of the region shows them occupying an extraordinary number of lakes, ponds, and sloughs that dot the land- scapes. They are numerous in the great deltas and flood plains of the lower Athabaska, Peace, and Slave rivers, but are especially abundant on the crystalline and metamorphic rocks of the Canadian Shield. Travelers for many years have noted the large numbers of small bodies of water along their routes, but full realization of their extent awaited the advent of aérial photographic mapping. An area of 16 square miles (4 miles square) selected at random in the country north of Lake Athabaska con- 1975] RAUP, SPECIES VERSATILITY 127 tains over 100 ponds and lakes large enough to appear on a map scaled at 4 miles to one inch. The number of smaller water bodies can only be conjectured, but a conservative estimate would be another 100. The ponds and small lakes throughout this region are infinitely variable in shape, size, and depth. The large lakes also present a wide variety of shorelines, from almost vertical rock cliffs to wide shelving beaches of sand, mud, or shingle. Further variation is found in the morainic and karst topography west of the Slave River, in flood-plain sloughs and deltas, and in the saline flats that border the Salt and Little Buffalo rivers. However these bodies of water were formed and whatever their subsequent history, their abundance and the large proportion of the total flora they harbor force us to consider their marginal plant life as one of the most important elements in the vegetation of the region. When this study was begun in 1926, major emphasis was placed on the “development of the vegetation.” The units of study were to be ‘‘com- munities” or “associations” of plants described in terms of form and floristic content. The “development” was largely confined to the theory of suc- cession among communities, leading to more or less stable climax or cli- maxes. Time scales for the processes were not clearly defined, but it was assumed that the present state of the vegetation could be rationalized by projection of these processes backward to the disappearance of the last glacial ice. The vascular flora of the region was not well enough known in 1926 to cover the needs of such a vegetational study. This applied not only to the less common species but also to many abundant ones which, as “dominant” species, gave form and character to “communities.” Consequently the collection and identification of the species was the first necessity. Between 1926 and 1935 the known vascular flora of the region was thus increased by about 30%. Most of the new records were range extensions, for the region has very little endemism. The writer’s earliest papers on the region reflect the above frame of reference (1928, 1930a & b, 1935). After the field season of 1935 this frame became almost wholly inadequate. A determined effort was made to use “communities” or plant ‘“associa- tions” as the basic units of study. This could be effective only if the assemblages of species, or at least of the so-called ‘“‘dominant” species, were largely repetitive within such habitat complexes as could be defined with the knowledge and facilities at hand. Because the identity of the “communities” rested upon floristic composition, it was thought that they probably had some form of internal organization among niga’ com- patible species which added validity to their use as study un Wide variation in species composition of the shore oo Mie began to appear in the early work on Great Slave Lake (1927). Seventeen small bodies of water were studied on Fairchild Point, a peninsula about 10 miles long in this lake. Each of these ponds was unique, either in the arrangement of its vegetation zones or in the “dominant” species com- position of the zones. The field seasons in the Wood Buffalo Park (1928— 128 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 30) brought out even greater variability, not only among the many ponds and small lakes that were studied, but also within habitats on the shores of individual bodies of water. A lake about 10 miles long on the upland west of the Slave River required eight transects for a fair sampling of its shore vegetation. Twenty-eight different “communities” of vascular plants were described in these transects, involving 20 “dominant” species. Field experience strongly suggested that in the region as a whole the study of more pond and lake shores would yield more different “communities,” more zonal variations in the vegetation, and additional “dominant” species. The use of the “community” or “association” as the basic unit for the study of the shore vegetation became extremely doubtful. Nonetheless, these terms continued to be used (Raup, 1934, 1935), and the complexity was in part avoided by annotated descriptions of assemblages believed to be “typical” of the various habitats. Maximum confusion was reached in the 1935 season when many shores around the whole of Lake Athabaska were examined, particularly those of the intricate lagoon systems on the south shore. Here no two of the hundreds available for study seemed to have the same “community”’ structures and contents. The idea of orderly successional development among “communities” had to be greatly restricted in space and time. The last cover of glacial ice did not retreat steadily, but in stages so that land surfaces available for colonization by plants were of varying ages. Owing to the general topog- raphy of the region and the geography of its drainage systems, there had been large variations in the levels of its major lakes and in the develop- ment of its flood-plain and delta systems (see below; also Raup, 1930b, 1931, 1946, and Cameron, 1922). Lengths of time during which physical habitats could remain relatively stable, and in which long-term biological successions could have occurred began to be notably shortened. A high water level seen at Lake Athabaska in 1935 was maintained throughout the growing season, and effectively drowned all the shore “successions” that were described in prior years. The frequency of such floods has been estimated recently by Stockton and Fritts (1973; see below), and it is not unlikely that time periods during which the shores of this lake can remain physically stable are shorter than the life spans of most of the perennial plants that make up the shore vegetation. If this is the case, successions in this vegetation are reduced to fragments which, if they exist at all, have indeterminate beginnings and ends. The extent to which analogues of these findings can be seen in the shores of smaller upland lakes and ponds is unknown. Many of these smaller water bodies are held up by morainic dams, are deposited at different times, have varying materials, and erode at different rates. Extreme cases occur in the karst topography west of the Slave River, where fluctuations im pond levels of 10 to 30 feet are not uncommon, giving rise to curious “duplications” of shore zonations at different levels in the same sink hole. Here the fluctuations are due to unpredictable changes in the movement of ground water through the underlying cavernous gypsum. With the failure of the “community” as a viable, repetitive unit for 1975] RAUP, SPECIES VERSATILITY 129 study and rationalization of the shore vegetation, and with the greatly restricted use of biological succession for interpreting the development of this vegetation, it became necessary to construct some other frame of reference. The present paper explores the use of the species as the basic study unit. There is abundant precedent for this in the literature of flor- istic plant geography (cf. Raup, 1942; Wulff, 1943; Cain, 1944; Bocher, 1954). But there is less precedent in ecological plant geography, which has been concerned primarily, during the present century, with the struc- ture, physiology, and “dynamics” of “communities” (cf. Gleason, 1926; Cain, 1947). The use of species as study units has been greatly stimulated since the 1920’s by research on ecotypic variation within species and by the realization that taxonomically defined species contain biotypes and ecotypes that behave differently in their relations to environments (Tures- son, 1922, 1925, 1927, 1929; Hultén, 1937a; Clausen, Keck, & Hiesey, 1940; Mayr, 1964). The implications of this research for the geography of plants were rather thoroughly reviewed by Cain in his “Foundations of plant geography” (1944). In the present paper the term “community” is replaced by ‘‘assemblage,” which carries fewer connotations of relationships among species that are unknown or nonexistent. The terms “primary” and “secondary,” though not common in ecological literature, are not new in the sense in which they are used here. They were so used by Hultén in his “Flora of the Aleutian Islands” (1937b). THE VASCULAR FLORA AND ITS SHORE HABITATS The total known vascular flora of the Athabaska-Great Slave Lake region numbers approximately 750 species. The shore flora contains 424 of these, or about 57% of the total. Seven species are excluded from the following studies. Three appear to be endemic or so localized that their ranges and local behavior are not well known. The other four, though they have wide ranges southward in the continent, are apparently sporadic in the southern part of our region. Thus the number for the total shore flora in the following analyses will be 417. Species units used here are those in the author’s catalogue of the flora of the region (1936) except for a few additions and changes made by more recent students. Sixty-three families are represented in the shore flora, and 177 genera. Twelve of the families are represented by 10 or more species each and supply two thirds of the flora (262 spp., 63%). The same families supply a similar proportion of all the primary species (93 spp., 64%). The 12 families are as follows (numbers in parentheses indicate first the total number of species and second the number of primary species): Cyperaceae (59-23), Compositae (38-5), Gramineae (37-22), Salicaceae (23-14), Rosaceae (18-7), Ranunculaceae (16-1), Zosteraceae (15-7), Juncaceae (13-3), Ericaceae (12-10), Caryophyllaceae (11-0), Scrophulariaceae (10-0), Saxifragaceae (10-1). Half of these families 130 JOURNAL OF THE ARNOLD ARBORETUM [ VoL. 56 produce five or less of the primary species so that nearly half of all the primary species in the flora come from only six of the families. These families are among those that have been most poorly collected in boreal America, because their numerous species are not commonly recomniaee in the field and usually have been lumped together as “willows, grasses, “sedges,” “rushes,” or the last three simply as “gramineous” plants. The genus Carex alone has 40 species in this flora, 14 of which were noted as primary in one or more assemblages. The Gramineae are represented by 10 genera and 37 species, among which 22 were primary. Salix has 2 1 species, of which 13 were primary. Of the 14 species of Potamogeton, SIX were found to be primary. The preceding four groups, which probably are the most frequently “generalized” by students of vegetation, contain more than one fourth of the shore flora of this region, and about 38% of all the primary species that give the shore scape its characteristic features. A common arrangement of shore vegetation in the region has four major “form types.” First there is a zone of aquatics, both submerged and emergent. Inshore from this is usually a zone of some kind of wet meadow made up principally of grasses, sedges, and rushes. The third landward zone is mainly of upright or decumbent shrubs. Finally there is a marginal zone of upright shrubs and trees which merges with the surrounding forest. For purposes of study and analysis this is an oversimplification. It gives no indication of the wide variation that occurs from one body of water to the next, or even on different shores of the same lake or pond. For purposes of analysis, therefore, 10 types are recognized, although it is probable that with further field work more would be found. Because the 10 types all occupy sites that differ in moisture regime, substrate or topographic posi- tion, they are considered as habitat-vegetation complexes, and the term “habitat” will be used for them in most cases. In the following list the numbers in parentheses are the approximate numbers of different assem- blages seen in each type. The term “muskeg” refers to vegetations that develop in undrained depressions with beds of hygrophytic mosses. 1. Aquatic habitats, with submerged and/or emergent plants (29). 2. Saline or brackish sloughs or wet meadows (15). 3. Muskeg grass-sedge meadows, with moss substrata (35). 4. Open (treeless) shrub muskegs (37). 5. Shrub-tree borders of muskegs (32). 6. Damp to wet sand and/or gravel on shores of rivers and ponds or on the lower beaches of large lakes (12). 7. Vegetation of upright shrubs and trees on upper beaches of large lakes (41). é 8. Grass-sedge meadows on river flood plains or local river deposits, with silt or silt and thin moss substrata (49). 9. Shrub-tree borders of meadows on flood plains or local river de- posits (25). 10 . Vegetation of herbs and low or trailing shrubs on middle beaches of large lakes (22). 1975] RAUP, SPECIES VERSATILITY 131 Data are not available from which to describe with any degree of pre- cision the physical and nutritional properties of these habitats. The ar- rangement (from 1 to 10) of the preceding list approximates, from greatest to least, a scale of moisture availability. Factors of physical disturbance are obvious in such places as the lower and middle beaches of large lakes and in local river deposits. Currents and waves are active in summer, and at the spring break-up of ice there is much scouring of shores along the large rivers. Ice-push on the shores of the large lakes displaces large quan- tities of material. Further, the levels of the large lakes are known to change by several feet owing either to flooding from the main rivers or to gale winds. The middle beaches are commonly of sand, which is moved by dry westerly winds. Though frost heaving and thrusting no doubt occur in many of the soils, their distribution and the variations in their intensity are not known. Water supply to upland ponds and muskegs varies greatly with precipitation, and in dry summers fire is known to run through some muskegs and grass-sedge meadows. It may be that such sites, apparently rather stable, are more susceptible to disturbance than is yet known. TOPOGRAPHY OF THE REGION The topography, geological structure, soils, and general climatic features of the Athabaska-Great Slave Lake region were reviewed at some length in an earlier paper (Raup, 1946). This material will not be repeated except in a broad outline intended to clarify discussions of the geographic ranges of species. The region is divided into two major subregions by a boundary running generally from S-SE to N-NW. Geologically this boundary is between Precambrian rocks to the east and Paleozoic or younger rocks to the west. Outcrops of limestone, shale or gypsum are few. Topographically this area has representatives of two physiographic provinces. There are extensive alluvial lowlands in the broad valleys of the main rivers (the Peace, Atha- baska, Slave, Buffalo, Little Buffalo, and Hay rivers) which make up the Mackenzie Lowland Province, with altitudes ranging from about 500 to about 700 feet above sea level in our area. This includes the wide deltas of these rivers at Athabaska and Great Slave lakes. Above it to the west of the Slave River, margined in places by well-defined limestone escarpments about 400 feet high, is a broad plain that gradually slopes upward to the southwest and is part of the Alberta Plateau Province. Much of this area is underlaid by gypsiferous rocks, on which an extensive karst topography is developed. At the west and southwest margins of our area are outliers of the Cretaceous portion of the Alberta Plateau, rising to altitudes of 2500 to 3000 feet above sea level. The dividing boundary runs northward along the eastern margin of the 132 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 lower Athabaska River valley, crosses the western end of Lake Athabaska, and then follows the eastern margin of the Slave River lowland to Great Slave Lake. It appears again on the eastern shore of the north arm of this lake. East of this boundary is the Laurentian Plateau Province, or “Canadian Shield.” In our area its highest altitudes reach to about 1700 feet above the sea. It is characterized by abundant outcrops of Precambrian rocks, and by thin and scattered deposits mainly of morainic materials and beach or glacio-fluvial sands and gravels. South of Lake Athabaska, with occa- sional representatives on the north shore, is a large area of sandstones and quartzites, the weathering of which has produced the extensive beaches, dunes, and sand plains that border the lake on the south. Between the Athabaska and Great Slave lakes, and around the east arm and east shore of the north arm of the latter, are many areas of ancient Precambrian, highly metamorphosed sedimentary rocks. Finally there are the granitic and gneissic rocks that are so wide-spread in the Canadian Shield that the ancient metamorphic rocks appear as “islands” interspersed among them. Drainage systems on both sides of the boundary are poorly developed, giving rise to a multitude of undrained or poorly drained depressions, which in this region contain shallow ponds and lakes and a great variety of sloughs, muskegs, and grass-sedge meadows. The muskegs are most extensive on the uplands, while sloughs and meadows are most abundant on the flood plains and deltas of the large rivers, where meandering streams have produced a plethora of abandoned channels containing lakes and ponds. Small bodies of water are most abundant on the Canadian Shield east of the boundary, where basins in the resistant rocks have for the most part remained intact since the glacial ice receded. Major features of the region are the two large lakes, Athabaska and Great Slave. The first is approximately 190 miles long, about 35 miles wide, and as presently mapped lies almost entirely in the Precambrian area. Formerly it had a large western extension over Paleozoic rocks and a southward extension up the Athabaska River valley, but these have been largely filled by alluvial deposits from the Athabaska and Peace rivers, leaving some shallow bodies of water, the largest of which are now mapped as Lakes Mamawi and Claire. Great Slave Lake is about 350 miles long from southwest to northeast. Its basin crosses the major boundary noted above, with a broad western portion on Paleozoic rocks. In an earlier period the western part was wider and had a long extension up the present valley of the lower Slave River. This has been filled with alluvium carried also from the Peace and Athabaska. The great alluvial deposits of these rivers are well known for the immense amounts of driftwood they contain. The present level of Lake Athabaska is about 690 feet above the sea, and Great Slave Lake is at about 495 feet. Earlier levels in post-glacial time have been placed at about 800, 1100, and 1600 feet above the sea Mier ini also Raup, 1946). ‘The higher levels are believed to water Gone ho at stages in the retreat of the glacier during which the € Peace and Athabaska rivers was impounded by glacial ice 1975] RAUP, SPECIES VERSATILITY 133 before the latter had released the normal flow through the upper Mackenzie River valley That major changes have occurred in the levels of the large lakes is evident in the abandoned gravel or sand beaches found high in the neigh- boring hills. These were measured to at least 240 feet above the current lake level on the north shore of Lake Athabaska, and they have been reported up to about 600 feet around the eastern arm of Great Slave Lake. They run in an apparently continuous series down to the present shores. It was assumed in our early studies of vegetation on the northwest shore of Lake Athabaska that the lowering of the lake was still going on, although very slowly and probably not rapidly enough to have much effect upon the development of shore vegetation. Evidence that the water level fluc- tuated to some extent was seen in September, 1932, when a southwest gale temporarily lowered it about four feet near the western end of the lake. Other evidence was in heavy driftwood found on broad sand _ beaches several feet above the existing lake level, but this was thought to be due to storm waves or ice-push. Raised barrier beaches, on the other hand, were believed to be the result of the long-term, though gradual, lowering of the general level of the lake. Measurements that later pertained to lake levels were made in 1926 of the plant zonation on shore rocks at Lake Athabaska (L. C. Raup, 1930). Four well-defined zones were seen, the lowest of which is a dark-colored crust of Verrucaria nigrescens (vertical width ca. 9 inches). The second zone, also a dark crust, consists of the same Verrucaria plus Dermatocar- pon miniatum (vertical width ca. 5 feet). The third is gray in color, the primary species being Rhizocarpon geminatum, Physcia caesia, and Leca- nora cinerea (vertical width ca. 2 feet). The fourth and uppermost zone forms a transition to the neighboring upland. On rocky headlands the primary species here are Parmelia saxatilis and Gyrophora Muhlenbergii. Where there is much sand on the upper beaches Stereocaulon tomentosum appears. Measurements of these zones and their heights above the lake level were made at 14 stations along the shore at Shelter Point, ranging from vertical cliffs to gently sloping shores of boulders, gravel, or sand. Heights of the zones above the lake were essentially the same, suggesting that they were related to the general water level rather than to wave or ice action, which would vary with the exposure of the shore. But lichens grow very slowly, and it was impossible to say whether they marked a general, though gradual, fall in the level of the lake. There were major floods in the Athabaska and Peace rivers during the Spring of 1935. In normal flow the Athabaska empties into the western part of Lake Athabaska and its water is carried through the western end to the Slave River. Most of the normal flow from the Peace River goes directly into the Slave, but there are reversible channels in its delta by which some flood water gets into Lake Athabaska and thence into the Slave. The floods in these main rivers in 1935 were so great that the level of Lake Athabaska was raised 6.5 feet above that seen by our field parties in 1926 and 1932. This took it above the two lowermost lichen zones and 134 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 about a foot into the third zone, as shown by examination of the stations measured in 1926. Similar lichen zones were seen on the shores of Great Slave Lake, but here they were much narrower, suggesting similar high water episodes that have a smaller magnitude. A recent study of water levels in Lake Athabaska (Stockton & Fritts, 1973), based on analyses of the growth rings of trees, shows that relatively large fluctuations of level have occurred in the past. Some gauge measure- ments of flow in the Peace and Athabaska rivers for the years 1935 to 1967 were available, with a few from the lake itself, and from the data the authors estimated the levels of the lake for these years. A peak level of about 693.2 feet above sea level is their estimate for 1935. They then projected their analysis backward in time to 1810. Their estimate for 1926, the year in which our field party made its first measurements, was about 687 feet. If this is approximately correct, the difference in 1935 would have been about 6 feet, while our actual measurements showed 6.5 feet. The frequency of these high water levels is not known with precision. The projected estimates of Stockton and Fritts show a similar peak in 1921 and somewhat higher ones in 1908 and 1900. From this time back to the mid-1830’s, large fluctuations apparently occurred, but at levels for the most part below 690 feet. From about 1821 to the mid-1830’s, several peaks were again high (ca. 692 to ca. 693.5 feet) THE PRIMARY SPECIES Of the 417 species considered in the shore flora, 145 were noted in one place or another as primary in their assemblages; that is, they were suffi- ciently abundant or prominent to give the assemblages their distinctive form and appearance. Some of them were found as single primary species, but more were members of combinations, with others having approximately equal rank in their respective assemblages. The disposition of the primary species in this respect is as follows: 74 spp. Found only in combinations of 2—4 spp. each 134spp. Found in 60 spp. Found in combinations or as combinations single primary spp. 71 spp. Found as single 11 spp. Found only as single primary spp. primary spp. The 134 primary species found in combinations represented 180 different assemblages. Another 71 assemblages were characterized by single primary species, making the total number of different assemblages seen in the shore vegetation 251. The total number of assemblages described was 550. An estimate of the number of times a given assemblage was repeated in the course of the field observations was thus about 2.2. This, of course, is an average. Some of the assemblages were unique, while others were seen 1975] RAUP, SPECIES VERSATILITY 135 several times. Owing in part to varying areas among the 10 habitat com- plexes, and in part to the varying extent of field studies among them, the numbers of different assemblages seen in them is far from uniform, ranging from about 12 on wet sand or gravel shores to as many as 49 in flood-plain meadows. Further, they add up to 297, which is 46 more than the total of 251 previously mentioned. The discrepancy is due to the 46 having been seen in more than one of the habitats. The following 10 primary species were found in 95 of the 180 combina- tions recognized (numbers of combinations in parentheses). In making these combinations they were associated with 59 other primary species. Alnus incana subsp. tenuifolia (19) Betula papyrifera subsp. humilis (13) Salix planifolia (18 edum groenlandicum Chamaedaphne calyculata (16) Myrica Gale (11 Carex aquatilis (15 Populus balsamifera (11) Equisetum fluviatile (13) Juncus balticus var. littoralis (10) The second 10 species, in order of decreasing numbers of combinations, were found in 33 and added 16 to the number of associated species. Picea mariana (9) Nuphar variegatum (8) Carex rostrata (9) Calamagrostis canadensis (8) Salix Bebbiana (9) Equisetum pratense (7) Empetrum nigrum (9) Arctostaphylos Uva-ursi (7) Equisetum arvense (8) Salix glauca var. acutifolia (7) Thus the 20 primary species found in the largest numbers of combina- tions ranging from 7 to 19, inclusive, appeared in 128 of the 180 com- binations observed. In these assemblages they were associated with 75 of the 134 primary species that were seen in combinations. All of the second 10 species noted above were included among those associated with the first 10. Thus the total number of primary species involved in the 128 assemblages was 85, or 63.4% of all species found in combinations. These observations raise some questions about the relations of primary species to their habitats. If 145 of them were to be distributed evenly throughout the 10 habitats described above, they would average about 14 in each. If it is assumed that there is a close and restrictive relationship of these species to their habitats, then either there are many undetected microhabitats within each of the 10, or there are possibly 14 primary species that have the same environmental requirements and have been randomly distributed throughout each of the 10 habitats. With present or foreseeable knowledge of these habitats, it would be possible to make a small number of subdivisions in some of them, such as on the beaches of large lakes or in some of the muskegs; however, definition of the theoretical 14, adding up to 145 in all, seems imprac- ticable, even with the most modern techniques of analysis. The problem is further complicated by the fact that the number 14 is far from realistic. When the numbers of primary species noted in each of the habitats are 136 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 56 added together, the total is 251 (See Ficure 13), indicating that nearly three fourths of them (106) were growing in more than one of the habitats, and about one fourth in as many as 5 to 7 different habitats (see below). Nearly half of them (66) had reached primary status in more than one habitat. In a relatively uniform site, such as the flood-plain grass-sedge meadow, 30 primary species were seen, and in the muskeg grass-sedge meadow there were 40. The tendency of the primary species to spread widely throughout the habitats suggests that the possibility of finding appreciable numbers of them having similar restrictive environmental requirements is remote. It also suggests a third alternative: that the habitat relations of a great many of the species are not narrowly restrictive and that the species have wider latitude in their selection of habitats than is commonly assumed for them. Another question arises with respect to compatibility among species growing together as “co-primaries” in their respective assemblages. If the compatibility is assumed to be to any extent restrictive, it becomes difficult to rationalize when 134 of the primary species are found in 180 different combinations of 2 to 4 each, and when individual primary species are seen in combination with as many as 19 different ones. HABITAT TOLERANCES OF THE SPECIES The term “‘tolerance” is used here in the sense of “versatility” or ‘‘flex- ibility” on the part of species with respect to the differing kinds of habitats in which they were found. These terms are equivalent to “ecological amplitude,” which has been used commonly in ecological literature. Inter- pretations of species versatility with respect to habitat have been primarily physiological in the literature of ecology, and they have been based largely on the idea that limiting factors in the environment may be recombined in such a way that species can live in differing habitats. Varying com- petition among species is thought to play a major role. A clear statement of this idea has been published by Kiichler (1967). In the total shore flora (417 spp.), 165 species were found in one habitat only. Thus more than half the flora (60.5%) showed capacity to live in two or more kinds of habitat. Ficure 1 shows the general distribution of species in terms of this capacity. Ficure 1A contains the distribu- tion in four groups: species found in 1, 2,3 to 4, and 5 to 7 habitats. The last three of these are added together in Ficure 1B to show the contrast between those found in only one habitat and those in 2 to 7. Methods of analysis used for the text figures and tables in the present paper aim only at relative comparisons of the behavior of species with respect to their occupance of habitats. They are meant merely to illustrate a group of ideas thought to be useful for a rationalization of the shore vegetation. The method of computing percentages, unless otherwise stated, will be uniform throughout the following analyses. The base numbers for the ' o He 2 vo» og 59 oe aa 8S 2> 68 . o's as aa og Bs 3 Sy 98. eq > 35 eo 2 gs P= Tw Me] ue} S § & i 2 eee GS eo. Se ee EE ee ~ @ > 2 4 23 2 > os ea. BA Be S% og . 83 52 5 Es Se zay % ee Te se: Be £8 £2 gs ge ss = I Ba Es Be ye 3 35 Bs aa 2a 34 3 5 3 = Ee a 3 og 3} os ou % fy am ion c, * x ro Lr, 0 807 ~~ 70F 70F / “gf / 60 a f F 60 ae: , Sea AA 50F sot Be A ont 7% ee a 40} a Be ‘ x 30F 30 / / f 20r 20F 10F 10F A B , i] ———— All species (417) Peles wae Primary species (145) ~~~" Secondary species (272) Ficure 1 (left). Distribution of shore species with respect to the number of habitats in which they were found. centages — on the total numbers of all species, primary species, and secondary species. F1cuRE 2 (right). Distsbatien of 134 primary species, found in varying numbers of combin ations with other primary species, with respect to the number of habitats in which they were found. Base numbers for percentages are the total numbers of primary species found in 7 to 19, 3 to 6, 2, and 1 combinations. 138 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 percentages will be the total numbers of species within the groups being analyzed. In Ficure 1, for example, there are three base numbers. Where the whole shore flora is concerned and it is desirable to know how all the species in this flora are apportioned in a range of the numbers of habitats occupied, the base number is 417. Similarly, for the primary and secondary species the numbers are 145 and 272 respectively. The primary species are relatively almost as abundant among those found in 5 to 7 habitats as among those found in only one (FIGURE 1A). The secondary species, on the other hand, though with more than twice the percentage of the primary species confined to one habitat, are represented among those found in 5 to 7 habitats by only about 1/8 the percentage of the primary species. Thus, in the shore flora as a whole, the primary species show far more tolerance of habitat variation than do the species that have secondary roles in the assemblages. They are more versatile in finding shore habitats in which they can grow. In some of these differing habitats they retain their primary position, while in others they join the secondary species. The capacity of 134 of the primary species to form combinations may be analyzed in the same way. To do this the numbers of combinations in which the species were found were grouped as follows: 7 to 19, 3 to 6, 2, 1. These groups were then analyzed in terms of their appearance in 1, 2, 3 to 4, 5 to 7, and 2 to 7 habitats (FicurE 2). The group for 7 to 19 com- binations are the 20 species noted above in the discussion of the primary species. Of the 20 species forming the largest numbers of combinations, nearly all were also found in more than one habitat. Only 5% of them were seen in only one (Ficure 2B). In contrast, the group of 46 species that were seen in only one combination showed about 44% in a single habitat. The 35 species forming 3 to 6 combinations appear to be almost as versatile in habitat selection as the 20 that were found in 7 to 19 combinations, while the 33 seen in 2 combinations are about midway between the two preceding groups. Thus there appears to be general coincidence between species’ tolerance of habitat variation and their capacity to form combina- tions with other primary species. It is proposed that the above differences in behavior of the species are, at least in part, inherent, are probably biotypic or ecotypic, and were prob- ably already in being during the invasion of the habitats following the re- treat of the glacial ice and the drainage of the postglacial lakes. Evidence for such historical conditioning of the species has been reviewed by Hultén (1937a), Anderson (1936), Cain (1944), Raup (1947a & b), and others. It is related to the varying biotype depauperation in species populations during the glacial period. If this proposal is realistic, it is probable that a large element of randomness should be inserted into any rationalization of the present vegetation. It is further proposed to use the apparent gra- dients of species versatility as criteria in comparative studies of geographic range patterns, the behavior of the life-forms of the plants, and the floras of the various habitats. ‘ n fe rs oo a 2 ue v ae te q as & _ cou 0] c = 5 ae ad &'& 2S 2 =. bo Pacer Bho oS r= b9 5 bp ce Bo @ S rer & 3 iss) = a8 Hg ee s= ee o) vo y a 28 ge g8 SE oor ¢ \ \ 70F 60F 50F- 40F 30F 20r 10- Percents of total shore flora(4l7 spp.) heh Patches Percents of primary species (145 spp.) —_-—-— Percents of secondary species (272 spp.) FIGURE 3. Proportional representation in the shore flora of the four major pada elements in the vascular flora of boreal America 140 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 THE GEOGRAPHIC RANGES OF THE SHORE SPECIES RANGES OF THE SHORE SPECIES IN NoRTH AMERICA The first of the geographic organizations follows one used by the present writer in studies of the Mackenzie Mountain flora (1947a). It contains four general range patterns into which the shore flora considered here can be placed. These patterns are as follows: —_ . Species wide-ranging in the boreal forest. . Species wide-ranging in arctic and alpine areas. . Species wide-ranging in the arctic timberline region, extending in a band across all or most of the continent on both sides of the tim- berline. Species more or less restricted to the Alaskan and/or Cordilleran regions or to their adjacent plains. Ww do The number of shore species in the four geographic elements, and their percentages of the total flora are shown in Ficure 3. It is obvious that this flora is composed primarily of species that range widely in the boreal conifer forest region of the continent, extending from Newfoundland to Alaska. A large number of these species (131) are not restricted to the boreal forest, but extend far southward in the mountains and interior plains and plateaus of Canada and the United States. The boreal forest group have their northern limits at or near the arctic timberline. The wide-ranging arctic and alpine plants, on the other hand, have their southern or lower limits at or near the timberlines. Most of them appear in this region only around the eastern or northern parts of Great Slave Lake, within a few miles of the arctic timberline. The “tim- berline” range pattern is made by a small number of species that have wide east-west ranges which extend across the arctic timberline but do not reach far into the forest or the tundra. More limited ranges are in a floristic element derived from the northern Cordillera and Alaska. Some of these Species extend eastward as far as the Hudson or James bays, but most reach only to our region or eastward on the arctic coast or islands. The boreal forest element outnumbers all the other affinities taken together by a factor of about three. Differences among the three less well represented elements are within a range of about 12%. : Ficure 4(A, B, & C) analyzes the behavior of all the species and of e primary and secondary species in the four geographic affinities in terms of their tolerance to habitat variation. In the shore flora as a whole (all species) those species showing the widest tolerance are clearly those from the boreal forest group and from the small timberline group, the latter showing a little more flexibility than the former. In both the other affinities there are fewer species found in 2 to 7 habitats than in one, with the Alaskan-Cordilleran group a little more versatile than the arctic-alpine. The primary species all show high tolerance ratings but are also in two groups. The most versatile are the Alaskan-Cordilleran and timberline 5 vo i=} 2 58 , 2 ry E : oe ° v o vo og _ 2 — = 8a | BB 8 2s a ° . 2 q ge ss sé £3 #° £8 ic °8 3 » ga Ps a 33 ts OBS ts #8 26 58 z& gs $3 658 25 33 35 ag ce aa 3 5 a3 #3 ce eg 83 5% es me gus me ns m3 24 wa U5 ga ya 3a 38 3& 3 & of .. 88 38 Ty Ease g Xe & 9 oO mo ad as} ‘ 90F / 90] 90F 90r & pe Bierce lle Sie Cc ree | Secondary species B Primary species ~ Wide ging in the boreal forest region (313 spp.) ee spear ide-ranging in the arctic-alpine oi ns (51 spp.) ~~~~~~Wide-ranging in the arctic-alpine regions (ll spp.) : cr alsemmaie ta ooo ~ —_- pore eens, ra (41 p.) ——-——- Alaskan and/or Cordilleran species (7 Pp. « 2 Spo.) a eee Wide-ranging in the timberline region (7 spp.) ments in the shore flora with ct to the numbers of ees seen am : 134 primary species that were found in —— Percestigss based on the total numbers of co blaation- eer primary species in each geo- graphic elemen 142 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 groups, with many more found in 2 to 7 habitats than in only one. The other two affinities form the other group, nearly equaling each other and showing about two and a half times as many of the more flexible species as were found in only one habitat. Among the secondary species all of the three lesser affinities show relatively low versatility, ranging within about 10% of each other and showing many more species found in only one habitat than in more than one. In the boreal forest affinity, on the other hand, nearly half of the secondary species were found in 2 to 7 habitats. Ficure 5 shows the distribution among the four geographic affinities of the 134 primary species found in combinations. The latter are grouped, as before, in terms of the numbers of combinations in which they were found (7 to 19, 3 to 6, 2, 1). Most of these species (ca. 81%) are derived from the boreal forest affinity. However, in spite of their large numbers, these species are the least versatile among the four geographic elements at forming combinations. The most versatile are the primary species in the Alaskan-Cordilleran and timberline elements, which is consistent with their versatility in habitat tolerance. Ficures 4 and 5 suggest that the boreal forest element in the shore flora, though it contributes about 75% of all the species and is relatively high in habitat versatility when the whole flora is considered, shows relatively low versatility among its primary species, in both habitat selection and the formation of combinations. The widest tolerance in both cases is shown by the two smallest geographic elements, the timberline and the Alaskan- Cordilleran groups. In the timberline group, with its wide transcontinental range, this is understandable, but why all of the seven primary species in the Alaskan-Cordilleran group should have wide habitat versatility is unknown. Another approach can be made to the relation of range size to species versatility by using the remarkable series of range maps published in recent years by Dr. Eric Hultén (1958, 1962, 1968, 1971). Of the 417 species treated in the present paper, 369 were mapped in Hultén’s papers. These species were arranged in two groups, the first of which (283 spp.) show wide continental ranges, spanning all or most of the tundra or boreal forest regions, or having wide ranges in the northern Cordillera, Alaska, and the neighboring interior plains. The second group (86 spp.) have much smaller ranges: in the western American Arctic, in Alaska, or in the northern Cordillera but extending eastward to the Athabaska-Great Slave Lake region. Maps were found elsewhere (Raup, 1947a, 1959) for four of the species not treated by Hultén, all of which are wide-ranging. Nearly all of the 44 remaining proved to be species of southern affinity in the boreal forest region, limited in our area to small, more or less isolated populations, most of them in the southern part. These were added to the 86 small or discontinuous ranges mapped by Hultén to make 130 species of limited = distinctly marginal range. These are contrasted with 287 wide-ranging pecies and with the whole flora (417 spp.) in FicurE 6. Hae pone versatility shown by the whole flora in Ficure 6 (solid equivalent to that shown in Figure 1B. In the whole flora, as well 1975] RAUP, SPECIES VERSATILITY 143 o> rs o> = o> Pg 5 N oh nN SZ “ Sa £2 pe £2 Be SB gs gs 7s 7s 7s 78 3-2 EE | 3-2 34 38 5.2 ae es Se os os os em i, ed ee ry, oe % % 80 | 80 70 70 60F ~ Re 60F x a“ Be 50F & 50r er pis 407 * < 40+ 30 fF 30F 20F 207 10r 10r 10F een —1 ee | All species Primary species Secondary species Total shore flora (417 spp.) eS alae Species with wide couscous ranges in tundra or boreal forest regions of North America (287 spp. ——-—--— Species with relatively small range areas in northwestern America, or with much disrupted ranges, or with main ranges farther south and represented ere by more or less isolated marginal populations (130 spp.) IGURE 6. Analysis of habitat versatility in two groups of species, one with large — range areas and the other with much smaller or discontinuous ranges. Data mainly from Hultén (1958, 1962, 1968, 1971). Base numbers for percentages are the total numbers for all, primary, and secondary species in each of the geographic groups. as among the primary and secondary species, the plants with small or dis- continuous ranges are considerably lower in versatility, as reflected by their populations in our region, than species with wide continuous ranges. Because there appears to be a relationship between “primaryness” in species and their wider versatility, it could be expected that a segment of the flora showing low versatility would provide proportionally fewer pri- Mary species than one with wider tolerance. This proves to be the case here, for the more restricted group is about 29% primary while the wide-ranging group is about 38%. SPECIES RANGES WITHIN THE ATHABASKA-GREAT SLAVE LAKE REGION Although the bulk of the shore flora is of species that range widely in northern America, there are many that have more or less limited ranges within our region. There are 170 species that are ubiquitous, their popu- iss} 4 wn igs) ao 2 Sf 9 2? oOo” o Oo n are} wg So ae) i) a's — af a ac O n> ee = VO Sox oD & So =e) =i a 8 = it 3A eo @ He ae 4 S o § gO oe 1) sa of Uy oH Py ae > © = % 10 ————All species (417) Primary species (145) Secondary species (272) Ficure 7. Analysis of the shore flora with respect to its local distribution within the Athabaska-Great Slave Lake region. Percentages based on total num- bers of all species, primary species, and secondary species. \ 1975] RAUP, SPECIES VERSATILITY 145 lations being essentially continuous throughout our whole region. Second is a group of 127 species whose main ranges are west of the major N-S boundary noted in the discussion of topography. Third are 120 species whose main ranges are east of this boundary. Thus for 247 species (59% of the flora) the boundary appears to be more or less restrictive. Of the 127 species mainly west of the boundary, 90 were found only in this area, while of the 120 species mainly in the eastern area, 94 are apparently confined to it. About one fourth of the nonubiquitous flora (63 spp.), therefore, shows some overlap of the boundary, usually not more than 10 to 20 miles. FicuRE 7 shows the percentage representations of shore species in the two geographic subdivisions of the region, and compares them to the pro- portions of wide-ranging (ubiquitous) species. It appears that (1) the wides are most abundant in the region as a whole and their proportions in the two subregions are about the same; (2) the primary species are most heavily represented (about 50%) among the wides, while in the subregions the other half of them are about equally divided; (3) the secondary species are within about 5% of being equally represented among the three elements of the flora. Analyses of the nonwide elements in the shore flora in terms of their versatility in habitat selection were made in order to see whether there were correlations between versatility and range size. First an effort was made to define the smallest geographic range patterns that would be commensurate with the volumes and variations in the dis- tribution of field data. Four of these smaller range areas were defined, two on each side of the major boundary described above. West of this bound- ary are the uplands with 13 species not found elsewhere in the region and the lowlands with 38 species not seen elsewhere. East of the boundary are the granitic and metamorphic rock areas north of Lake Athabaska and around the eastern parts of Great Slave Lake, with 48 restricted species, and the sandstone and quartzite areas south of Lake Athabaska with 15 species. Thus there are, in all, 114 species that appear to be restricted to one or another of these lesser geographic areas. Figure 8 compares the behavior, with respect to species versatility in habitat tolerance, of the ubiquitous species and those of the smallest geo- graphic extent. F1GuRE 8A shows that the ubiquitous species found in more than one habitat greatly outnumber those found in only one, whereas less than half of the geographically restricted species seem able to live in more than one. As noted earlier the primary species in the shore flora as a whole show greater tolerance of habitat variation than do the secondary species. This is reflected in Ficure 8(B & C). The wide-ranging primary species found in more than one habitat are about six times as numerous as those found in only one. In the geographically restricted group the versatility of the primary species, though much less than among the wides, is still much greater than that of the secondary species. The secondary species show a contrast approaching that of the wides, though with generally less versatility in evidence. o v ~ o o> ph cm ~ eo ian) Ld o> ~ 2> ~ e ; 3 wg “ey : 5 a, 8 B, 83 : ow £3 fa 28 So £8 Bo a2 os a 8 A-7m £8 5 a % ~ 3 a ms 3 a cS 0 S home} home] 9 § 30 8 Pome » 97 8 3 So = = 2s pI es Ba aa 2 h—| 9 = # 9 = = gs sé 83 a2 aa 34 52 5-2 | 5.4 aa 53 aq 3 9 ° ° a8 ) og fe) ) Le es ea La es es cs oa es ee es cs % % % % % All species Primary species Secondary species All species Primary species re | Secondary species ———Species found only in areas underlain by Ligeia or Cretaceous rocks, or by alluvium derived from these rocks (90 ide-ranging species in the Ath habaska - ee pare Lake . py: seep aeae? —Species found only in areas eR lain by Praccniisel rocks —---~—Species having greatly restricted ran nges, i. ing in all b nother 94) —-—-—Species with main ranges over Paleozoic and/or Cretaceous, or over of the minor subregions (114 , Precambrian rocks, but wit is some overlap of these ranges (63) Ficure 8 (left). Analyses, Sere or to at versatility, of 170 species of wide continuous range within the Soe eam Slave Lake and of 1 cies apparently restricted to much smaller areas within Percentages As, on numbers a ‘all species, me oup. Fic URE 9 (ri ire with respect to habitat eratility. of species found only on one side or the other of the Paleozoic- Prec ae boundary and of species with main ranges on one side or the other, but with some overlap of = boundary Percentages based on numbers of all species, primary species, and secondary species in each geographic grou 1975] RAUP, SPECIES VERSATILITY 147 Analogous results appear when the ubiquitous species are eliminated and only those species whose main ranges lie on one side of the major boundary or the other are considered. In FicurE 9 the two wholly restricted groups and the group with some boundary overlap are analyzed and compared in terms of relative tolerance of habitat variation. About half of the over- lapping species have their main ranges to the east, and the other half to the west of the boundary. The species with overlapping ranges appear to have much higher tolerance ratings than do those in the more restricted areas. Consistent with the preceding analysis (FicuRE 8), the least dif- ferences are among the primary species. It is notable that only three of the overlapping primary species are primary on both sides of the boundary, and it is suggestive that primary species found only east of the boundary have considerably wider habitat tolerance than those confined to the area west of the boundary. It was shown earlier that the number of combinations formed among primary species appeared to reflect their relative versatility in habitat nation-forming proclivities and are compared to those of the overlapping primary species. FicurE 10 is analogous to Ficure 9B. The overlapping species show proportionately many more eevee ons than do those found only in one or the other of the two mae subregions. The data from analysis of the species’ ssaicaphi patterns indicates a positive correlation between size of range and versatility in the occupance of habitats. In the flora as a whole species derived from the largest ranges show the largest proportions of the more versatile species (FIcurEs 4A & 6). Relations to size of range are more striking when the behavior of plants ubiquitous in our region is compared to that of species greatly restricted in range (Ficure 8). In the latter the primary species show even fewer growing in more than one habitat than in one. The relation of habitat versatility to a prominent vegetative boundary is shown in Ficure 9, where the nonubiquitous species that do not cross the boundary are compared with those that do cross it for relatively short distances. The latter show notably greater habitat versatility than the former, LIFE-FORMS IN THE SHORE FLORA The shore flora of the region is here classified in six rather generalized life-form groups: 1. Trees: all single-stemmed woody plants. PA pride all multiple-stemmed woody plants, whether upright, de- cumbent, or trailin 3. Petal herbs with only fibrous roots as underground organs: most- ly caespitose plants; term usually shortened in the following text to “perennials with fibrous roots” or “fibrous- rooted perennials.” 148 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 = vo u a = g 3° c oc of £9 ES os ee] BE £8 2 Lee ZE ee a6 38 =o a 9 70 60 50 Ss == 40 30 20 Dei . ee es A Pa} 4 Primary species zB or Cretaceous uplands and/or Mackenzie Lowlands (18 spp.) 4 n p ; ape Primary speci rocks (24 spp.) Dri 3 s+, Primary species (91 ) YP Ficure 10. Analysis of the primary species in Ficure 9 with respect to the numbers of combinations in which they were found. Percentages based on the total numbers of primary species found in combinations and restricted to oF overlapping the two subregions. 4, Perennial herbs with caudexes, rhizomes, runners, stolons, or with stems that root at the nodes: this group brings together most of the plants that have means of vegetative propagation by under- ground or aboveground organs; term usually shortened in the following text to “perennials with rhizomes” or “rhizomatous perennials.” 5. Perennial herbs with taproots, bulbs, corms, tubers, or turions: these plants have storage organs, but no means of vegetative traveling ; term commonly shortened to “taprooted perennials” in the fol- lowing text. 6. Annual or biennial herbs. FicuRE 11 (solid line) shows the numbers of species in the above life- form categories and their percentage representation in the whole shore flora. Perennial herbs with rhizomes, caudexes, etc. are predominant, comprising a little over half of the total flora, with about three times aS many species as fibrous-rooted perennials and nearly four times as many ‘ x 8 En 5 o 8& 2 a Pe 2 a B 2 8 Z ga % : iy 2 2 =Bg z A 8 =} 6a a aE Fe 8 83 2 P ee F : | ‘4 es g 8 a5 se ga 5 = Bo iY oi oe ee 4. G2 % # S$ f) 2 #5 3 3 sb 83 be Se Gan i So Re: Bea ee a df # as 3 4 : gE I ‘a e Ss #8 #2 8s oe a ae ee Ee 23 2 28 i Ps gs ge 2s os ERI ae ah ~ ; Pr re 32 e¢ : Total nos .of spp. 9 58 219 m 30 30 é bal 3 $5 BE Nos . of Rae spp. 7 37 16 9 _ e Oe £2 Fe : Total nos, of spp. 9 58 219 71 30 30 Nos.of primary spp. 7 37 6 16 9 7 % 80, Be 70¢ isi ie 60} x \ 50+ 40+ “t ~. ——— 20} * ‘ \ 10} ween All sp ish flora, 417 spp.) -- P y speci P t pri PP 145) Primary species (F 1 P y Spp Allspecies = 22 ------ Primary ‘areca: Pm ONO WR RUN ee aes es SE eer de ae ee ee! Secondary specie: Ficure 11 (left). Proportional representation of life-forms among all species ae all primary species in the shore flora; also the proportions of primary species in each life-form group. FicuRE 12 (right). Spagna of aoigies for relative versatility in the occupation of more than one habitat. Percentages based on th num of all species, primary species, and secondary species in each life-form found growing in more he one habitat (2:49 7). 150 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 as the shrubs. Tree species are least numerous, while taprooted plants and the annual-biennial group come between the trees and the shrubs The primary species in Ficure 11 are plotted in two ways. The dashed line shows the percentages of the life-forms based on the total number of primary species in the whole flora (145). The trend of this curve resembles closely that for the whole flora except in the trees and shrubs, where the proportions of primary species exceed those in the flora as a whole. In the second method of plotting, the life-form groups are considered as separate elements of the flora and the fraction of primary species in each is shown by the dot-dashed line. Here the trees and shrubs show much larger proportions of their species as primary than any of the other forms. The most numerous group in the flora, the rhizomatous perennials, has only about 30% of its species primary, while the shrubs are nearly 65% pri- mary. All of the nonwoody forms vary from about 24% to about 32% primary. In FicureE 12 the six life-form groups are analyzed for the contributions they make to high tolerance of habitat variation. The curves show varia- tions in the proportions, within each group, of species found in more than one habitat. For example, among all the rhizomatous perennial herbs in the flora (cf. solid line) about 55% were found in more than one habitat. About 67% of the primary species in this group were in more than one habitat (dashed line), and about 45% of the secondary species (dot-dashed line). Curves for species found in only one habitat would, of course, be mirror images of these. In the shore flora as a whole (solid line) the trees and shrubs are by far the most versatile, while all the herbaceous forms vary within a range of about 9% (47-56%) near the median point, where about half are ver- satile and half were seen in only one habitat. Among the primary species (dashed line) the shrubs and trees were 9 to 10 times more likely to be found in 2 to 7 habitats than in only one. Fibrous-rooted perennials proved to be almost as tolerant as the shrubs, and considerably more so than the far more numerous rhizomatous peren- nials. Least versatile of all the life-forms appear to be perennials with taproots, etc., with only about a third of their primary species showing wide tolerance, even less than that of the primary annual-biennial group or of their own secondary species. The secondary species (dot-dashed line), excepting the trees, all vary within a range of about 12% around the median point of about 50% versatility. The percentages for trees probably are exaggerated, for only two secondary species are involved, both of them found in more than one habitat. Comparison of Ficures 11 (dot-dashed line) and 12 shows that the high percentages of primary species among the trees and shrubs are consistent with the wide habitat versatility in these forms. But in the herbaceous forms the coincidence does not occur. Although the primary species among these forms show only small differences around 25-30%, they differ widely in versatility, from about 35 Yo among taprooted species to about 879% among fibrous-rooted perennials. 1975] RAUP, SPECIES VERSATILITY 151 Analyses of the life-forms of the primary species in the four geographic affinities of the shore flora were also made to show the incidence of varying habitat versatility among them. In the predominant boreal forest element, the tolerance ratings are not much different from those seen in FicurE 12, though rhizomatous perennials show somewhat less versatility. The tim- berline element, though small, also reflects the ratings in Ficurr 12. The most striking departure from this pattern was found in the arctic-alpine affinity, which deserves particular attention. In the 14 primary species of the arctic-alpine element of the shore flora, the taprooted and fibrous-rooted perennials have the greatest flexibility in habitat selection, with all of them found to be living in more than one habitat. The shrubs, with three times as many in more than one habitat as in one. are second in the scale of tolerance. If those in the arctic-alpine element are considered as taprooted perennials, the most tolerant group here would be further accentuated (see below). The rhizome perennials habitat. There are, of course, no trees from this affinity, and no primary annual or biennial plants. It may be useful to contrast the findings on life-forms here with those in the high Arctic. For comparison, a study made in the Mesters Vig district of Northeast Greenland will be used (Raup, 1969). The classifi- cation used there was based on the writer’s own observations supplemented by those of Gelting (1934) and Bécher (1938). In the part of Greenland covered by the above studies there are no trees, and woody plants are limited to low or trailing shrubs. Following the practice of Gelting, all of the shrubs (11 spp.) were classified as taprooted perennials. It may be that many of the shrubs in the Athabaska-Great Slave Lake region could be so treated, but not enough is known of their root systems to justify such a classification. Also absent in the Mesters Vig district, as in most of Northeast Greenland, are nearly all annual and biennial herbs. Thus comparison of the two floras must be limited to the perennial herbs. In the Mesters Vig area the classification was as follows: Species with fibrous roots predominant 64 (41.6%) Species with taproots or short, oblique rhizomes 65 (42.2%) Species with well-developed underground rhizomes 25 (16.2%) Agha bs rei es of these groups in the Athabaska-Great Slave Lake region a Perennial herbs with rhizomes, caudexes, etc. 219 (68.4%) Perennial herbs with fibrous roots 71 (22.2%) Perennial herbs with taproots, bulbs, etc. 30 (9.4%) The species with taproots and fibrous roots are the predominant forms in the arctic flora at Mesters Vig, while rhizomatous species so numerous in the region studied here are reduced to about 16% of the flora. It is possible that the high versatility shown by the fibrous and taprooted species 152 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 in the arctic-alpine element of our flora reflects the predominance of these forms in the arctic tundra. A large proportion of this element was found in the areas nearest the arctic timberline. In the Alaskan-Cordilleran element there are only seven primary species, but it is notable that the taprooted plants have a high rating for versatility, as in the tundra, and that the rhizomatous perennials are even lower in the scale than in the arctic-alpine element. ANALYSES OF VEGETATION TYPES IN THE SHORE FLORA FIGURE 13 shows the number of species found in each of the 10 habitat- vegetation complexes defined earlier, and the percentage of the total shore flora found in each (solid line). The numbers of primary species in each habitat are also shown, with the percentage of total primary species (145) in each (dashed line). ravel on shores of ower beaches of { @ g Upper beaches of large lakes: vegetation of posits, with silt or with both submerged s on river floodplains and emergent species t sand and/or ponds or on rivers an d ge meadow wet meadows z ala meadows with moss substrata shrub muskegs of muskegs or on local river de p to we floodplains or local river deposits Saline or brackish sloughs and upright shrubs and trees silt and thin moss substrata Aquatic habitats large lakes Shrub-tree borders of meadows on Open (treeless) Grass-sed Total nos.of spp. ~ Nos .of primary spp. Eg wo ~ Muske, Oo ow wm az rea ros) oo — S S 88 ts» @ Middle beaches of large lakes: vegetation of herbs and low or trailing shrubs t% @ Shrub-tree borders RN) NE Dam Percents of total shore flora (417 spp.) found in each habitat. Percents of total primary species (145) found in each habitat. _ FIGURE 13. Proportional representation of all species and of all primary SPE | cies among ten shore habitats 1975] RAUP, SPECIES VERSATILITY 153 correlation, however, does not occur. The treeless shrub muskeg, for ex- ample, had the largest number of species (161), seen in 37 different assemblages, while the flood-plain meadows, with the largest number of different assemblages (49), had only 108 species listed. The next largest number of species was in the damp to wet sandy shores of lakes and rivers (114) and was noted in the smallest number of different assemblages (12). A somewhat better coincidence is with the probable areas occupied by the habitats. No accurate figures are available for this, but it is probable that shrub muskegs occupy more area in the shore vegetation than any other type. A tentative scale of areas, based on the writer’s field obser- vations, is given below. The habitats are listed from largest to smallest, with the numbers of species, from greatest to least, listed on the right as they occur in the areas. 1. Treeless shrub muskegs 1 2. Flood-plain meadows 3 3. Shrub-tree borders of flood-plain meadows 4 4. Damp to wet sand or gravel lake and river shores .................... 2 5. Shrub-tree borders of muskegs 5 6. Muskeg meadows 8 7. Shrubs and trees on upper lake beaches 7 8. Aquatic habitats 10 9. Middle beaches of large lakes 6 10. Saline or brackish habitats 9 The correlation here is far from complete, but it suggests that size of area may have some significance. Addition of the numbers of species in the 10 habitats gives a total of 896, which is a little over twice the number in the shore flora and indicates the extent to which in general, the species showed their habitat versatility. Ficure 14 gives the proportional representation, in each of the 10 habi- tats, of the primary and secondary species that were found in more than one habitat (2 to 7). The base numbers for percentages in both are the total floras of the habitats. Curves for species found in only one habitat would be mirror images of those in Ficure 14. Reasons for variations in the proportions of more versatile species from one habitat to another, ranging from about 20% to 100%, can only be suggested with present knowledge of the habitats and without more infor- mation on the gradient of versatility that seems to exist among the plants. It is probable that there is an inverse relationship between gradients of structural and physiological specialization on one hand, and of habitat versatility on the other. The most highly specialized species in the shore flora probably are the aquatics and the halophytes, and Ficure 14 shows them to be at the bottom of the scale of versatility. ae A certain amount of specialization for resistance to desiccation is to be expected, if the above reasoning is tenable, toward the dry end of the moisture gradient. If the halophytes were considered specialized for physiological dryness, they could be placed at the opposite side of the graph in Ficure 14 and would accentuate the drop in versatility that is suggested 154 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ponds or on lower beaches of , with silt or 1 river deposits lakes: vegetation of Ailing Shrubs sedge meadows on river floodplains or on local river deposits silt and thin moss substrata beaches of lar s and low or tr. e uskeg grass-sedge meadows with idd! Mie and emergent species moss substrata shrub muskegs wet meadows of muskegs Shrub-tree borders of meadows on Saline or brackish sloughs and floodplains or loca Shrub-tree borders rivers and large lakes upright shrubs and trees sw Aquatic habitats, with both submerged Grass- Nos .of prima pp- Nos.of secondary spp. 22 tw Open (treeless) o i=] e M ~ es Damp to wet sand and/or gravel on shores of S oS P| xo re ~J wow Upper beaches of large lakes: vegetation of a o BS cS a w ao ed w wn ~] oe al a i . aie cower ten see ae emer TEE Primary species found in 2-7 habitats. Secondary species found in 2-7 habitats. leas 14. Analyses of shore habitat floras with respect to the habitat ver- satility of the primary and secondary species found in them. Base numbers for percentages are the numbers of primary and secondary species in each habitat. and wet sand or gravel shores would be expec s flexibility in the flood-plain meadows and their shrub-tree borders. The latter sites are subject to flooding in spring or early summer, but become relatively dry in mid- or late summer. Their silty alluvial soils are fairly well drained after the floods recede, and most of them do not have thick moss mats to hold water and retard evaporation. Their shrub-tree borders usually are on low levees where drainage is better than in the meadows. 1975 || RAUP, SPECIES VERSATILITY 155 The middle beaches of the large lakes are the driest sites on the shores owing to their topographic position, their exposure to winds, and their coarse-textured soils. Most of the high versatility in FicurE 14 is in vegetations containing large percentages of the upright shrubs and trees of the flora. Ficurr 12 high versatility. It is aetun that their presence has influenced the trends of the curves in FicurE Seventy-nine of the primary species in the shore flora (54.5%) were found to be primary in only one or another of the 10 habitats. Thus nearly half of the primary species noted in any one habitat were likely to appear as primary in at least one other and possibly in six others. Of the 66 more versatile of the primary species. The exception is Nuphar variegatum, a highly specialized aquatic TABLE 1. tana . habitat floras for their percentage — of life-forms. mbers in parentheses are for primary spec ge meadows on river floodplains or on local river deposits, with silt or silt and thin moss substrata of rivers and ponds or on lower beaches of upright shrubs and trees Damp to wet sand and/or gravel on shores of large lakes floodplains or local river deposits Middle beaches of large lakes: vegetation of herbs and low or trailing shrubs Muskeg grass-sedge meadows with Shrub-tree borders of meadows on and emergent species wet meadows moss substrata Open (treeless) shrub muskegs Shrub-tree borders of muskegs Aquatic habitats, with both submerged Grass -sed, Saline or brackish sloughs and o| Upper beaches of large lakes: vegetation nan ~ ~) wo ro z > a _— woo ao wo \o) o 1S (19) | (27) P43 62°04 0. 6.0 | 6.7 (4.9) | (2.6) | (9.0 | (©) | a.o | © 81 lh (21) _| (27) | (30) _~ ~~ i ~ ~ a ~~ : 42 Nos. of species (20) Trees (0) o — o — © o oo Ss > w Se w oa 0 0. 5.1 21. 7:0 1 16.7. | 39.4 | 9.3 | 35. : Shrubs (0) (0) | (3.8) | (9.9) | (17.3) | (7.0) | (25.8) | (0) | (12.0) | (9.0) Perennial herbs 0.5). 24 219.2 Pa Fee) 22 i eee 8.0 14.6 with fibrous roots (0) (3.5) | (6.4) | (0.6) (0) | (4.4) | (1.5) | (1.9) ] (0) (4.5) Perennial herbs 71.4 52.6 67.9 48.4 39.5 41.2 7. ‘ 8.0 34.8 with rhizomes (31.0) | (12.3) | (37.2) | (5.0) | (3.7) | (8.8) | (7-6) | (23.1) | (6.0) | (13.5) Perennial herbs 16.7 3:5 3.8 6.8 7.4 7.9 6.1 a7 3.0 10.1 with taproots (14.3) | (1.8) | (3.8) | (0.6) | (0) (0) | @.5) } (0) (0) | (2.2) Annual and 2.4 19.3 3.8 2.5 12 7.9 io 9.3 (0) 4.5 biennial plants (2.4) | (3.5) | (0) (0) (0) | (0.9) | (0) (2.8) | (0) (1.1) 156 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 The predominance of perennial herbs with rhizomes, caudexes, etc., noted earlier, appears again in TABLE 1, where the 10 habitat floras are analyzed in terms of life-forms. They show the highest percentages in all but one of these floras. The exception is among the trees and upright shrubs on the upper beaches of large lakes, where they are least repre- sented. They are most abundant in the grass-sedge meadows and in aqua- tic habitats, in which they range between 62 and 71% of the floras. Except on the upper beaches noted above, they do not fall below about 35% in any of the habitats. Next in descending order of abundance are the shrubs, which of course reach their largest percentages in the shrub muskegs and in the shrub-tree borders of meadows and lake beaches. In these habitats they range be- tween 21 and about 40% of the species. In the meadows they range from 5 to about 10%. The middle beaches of large lakes have a larger propor- tion of shrubs than the shrub muskegs, but most of them are decumbent or trailing, while in the muskegs most are upright. Third are fibrous-rooted perennial herbs, ranging from about 8% to about 20% of the habitat floras. They have their lowest percentages in aquatic and shrub-tree border habitats, and their highest in muskeg grass- sedge meadows and in the damp to wet sand and gravel shores of lakes and rivers. They have a relatively large percentage (14.6) on the middle beaches of large lakes, where they represent a tundra element of the flora in which their life-form is much more common than in our region. Perennial herbs with taproots, bulbs, corms, tubers or turions range, with two exceptions, from 3% to about 8% of the floras. The exceptions are in aquatic and middle beach habitats, at the two ends of the moisture gradient. They are relatively prominent among the aquatics because some of these plants perennate by detached winter buds (turions). On the middle beaches, with 10.1%, they are mainly taprooted plants which, like the fibrous-rooted species, represent the tundra flora in which plants with taproots are abundant. : Many of the most characteristic plants of saline or brackish habitats in this region are annuals, and the category of annual or biennial herbs has its highest percentage in these sites (19.3). In all the others they range from 1.2 to 9.3%, in most of them below about 5%. All of the habitats in which their percentages are above about 5% are located mainly in the lowlands along the main rivers, which have been the major travel routes since the early fur trading days. Many of the annuals in the shore flora are introduced weeds, so that it is not surprising to find relatively large proportions of this form in the flood-plain meadows and on river banks. Since the field work was done for this paper there has been much more travel away from the old routes, notably eastward into the Canadian Shield. It is probable that annual and biennial weed species have increased in numbers and distribution during the last 40 years. The trees have minor roles in most of the habitats, although they have some prominence in the shrub-tree borders of muskegs and meadows, and particularly on the upper beaches of large lakes. They were found in small 1975] RAUP, SPECIES VERSATILITY 157 numbers, as seedlings or very small trees, in all the other habitats except in open water and in muskeg meadow. TABLE 1 gives the percentages of Hen species produced by each of the life-forms in the various habitats. The only life-form that had primary species in all of the habitats is that of rhizomatous perennial herbs. In general, the forms that showed very low representations in one or more of the habitats produced no primary species or very few. On the other hand, rhizomatous perennials which showed consistently high percentages of all species produced some very low numbers of primary species. As might be expected, these were in the shrub muskegs, the shrub-tree borders, and in the saline or brackish habitats. It was noted earlier that by far the largest geographic element in the shore flora is a group of 313 species that range widely in the boreal forest tinent from Newfoundland to Alaska (Ficurr 3). The predominance of this affinity appears again in Tasre 2, where the representations of the TABLE 2. Analysis of habitat floras for their percentage representations of the four major geographic elements of the shore flora. Numbers in parentheses are for primary species. 2 2 s2 18 |as 8 ag co » 3% s3 )8 182 1_e| 83 M3 s gs we as So 2 v : ee # ag °o@ ee 5 4 ge i [uy bf eetas a g 3 8 | #o|2.8|) 80) oy r=] 2 3 oe | XO | HSS go] sa s % pe S8)§38) g2 3 2.1/2? |§ Sy |] eg | case] Bs c=] S E 3 be | 8u'a gai ku = 4 a ) 62 oA Wis 3 89 s 2 Ey eo |82 | Salen a Rice .| @ 3 ce) v ee) ws3ige on 3% g®@| 3 eolaehl 2 |scel Cel Enfl Bs] es § + Sn new 1 ee 3 ovo! Yc ey = S$ Ss ® & vn 2 esa] 2° 1eds| 28 a5 Ae] 8S oo. | as » m1 c4| Se | Bs: re ee 3 oes Eo o£ ov |F? 1 Bo~ o 2 Se) 38] 8°) bo] Belesh] So}ec a) 24 gS) 28/83) 22 | gelens| g3|252| a3) 32 ee) 4a8| 36] 22) Fel Gos] Bs | e52| 82) Bs a7 tai s nA 3 Oo a = Mia ol Leo ee el | | Be s or Specte$ to | ay | vo | eo | ep | 27 | Go | Go | a» | 2D 95.2 | 80.7 | 78.2 | 75.2 | 81.5 | 71.9 | 77.3 | 88.9 | 85.0 | 62.9 — (47.6) | 49.3) | (42.3) | 2.4) | 9.8) | (2i.1) | (34.8) | (26.9) | 7.0) | (15.7) sce 2.4 | 18 | 12.8 | 13.7 | 7.4] 15.8 | 9.1 | 0.9] 3.0 | 18.0 sia co) | «) | (2.6 | 0.6} @.2]| (0.9) } (4.5)] @ | () | at.2) 2.4 /15.8 | 3.8 | 68 | 4.9] 8.8 | 10.6 | 10.2 | 10.0 | 12.4 Cordilleran (0) (0) | (2.6) | (0.6)] (2.5)] (0.9) | (4.5)} (0.9)] (2.0)] (1.3) $016 | 2.0} 6.7 Ti oP 4 SEP ae ost 34 rns « | © | 3.8] 2.59] 253] @9] as} @ | © | (2.6 four major geographic elements of the flora are noted as they appear in the ten habitats used in the present study. There is wide variation in their distribution among the habitats. 158 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 The boreal forest group shows a range of representation of about 33%. It is highest in aquatic habitats and lowest in the shrub muskegs and on the middle beaches of the large lakes. Other relatively high points are reached in the lowland meadows and in the shrub borders of these mea- dows. Another relatively low point is on the wet to damp sand or gravel beaches and river shores. All the other habitats have median percentages, ranging from about 77 to 81. The primary species produced by the boreal forest group vary from this pattern, although the highest percentage is also reached in the aquatic habitats. Their lowest point is in the shrub muskegs. Relatively high percentages appear in the grass-sedge muskeg meadows and in the shrub-tree borders of the upper beaches of large lakes. Though this element makes one of its largest contributions in the lowland meadows and their borders, its primary species in these sites are median. The reverse proportions appear on the upper beaches and in muskeg mea- dows, where the element has produced relatively large percentages of primary species. The second major element of the shore flora, derived from wide-ranging arctic-alpine plants, contains 51 species. It makes very small contributions to the saline and aquatic habitats, none at all to lowland meadows, and only minor ones to the shrub-tree borders of these meadows. In the last two of these, the boreal forest plants are heavily represented. On the other hand, the element shows the highest percentage on the middle beaches of the large lakes, where the boreal forest group was near its lowest point. It is relatively high in damp to wet sand or gravel beaches and in muskegs, and in both of these habitats the boreal forest group is median. Thus the arctic-alpine species, in general, complement the boreal forest group in their distribution, suggesting that in general the wet sand and gravel beaches, the middle beaches of the large lakes, and possibly some of the muskegs most closely resemble the arctic habitats, while the lowland mea- dows and the shrub-tree borders more closely resemble habitats in the boreal forest region. Primary species in the arctic-alpine element show very low percentages except in the middle and upper beaches of the large lakes, particularly in the former. This further suggests the general predominance of the boreal forest element, which is represented not only by the largest number of species, but also by a large proportion of the primary species. The unique position of the middle beaches is shown by the fact that the arctic-alpine group supplies almost as many primary species there (within about 5%) as the much more numerous boreal forest group. The last two geographic affinities to be considered are the Alaskan- Cordilleran group, with 41 species, and the timberline group, with only 12 species. Both make only small contributions to the flora, but they differ considerably. The Alaskan-Cordilleran plants are most numerous on the middle beaches and in the saline or brackish habitats, and are relatively common on the sand and gravel shores and in the lowland meadows or their borders. Their lowest proportions are in the aquatic habitats, the muskegs and muskeg borders. Judged by distributions in the preceding 1975] RAUP, SPECIES VERSATILITY 159 two elements, this proportion is indicative of the mixed boreal forest and arctic-alpine character of the Alaskan-Cordilleran element. It will be seen that the Alaskan-Cordilleran group contributes very small numbers of primary species to the vegetation (less than 5%) and none at all to the saline and aquatic habitats. The timberline group is by definition also a mixed one, bridging the arctic timberline. Compared to the Alaskan-Cor- dilleran element, it contributes, relatively, many more primary species. SUMMARY AND DISCUSSION This study deals with the shore vegetation of lakes and rivers in the Athabaska-Great Slave Lake region of northwestern Canada. It is based on about 130 transects that extended from open water to the shrub-tree borders. Ten habitat-vegetation complexes are defined to embrace the principal variations that were found. Definitions of the habitats are based mainly on differences in local topography, substrata, and moisture regimes. Vegetative components are defined physiognomically as grass-sedge mea- dows, treeless shrub muskegs, shrub-tree borders, etc. Within the habitats the vegetation is described in terms of assemblages of vascular plant species which are visibly different from one another owing to the abundance and/or prominence of one or more “primary” species. All other species in the assemblages are considered “secondary.” In the course of the field work 424 species of vascular plants were noted, seven of which were eliminated from the analyses because they were endemic or marginal and their behavior was not sufficiently known. Assemblages described numbered 550. Of these, 251 were found to differ from one another in their primary species composition. Thus the average number of times a given assemblage was repeated was 2.2. One hundred and forty-five of the shore species were noted as primary in one or more of the different assemblages in which they occurred. All but 11 of them (134 spp.) were found in varying combinations of two to four species each, and 60 of these were also found as single primary species in their assemblages. The 134 primary species formed 180 different com- binations. Twenty of these species were found in 7 to 19 combinations each, involving 75 other primary species and accounting for 128 of the 180 tombiriations observed. With so little repetition, among the assemblages, the feasibility of gen- eralizing or rationalizing the vegetation in terms of these assemblages becomes remote. The large number of different combinations among the primary species suggests that most of the latter have very wide latitude in their “choice” of associates. It suggests a greatly reduced probability that species compatibility, or some kind of obligate relationship among species, has much effect upon the primary composition of the assemblages Coefficients of species’ group relations to habitat, or of “preferred” associations among species, could be derived statistically, but the scale of refinement thus achieved would be far from commensurate with the scale of our present or foreseeable knowledge of the habitats; nor would it be 160 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 commensurate with our limited understanding of differences in behavior known to occur among the species. About 60% (252) of all the shore species were found growing in more than one of the 10 habitats, some of them in as many as 5 to 7 (FIGURE 1). The “most successful” species — those that were found to be primary in the assemblages — were drawn mainly from those species growing in more than one habitat. It is proposed that the number of different habitats used by a given species is a rough index of its inherent tolerance or ver- satility (“ecological amplitude”) in adjusting to habitat variation. It is suggested that the primary species have attained this rank at least in part because they are inherently more versatile than the secondary species. Their versatility appears to apply to both physical and biological habitats, for the primary species growing in the greater number of different habitats also formed the greater number of combinations with other primary species (Ficure 2). Size of geographic range appears to be correlated with differing toler- ances of habitat variation. In general, the larger the continuous range, the greater the incidence of wide tolerance among the species. This is suggested by analysis of the major geographic elements of the flora (FIcuRES 4, 5, & 6), but is shown more clearly by species that have more or less limited ranges within the Athabaska-Great Slave Lake region (Ficures 7 & 8). A major floristic boundary shows much greater tolerance among the species that cross it even for short distances than among those that do not (FIc- URES 8 & 9). Wide versatility in habitat occupance is not evenly distributed among life-forms of the plants. In the shore flora as a whole the trees and shrubs are the most versatile, while the herbaceous plants form a second group that do not differ greatly among themselves (FicurE 12). The primary species in this group, however, show notable differences. Perennials that have fibrous roots as underground organs show considerably more ver- satility than the much more numerous perennials with caudexes, stolons, runners, or rooting stems. They are nearly as versatile as the primary shrubs. Least versatile are the perennials with taproots, bulbs, corms, tubers, or turions. Primary annual and biennial species are also very low in the scale of tolerance. The life-forms of species in different geographic affinities show some notable variations from the above. Plants whose general ranges are arctic- alpine have appreciably greater versatility in their fibrous-rooted am taprooted perennials than is shown by these forms in the boreal forest oF timberline affinities. This difference is shared in part by the Alaskan-Cor- dilleran affinity, which has in it an arctic-alpine element. It is probable that the wider tolerance in these forms reflects their predominance in the arctic tundra. oS the incidence of wide versatility in the floras of the 10 i is shown in Figure 14, An explanation of the variation can only be suggested. It may be assumed that the most highly specialized species 1975] RAUP, SPECIES VERSATILITY 161 in the flora, morphologically and physiologically, are the aquatics and the halophytes. If this is the case, they are the least likely to be found in other habitats and should show the least versatility, as they do in F1cuRE 14. By the same reasoning, there should be some effects of specialization for partial desiccation toward the drier end of the moisture gradient. This is suggested among the last three of the habitats on the right side of the figure, where percentages of widely tolerant species are appreciably lower than in the preceding five habitats. In view of the findings in this paper, it appears that the shore species of the Athabaska-Great Slave Lake region are behaving not so much as members of “communities” in which there are necessary relationships to specific habitats or to other species, but as populations of individual species that have found, perhaps in part by chance, sites that are satisfactory to them. Their adaptation to site seems to have considerable flexibility, which varies from one species to another. The flexibility is most pronounced among the primary species — those that give form and color to supposed “communities” and make the shore vegetation look the way it does. The present paper, therefore, has dealt primarily with the behavior and dis- tribution of species rather than of “communities.” The term “community” is replaced by “assemblage,” which carries fewer implications of relation- ships that are nonexistent or unknown. Only the effects of differences in versatility among the species are ap- parent, in local or regional behavior and distribution. It is presumed that the differences are due to biotypic or ecotypic variations within the popu- lations which, in turn, have been conditioned historically. Such variations are known to occur in species that have been studied cytotaxonomically and experimentally (Turesson, 1922, 1925; Anderson, 1936; Clausen, Keck, & Hiesey, 1940; Mayr, 1964; Johnson & Packer, 1965). Their probable significance in the study of “dominance,” and in the concept of “niche” in ecological systems, has been stated by McNaughton and Wolf (1970). The genetic differentiation of plant populations within small areas has been discussed by Bradshaw (1972), who concludes that “the eco- logical amplitude of most species . . .. has a strong genetical compo- nent.” Further understanding of the ecological and geographic behavior of the vegetation discussed here will depend in large measure upon inves- tigations of its history and the processes of its inheritance. The starting point for this is at the species level. ACKNOWLEDGMENTS The author is greatly indebted to the institutions that supported the field work on which this paper is based: the Arnold Arboretum and the Milton Fund for Research, both of Harvard University, the National Research Council, the National Museum and the Geological Survey of Canada, and the Canadian administrative unit known in the 1920’s and 30’s as the Northwest Territories and Yukon Branch. Welcome sugges- 162 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 tions have come from the following persons who have read the manuscript: Dr. James White, Dr. David M. Raup, Dr. Mark Swan, and Lucy G. Raup, who also participated in all of the field work. LITERATURE CITED ANDERSON, E. 1936. The species problem in /ris. Ann. Mo. Bot. Gard. 23: 457-509. Bocuer, T. W. 1938. Biological distributional Pe in the flora of Greenland. song! om Grgnl. 106(2): 1-339. 147 figs. . 1954. Oceanic and continental eae complexes in Southwest Greenland. /bid. 148(1): 1-336. 74 figs. 4 BrapsHaw, A. D. 1972. Some of the evolotionsty consequences of being a plant. Evol. Biol. 5: 25-47. Carn, S. A. 1944. Foundations of plant geography. 556 pp. 63 figs. New York & London. . 1947. Characteristics of natural areas and factors in their development. Ecol. Monogr. 17: 185-200. 2 tabs Cameron, A. E. 1922. Post-glacial lakes in the Mackenzie River basin, North- west Territories, Canada. Jour. Geol. 30: 337-353. CuausEN, J., D. D. Kecx, & W. M. Hiesey. 1940. Experimental studies on the nature ot species: 1. Effect of varied environments on western North American plants. Carnegie Inst. of Washington, Publ. no. 520. 452 pp. 155 gs. GELTING, P. 1934. Studies of the vascular plants of East Greenland between Franz Joseph Fjord and Dove sis (Lat. 73°15’-76°20’ N.). Meddel. om Grgnl. 101(2): 1-340. 47 figs. 4 pls. Gieason, H. A. 1926. The individualistic concept of the plant association. Bull. Torey Bot. Club 53: 7-2 HuLTEN, E. 1937a. Outline Ei the ay of arctic and boreal biota during the Quarternary Period. : . 43 pls. Stockholm . 1937b. Flora of a Aleutian ck 397 pp. 6 figs. 47 7 maps. 16 pls. Stockholm. ———. 1958. The Amphi-Atlantic . and their phytogeographical connec- tions. K. Sv. Vet. Akad. Handl. Ser. 4. 7(1): 1-340. 279 maps . The circumpolar plants. oa: Vascular cryptogams, conifers, mo- maps. nocotyledons, Ibid. 8(5): 1-275. 228 m 1968. Flora of Alaska and neighboring territories. 1008 pp. text figs. maps. photos. Stanford. ee 971. The betes: plants. II. Dicotyledons. K. Sv. Vet. Akad. maps. Handl. Ser. 4. 13(1): 1-463. 301 m Jounson, A. W., & J. G. bee 1965. ons ga and environment in arctic Alaska. Science 148: 237-239. 1 fig. 1 tab. KUtcuter, A. W. 1967. Vegetation ae 472 pp. 21 figs. 30 tabs. Ronald Press, New York. Mayr, E. 1964. Systematics and the origin of species. Dover ed. 334 pp. 29 figs. New York. McNaveuton, S. J., & L. L. Wot. 1970. es and the niche in eco- logical systems. copie 167: 131-139. 9 figs. AUP 19 8. urvey of the vegetation a f Shelter Point, Athabaska inte (Abstract.) Univ. of Pittsburgh Bull. 25. 11 pp 1975] RAUP, SPECIES VERSATILITY 163 . 1930a. The vegetation of the Fort Reliance sand plain. Ann. Carnegie Mus. 20: 9-38. 6 pls. . 1930b. The distribution and affinities of the vegetation of the Atha- basca-Great Slave Lake region. Rhodora 32: 187-208. 37 figs. 1 tab. 1934. Phytogeographic studies in the Peace and upper Liard river regions, Canada, with a catalogue of the vascular ean Contr. Arnold Arb. - 230 pp. 7 figs. 9 pls. map. Jamaica Plain, Mas . 1935. Botanical bec in Wood Buffalo Park. Nat. Mus. Can. Bull. 74 (Biol. Ser. 20): 1-174. 15 figs. 13 pls. . 1936. Phytogeographic studies in the Athabaska-Great Slave Lake region. I. Catalogue of the vascular plants. Jour. Arnold Arb. 17; 180-315. ap. ———. 1941. Botanical problems in boreal America. Bot. Rev. 7: 147-248. . 1942. Trends in the development of geographic botany. Ann. Assoc. Am. Geogr. 32: 319-354. 1946. Phytogeographic studies in the Athabaska-Great Slave Lake region, II. Jour. Arnold Arb. 27: 1-85. Is. 1947a. The botany of southwestern Mackenzie. Sargentia 6: 1-275. 16 figs. 37 pls. 1947b. Some natural floristic areas in boreal America. Ecol. Monogr. 17: 221-234. 8 figs. 3 tabs. . 1959. The willows of boreal western America. Contr. Gray Herb. 185: 3-95. 3. figs. . 1969. The relation of the vascular flora to some factors of site in the Mesters Vig ae Northeast Greenland. Meddel. om Grgnl. 176(5): 1-80. 15 figs. 3 tabs. 1 pl. Ravp, L. C. 1930. She lichen flora of the Shelter Point region, Athabaska Lake. Bryologist 33: 57-66. 4 pls. Stockton, C. W., & H. C. Fritts. 1973. Long-term reconstruction of water level changes for Lake Papeete by analysis of tree rings. Water Res. Bull. 9: 1006-1027. 6 figs. 5 tabs. TurEsson, G. 1922a. The species and the variety as ecological units. Hereditas 3: 100-113, . 1922b. The genotypical response of the plant species to the habitat. Ibid. 3: 211-350. 1925. The plant species in relation to habitat and climate. Jbid. 6: 147-236. . 1927. Contributions to the genecology of glacial relics. /bid. 9: 81-101. ——. 1929. Zur Natur und Begrenzung der Arteinheiten. /bid. 12: 323-334. Wutrr, E. V. 1943. An introduction to historical plant geography. (Translated by ELizABETH BRISSENDEN.) 223 pp. 35 figs. Chronica Botanica Co., Waltham, Mass. HARVARD Fores HARVARD pole ITY PETERSHAM, MASSACHUSETTS 01366 164 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 56 THE TAXONOMIC STATUS OF THE GENUS BAUERELLA (RUTACEAE) * THomas G. HARTLEY IN THE COURSE OF a recent study of the genus Acronychia (Jour. Arnold Arb. 55: 469-567. 1974), it became apparent to me that its generic limits were never very clearly established and that as a result an unusually diverse assemblage of plants have been included in it — some having bisexual flowers, others having unisexual flowers; some with eight stamens, others with four; and some having drupaceous fruits, others having cap- sular fruits. Such diversity may not necessarily be excessive in tropical genera (see, for example, Gillett’s discussion of the generic limits of Cyr- tandra, 1970), but in this instance I believe it is. I have found that Acronychia, when rather narrowly interpreted around the type species, A. laevis J. R. & G. Forst., comprises a clearly mono- phyletic genus of 42 species distributed from India south and east to New Caledonia and Australia. The majority of the species are endemic to either Australia or New Guinea and a number of them, having narrow distribu- tions and, in some cases, being geographically disjunct vicarious species, appear to be relicts. The major unifying characteristics of these plants are opposite leaves, bisexual flowers, and drupaceous fruits. As far as I have been able to determine, this combination of characters serves to distinguish the species from all of the other genera of the Rutaceae in the Indo-Pacific region. If broader generic limits are accepted for Acronychia, such as those presented by Engler (1931: 309, figs. 140 and 141), in the standard major work for the Rutaceae of the Indo-Pacific region, then the mutually close relationships of the species, and their apparent phylogeny, would be ob- scured. Also, the genus would then be indistinguishable, taxonomically, from several other genera, including Melicope, Euodia, and Evodiella. Among the plants which I have excluded from Acronychia is A. bauert Schott, the type species of the genus Bauerella Borzi. In carrying out his work on the floras of Norfolk and Lord Howe Islands, Peter Green (19 70) made a thorough study of this species, the type of which may have come from Norfolk Island. He determined that it is conspecific with A. sim- plicifolia (Endl.) McGillivray & Green and recognized therein three ge0- graphical subspecies: one from eastern Australia (from northeastern Queensland south, quite continuously, to southeastern New South Wales) * This is the sixth in a series of papers on the Rutaceae. The series was initially restricted in its coverage to genera of the Malesian region, but, as I am finding 1 increasingly evident that Australian genera often hold the key to the understanding of Malesian genera, I would now like to expand its coverage to include the Australasian region (Australia, New Zealand, New Caledonia, and Papuasia). 1975] HARTLEY, BAUERELLA (RUTACEAE) 165 and Lord Howe and Norfolk Islands; one from New Caledonia and the New Hebrides; and one from Fiji. He also described an additional, closely related species fron New Caledonia, A. leiocarpa P. S. Green. I agree with Green’s delimitations of the species and subspecies of these plants, but I am of the opinion that they are more correctly placed in Bauerella than in Acronychia. Bauerella has been recognized as being distinct from Acronychia by Engler (1900: 35 and 1931: 310) —on the basis, however, of characters that are hardly diagnostic, considering the broad range of plants he included in the latter — and, in recent years, by students of the New Caledonian flora, including Diniker (1932) and Guillaumin (1948). Australian bot- anists, on the other hand, have preferred to include the genus in Acrony- chia, one reason being, perhaps, that Bentham (1863) accepted A. baueri without giving any indication that it might be generically distinct from A. laevis and A. imperforata F. Muell., both of which belong to Acronychia sensu stricto With the exception of Acronychia and Phellodendron, the drupaceous fruits and opposite leaves of Bauerella serve to distinguish it from all of the recognized genera of the Rutaceae in the Indo-Pacific region. The three species from northwestern Malesia and adjacent mainland Asia which I have excluded from Acronychia, but have not yet placed generically (A. obovata Merr., A. oligophlebia Merr., and A. porteri Hook. f.), are similar to Bauerella in having unisexual flowers and drupaceous fruits, but differ in having petals that are deciduous in fruit and stamens with narrow, geniculate filaments. Phellodendron, a genus of possibly a dozen species distributed in subtropical and temperate eastern Asia, also has opposite leaves and drupaceous fruits, but differs from Bawerella in several floral characters and in its pinnately compound, as opposed to simple, leaves. The taxonomic differences between Acronychia and Bauerella are sum- marized in the following table, and the comparative floral morphology is illustrated in Ficure 1. Acronychia Bauerella Plants with bisexual flowers Plants apparently always dioecious, with functionally unisexual flowers Flower buds longer than wide Flower buds globose or subglobose Sepals usually imbricate Sepals usually valvate Petals valvate Petals narrowly imbricate in bud Petals deciduous or rarely Petals persistent in fruit semipersistent in fruit ; Stigma scarcely differentiated Stigma (in functionally carpellate from the style flowers) broadly 4-lobed, peltate An amplified generic description of Bauerella and an enumeration of the known species and subspecies are included in this paper. A large number of herbarium specimens were examined in this study, but only a few are cited, since the majority were previously cited by Green. The contributing herbaria are listed below, however, with abbreviations FIGURE 1. a cag ee ris morphology of Acronychia and Bauerella, all drawn to the same scale fro flo preserved flowers: a, bisex piel of wh a murina (Pullen 5290) — the enlarged disc is Segre of this species, but in some alee species of Acro a it is similar to . Bauerella simplicifolia; b, func- tionally carpellate flower of Bauerlla simplicifoia “to oriarty 1510) — e poorly developed anthers and peltate stigma; c, functionally staminate flowe hs Bauerella implicifolie. (M ie 1511) —note the eae ovary, lacking ovules, and the undifiereitiated BS sg 1975] HARTLEY, BAUERELLA (RUTACEAE) 167 from Lanjouw and Stafleu’s /ndex Herbariorum, Part I. ed. 5 (Regnum ' Vegetabile 31. 1964). A Arnold Arboretum of Harvard University, Cambridge AD State Herbarium of South Australia, Adelaide BISH Bernice P. Bishop Museum, Honolul BM British Museum (Natural History), London BRI Queensland Herbarium, Brisbane CANB- Herbarium Australiense, C.S.I.R.O., Canberra GH Gray Herbarium of Harvard University, Cambridge K Royal Botanic Gardens, Kew MEL’ National Herbarium of Victoria, Melbourne MICH University Herbarium, University of Michigan, Ann Arbor Nsw_ National Herbarium of New South Wales, Sydney NY New York Botanical Garden, New York P Muséum National d’Histoire Naturelle, Paris PR Botanical Department, National Museum, Prague uc Herbarium of the University of California, Berkele y US National Museum of Natural History (Department of Botany), Smithsonian Institution, Washington, WwW Naturhistorisches Museum, Wien I wish to thank the directors and curators of these herbaria for making specimens in their care available to me. Thanks are also extended to L. A, Craven, of the C.S.I.R.O. Division of Plant Industry, and V. K. Moriarty, of the C.S.I.R.O. Division of Applied Chemistry, for their special efforts in making field observations and collections for me. Bauerella Borzi, Bol. Orto Bot. Palermo 1: 155. 1897. TYPE SPECIEs: Bauerella ibetv slic Borzi, nomen illegit. (== Bauerella baueri (Schott) Daniker, = Acronychia baueri Schott). Shrubs or small to medium trees; apparently always dioecious; indu- mentum of minute, simple trichomes. Leaves opposite or rarely in whorls of three, simple, petiolate; leaf blades pellucid-dotted, entire, pinnately veined. Inflorescences axillary, pedunculate, narrowly paniculate to subra- cemose. Flowers functionally unisexual, small and inconspicuous, globose or subglobose in bud; sepals 4, distinct or basally connate, valvate or rarely basally imbricate, persistent in fruit; petals 4, distinct, narrowly imbricate in bud, persistent in fruit; stamens 8, distinct, shorter than the petals, the antesepalous slightly longer than the antepetalous, filaments flat, elliptic-oblong, ciliate, anthers 2-celled, obtuse or obtusely apiculate, dorsifixed, without pollen in functionally carpellate flowers; disc intra- staminal, pulvinate; gynoecium a single, 4-carpellate, 4- loculate pistil, rudimentary (reduced in size and without fully differentiated stigma or functional ovules; the latter usually not visible with 10 magnification ) in functionally staminate flowers, ovules 2 per locule, subcollateral or superposed, style short, stigma peltate, broadly 4-lobed. Fruit a 4-loculate drupe; mesocarp drying spongy-crustaceous to subwoody, endocarp car- 168 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 tilaginous. Seeds carunculate, 2 or (by abortion) 1 per locule; testa longitudinally roughened, with a thin, crustaceous outer layer (often not completely covering the seed) and a thick, bony inner layer; endosperm fleshy; embryo straight, cotyledons flattened, hypocotyl terminal. The leaves range in length from about 3 to 20 cm. The leaf blades vary from chartaceous to subcoriaceous and range in shape from narrowly elliptic to obovate. The petioles are usually about one-third the length of the leaf blades. Inflorescences range in size from one-half to one and one-half times the length of the subtending petiole and tend to be narrowly paniculate, with a relatively large number of sessile or subsessile flowers, when functionally staminate, or subracemose, with relatively fewer pedi- cellate flowers, when functionally carpellate. Also, as is shown in Ficure 1, there is a considerable size difference between the sexes of the flowers. Variations in size and shape of the drupes are shown by Green (1970: 212; fe. T). Collections and field observations made of Bauerella simplicifolia — simplicifolia in Brisbane (Moriarty 1510 and 1511, both cans) and on Mt. Dromedary, in southeastern New South Wales (Craven 2583 and 2588, both cans), have shown that the plants are dioecious. This is almost certainly the condition throughout the genus, because, in over 250 different collections examined, I have not found any single specimen bearing flowers of both sexes or both fruits and male flowers. In its distribution, Bauerella demonstrates, as do a significant number of other eastern ‘Aceitralinn rain forest genera, a strong bliytogense link between Australia and New Caledonia. Its further eastward presence in the New Hebrides and Fiji, however, coupled with its absence in New Guinea, is quite unusual. Interestingly, this distribution closely parallels that of the curious amentiferous genus Balanops (Balanopaceae). ENUMERATION OF THE SPECIES AND SUBSPECIES 1. Bauerella simplicifolia (Endl.) Hartley, comb. nov. Vepris simplicifolia Endl. Prodr. Fl. Norfolk 89. 1833. Type: Bauer, De- cember 5, 1804, Norfolk Island [w (sterile specimen so original Bauer pencil sketch of a flowering and fruiting specimen), holotype]. Ae ae eas (Endl.) McGillivray & Green, Toe ger Arb, 51: 1970. ja. Bauerella simplicifolia (Endl.) Hartley subsp. simplicifolia. Acronychia simplicifolia (Endl.) ciel! & Green subsp. simplicifolia, Jour. Arnold Arb, 51: 209, fig. fa. 1970. Acronychia endlicheri Schott, pice Frag. Bot. 3, t, 2. 1834, nomen illegit., based on Vepris simplicifolia Endl, ecm baueri Schott, Rutaceae. Frag. Bot. 5, t. 3. 1834. TYPE: Bauer, unknown, possibly Norfolk Island (not seen). in. hillit F. Muell. Frag. Phytogr. Austral. 1: 26. 1858. SYNTYPES: 1975] HARTLEY, BAUERELLA (RUTACEAE) 169 Hill, Queensland, — me —_ Mueller, July, 1855, Queensland, Brisbane River , GH, K, ME Bauerella pale ‘Bor rzi, Bol. a Bot. Palermo 1: 155. 1897, nomen illegit., based on Acronychia baueri Schott. Bauerella baueri (Schott) Daniker, Viert. Naturf. Ges. Ziirich 77 (Beibl. 19): 202. 1932 1b. Bauerella simplicifolia (Endl.) Hartley subsp. neo-scotica (P. S. Green) Hartley, comb. nov Acronychia simplicifolia (Endl.) McGillivray & Green subsp. neo-scotica P. S. n, Jour. Arnold Arb. 51: 211, fig. 1b. 1970. Type: Deplanche 511, New Caledonia, Port-Boisé (xk, holotype) Ic. Bauerella simplicifolia (Endl.) Hartley subsp. petiolaris (A. Gray) Hartley, comb. nov. Acronychia petiolaris A. Gray, U. S. Expl. Exped. (Wilkes Exped.) 14 (Bot. 1): 335. 1854 & Atlas, t. 334. 1857. Type: U. S. Expl. Exped., Fiji, Ma- thuata (cH, holotype; us, isotype). Acronychia simplicifolia (Endl.) McGillivray & Green pin petiolaris (A. Gray) P. S. Green, Jour. Arnold Arb. 51: 212, fig. le. 2. Bauerella leiocarpa (P. S. Green) Hartley, comb. nov. Acronychia leiocarpa P. S. Green, Jour. Arnold Arb. 51: 213, fig. 1d. 1970. YPE: Green 1211, New Caledonia, NE slope of Ouen Toro, Nouméa (Kk, holotype). Although it probably never will be settled, there is some question as to whether or not it is correct to treat Bauerella baueri as a synonym of B. simplicifolia. Schott described Acronychia baueri as being distinct from Vepris simplicifolia (as Acronychia endlicheri) mainly on the basis of its having staminal filaments that were eglandular, those of V. simplicifolia having been described as glandular. Unfortunately, I have not been able to check the accuracy of the descriptions of these species, because the only authentic (and probably the only extant) plant material at hand is a single, Sterile sheet of V. simplicifolia. However, all of the flowering specimens I have seen, including several from Norfolk Island, the type locality of ¥, simplicifolia, agree with the description of A. baueri in having eglan- dular filaments. I suspect that the condition described for V. simplicifolia may have been the result of a misinterpretation of the material by Bauer and subsequently by Endlicher; the glands shown on the filaments in Bauer’s sketch (w) are sessile and possibly are “blisters” caused by boiling the flowers. I do not think it is at all likely that two distinct species are involved. LITERATURE CITED BentHAaM, G. Acronychia Baueri. In: Flora Australiensis. Vol. 1. 508 pp. London. 1863, [P. 366.] 170 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 DAniKer, A. U. Katalog Neu-Caledonien. [Bawerella Baueri.] Viert. Naturf. Ges. Ziirich 77 (Beibl. 19): 202. 1932. ENcLer, A. Rutaceae. Nat. Pflanzenfam. Nachtr. I: 34, 35. 1900. utaceae. Nat. Pflanzenfam. ed. 2. 19a: 187-358. 1931. Gutetr, G. W. The taxonomic status of Protocyrtandra (Gesneriaceae). Jour. Arnold Arb. 51: 241-246. ; GREEN, P. S. Notes relating to the floras of Norfolk and Lord Howe Islands, I. Jour. Arnold Arb. 51: 204-220. 1970. Gumitaumin, A. Bauerella. In: Flore de la Nouvelle-Calédonie. Phanero- games. 369 pp. Paris. 1948. [P. 168.] HERBARIUM AUSTRALIENSE CS.LR.O. DIVISION OF PLANT INDUSTRY CANBERRA, AUSTRALIA 2601 1975] McVAUGH, CARYOPHYLLUS COTINIFOLIUS 171 WHAT AND WHENCE WAS MILLER’S CARYOPHYLLUS COTINIFOLIUS? Rocers McVaucHu PuItip MILLER, in the 8th edition of his Gardeners Dictionary (1768), took up the genus Caryophyllus Linnaeus for a group of myrtaceous plants including the clove, Caryophyllus aromaticus L., the type of the generic name. Caryophyllus in Miller’s sense was a heterogeneous taxon, includ- ing C. aromaticus (now usually treated as a species of Syzygium), C. pi- mento (a species of Pimenta), C. racemosus (also assigned to Pimenta), and two other species, C. fruticosus and C. cotinifolia [sic]. Neither C. fruticosus nor C. cotinifolia = cotinifolius) has been satisfactorily accounted for since Miller’s time Since 1828 (DC. Prodr. 3: 276) C. fruticosus has been considered to be a synonym of Eugenia biflora (L.) DC. This verdict was accepted by Urban in his account of West Indian Myrtaceae (Bot. Jahrb. 19: 630. 1895). Miller’s specimen at BM, however, represents another species of Eugenia, namely the same as that represented by Miller’s specimen of Caryophyllus cotinifolius, discussed below. Miller’s description of C. fruticosus, in which the leaves are said to be “shorter and rounder at their points than those of the last species [C. pimento],” would seem to apply to the plant in the herbarium, not to any of the known forms of Eugenia biflora. There is of course the possibility that Miller’s specimen at BM has become mislabelled at some time during the last two centuries. In any event the question is academic, because the name Eugenia fruticosa is pre- occupied. The name Caryophyllus cotinifolius has been treated even more cursorily. Miller evidently derived the specific epithet from ‘“Myrtus cotini folio Plum. Cat. 19,” which he cited in synonymy. His description, however, was based entirely on a plant which he said he received from “the late Mr. Robert Millar, surgeon, from Carthagena in New Spain.” Miller’s plant at BM, which I take to be the type of his name, is a species of Eu- genia, whereas the basis for Myrtus cotini folio is a species of Myrcia, M. citrifolia (Aubl.) Urb. Plumier’s drawing corresponding to “Plum. Cat. 19” formed the basis for Burman’s plate 208, fig. 2, representing Myrtus cotini folio (in Plumier, Pl. Amer., 1759). De Candolle (1828, p. 243), in describing Myrcia coriacea, cited “Plum. ed. Burm. t. 208. f. 2” in syn- onymy, wherefore Buek, in the index to De Candolle’s Prodromus, pre- sumably reasoning back from this to “Plum. Cat. 19,” referred Caryophyl- lus cotinifolius Mill. to the synonymy of Myrcia coriacea. Taking the same view, the authors of the Index Kewensis equated Caryophyllus co- 172 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 tinifolius with Myrcia coriacea, and Urban (Bot. Jahrb. 19: 577. 1895), although with expression of considerable doubt [‘‘??”], concurred. Urban later (loc. cit., p. 672), after studying a fruit taken from Miller’s specimen at BM, stated that the plant must be a species of Eugenia. Except for these scanty references, Caryophyllus cotinifolius seems to have been Euyena cotmufol a FicuRE 1. Eugenia sent from 3. 1768. Ap- sonatas 7/8 original si Jacquin, Obs. Bot. 3: pl. 5 1975] McVAUGH, CARYOPHYLLUS COTINIFOLIUS 173 overlooked. Berg apparently did not mention it in his treatment of Ameri- can Myrtaceae (1855-1861). Miller’s specimen at pM represents a Eugenia with coriaceous, obtuse, obovate, essentially glabrous leaves, and small globose or somewhat elon- gate fruits on essentially glabrous peduncles a centimeter long or a little more. As Miller says, “the flowers are produced from the side of the branches, sometimes four, five, or six foot-stalks arise from the same point; at other times, they come out single, or perhaps by pairs.” The leaves resemble those of Mvyrcia citrifolia in size and shape, in having short petioles, and in having the midvein somewhat elevated on the upper sur- face. Because Miller’s name was published in 1768 it seems highly likely that it is the valid name for the species to which it pertains. The prob- lem is that, up to the present time, nothing like this plant seems to have been found in northern South America (the supposed type-region), or in- deed anywhere else in tropical America. To complicate the situation, Jacquin published in the same year (Obs. Bot. 3: 3. pl. 53. 1768) the name Eugenia cotinifolia, based on a speci- men of unknown origin, in the herbarium of Gronovius. I have not been able to locate Gronovius’s specimen that Jacquin saw, but Jacquin pub- lished a plate (presumably drawn from the same specimen) showing a Eugenia with broad, coriaceous, obtuse leaves like those of Myrcia citri- folia, and long-pedicellate solitary flowers. As far as one can tell from the plate, it seems to represent the same species as Caryophyllus cotinifolius. Linnaeus (Mant. 243. 1771) accepted E. cotinifolia Jacq. as a valid species, . stating that it came from “Cayenna.” Thus there seem to have been at least two contemporary 18th-century collections (perhaps three, if Miller’s specimen of C. fruticosus is not mere- ly a mislabelled duplicate of C. cotinifolius), of a tropical American species that has not been found since. Miller says his collection came from Car- tagena, in the northern lowlands of Colombia; his specimen of C. fruti- cosus, if correctly labelled, came from Jamaica; we do not know the source of the Gronovius-Jacquin specimen, but Linnaeus said it came from the Guianas. It is entirely possible that the Gronovian specimen came from Miller. Miller was in no doubt that his specimens came from “Car- thagena,” where the surgeon Robert Millar collected, but it is certainly conceivable that the latter stopped somewhere in the West Indies and gathered some seeds, while en route from Europe to the Spanish Main, or on his return voyage. Accordingly it is of particular interest that what seems to be a slightly ewer specimen of the same species has come to light. In 1895 Urban de- scribed a species called Eugenia dussii, based in part on a fruiting specimen from Guadeloupe (Duss 2200), and in part on a flowering specimen from St. Lucia (Anderson, in herb. Kew). Duss 2200 seems to have been a mixture; at least an isosyntype, at NY, consists of a vigorously grown but quite sterile, glabrous, leafy branch of Eugenia pseudopsidium or possibly : lambertiana, and detached fruits and pedicels of what is presumably Eugenia monticola. Urban referred in the protologue to the “pedicellis .. . 174 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 brevissime patenti-pilosis,’ and the “baccae ... minute pilosulae v. glabrescentes,” suggesting that the material he studied was similar or RE 2. Caryophyllus cotinifolius; Philip Miller’s specimen at BM, photo- eke in 1964. Approximately 7/8 Sabaal tee. : 1975] McVAUGH, CARYOPHYLLUS COTINIFOLIUS 175 identical to that on the sheet at Ny. The Anderson specimen at k, which I have seen through the courtesy of the Director, is a flowering specimen of quite another species. The leaves are elliptic-obovate, rounded at apex and prolonged into somewhat flattened petioles at base, exactly as in Mil- ler’s Caryophylius cotinifolius. They are also very copiously glandular- punctate beneath, unlike EF. lambertiana and E. pseudopsidium. In the disposition and number of flowers in the inflorescence, in length of pedi- cels, and in other observable details, the two specimens agree well. The pedicels and hypanthium are minutely hispidulous in the Anderson plant, whereas these parts in Miller’s fruiting specimen are essentially glabrous, as might be expected through erosion of the pubescence in age. In short, were these not the only specimens representing their respective species, I should not hesitate to call them conspecific. If they do represent the same species, what is the correct name of that species? Miller’s Dictionary was published, according to Stafleu (Tax. Lit. 314. 1967), on 16 April 1768. Apparently the precise date of publi- cation of the 3rd volume of Jacquin’s Observationum Botanicarum is un- known, but the year was 1768. If page 3 and plate 53 were published be- fore 16 April, and if Jacquin’s Eugenia cotinifolia is indeed the same as Miller’s Caryophyllus cotinifolius, then the correct name is Eugenia cotini- folia Jacq., and E. dussii falls into synonymy. If on the other hand the third volume of Obs. Bot. was published after 16 April 1768, the name Caryophyllus cotinifolius has priority but cannot be transferred to Eugenia because of the existing F. cotinifolia Jacq., based on a different type. Under these circumstances the name Eugenia dussii Urb., with the lectotype the flowering specimen collected by Anderson and now at K, would seem to be the correct one for the species. Although Eugenia dussii was described in 1895, the lectotype and only known specimen must have been collected before 1811, the date of death of Alexander Anderson. Anderson was superintendent of the botanical garden on St. Vincent for many years, and introduced to the garden a large num- ber of species from the West Indies and from other parts of the world (cf. Guilding, L., An account of the botanical garden in the island of St. Vin- cent, from its first establishment to the present time. 47 pp., Glasgow, 1825). It is interesting to speculate upon the source of Anderson’s collec- tion of E. dussii and of the 18th-century collections that appear to belong to the same species. Perhaps the species is extinct; on the other hand a new generation of explorers may discover it anew on St. Lucia, or even as far around the Caribbean as Cartagena. UNIVERSITY HERBARIUM UNIversITY or MICHIGAN ANN Argor, MICHIGAN 48104 176 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 KADSURA HETEROCLITA — MICROSPORANGIUM AND POLLEN M. R. VIJAYARAGHAVAN AND USHA DHAR THe SCHISANDRACEAE, among the Ranales, reveal many interesting features of morphology, anatomy, and palynology (see Wodehouse, 1935; Bailey & Nast, 1948; Erdtman, 1952). Kadsura Juss., a genus of woody, evergreen, climbing shrubs, is distributed in temperate and subtropical Asia. In India it is found in Assam. Perusal of literature suggests that embryological studies in this genus are meager (see Hayashi, 1960). The ontogeny of the anther wall has never been investigated. The present work deals with the vasculature of the stamen, development of wall lay- ers, and the morphology of the pollen in K. heteroclita Craib. MATERIAL AND METHODS The male flowers of Kadsura heteroclita were obtained through the courtesy of D. B. Deb, Botanical Survey of India, Assam, India, 19 August, 1963. Formalin-acetic-alcohol was used as a fixative and the material was subsequently preserved in 70 per cent ethanol. Dehydration, infiltration, and embedding were done in the conventional way (Sass, 1958). The sections were cut between 7 and 10 pm. and stained with a safranin-fast green combination. The pollen grains were acetolysed fol- lowing the revised technique of Erdtman (1960). A few mature stamens were cleared in a 2.5 per cent aqueous solution of sodium hydroxide se study of the vasculature. They were dehydrated through ascending grades of alcohol; stained in a 1 per cent solution of safranin (prepared in a i mixture of absolute alcohol and xylene); and finally transferred to xylene and mounted in canada balsam. OBSERVATIONS Microsporangium. The anthers are tetrasporangiate (Ficure 1A). Two sporangia of one anther lie close to the two sporangia of the adjacent anther (Ficure 2A). Anther lobes are widely separated by a massive connective. Each stamen is vascularized by a single trace which bifurcates in the region of the connective (Ficure 2F). The youngest anther available revealed the epidermis and the two secondary parietal layers pl, and plo. The inner of the two parietal layers, pl, matures directly into the tapetum, whereas the outer parietal layer, pli, segments periclinally to form two layers (Ficure 1B). Of these, the outer layer develops into the endothecium and the inner into the middle layer. The anther wall thus consists of four layers, namely, epidermls, 1975] VIJAYARAGHAVAN & DHAR, KADSURA 177 endothecium, middle layer, and tapetum (Ficure 1C). A few cells of the endothecium and middle layer are occasionally two-layered (F1GURE 1D). The following chart summarizes the development of the anther wall: Undifferentiated anther ss ' aes | Epidermis Archesporium r | Primary parietal Primary sporogenous. cells Secondary Secondary Secondary sporogenous parietal parietal cells cells (pl) cells (pl) Epi- Endo- Middle Tapetum Microspore mother dermis thecium layer cells The development of the anther wall conforms to the dicotyledonous type (Davis, 1966). The epidermis consists of isodiametric cells, and as the anther matures, in the region of the connective, a few of its cells become papillate (FIGURES 1F, 2C). The cells of the endothecium, prior to dehiscence, develop fibrous thickenings (Ficure 1F). A few cells of the connective, interestingly, show such thickenings. At about the tetrad stage the middle layer be- comes flattened and the tapetum degenerates (FicurE 1E). The cells of the tapetum are uninucleate and rarely become binucleate. At the time of dehiscence, only the epidermis and the fibrous endothecium persist (Ficure 2D). The septum between the adjacent loculi breaks down and the two loculi become confluent (FicureE 1F). Tannin-containing cells and ethereal oil cells are present in the con- nective (Ficures 1F, 2B). Crystals are also seen in some cells (FIGURE 2E). Microsporogenesis and male gametophyte. Cytokinesis is of the simultaneous type. Both tetrahedral and decussate tetrads are formed, the former being more frequent (Ficure 1E). The deposition of callose is conspicuous at the microspore tetrad stage (Ficure 11). Young micro- spores are uninucleate with dense cytoplasm (Ficure 1J). Pollen grains are shed at the 2-celled stage (Ficure 1K). Each pollen grain is hexacolpate and possesses three long and three short meridionally arranged furrows. The longer furrows meet and fuse at one of the poles to form the triradiate mark (Ficure 1G). All six furrows end evenly around the area at the blank pole (Ficure 1H). The short furrows extend about as far toward the convergent pole as toward the blank pole. Both kinds of furrows are linear, each with a median thickening of the furrow membrane. The exine is reticulately sculptured. 178 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 wer es SBT Cr POR OE IG Sy SERS Mares\ixaniss (? Oa! es, veces ce OH RAR <3 Sq xy rey REPRE S262 os oi een @ wy, @250// is aeaed||aaes ate 2D, Ong) LOY ac 2, )eestswes Secsty oy YS KS PO FI . : : GURE 1. Kadsura heteroclita, microsporangium, microsporogenesls and male ther sie 37. B, transverse section of a portion of an anther | showing periclinal divisions of the outer secondary parietal layer (ph) to fo™ 1975] VIJAYARAGHAVAN & DHAR, KADSURA 179 DISCUSSION Position of anther sacs. The stamen in Kadsura heteroclita is differ- entiated into a filament, a connective, and an anther with four protuberant, lateral sporangia. This is in contrast to the broad, leaflike stamens with more or less embedded sporangia, either on the adaxial side as in the Magnoliaceae (Canright, 1952) and Austrobaileyaceae (Bailey & Swamy, 1949) or on the abaxial side as in the Degeneriaceae (Swamy, 1949) and Himantandraceae (Bailey et al., 1943). The connective is massive with cells containing tannin, ethereal oil, and crystals. Accumulation of tannin is reported in the epidermal cells in Schisandra grandiflora Hook. f. & Thomson (Kapil & Jalan, 1964). Crystals are observed in S. neglecta A. C. Smith but are absent in S. grandiflora (Kapil & Jalan, 1964). Raphides are common in the connective of stamens in all genera of the Tetraceroideae (Dickison, 1970). Vascular supply of the stamen. Each stamen in Kadsura heteroclita is traversed by a single vascular trace which bifurcates in the connective, the branches being directed toward the sporangia. Ozenda (1952) in Schi- sandra henryi C. B. Clark and Jalan (1962) in S. neglecta also reported bifurcation of the vascular trace. In S. grandiflora, however, the trace usually terminates blindly near the apex or rarely branches. In Pseudo- wintera colorata (Raoul) Dandy (Winteraceae) generally a single strand enters and bifurcates, but rarely, two independent traces enter the stamen (Bhandari, 1963). According to Eames (1961), branching in the con- nective is rare in stamens with one trace. The stamen of K. heteroclita can be regarded as advanced in possessing a single vascular trace, but its branching in the connective, with each pair of sporangia receiving a sep- arate trace, is a primitive feature. Microsporangium wall. Little is known about the ontogeny of the anther wall in the Schisandraceae. In Kadsura heteroclita it has been ob- served to be of the dicotyledonous type (Davis, 1966). The anther wall the endothecium and the middle layer, the inner layer (pl.) rash ypags form- ing the tapetum, X 615. C, magnified view of the portion marke in a cell of the endothecium “<61 nsverse section of a portion of a t at the microspore tetrad stage, showing tetrahedral and decussate ae The middle layer is flattened and tapetal cells are — cells, X 73. G, casi hee grain in dor. The exine is reticulate, < 1261. H, ventral view rot “the peccolige grain, X 12 261. I, tetrahedral tetrad. Thick callose surrounds the microspores, X mG Re me 2 ~celled pollen grains, X 6 c = callose; en = endothecium; ep = tmis; gc = generative cell; a = middle layer; pe = eae illate epyierinis; pl = pear ‘acer parietal layer; sp = sporogenous cells; ta = tapetum; tn = tan- nin; vc = vegetative cell.) 180 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 RE 2. Kadsura — microsporangium. A, transverse section of sta- one anther juxtaposed with two sporangia FIcu mens showing the two spora ja Ae ee B. cross section through stamen to show ma ssive connective with cells wiper ome, tannin and ethereal oil, * 56. C, a part of the i ified to the papillate epidermis, 5 th x 56. , portion anther showing fibrous thickenings in en oe and hexacolpate pollen grains, X 195. crystals in connective, < 2 F, a cleared stamen with ee branched vascular trace, 1: eo = ethereal oil cell; pe = papillate epidermis; pe = = pollen grain; tn = nin; vt = vascular tra ce.) comprises the epidermis, endothecium, middle layer, and tapetum. The epidermal cells of the anther wall are senate} in K. heteroclita but papil- late in Schisandra grandiflora (Kapil & Jalan, 1964) and Cae fertilis Walt. (Calyc anthaceae; Mathur, 1968). However, a few epide mal cells of the connective in K. heteroclita become papillate. Pricr to 1975] VIJAYARAGHAVAN & DHAR, KADSURA 181 dehiscence, endothecial cells and a few cells of the connective develop fibrous thickenings such as in S. grandiflora. The tapetal cells are uninu- cleate and rarely become binucleate. In both Schisandra nigra Maxim. and Kadsura japonica Dunal the tapetal cells are initially uninucleate but later become binucleate (Hayashi, 1960). Kapil and Jalan (1969) re- ported multinucleate tapetal cells in S. grandiflora. Binucleate tapetal cells were also observed in Austrobaileya C. T. White (Austrobaileyaceae; Bailey & Swamy, 1949), Pseudowintera colorata (Winteraceae; Bhandari, 1963), and Sarcandra irvingbaileyi Swamy (Chloranthaceae; Vijayaragha- van, 1964). Microsporogenesis and microspores. Divisions of the microspore mother cells are simultaneous in Kadsura heteroclita, and both tetrahedral and decussate types of tetrads are formed, as observed in Schisandra grandiflora (Kapil & Jalan, 1964). Only tetrahedral tetrads, however, oc- cur in S. nigra and Kadsura japonica (Hayashi, 1960). In K. heteroclita there is a deposition of thick callose around the microspore tetrads. Such callose deposition has not been reported earlier in this family. The pollen grains in Kadsura heteroclita are unique in being heteropolar with 6 colpi, three long and three short, the longer ones meeting at one of the poles to form a triradiate mark as observed in K. roxburghiana Arn. (unpublished work) and other taxa of the Schisandraceae. There are variations in the size of the furrows. In K. peltigera Rehder & Wilson, K. japonica Juss., Schisandra chinensis K. Koch (Wodehouse, 1935), K. roxburghiana (unpublished work), and K. heteroclita, the short furrows are rather long, extending as far toward the convergent pole as toward the blank pole. On the other hand, in K. paucidenticulata Merr. and S. coc- cinea Michx. (Wodehouse, 1935), the short furrows extend farther toward the blank pole than toward the convergent pole. Parasyncolpate and syn- rugoidate types of pollen grains have been reported in S. chinensis (Erdt- man, 1952), and in S. grandiflora and S. neglecta (Jalan & Kapil, 1964). In K. heteroclita and K. roxburghiana, however, they are absent. Wode- house (1936) remarked, “Thus we find combined in this remarkable grain € main features of the pteridosperms, of the higher gymnosperms and of the higher dicotyledons . . .” and stated that the triradiate mark is homologous to the triradiate crest found in fern spores. Pollen grains are shed at the 2-celled stage in K. heteroclita as in S. nigra (Hayashi, 1960) and in S. grandiflora (Kapil & Jalan, 1964). ACKNOWLEDGMENTS We are grateful to Professor H. Y. Mohan Ram for encouragement and to Miss Sharada Ratnaparkhi for her critical reading of the manuscript. LITERATURE CITED Battey, I. W.. & , & C. G. Nast. 1948. Morphology and relationships of Jllicium, Schisandra and Kadsura. I. Stem and leaf. Jour. Arnold Arb. 29: 77-89. 182 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ,& A. C. SmitH. 1943. The family Himantandraceae. Jour. eae a Ath, 24: 190-206. & B. G. L. Swamy. 1949. The morphology and relationships of Austro- baileya. Jour. Arnold Arb. 30: 211-226. Buanpart, N. N. 1963. Embryology of Pseudowintera colorata—a vesselless dicotyledon. Phytomorphology 13: 303-316. Canricut, J. E. 1952. The comparative morphology and relationships of the Magnoliaceae. I. Trends of specialization in the stamens. Am. Jour. Bot. 39: 484-497. Davis, G. L. 1966. Systematic embryology of the angiosperms. vili + 528 pp. John Wiley & Sons, New York. Dicxison, W. C. 1970. Comparative morphological ey in Dilleniaceae. VI. Stamens and young stem. Jour. Arnold Arb. 51: Eames, A. J. 1961. Morphology of the oie xii ee 539 pp. McGraw- Hill Co., New York. ERDTMAN, G. 1952. Pollen oi anid and plant taxonomy. xiv + 538 pp. Almqvist and Wiksell, Stockhol . 1960. The acetolysis ik A revised description. Svensk. Bot. Tidskr. 54: 561-564. HAYASHI, Y. 1960. On the microsporogenesis and pollen aprnnoloe?, in the fam ily Magnoliaceae. Sci. Rep. Tohoku Univ. IV Biol. 26: 45-5 JALAN, S. 1962. Morphological, anatomical and embryological Pet on some Ranales. Ph.D. Thesis, Univ. Delhi. & R. N. Kapiz. 1964. Pollen grains of Schisandra Michaux. Grana Palynol. 5: Peaieen KapiL, R. S. JALAN. 1964. ened Michaux — its embryology and systematic sa Bot. Not. 117: 306. MatHUR, S. 1968. Development of the nits and female sean ae of Caly- conthus fertilis Walt. Proc. Nat. Inst. Sci. India 34B: 323-329 OzeNDA, P. 1952. — sur quelques interpretations de Stain Phyto- morphology 2: 225-23 Sass, J. E, 1958. ecient microtechnique. 3rd ed. ix + 228 pp. Iowa State niv. Press, Ames, Iow; Swamy, B. G. L 1949. Further sions to the morphology of the De- eneriaceae. Jour. Arnold Arb. 30: 10-38. VIJAYARAGHAVAN, M. R. 1964. iieaney and embryology of a vesselless dicot yledon — Sarcandra irvingbaileyi Swamy, and systematic position of the Chloranthaceae. Phytomorphology 14: 429-441. WovEHousE, R. P. 1935. Pollen Grains. xv + 574 pp. McGraw-Hill Co., New Yor . 1936, Evolution of pollen grains. Bot. 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Alt “Subseriptions and remittances should be: sent to Ms: Kathleen Clagett, -Amold Arboretum, 22 Divinity Avenue, Cambridge, Massachusetts 02138, . beh rack ices ue not be: p aceenres after six months from the date 0 ' ee L XLV, ee and some back numbers of volumes 46-50 a from the: ‘Kraus Reprint Corporation, Route 160; Millwood, vers 10546, ie SAL JOURNAL OF THE ARNOLD ARBORETUM VoL. 56 APRIL 1975 NUMBER 2 REPRODUCTIVE ADAPTATIONS IN PROSOPIS (LEGUMINOSAE, MIMOSOIDEAE)! Otto T. So_sric AND Puitie D. CANTINO THE GENUS Prosopis L. comprises about 40 species of shrubs and trees, which are distributed over the drier, warmer areas of the Americas, Africa, and western Asia (Burkart, 1940; Johnston, 1962). In this paper we will present quantitative data concerning the phenology, the production of flowers, fruits, and seeds, the destruction of seeds by bruchid beetles, and the percentage of seed germination in three related arborescent species of Prosopis. On the basis of this data, together with some additional qualita- tive observations, we will discuss some aspects of the adaptive “strategy” of reproduction in these species, a “strategy” that is probably shared by other arborescent phreatophytes of semidesert regions, particularly those belonging to the Mimosoideae. This study is part of a comprehensive in- vestigation of convergent adaptation in desert regions with similar cli- mates (Solbrig, 1972a). MATERIALS AND METHODS Although some data will be presented for other species, we are pri- marily concerned with the South American species Prosopis chilensis (Mol.) Stuntz and P. flexuosa DC. and the North American species P. velutina Wooton.2 More precisely, P. chilensis occurs in southern Peru, central Chile, and west-central Argentina (Burkart, 1940); P. flexuosa is endemic to west-central Argentina (Burkart, 1952); P. velutina occurs in Arizona and the Mexican state of Sonora (Benson, 1941; Johnston, 1962). All three species are trees of medium height (rarely exceeding 18 meters) which, owing to their extremely deep root systems, are able to survive as phreatophytes in semiarid shrublands where few other trees can grow. Although there are no precise studies of the underground water resources at the particular study sites of this investigation, anecdotal information from wells in the areas where the three species occur indicates * Contribution of the Structure of Ecosystems Program of the US/IBP. * Nomenclature follows Burkart (1952) for South American species and Johnston (1962) for North American species. © President and Fellows of Harvard College, 1975. 186 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 that at depths of from 30 to 100 meters there are permanent sources of water. Observations by Vervoorst (1954) indicate that roots of P. flexuosa may reach 80 meters in depth, making the tree capable of tapping a deep supply of water that is unavailable to most other plants. We feel it to be a reasonable assumption that the other two related species, of similar height and occurring under much the same environmental conditions, have the same mode of survival. The bulk of the observations were made in two areas. In South America the study sites were located in the Bolsén de Pipanaco, near the town of Andalgala, Catamarca Province, Argentina. The Bolsén is a basin of about 3000 square miles, nearly surrounded by mountains, with an an- nual rainfall ranging from 75 mm. at the southern end to 300 mm. at the northern end. Nearly all of the rain comes during the summer months, December through March (Ficure 1). In North America our observa- tions were made in the area surrounding Tucson, Arizona, principally on the Silver Bell Bajada. The climate here (Ficurr 2) is generally similar to that of the Argentine study site, with a comparable total annual rain- fall; one notable difference, however, is that in Arizona the rain is di- vided between two rainy seasons, one in the winter and one in the sum- mer. The vegetation of the two areas is similar in structure and biomass, but not in floristic composition. There are, however, several dominant genera (Prosopis, Larrea, Acacia, Cercidium) that are represented in the two areas by the same or closely related species (Solbrig, 1972a, b). Phenology. Over a two-year period, an investigation was conducted on the phenology of Prosopis chilensis and P. velutina.2 Six populations of the former and three of the latter were studied, with ten trees in each population randomly selected and marked for observation. At regular Flower and fruit production. An investigation of flower and fruit pro- duction was carried out with two objectives: the determination of the re- lationship between the number of flowers produced and the number of mature fruits, and the estimation of the annual seed yield of an average tree. In order to obtain the necessary data, we adopted the following pro- 3 : : : The observations in Argentina wer : e made by J. i : vn and P. Cantino; the Arizona observati ED sepa One deal ame at ons by T. W. Yang and Y. Abe. 1975] SOLBRIG & CANTINO, PROSOPIS 187 cedure. Ten trees of each of the three species were chosen at random, with no more than five trees in the same population. (Five populations of Prosopis flexuosa were sampled, seven of P. chilensis, and two of P. velutina.) On each tree one or two large branches were chosen for ac- curate flower-counts; the choice of branches was not random in that only branches within reach of the ground were considered, but within the subset of conveniently located branches the choice was made randomly. On each branch an accurate count was made of the number of inflores- cences and the lengths of 25 of them, the number of incipient fruits pro- duced, and the number of mature fruits. The counts and measurements were done without removal of inflorescences or fruits. From other branches on the same trees inflorescences were removed, their lengths measured, and the number of flowers counted, from which data a calculation was made of the average number of flowers per centimeter of inflorescence. By mul- tiplying the average number of flowers per cm. times the average inflo- rescence length (calculated from the 25 inflorescences measured on the marked branch) times the number of inflorescences on the branch, we arrived at an estimate of the number of flowers on the branch. Using this estimate and the counts of incipient and mature fruits on the branch, we calculated the number of fruits initiated and fully developed per thousand owers. Seed destruction by bruchid beetles. Using the same ten trees of each species chosen for the study of flower and fruit production, we con- ducted an investigation to determine the extent of seed destruction by developing bruchid beetles, the timing of the damage, and the variation in the amount of damage from tree to tree. In the case of Prosopis chilen- sis, eight of the trees were located in a district that was heavily grazed by herds of domesticated goats. After only a few weeks the goats had removed all the fruits from the ground, necessitating the selection of four new trees in another area to continue the study. Unfortunately there was a time lapse of several weeks between the last sampling of the original trees and the first sampling of the newly chosen trees. In Argentina a weekly sample of ten fruits was taken from each tree and a second sample of ten fruits from the ground beneath the tree. The Sampling was initiated when the fruits appeared nearly ripe and was con- tinued for three and one-half months. Each of the collected fruits was inspected and the number of seeds with and without bruchid emergence oles was recorded. The weekly samples of eight of the trees (four of Prosopis flexuosa and four of P. chilensis) were sent to Ing. Agr. Arturo Teran, who recorded further bruchid emergence in the succeeding weeks and identified the bruchids. In Arizona fruit samples from P. velutina were collected only once, at maturity. The bruchids that emerged were sent to Dr. John Kingsolver for identification. In an additional study of seed damage by bruchids, samples of mature fruits were collected over a three-year period from 290 Prosopis trees and shrubs, representing 83 populations and 15 species, in Argentina, Mexico, 188 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 and the United States. Up to 10 fruits from each tree were shelled, the tough endocarps broken, and the number of fully developed, underde- veloped, and bruchid-damaged seeds recorded. In all, close to 30,000 seeds from about 2600 fruits were inspected. Because of the time-consum- ing nature of the seed-inspection process, it extended over a six-month period after collection of the fruits, allowing for some secondary infection of the fruits resulting from oviposition by emerging adult bruchids. As a re- sult, the data may indicate a greater amount of seed damage, in some cases, than actually existed at fruit maturity. Nevertheless, the data serve to give a rough idea of the amount of damage that occurs in different populations and species of Prosopis. Germination and seedling development. Many of the seeds col- lected in the previous study were germinated for subsequent use in genetic studies using isozymes (Solbrig & Bawa, in preparation). The seeds were removed from the endocarps, scarified, and planted in a sandy-loam mix- ture in plastic trays. The trays were placed in an incubator with artificial light, watered copiously, and maintained at a constant temperature of 68° F. After approximately six weeks, the seedlings were transplanted into three-inch pots and kept in a greenhouse; after a year, they were trans- planted into six-inch pots. Measurements of the seedlings were made at regular intervals. An additional experiment was conducted with the seeds of Prosopis chilensis to investigate the effect on the germination rate of previous pas- sage through the intestinal tract of livestock. In two trials, seeds were removed from the excrement of goats and horses and planted in trays of soil collected at the edge of a wash where P. chilensis occurs naturally. The soil was strained before use to remove any seeds already present. Two other sets of seeds were planted as a control, one consisting of seeds re- moved by hand from their endocarps without intentional scarification of the seed coat and the other consisting of seeds with endocarps intact. The soil was kept moist for a two-week period, after which time the number of seedlings in each category was recorded. No attempt was made to maintain a constant temperature during the experiment; the trays were kept side by side on a window sill, where they received full sunlight during part of the day. Room temperature ranged from a mini- mum of 69° to a maximum of 97° F RESULTS Phenology. The timing of leaf production in Prosopis chilensis, which has a winter-deciduous habit in the region of our study, was highly regular, varying little from site to site or between the two years of the study. ins initiation commenced in September, well before the onset of the summer rains, proceeded at a high rate for about two months, and then continued at a much reduced and rather irregular pace throughout the summer. In April and May the production of new foliage ceased and 1975] SOLBRIG & CANTINO, PROSOPIS 189 leaf-fall ae leading once again to the nearly bare trees of midwinter ( FIGURE Fseing of Prosopis chilensis occurred in a single burst of bloom in October and November. The timing varied by as much as two weeks from site to site, but within any given population the onset of flowering was highly synchronized. The regularity of the event, coupled with the fact that it occurred before the end of the winter drought, leads us to be- lieve that flowering must be triggered by an environmental factor other than water supply, most likely photoperiod. The fruits reached maturity in mid-to-late December and dropped soon afterwards, the vast majority falling to the ground by the end of January (Ficure 1). Although we have no quantitative data on the phenology of Prosopis flexuosa, we observed that the entire pattern of foliage, flower, and fruit production was very similar to that of P. chilensis. The Arizona data, generously given to us by T. W. Yang, plus previous work on the phenology of Prosopis velutina (Glendening & Paulsen, 1955; Turner, 1963), indicate a pattern of phenology for that species (FIGURE 2) that is basically similar to that of P. chilensis, but the data and result- ing charts are a bit difficult to interpret for two reasons. First of all, the timing of the rainfall in 1972 at the Arizona site (FIcuRE 2) was highly unusual. February and March, months during which rains can be ex- pected in that region, were exceptionally dry, whereas October and No- vember, normally dry months, experienced heavy rains. The timing of the rainfall in 1973 was more typical of the region. Secondly, data col- lection began in June, 1972, after that season’s leaf production and bloom- ing were already in progress. In 1973, leaf initiation in Prosopis velutina began in March, proceeded at a high Tate on all trees until mid-May, and declined to zero by the end of July. In 1972, leaf initiation may also have begun in March, but there were additional periods of peak leaf production in July and August, and again in October, the latter presumably in response to the exceptional October rainfall. The initiation of blooming in Prosopis velutina, as in P. chilensis, is synchronized within populations and very likely under photoperiodic control. In 1972, blooming probably began at the Arizona site in May, as it did in 1973; we lack data earlier than June, 1972, but the produc- tion of fruits in June and July of 1972 is proof that blooming must have occurred before the study was initiated. The fact that only 40 per cent of the trees produced fruits during that period is evidence that this was a poorer bloom than that of May, 1973, probably because of the scarcity of rainfall in February and March - 1972. Additional periods of bloom occurred in July and in late August, 1972, in response to sum- mer rainfall. In the more “normal” year, 1973, on the tee hand, there was a single period of bloom, peaking in May and Jun In summary, it appears that blooming in both igi chilensis and P. velutina, and perhaps leaf production as well, are initially triggered by an environmental stimulus other than water availability, probably photo- aigeter 190 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 CHILENSIS 100 : 7 a V is ) 50; ; bx +s 4; 1007 | ( FI \ ge \ { \ 72) \ \ d \ 50 4 \ ' | \ \ \ \ \ \ L +40 20 7 — a A a nes 1, We 4 Men sictm co sh RE 1. Phenology of Prosopis chilensis in And: algala. Upper GRAPH: leaf growth and ea ie as a percentage of plants i in the maa ha (solid line, leaf 973). Po ln 3; aaa leaf piste in 1973-74; dashed dots, leaf yeas id li : flowering an as a percentage of plants in poiielitic eee line, 1972-73; Lesage line, Fag Pt a emt Pape tempera- f fal (white need Peron! set oan 72-73; broken line, sea sip rain- ~f9, Gasne 1973-— ; ordinate r represents pe 973-74). Abscissa represent mon low- os graph, Weft) and millimeters fice ee . see degres = (lo 1975] SOLBRIG & CANTINO, PROSOPIS 191 VELUTINA TEES ae i '73! 50 H i é 100 : \ + eae, Sans e H 50 errr 4 ~ 4 i a eel —---F 10 ] 2 3 4 5 6 7 8 ? 10 H 12 Phenology of — velutina in the Tucson area. UPPER G leaf ens and leaf fall as a per e of plants in the populatio 5 (not line, leaf gro 1972; dotted line, leaf pels in 1973; dashed dot leaf fall in 1972). MippLe H: flowering and fruiting as a percentage of plants in the Population (dashed line, flowering in 1972; solid line, flowering in 1973; dotted li iting i broken line, fruiting in 1973). Lows GRAPH : temperature in degrees centigrade (solid line, 1972; dashed line, 1973) and rainfall in = girl. mite bars, 1972; hatched = 1973). Abscis represents months 5 & : =a 5 3 2 yea percen graph, left) and millimeters foes gine rig 192 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 TABLE 1. Number of flowers, incipient fruits, and mature fruits. TREE NO. No. FLOWERS INCIPIENT FRUITS MATURE FRUITS No. » No. 00 Prosopis flexuosa 1 184,000 689 3.74 222 1.21 2 76,000 50 0.66 25 0.33 3 86,000 427 4.97 56 0.65 4 38,000 40 1.05 1 0.03 5 18,000 21 1.17 0 — 6 20,000 55 2.75 25 1.25 7 45,000 2 0.09 0 a 8 28,000 75 2.68 32 1.14 9 37,000 51 1.38 28 0.76 10 28,000 40 1.43 15 0.54 ! uw de S Oo _ > wn 2.59 40.4 0.72 1 45,000 92 2.04 3 0.07 2 47,000 13 0.28 0 — 3 43,000 148 3.44 0 4 28,000 31 1.11 1 0.04 5 20,000 14 0.70 0 _ 6 16,000 15 0.94 2 0.13 7 40,000 73 1.83 4 0.10 9 60,000 100 1.67 11 0.18 10 115,000 145 1.26 15 0.13 * 46,000 70.1 1.52 4 0.09 Prosopis velutina U 263,905 _ — 116 0.44 2 89,300 — — 52 0.58 3 19,975 arse ce 7 0.35 4 62,980 ow Se 130 2.06 5 119,850 son ae 211 1.76 70,005 ~ ~ 13 0.14 7 18,095 sae a 6 0.33 : 39,245 — — 98 2.50 287,408 = — 89 0.31 10 123,845 ee Ge 9 0.07 x 111,461 a on 73 0.65 period; but the existence of later blooms and the continuation of leaf Production are dependent on sufficient rainfall. Flower and fruit production, Each of the three species studied produced an average of between 220 and 240 flowers per inflorescence, of which 1975] SOLBRIG & CANTINO, PROSOPIS 193 usually no more than two developed into mature fruits; many inflorescences produced no fruit at all. In Prosopis flexuosa only 26 flowers in 10,000 initiated development into fruits, and about 7 reached maturity (TABLE 1). In P. chilensis only about one in 10,000 flowers developed into a ma- ture fruit. The fruit/flower ratio of P. velutina was similar to that of P. flexuosa. The possible causes of this extremely low ratio will be dis- cussed later. Seed destruction by bruchids and percentage of underdeveloped seeds. The bruchid beetles found emerging from the seeds of Prosopis chi- lensis have been identified as Rhipibruchus picturatus, Scutobruchus cera- tioborus, and Scutobruchus spp. (two undescribed species); those from P. flexuosa as Rhipibruchus picturatus, Scutobruchus ceratioborus, and Scuto- bruchus sp. (undescribed) ; and those from P. velutina as Neltumius arizo- nensis, Algarobius prosopis, and Mimosestes amicus. In the 15 species of Prosopis surveyed (TABLE 2), averages of from 1 to 25 per cent of the seeds had been damaged by bruchids by the time of collection (shortly after fruit maturity). The variation within species was great, however, with several populations having more than 60 per cent damage. Species belonging to section SrrompBocarPa (P. reptans, P. strom- bulifera, and P. torquata) exhibited less damage than most of those in section ALGAROBIA (all other species in TaBLE 2). The percentage of the seeds that were underdeveloped ranged from about 2 per cent to 53 per cent in the 83 populations surveyed, with averages for the 15 species ranging from about 7 per cent to 25 per cent. The results obtained in the study of bruchid damage to the seeds of Prosopis flexuosa as a function of time are shown in TaBLE 3 and FicurRE 3. By the end of the first month after fruit maturity, all the fruits had fallen to the ground, and only 2.7 per cent of the seeds had bruchid emergence holes. When the study was terminated at the end of 15 weeks, fruits could still be found beneath seven of the original nine trees, and 26.1 per cent of the seeds had bruchid emergence holes. During the first five weeks of the study, the percentage of seeds with bruchid holes re- mained relatively constant, but starting in the sixth week, the percentage of seeds damaged climbed at an approximately linear rate (FicurE 3). The equation Y = 2.13 T — 9.56, obtained through linear regression analy- sis (r=0.94), estimates the amount of seed damage at any time between the fifth and fifteenth week following fruit maturity (with Y equal to the percentage of seeds with bruchid holes and T equal to the number of weeks since the first fruits reached maturity). anche variation is evident among the nine trees studied (FIGURE 3). Trees no. 3 and no. 4 form a striking example, growing less than 50 meters can and suffering 0.7 per cent and 53.5 per cent seed damage respectively at the end of 15 weeks. Because the seeds of tree no. 3 were a bit smaller than average, we consid- ered the possibility that they might not have been viable, but a test yielded 56 per cent germination, a rate that is consistent with the results of other germination tests with P. flexuosa (see TABLE 4 and the next section). TABLE 2, Number of seeds per fruit, bruchid-damaged seeds, and underdeveloped seeds in species of Prosopis. SPECIES No, OF No, OF No. OF No. OF SEEDS/ % Good % BRUCHID- % UNDERDE- POPUL. TREES FRUITS FRUIT SEEDS DAMAGED VELOPED SEEDS SEEDS Section ALGAROBIA (South America) P. alba 17 22 213 17.92:1.5 70.3+5.6 16.9+4.7 13.6+2.7 P. caldenia 4 47 377 19.2+0.9 62.345.7 15.9+3.1 22.743.9 P. chilensis 6 29 340 18.9+2.3 72.744.5 13.4+3.7 14.0+4.3 P. flexuosa 4 12 146 11.5+1.5 73.9474 10.2+6.0 15.0+5.4 P. kuntzet 8 9 85 9.44£1.7 61.2+8.2 24.2+7.1 14.6+2.0 P. nigra 10 10 126 P. pugionata 1 3 24 12.240.6 91.640.8 1540.1 7,140.7 P. ruscifolia 11 62 600 13.5+1.1 71.645.7 11.3+2.0 12.8+4.2 P. sericantha 3 she 196 8.0+0.7 76.82:4.5 2.8+1.5 20.4+5.2 Section ALGAROBIA (North America) P. glandulos 2 7 57 P. laevigata 5 16 55 14.8+0.7 63.044.5 18.9+3.8 17.7424 P. veluti 6 6 60 Section STROMBOCARPA (South America) P. reptans 1 6 35 3.2+0.3 73.5+4.1 1.7+0.7 24.844.2 P. strombulifera 1 17 124 6.3+0.4 66.8+1.8 8.5+1.0 24.941.6 ry at 3 12 144 9.3+0.4 80.2+6.1 1.2+0.4 18.6+5.7 v6l WOALAMOGUY GIONUV AHL 40 TvNunol 9g “10A] TABLE 3. Bruchid damage to seeds of P. flexuosa. TREE # 1 2 3 5 7 8 9 TOTAL DATE no.* % no. % no. % no. % no. % no. % no. % no. % no. % no. % ON GROUND JAN. 1 Oo 9 13. 7.9 0 0 ee 0 0:0 0 0 2 18 245 = 25 20 8 0 0 & 36 1 &7 6 3.4 S257 3 29 i 07 13 10.7 6 44 46 3.1 18 2 16 L O7 0 0 A223 4 3.3 ee & 2.5 10 7.11 8 4.7 36 © 2.7 25 0 0 2 24 0 0 4 2.3 $225 8 4.8 3: 22 6 3.3 4 2.5 31°23 Fes. 1 1 0.8 4 33 1 a7 7-34 6 5.6 6 3.8 0 0 7. 22 oie Oe cae 8 1 0.8 > 34 0 0 18 11.0 2h? 3 19 8 6.5 - 4.5 WO s75 .. 49°38 18 2 1.6 8 6.3 0 0 30 20.4 17 11.3 oS £2 4 2.9 19 13.9 oF. 197 7220-92 25 $ 23 19 12.8 0 0 m.94 10 6.1 7 ae 6 6.0 15 10.9 72 6.6 Mar, 1 0 0 33 25.6 0 0 34291 — — 10 6.5 10 6.6 6 4.9 H.389 ©1064. -09 15 a 20 40 510 0 0 996 2 a 3. 338 2. RO ewe cor 1D 12.8 ig) As 22 + as 1732.0 0 0 3730 = 8 3A 1 OS. poe ee ed? 183 99 10.4 Apr. 2 > 49 (35 30.4 2 AA 68 466 — — 7200 «620 14.20 oe cs 66 46.5 “231 240 6 0 0 17. 12,7 +0 88 57.1 oo A 8,7 eS ee 61 96.8 256 355 15 0 0 53 39.6 1 a7 e335 Se oe 16.8 27. 21.1 ae oe BL O0.B 2 2G5 6k IN TREES JAN. 1 0 0 P87 0 0 1.0 2 14 0 0 0 0 a .3.1 1 0.6 12 08 8 0 0 0 0 0 0 +06 0 0 Oo 86 0 0 0 0 0 0 1.01 18 of 3 24 1 O08 .— — 1 0.8 3 18 0 0 7 3.9 7 28 2 20557 25 4 2.6 0 0 0 0 — << 6 4.8 6.37 5 3.0 9 4.6 L DB = Sleds nr ee a gee a ee ee oye es * Number of seeds with bruchid emergence holes. SIdOSOUd ‘ONLLNVO ®% DIMA TOS [SL6I S6r 196 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 It is conceivable that the seeds were too small to support the full develop- ment of a bruchid; however, tree no. 1, with average-sized seeds, also suf- fered virtually no bruchid damage. All of the above data concerning seed damage (including TaBLe 3 and Ficure 3) are based on the observation of bruchid emergence holes on the outer surface of the pods. It should be noted that the actual damage at a given time is always greater than that implied by the number of emergence holes. There is no way to determine by simple observation the number of seeds that contain partially developed bruchids. FicurRE 4 pre- sents graphically the relationship between apparent seed damage (i.e. the percentage of seeds with emergence holes) and actual seed damage (i.e. the percentage of seeds with emergence holes plus the percentage of seeds containing developing bruchids). The graph is based on data supplied to us by Ing. Agr. Arturo Teran, who tabulated the bruchid emergences subsequent to the collection date from the weekly samples of pods col- lected beneath eight of our study trees of Prosopis flexuosa and P. chilen- sis, (However, only the data from the four trees of P. flexuosa were used in the preparation of Ficure 4, involving approximately 500 pods and 7000 seeds. ) Because of several unexpected problems in the field, we do not have sufficient data to describe seed damage as a function of time for Prosopis chilensis and P. velutina. In the case of P. chilensis, the fruits rapidly disappeared from beneath the trees, mostly having been eaten by goats; at the end of 13 weeks, we found fruits under only two of the 13 trees involved in the study, and 90 per cent of the seeds in these remaining fruits had bruchid holes. Thus from the limited data that we have, it appears that seed destruction proceeds at a much faster rate in P. chilensis than in P. flexuosa. Prosopis velutina was sampled only once, about one month after maturation of the first fruits in the population, and 11.5 per cent of the seeds were found to have bruchid holes. Glendening and Paul- sen (1955) studied the bruchid damage to seeds of P. velutina over a 400-day period following fruit maturity. Their data indicate a linear in- crease in bruchid damage between the fifth and tenth weeks, during which time the percentage of seeds showing bruchid emergence holes climbed from about 10 per cent to about 50 per cent. After the tenth week, there was a gradual decrease in the rate of appearance of new emergence holes, so that the overall curve of damage versus time is sigmoid. Thus P. velutina appears to suffer a more rapid rate of damage than P. flexuosa, but a slower rate than P. chilensis. Germination. The seeds of section ALGaRosia of the genus Prosopis, to which the species under study belong, weigh 20-40 mg. and have the ap- proximate dimensions 5.5 & 3.5 & 2.0 mm. (Palacios & Bravo, 1974). The leathery endocarp that surrounds each seed is impermeable to water and must be broken for the seed to germinate; repeated attempts to ger- minate seeds with intact endocarps yielded less than one per cent ger- mination. 1975] SOLBRIG & CANTINO, PROSOPIS 197 LL - Ps ss ; : > : a eo % 94 n*9 “2 Y » “Ge re € 38 2 . = : Pete a @ g 2 Te e et % Mf, : % ~~. E +> ” ; $ D ‘ ay F 7M a) “fe a? 3 “gf Br, Mee ? <7 Ae igh G > Le i) «% ts >. ae iGee > ote :° + wo ; “ge 4 a LO + J wy oI FIGuRE 1. ee of Gentianaceae, X 750: A, Bartonia verna, — : ; B, Calolisianthus frigidus, Sera is, m = 40; a Che onan- thus bifidus, Diakinesis *, = “e D, Chironia baccifera, Diakinesi es Coutoubea spicata, Dia 5: F, Gentiana seditolia, Diakinesis, n= ; G, Gentianella darytiides, Meta phase II, n = 18; H, Halenia inaequa 4) bie eth, we 14; acr ee pats, Diakinesis, nm = 21; K, Sy bolanthus tricolor, Diakinesis, n here. Although c frigidus (Sw.) Gilg does not deviate strikingly from other species in the genus in terms of its floral and vegetative features, Nilsson (1970) found that its pollen more closely resembles that of species of Symbolanthus than that of its supposed congeners. The chromosome number of C. frigidus,n = 40, is the same as that of the two Symbolanthus species investigated so far. However, until more is known of the chromo- some numbers in both genera, we prefer not to draw any conclusions con- cerning the relationship of C. frigidus to Symbolanthus. It certainly would not appear to fit morphologically into that genus. Chelonanthus (Griseb.) Gilg The 15 to 20 species of Chelonanthus are distributed through much of mainland tropical America. Previously, a chromosome number, » = 20, was reported only for C. alatus (Aubl.) Pulle (Weaver, 1969). The two 1975] WEAVER & RUDENBERG, GENTIANACEAE 213 species investigated in this study also have this same number of chromo- somes. Although these three species comprise one-fifth or less of the total number of. species in the genus, they represent the primary mor- phological groups: C. alatus, with a gibbous-campanulate corolla, a di- chasium with long, secund, racemelike side branches, and pollen in tetrads; C. bifidus (HBK.) Gilg, with a funnelform corolla, a normal compound dichasium, and pollen in tetrads; and C. uliginosus (Griseb.) Gilg, with pollen in polyads. Therefore it is to be expected that m = 20 is general in the genus. Chironia L. Most of the species of Chironia, of which there are around 35, are South African in distribution, but several range northward into tropical Africa and Madagascar. This genus and the very closely related monotypic Orphium E. Mey. comprise Gilg’s Gentianeae-Chironiinae, delimited pri- marily on the basis of the large pollen grains of the plants. The chromo- some number of C. baccifera L. (n = 34), reported here for the first time, is the only published one for the genus. Chromosome numbers based on x = 17 are rare in the family, having been found elsewhere up to now in only three species of Sabatia Adans. (Perry, 1971) and one of Canscora Lam. (Mukherjee, 1968). Chironia baccifera, restricted to South Africa, is the only species in the genus with a berrylike fruit, and it has been considered to constitute a monotypic subgenus. Coutoubea Aubl. The three to five species of Coutoubea are restricted in distribution to northern South America, with the exception of C. spicata Aubl., which ranges north in Central America to British Honduras. The chromosome number m = 15, reported here for C. spicata, represents the first published count for the genus. Gentiana L. A large genus, primarily of the Northern Hemisphere, Gentiana in the strict sense has been subdivided into ten sections of greatly varying size. The only species investigated in this study, G. sedifolia HBK., belongs to the section CHoNDROPHYLLAE Bunge, a group of species low in stature with + hyaline-margined leaves, usually solitary flowers, symmetrical corolla plaits which are often nearly as large as the corolla lobes, distinct anthers and stigmas, often long-stipitate capsules, and wingless seeds. Most of the species are high-elevation plants, and they are particularly di- verse in the Himalayas and the mountains of China. Members of this section are the only species of Gentiana found in the Southern Hemisphere. Previously, chromosome numbers have been reported for eleven species in this section, the base numbers being x = 5 (seven species), x = 9 (one species), and x = 13 (three species). All of these base numbers are 214 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 present in other sections of Gentiana, x = 13 being perhaps the com- monest and most widespread one in the genus. However, x = 5 is com- mon only in sect. GENTIANA and x = 9 in sect. MEGALANTHE Gaudin (= sect. THYLACITES Griseb.). The section CHONDROPHYLLAE contains both annual (or monocarpic) and perennial species, and several authors have subdivided the section into series along these lines. All of the perennial species for which chromo- some numbers are available are » = 13, while all of the annuals are m = 10 or m = 20 except for G. douglasiana Bong. (n = 13) and G. prostrata Haenke (n = 16-18, 18). Gentiana douglasiana probably does not be- long in sect. CHONDROPHYLLAE. It is unique among Gentiana species in its lack of an intracalycine membrane and in its pollen grains, which ac- cording to Nilsson (1967) have three colpoid apertures without ora in addition to the three oriferous colpi typical in the family. The taxonomy of the New World CHONDROPHYLLAE is somewhat con- fused. The common alpine and arctic species of western North America is usually considered to be conspecific with Gentiana prostrata Haenke of the eastern Alps. Kusnezow (1894) referred the annual Andean Gentiana (as subg. EuGENTIANA) to this same species, but he also recognized G. sedifolia, which he considered to be a biennial, as the only other repre- sentative of the genus in South America. Gilg (1906) referred all of the Andean Gentiana to G. prostrata, but later (1916) changed his mind. Pringle (in litt.) considers at least three taxa of Gentiana to be present in the Andes: G. sedifolia in Venezuela, Colombia, Ecuador, and northern Peru; an unnamed taxon in the central Andes of Peru; and a plant which may be conspecific with G. prostrata, from central Chile south to Tierra del Fuego. One of the two reported chromosome counts for “‘Gentiana prostrata” was made from material collected in Peru (mn = 18, Diers, 1961). The report here of a different number for G. sedifolia (n = 20) lends support to the contention that there are at least two species of Gentiana in the es. Gentianella Moench The genus Gentianella, comprising perhaps 250 to 300 species, is nearly cosmopolitan in its distribution, but the center of diversity is in the _ Andes, a region from which Gilg (1916) recognized 182 species. The genus has never been monographed in its entirety, and the existing sec- tional classification is a residual one from Kusnezow’s treatment (in Gilg, 1895) of what he called Gentiana subg. GENTIANELLA, several of his sec- tions having since been elevated to generic status. Including those in this paper, chromosome numbers have now been reported for about 30 species in three sections: sect. GENTIANELLA, sect. ANDICOLA (Griseb.) Holub, and sect. ARCTOPHILA (Griseb.) Holub. All species have m = 18 chromo- somes, with the exception of the following three: G. moorcroftiana (Wall. ex Griseb.) Airy Shaw, with m = 9 (Mehra & Vasudevan, 1972) and 2n = 26 (Wada, 1966); G. auriculata (Pall.) Gillett, with » = 24 (Soko- 1975] WEAVER & RUDENBERG, GENTIANACEAE 215 lovskaya, 1968) ; and G. wert (Willd.) Borner, with » = ca. 27 (Holmen, in Love & Léve, Therefore, Gentianella in fos strint sense appears to be quite homo- geneous in sib to chromosome number, apparently with a base num- ber of x = 9 (except for G. auriculata and, if the study material for Wada’s report was correctly identified, for G. moorcroftiana), strengthening the argument for the separation of Comastoma (Wettst.) Toyokuni (x = 5) and Gentianopsis Ma (x = 11, 13) as distinct. Although Gentianella and Gentiana L. are widely recognized as gen- erically distinct, many specific transferals remain to be made. We propose the following new combinations relevant to this study: Gentianella corymbosa (HBK.) Weaver & Riidenberg, comb. nov. BAsIONYM: Gentiana corymbosa HBK. Nov. Gen. & Sp. 3: 133 (fo- lio ed.); 171 (quarto ed.). 1818. Gentianella dacrydioides (Gilg) Weaver & Riidenberg, comb. nov. BasIonyM: Gentiana dacrydioides Gilg, Engl. Bot. Jahrb. 22: 311. Gentianella nevadensis (Gilg) Weaver & Riidenberg, comb. nov. Ba- SIONYM: Gentiana nevadensis Gilg, loc. cit. 313. Halenia Borkh. Most of the 70 to 80 species of Halenia are high-elevation plants of Central and South America. Two species are native to the Old World. Previously, chromosome numbers have been reported for eight species, representing both Old World and New World plants, and all are m = 11. e six species reported here all have that same number. In addition, a Costa Rican collection (Weaver 2734) tentatively identified as H. rhya- ls Allen, also m = 11, may represent an undescribed species. observations of one bud of Halenia inaequalis (Weaver 2624) siidwed | inversion bridges with or without eb pcalcaga at Anaphase I. How- ever, buds from another plant had cells based on m = 11 without irregulari- ties. In addition, 11 bivalents plus two single, small chromosomes were observed at Metaphase II in a bud of H. brevicornis (Weaver 2600). The two single chromosomes did not pair, one of them lying free in the cyto- plasm and the other located in close proximity to the end of one bivalent. Unfortunately, the material was so scarce that this collection contained only one bud with pollen- mother-cells at a countable stage. Another collection of this species (Weaver 2625) lacked these small chromosomes. Lagenanthus Gilg The sole species of this genus, the magnificent Lagenanthus princeps (Lindl.) Gilg, is restricted in distribution to the mountains of a small area in southwestern Venezuela and adjacent Colombia. Ewan (1952) de- 216 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 scribed a second species, L. parviflorus, from Panama. The type (and only specimen) (Allen 3601, mo), which has been examined, consists mere- ly of a vegetative scrap and a detached flower lacking the gynoecium. Nevertheless, it is clear that this plant is not a member of the Gentiana- ae. Our collection of Lagenanthus princeps produced only a few cells at all suitable for study, and none of these were sufficiently clear to make an absolutely certain chromosome count. However, the haploid number ap- pears to be m = 40. This number would coincide well with the results obtained from the only other supposed close relatives of Lagenanthus in- vestigated to date, all of which have chromosome numbers based on ¥ = 10: Calolisianthus frigidus (n = 40), Symbolanthus (2 species, n = 40), and Chelonanthus (3 species, m = 20). Macrocarpaea (Griseb.) Gilg A genus of perhaps 50 species, many of which are represented in col- lections but not yet described, Macrocarpaea is distributed primarily in the higher elevations of tropical South America, with outliers in Costa Rica, Panama, and the Greater Antilles. Chromosome numbers have now been reported for four species: the Jamaican M. thamnoides (Griseb.) Gilg (Weaver, 1969), the Costa Rican M. valerii Standl. (Weaver, 1972), and the two Colombian species reported here. All have n = 21. In addi- tion, two collections representing undescribed Colombian species (Weaver 2634, 2050) have this same number of chromosomes. However, consider- ing the large number of species and their diversity, it would be premature to expect that 2 = 21 is general in the genus. TABLE 1. Chromosome numbers of Gentianaceae determined during this study. HAPLoIp TAXON NUMBER LOCALITY Bartonia verna a= 22 Unirep States. North Carolina: (Michx.) Muhl. Brunswick Co., 10 mi. NNE of Supply, Weaver 1961 (DUKE). een ee frigidus n= 40 St. Vincent: Soufriére, Howard, (Sw.) G Cooley, & Weaver 17712 (A) certo n= 20 Cotompta. Meta: ca. 5 km. N of (HBK.) Gil Villavicencio, Weaver 2640 (A)- Chelonanthus uliginosus n= 20 Coromsta. Cundinamarca (Griseb.) Gilg ween Bogota & Villavicencio, Weaver 2639 (a). Chironia baccifera L. = 34 Cuttivatep: greenhouses of the Arnold Arboretum, Jamaica Plain, Mass., U.S.A.; seeds received from the National Botanical Garden, 1975] Coutoubea spicata Aubl. Gentiana sedifolia HBK. — otras eas ) Wea er & Riidenb Gentianella sea (Griseb.) Fabris Gentianella ne (Gilg) Weaver & Riidenber. —— oe . Gilg) Weaver & Riidenb Halenia brevicornis ( ee G. Don Halenia cuatrecasasii Allen Halenia phyllophora Allen Halenia rhyacophila Allen Halenia viridis (Griseb.) Gilg Halenia inaequalis Wedd. Lagenanthus princeps (Lindl.) Gilg Macrocarpaea densiflora (Benth.) Ewan Macrocarpaea glabra (L. f.) Gilg Symbolanthus tricolor Gilg = = WEAVER & RUDENBERG, GENTIANACEAE ca. 40 217 mea South Africa, Wea- ver 2737 (AAH). BritIsH Honpburas: just W of Hattieville on the Western High- way, Weaver 2735 (A). VENEZUELA. Mérida: Laguna Mu- cubaji, Weaver 2620 (A). CoLomsiA. Cundinamarca: serrate, Weaver 2631 (A). CoLomsIA. Narino: Volcan de Ga- leras, Weaver 2656 (A). CoLtomsiA. Putumayo: between El Encano & Santiago, Weaver 2655 (A) VENEZUELA. Mérida: Laguna Mu- cubaji, Weaver 2606 (A). VENEZUELA. Mérida: Cuenca San- to Domingo, Weaver 2600 (A). VENEZUELA. Mérida: Teleferico de Mérida, between La Aguada La Montana, Weaver 2625 (A). Mon- Mon- CoLomsiA. Cundinamarca: serrate, Weaver 2630 (A CotomsiA. Putumayo: between El Encano & Santiago, Weaver 2654 (A). Costa Rica. Cartago: Cerro Buen- avista, Weaver 2733 (a). VENEZUELA. Mérida: Laguna Mu- cubaji, Weaver 2605 (a). VENEZUELA. Mérida: Teleferico de Mérida, between La Aguada & La Montafia, Weaver 2624 (A). rs Tachira: base of amo de Tama, Weaver 2612 CotomsiA. Tolima: between Fres- no & Manizales, Weaver 2644 (a). Se gee Cundinamarca: above ogota on road to Villavicencio, ee 2636 (A). CotomsiA. Cundinamarca: near San Miguel, Weaver 2635 (A). 218 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ACKNOWLEDGMENTS We wish to acknowledge a most generous grant from the Atkins Fund, which made most of the field work possible. We are grateful also to Dr. James Pringle of the Royal Botanical Gardens, Hamilton, Ontario, Canada, for making available his unpublished observations on Gentiana in South America. LITERATURE CITED BEAMAN, J. H., D. C. D. DEJonc, & W. P. SrouTaMiRE. 1962, Chromosome studies in the Pe: and subalpine forms of Mexico and Guatemala. Am. Jour. Bot. 49: 41-50. BorRGMANN, E. nog Anteil der aes pia - bi Flora des Bismarckgebirges von Ostneuguinea. Zeitschr. Bot. 52: Concer, A., & L. FAtmRcHILD. 1953. A ail rere method for making smear slides permanent. Stain Technology 28: Diers, L. 1961. Der Anteil an aseeee ae in oe cuties der West- kordillere Perus. Zeitschr. Bot. 49: Ewan, J. 1952. A review of the at lisianthoid genus Lagenanthus (Gen- aceae). Mutisia 4: 1-5 Favarcer, C. 1949. Contribution a l’étude caryologique et biologique des Gen- tianacées. I. Bull. Soc. Bot. Suisse 59: 62-86. . 1952. Contribution a l’étude caryologique et biologique des Gentiana- cées. II. Ibid. 62: 244-257. . 1965. Notes de caryologie alpine IV. Bull. Soc. Neuchat. Sci. Nat. (Ser. 3) 88: 5-60. H. L. orcas Taxon 14: 86-92. 1965. In: IOPB chromosome number reports IV. Uprer. 1968. Contribution a la cytotaxonomie de la flore alpine des Pyrénées. Collect. Bot. 7: 325-357. GILG, E. 1895. leap rer ae ie A. ENGLER & K. PRAntL, Die Natiirlichen Pflanseitfamilien 4(2): 5 19 eitrage zur ‘Kemi der Gentianaceae iii. Gentianaceae an- dinae. Repert. Sp. Nov. 56. 1916. Micnsetehe ca Zusammenstellung der Gentiana-Arten Siid- Amerikas. Bot. Jahrb. 54(Beibl. 118): 4-89. Gittett, J. M. 1959. A revision of Bartonia and Obolaria (Gentianaceae). Rhodora 61: 43-62. Huynu, H. L. 1965. Contribution a l’étude caryologique et embryologique des phanérogames du Pérou. Denkschr. Schweiz. Nat. Ges. 85: 1-178. Jounson, A. W., & J. G. Packer. 1968. Chromosome numbers in the tlora*et gotruk Creek, N. W. Alaska. Bot. Not. 121: 403-456. Kuprer, P., & C. FAVARGER. 1967. Premiéres prospections caryologiques dans la flore orophile des Pyrénées et de la Sierra Nevada. Compt. Rend. Acad. Paris 264: 2463-2465. KusNezow, N. I. 1894-1904. —— Eugentiana Kusnez. generis Gentiana Tournef. Acta Horti Petrop. 15: 1-507. 1975] WEAVER & RUDENBERG, GENTIANACEAE 219 Love, A., & D. Love. 1956. het conspectus of Icelandic flora. Acta Horti Gothob. 20: 65-290 & ; Chromosome arta of central and northwest Euro- pean plants. Op. Bot. (Lund) 5: Love, D. 1953. Cytotaxonomical Par on the Gentianaceae. Hereditas 39: 225-235. Menra, P. N., & L. S. Git. 1968. Jn: IOPB chromosome number reports XVIII. Taxon 17: 420, 421. & K. N. VaAsupEvan. 1972. Jn: IOPB chromosome number reports XXXVI. Taxon 21: 341-344. MUKHERJEE, B. 1968. Cytotaxonomic studies of some genera of Gentianaceae. Nucleus, Suppl. vol. 1968: 45-48 Muttuican, G. A. 1967. Im: IOPB chromosome number reports XIV. Taxon 16: 567 Nienavs, T., & L. Wonc, ee In: IOPB chromosome number reports XII. Taxon 20: 353 Niusson, S. 1967. Pollen moro studies in the Gentianaceae — Gen- tianinae. Grana Palyn. 7: 4 1970. Pollen pepiiecs contributions to a taxonomy of Lisian- thus L. s. Jat. (Gentianaceae). Sv. Bot. Tidskr. 64 3. Perry, J. D. 1971. Biosystematic studies on the North Aastra genus Sabatia Centianacéir). Rhodora 73: 309-3 Rork, C. 1949, Cytological studies in the Gentianaceae. Am. Jour. Bot. 36: 687-701. SKALINSKA, M. 1952. Cytological studies in Gentiana- pontine from the Tatra and Pieniny Mts. Bull. Acad. Polon. Sci. & Lettr. 1951: 119-136. SokoLovsKaya, A. P. 1963. Geographical distribution of ee in plants. Vest. Leningrad Univ. (Ser. Bot.) no. 15: 38-52 1968. A karyological investigation of the flora of Koriakian Land. Bot. Zhur. 53: 99-105 a & OO: Staeteova. 1938. gages : the high mountains of Pamir and Altai. Compt. Rend. Acad. URSS. 21: 69-71. TaytLor, R. L., & G. A. MULLIGAN. on Flora of the Queen Charlotte Is- lands. Part 2. Cytological aspects of the vascular plants. 148 pp. Queen’s Printer, Ottawa Wana, Z. 1955. Cytological studies of four species of Swertia and one species of Halenia. Jap. Jour. Genet. 30: 191. 1956. Cytological Studies in Gentianaceae. /bid. 31: - 1966. Chromosome numbers in Gentianaceae. Chromosome Inf. Serv. 7: 28-30. Weaver, R. E., JR. 1969. Cytotaxonomic notes on some neotropical Gentiana- ceae. Ann. Missouri Bot. Gard. 56: 439-443 i . 1972. The genus Macrocarpaea (Gentianaceae) in Costa Rica. Jour. Arnold Arb. 53: 553-557. JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 APPENDIX. Previously reported chromosome numbers in the genera of Gentianaceae investigated during this study. HaAPLorp TAXON NUMBER REFERENCE Bartonia Muhl. Bartonia paniculata (Michx.) 26 ~=Rork, 1949 Muhl Bartonia virginica (L.) BSP. 76 - Rork, 1 a. 26 sees in 4 1959 Chelonanthus (Griseb.) Gilg Chelonanthus alatus (Aubl.) 20 Weaver, 1969 ae Gentian Sect. Cuoieacpietian Bunge Gentiana altaica Laxm. 13. Sokolovskaya & Strelkova, 1938 Gentiana argentea Royle 10 Mehra & Vasudevan, 1972 Gentiana carinata Griseb 10 Mehra & Gill, 1968 Gentiana capitata Ham 10 Mehra & Vasudevan, 1972 Gentiana crutwellii H. Sm 10 Borgmann, 1964 Gentiana douglasiana Bong. 13. Taylor & Mulligan, 1968 Gentiana ettinghausenii F. Muell. 10 Borgmann, 1964 Gentiana piundensis Van Royen 10 Borgmann, 1964 Gentiana prostrata Haenke 18 Diers, 1961 16-18 Johnson & Packer, 1968 Gentiana pyrenaica L. 13. Kupfer & Favarger, 1967 13 Favarger & Kiipfer, 1968 Gentiana zollingeri Fawcett 10 Wada, 1956 10 Wada, 1966 Gentianella Moench Sect. GENTIANELLA — acuta (Michx.) 18 A. Love, 1954 Gentianella amarella (L.) Borner 18 D. Love, 1953 subsp. lingulata (Ag.) 18 A.& D. Love, 1956 Live & Live Gentianella anisodonta (Borbas) 18 Favarger, 1965 Love ove —— aspera (Hegetschw. 18 Favarger, 1965 & Heer) Dorstal ex Skalicky, Chrtek, & Gill Gentianella auriculata (Pall.) 24 Sokolovskaya, 1968 J. M. Gillett Gentianella austriaca (A. & J. 18 Favarger, 1952 Kern.) Holu ae ag campestris (L.) Born mabe. campestris 18 Favarger, 1949 1975] WEAVER & RUDENBERG, GENTIANACEAE 221 subsp. islandica (Murb.) Dorfler Gentianella engadinensis (Wettst.) Holub Gentianella germanica (Willd.) rg Gentianella hypericifolia (Murb.) Pritchard Gentianella insubrica (H. Kunz) Holub Gentianella moorcroftiana (Wall. ex Griseb.) Airy Shaw Gentianella rhaetica ie & J. Kern) A. & D. Lov Gentionell uliginosa "(Willd,) Sect. uk (Griseb.) Holub Gentiana aff. briquetiana Gilg * —— aff. brunneo-tincta en aff. dolichopoda Gilg * G. Gentiana aff. kuntzei Gilg * Gentianella peruviana (Griseb.) Fabris Gentiana primuloides Gilg * Gentiana pulla Fabris * Gentianella punicea (Wedd.) Holub Gentianella saxosa (G. Forst.) Holub Gentianella umbellata R. & P.) Favarger Sect. ARcToPHILA (Griseb.) Holub Gentianella aurea (L.) H. Sm. Gentianella quinquefolia (L.) Small : Halenia Borkh. Halenia crassiuscula Robins. & eat. Halenia corniculata (L.) Cornaz Halenia decumbens Benth. Ca. 18 18 18 18 18 18 18 _ oo 11 11 A. & D. Love, 1956 Favarger, 1965 Reese, in A. & D. Love, 1961 Kupfer & Favarger, 1967 Favarger ; Kiipfer, 1968 Favarger, 1952 Mehra & Vasudevan, 1972 Wada, 1966 Favarger, 1965 Holmen, in A. & D. Love, 1961 Diers, 1961 Huynh, 1965 Diers, 1961 Diers, 1961 Diers, 1961 Diers, 1961 Diers, 1961 Diers, 1961 Diers, 1961 Favarger, 1952 Huynh, 1965 D. Love, 1953 Rork, 1949 | Beaman, et al., 1962 Sokolovskaya, 1963 Wada, rare . hele Jr., 1971 222 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Halenia deflexa (Sm.) 11 Mulligan, 1967 rise Halenia elliptica D. Don 11 Favarger, 1952 Halenia multiflora Benth. 11 Niehaus & Wong, Jr., 1971 Halenia shannonii Briq. 11 Beaman, et al., 1962 Halenia umbellata (R. & P.) 11. Favarger & Huynh, 1965 Gilg 11 Huynh, 1965 Macrocarpaea (Griseb.) Gilg carpaea thamnoides 21 Weaver, 1969 (Griseb.) Gilg Macrocarpaea valeriu 21 Weaver, 1972 Standl Symbolanthus G. Don Symbolanthus pulcherrimus 40 Weaver, 1969 Gilg * Combination in Gentianella not yet made. R. E. W., Jr. ki ARNOLD ARBORETUM HARVARD gyri HERBARIA VARD UNIVERSITY 22 Divinity AVE JAMAICA PLAIN CAMBRIDGE, Sy cus ca 02138 MASSACHUSETTS 02130 1975] ROBERTSON, OXALIDACEAE 223 THE OXALIDACEAE IN THE SOUTHEASTERN UNITED STATES ! KENNETH R. ROBERTSON OXALIDACEAE R. Brown in Tuckey, Narr. Exped. Congo 3. 1818, “Oxalideae,”’ nom. cons. (OxALIs FAMILY) Perennial or annual herbs [or shrubs (often dendroid), lianas, or trees]. Leaves alternate, palmately compound [or even- or odd-pinnately com- pound or unifoliolate], frequently in basal rosettes or apical clusters, petioled [or sessile], the petiole with a basal joint; leaflets pinnately nerved, often showing “sleep” movements, the petiolules with a basal pulvinus; stipules (or stipulelike appendages) present or absent. Inflo- rescences axillary or seemingly terminal [sometimes cauliflorous], brac- teate, few- to many-flowered cymes, pseudoumbels [panicles or racemes] or the flowers solitary; pedicels articulated. Flowers perfect [very rarely some imperfect, the plants then androdioecious or dioecious], regular, 5- merous, often heterostylous, sometimes cleistogamous; disc absent. Sepals , free or basally connate, persistent in fruit, imbricate in aestivation. Petals 5, free or coherent above the base, often clawed, contorted [quin- cuncial or cochlear] in aestivation, inserted at the base of the staminal tube. Androecium of 10 [or 15] stamens; filaments of 2 lengths, the epi- petalous ones shorter than the episepalous ones, all connate below into a ring or tube, persistent in fruit; anthers dorsifixed, versatile, 2-locular at anthesis, dehiscing extrorsely by longitudinal slits. Gynoecium of 5 [rarely 3] united, superior, epipetalous carpels; styles free [or united], terminal, persistent; stigmas terminal, capitate, punctate, or penicillate, collateral, bitegmic, tenuinucellar [or crassinucellar] ovules pendulous rom an axile placenta, the micropyle apical and abaxial. Fruit a locu- licidal capsule (sometimes appearing septicidal due to deep septal folds) ‘Prepared for a generic flora of the southeastern lapis States, a joint project of the Arnold Arboretum and the Gray Herbarium of Harvard University made possible first paper in ap series (Jour. Arnold Arb. 39: 296-346. 1958). The area covered includes North and jose Carolina, Georgia, Florida, Tennessee, Alabam Mississipp i, Arkansas, - Louisiana. The descriptions are based primarily on si - in this area, with additional informa ion from extraterritorial taxa in brackets. Ref- erences that I have not seen are marked by an asterisk. he illustrations are the careful work of Karen S. Velm They were made from materials collected by R. J. Eaton, R. K. Godfrey, S. e Sibieticis, R. E. Umber, C. E. Wood, Jr., and myself. - am particularly grateful to Dr. Carroll E. Wood, Jr. for his continuing advice and o Dr. Alicia Lourteig, Muséum National d’Histoire Naturelle, Paris, for discussing eh of her ideas on Oxalis with me during her recent visit to Harvard University. 224 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 56 [or a berry or rarely dry and indehiscent]. Seeds usually arillate; endo- sperm abundant [rarely absent]; embryo straight [or oblique], the radicle superior. Embryo sac development of the Polygonum type, embryo de- velopment of the Asterad type. Type Genus: Ovxalis L. Perhaps 800 or more species in seven genera. The vast majority of species belong to Oxalis, the only genus in our area. Biophytum DC.., the next largest genus (with about 70 species), is pantropical in distribution; evidently no species are common to both hemispheres. The other genera are Dapania Korth. (one species in Madagascar, two in western Malesia), Sarcotheca Blume (11 species in western Malesia), Averrhoa L. (two species, cultivated pantropically), Lepidobotrys Staudtii Engler, of trop- ical West Africa, and Hypseocharis Remy (nine described species of Peru, Bolivia, and Argentina). Within the family, it is clear that Oxalis and Biophytum form a natural group, while Averrhoa, Sarcotheca, and Dapania constitute another (some- times separated as Averrhoaceae). Both Hypseocharis and Lepidobotrys are poorly known, and their affinities are less certain; they have been segregated as Hypseocharitaceae and Lepidobotryaceae. Veldkamp (1971) speculated that Hypseocharis seems to link Oxalidaceae and Geraniaceae. (including Dapania and Sarcotheca) with the Malpighiales. There is rather general agreement (Cronquist, Hutchinson, Scholz, Takhtajan, and Thorne) that Oxalidaceae sensu stricto, Geraniaceae, Tropaeolaceae, and Balsaminaceae are related families. Averrhoa is one of the few genera of flowering plants with more than a single species that is known only in, or as an escape from, cultivation. The geographical origin of A. Carambola L., 2n = 22, 24, and A. Bilimbi hi 2n = 22, 24, is uncertain. It is commonly said that both are of Indo- Malesian origin, since in pre-Linnaean literature they are always attributed to that region and their closest relatives are plants of Malesia and Mada- gascar (see Veldkamp). An American origin for the species has also been postulated, and Webster presents an example of convergent evolution in support of this hypothesis. In overall appearance Phyllanthus acidus (L.) Skeels, of the Euphorbiaceae, is remarkably similar to the two species of Averrhoa, particularly A. Bilimbi. (Linnaeus, in fact, described Phyllanthus acidus as a species of Averrhoa.) All three of these species are cultivated throughout the tropics and are of uncertain provenance. According to Webster, Phyllanthus acidus is of New World origin, since its closest con- geners are from that region and since a collection from the Para River delta in northeastern Brazil is evidently the only known specimen of this species from its native habitat. “By analogy with the documented evidence for P. acidus, it appears most likely that both species of Averrhoa are also originally American plants which have had a similar history. The great superficial resemblance between these three species may not be entirely coincidence, for it is possible that all three are members of the sub-littoral forests of the South American coastline; and their similarity in life form 1975] ROBERTSON, OXALIDACEAE 225 may have a selective basis. Probably, as suggested by Merrill and Trimen, these plants were first encountered by the Portuguese on the Brazilian coast and from there carried to India and other parts of the Old World” (Webster). Heterostyly is common in the family. Many species of Oxalis, a few of Biophytum, and Averrhoa Bilimbi are tristylous. Distyly occurs in Averrhoa Carambola and in species of Oxalis, Biophytum, Sarcotheca, and Dapania (with two species androdioecious). Some species of Oxalis and Biophytum are homostylous. The species of Hypseocharis evidently are homostylous, although the styles elongate after anthesis. Lepidobotrys Staudtii is described as dioecious. Cleistogamous, as well as chasmogamous, flowers occur in certain species of Oxalis. It has been postulated that the breeding system of ancestral Oxalida- ceae combined morphological heterotristyly and physiological self-incom- patibility (see Ornduff; Eiten argues, however, that homostyly is the original condition). In the idealized oxalidaceous tristylous system, there are three positions or levels for the one set of stigmas and the two sets of anthers. Long-styled flowers have the stigmas at the highest position, with the two sets of anthers at the middle and lowest positions. In mid- styled flowers, one set of anthers is in the highest position, the stigmas are in the center position, and the other set of anthers is in the lowest position. The anthers occupy the upper and center positions in the short-styled flowers, with the stigmas in the lowest position (see Ficure 1, 0-q). In addition to differing in the lengths of the styles and filaments, the three types of flowers can differ in the size of the pollen grains (which are largest in anthers of the upper level and smallest in anthers of the lowest position), in the shape of the stigmas, in the pubescence of the filaments and styles, and in the curvature of the styles. In this idealized situation, pollen from anthers of the uppermost position of midstyled and short- styled flowers will be compatible only with stigmas of long-styled flowers; pollen from anthers of the middle level of long- and short-styled flowers will germinate only on stigmas of midstyled flowers; and pollen of the lowest position of long-styled and midstyled flowers will be compatible only with stigmas of short-styled flowers. Some species, among them Ovxalis valdiviensis Barnéoud (Chile), O. Regnellii Miq. (South America), and O. purpurea L. (including O. Spe- ciosa Ecklon & Zeyher; South Africa), have retained this type of breeding System of tristyly and self-incompatibility. However, it seems that many Or most species of the family have shifted away from a system that re- quires cross-pollination toward ones that allow autogamy. In many cases, there is a partial to complete loss of self-incompatibility, which may or may not be accompanied by morphological changes. Thus, some popula- tions of O. Dillenii subsp. filipes are strongly tristylous and wholly self- compatible. According to Denton (p. 482), the reverse occurs in Oxalis sect. IoNoxaLIs, and even the homostylous species are self-incompatible. One or two of the possible flower forms may be lost within a species, resulting in distyly or homostyly. Only long- and short-styled flowers 226 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 seem to occur in Oxalis violacea, O. Priceae subsp. Priceae, Biophytum Petersianum Klotzsch., Dapania pentandra, and the species of Sarcotheca. Long-styled and midstyled flowers are found in O. albicans and Averrhoa Carambola. Evidently, only long-styled flowers occur in O. thelyoxys (Cuba), O. magellanica (Southern Hemisphere), and O. Acetosella subsp. Griffithii (Asia). It is sometimes said that this is the situation in O. Acetosella subsp. Acetosella and subsp. montana, but an examination of herbarium specimens shows that the level of insertion of the stigmas is mostly either considerably above the upper whorl of anthers or slightly below them; it needs to be determined whether this is a variable charac- ter or a case of distyly with long-styled and midstyled flowers. Darwin thought that European populations were variable in this respect. The distance between the stigmas and anthers is small enough in some species, or in populations of some species, to ensure self-pollination, even though the flowers are heterostylous. Ornduff (1972) called such flowers “quasi-homostylous” and noted their occurrence in Oxalis Dillenii subsp. filipes and subsp. Dillenii. Another mechanism that promotes self-pollina- tion is a change in the relative lengths of the filaments and styles so that the stigmas are inserted at the same level as either the upper or lower whorl of anthers. This condition, termed “semihomostyly,” has been ob- served in O. Dillenii subsp. filipes and subsp. Dillenii, and in a species of Biophytum (Mayura Devi, 1966).? According to Veldkamp (1971), the pollen is shed in the buds of some species of Biophytum. Evidently, some seemingly normal flower buds of certain Oxalis species do not open, but are autogamous and set fruit; this seems to occur mostly late in the growing season, at least in Massa- chusetts. Much reduced, truly cleistogamous flowers are produced in O. Acetosella and some other species (see FIGuRE 1, Cc). Several different genetic systems have been proposed to explain the in- heritance of style length in the few species of Oxalis that have been studied in this respect (see discussion and table in Mulcahy). Two species that occur in our area, O. Priceae and O. Dillenii subsp. filipes (see Mulcahy and Ornduff, respectively), seem to have a system with two loci and two alleles at each locus. “Short” is dominant and has the generalized geno- type of S__mm or S__M__. “Medium” is recessive to “Short” and its genotypes are ssMm or ssMM. “Long” is a double recessive, ssmm. Al- though much has been written about breeding systems of Oxalis, very few species have been examined in detail, and it may very well be that generalizations accepted now will have to be changed. le amily is of only slight economic importance. Several species of Oxalis are cultivated as ornamentals; some are especially well suited to the rock garden and alpine house. Averrhoa Carambola is cultivated com- mercially to some extent and in dooryards in southern Florida. The yel- low to orange, deeply angled fruits, star-shaped in cross section and up *Mayura Devi identifies the plants as Biophytum sensitivum DC., but Veld- kamp (1971) says they certainly do not belong to this species. 1975] ROBERTSON, OXALIDACEAE 227 to five inches long, vary greatly in degree of acidity from tree to tree. The fruits are eaten fresh, used in drinks, or made into jelly and jam. The flavor and odor are sometimes likened to quince, Cydonia oblonga. Averrhoa Bilimbi, the cucumber or pickle tree, which has rather cylindri- cal, extremely acid fruits that are used in drinks, jellies, pickles, and cur- ries, is seldom grown in Florida. Leaves of Oxalis species are used in salads, but excess use should be avoided because of the presence of oxalic acid. Oxalis Pes-caprae and O. corniculata are known to accumu- late lethal concentrations of soluble oxalates under certain conditions. Oxalis tuberosa Molina, oca, 2n = 14, 60, 63-64, 68-70, is a major food crop in Andean South America, particularly in the area around Lake Titicaca. The tubers contain large amounts of oxalates and are treated in various ways, such as by submerging them in water for several weeks and then placing them in open areas, where they are exposed to freezing by night and drying by day. Several species of Oxalis sect. CORNICULATAE act as aecial hosts for the maize, sorghum, and andropogon rusts (see dis- cussion in Eiten, 1963). REFERENCES: Battton, H. Géraniacées. Hist. Pl. 5: 1-41. 1874. [English transl. M. M. Hartoc, The natural history of plants. 5: 1-41. London. 187 BENTHAM, G., & J. D. Hooker. Geraniaceae tribus VI. Oxalideae. Gen. Pl. 1: 270, 277; 1867. BoLKHOVSKIKH, Z., V. Grir, T. Matvejeva, & O. ee Chromosome numbers of flowering plants. Ed. by A. A. Feporov. (Russian and English prefaces.) 926 pp. Leningrad. 1969. Sdiaidaceie: 478, 479; includes literature to 1967, but does not include indices of plant chromosome num- bers for 1965 (Regnum Veg. 50) or 1966 (Ibid. 55).] Brouwer, W., & A. StAHLIN. Handbuch der Samenkunde. Introd. + 656 pp. Frankfurt am Main. 1955. [Oxalidaceae, 389, 390.] CANDOLLE, A. P. pe. Oxalideae. Prodr. 1: 689-702. 1824. CHATTERJEE, A., _ K. SHarma. Chromosome study in Geraniales. Nucleus 13: 179-200. 1970. [Oxalidaceae, 184-186, 192-194. Cuavuvet, F. Recherches sur la famille des Oxalidacées. Théses, Univ. Paris. 5 pp. 1903.* Cronguist, A. The evolution and classification of flowering plants. x + 396 pp. Boston. 1968. [Geraniales, 269-272. Davis, G. L. Systematic embryology of the —— x + 528 pp. New York. 1966. [Oxalidaceae, 197; Averrhoaceae, 51, ErpTMAN, G. Pollen morphology ata plant taxonomy. i Corrected reprint and new addendum. xiv + 553 pp. New York. 1966. < aitey ina 302, 303 HEGNAUER, R. Chemotaxonomie der Pflanzen. Band. 5. Dicotyledoneae: Mag- noliaceae—Quiinaceae. 506 pp. Basel & Stuttgart. 1969. [Oxalidaceae, 255— 258. Hutcuinson, J. The families of flowering plants. ed. 3. xx + 968 pp. Oxford. 1973. [Averthoaceae, 442, 443; Lepidobotryaceae, 326; Oxalidaceae, 617.] -———.. The genera of dowerne plants. Vol. 2. xi + 659 pp. London. 1967. ee ace 610, 611.] 228 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Hvuynu, K. L. Etude du pollen des Oxalidaceae I. Morphologie générale — palynotaxonomie des Oxalis américains. Bot. Jahrb. 89: 272-303. pls. 3-5. 1969; II. Palynotaxonomie des Oxalis sud-africains — considérations gén- érales. Ibid. 305-334; III. Le pollen de Dapania pentandra Capuron et sa position taxonomique. Ibid. 90: 524-526. 1971. Knutu, R. Oxalidaceae. Pflanzenreich IV. 130(Heft 95): 1-481. 1930. . Oxalidaceae. Nat. Pflanzenfam. ed. 2. 19a: 11-42. 1931. Léonarp, J. Lepidobotrys Engl., type d’une famille nouvelle de Spermatophytes: les Lepidobotryaceae. Bull. Jard. Bot. Bruxelles 20: 31-40. 1950. [See also . C. TIssERANT, Bull. Soc. Bot. France 96: 214-216. 1949.] Lupsock, 7,4 contribution to our knowledge of seedlings. Vol. 1. viii + 608 p. London & New York. 1892. [Geraniaceae, 294-316 Martin, x C. The comparative internal se imatiad of seeds. Am. Midl. Nat. 36: 513-660. 1946. [Oxalidaceae, 602, 603. | MatuHew, P. M. Cytology of Oxalidaceae. Cytologia 23: 200-210. 1958. Mayura Devs, P. Heterostyly in Biophytum sensitivum DC. Jour. Genet. 59: 41-48. 1964. . Homostyly in heterostyled Biophytum sensitivum DC. Ibid. 245-248. 1966. Moore, R. J. Index to plant chromosome numbers. ee Regnum Veg. 90: 1-539. 1973. [Oxalidaceae, 254; see BOLKHOVSKIKH, al. | MosepacH, G. Die Fruchtstielschwellung der Oxalidaceen a Geraniaceen. Jahrb. Wiss. Bot. 79: 353-384. 1934. Narr, R. VasupEvAN. Observations on the breeding mechanism of Biophytum Candolleanum Wt. Jour. Bombay Nat. Hist. Soc. 71: 99-108. 1 pl. 1974. Narayana, L. L. Development of embryo in Biophytum intermedium Wight and Oxalis pubescens H. B. & K. Jour. Indian Bot. Soc. 41: 156-159. 1962. sod er to the floral anatomy of Oxalidaceae. Jour. Jap. Bot. 41: 321-328. SAvER, H. Bliite a | Frucht der Geidascen, Linaceen, Geraniaceen, Bigooasis ceen und Balsaminaceen. Vergleichen Unt suchungen. Plaats 19: 417-480. pl. 1. 19 933. ScHOL LZ, H. Geraniales. Jn: H. Me tcuior, Engler’s Syllabus der Pflanzenfa- SMALL, J. K. Oxalidaceae. N. Am. Fl. 25(1): 25-58. 1907. Soukup, J. Las Krameriaceas, Podostnshceas, Oxalidaceas, Geraniaceas, Tropeo- liceas, Zigofiliceas, Lindceas y Humiridceas del Peru, sus géneros y lista de especies. Biota ve 83-102. 1968. —_— C. G. G. J., van. The Malaysian pen of Biophytum (Oxalidaceae). ull. Jard. Bot. baleen 18: 449-455. — D. Fruits for southern Florida. yon pp. frontisp. Stuart, Florida. 1959. [Averrhoa, 136-138; see also Tropical fruits for southern Florida and Cuba and their uses. Tamaica Plain, Massachusetts. 1940. ] TakHTAJAN, A. Flowering plants: origin and dispersal. ieee: C. JEFFREY.) x + 310 pp. 2 charts. Edinburgh & Washington, D. C. 1969 THORNE, R. F. Synopsis of a poyenet J phylogenetic clessification of the flow- ering plants. Aliso 6: 57-66. 1968. [Geraniales suborder Geraniineae, 62.] THANIKAIMONI, G, Index bibliographique sur la morphologie des pollens d’an- giospermes. Inst. Frang. Pondichéry Trav. Sect. Sci. Tech. 12(1): [vi] + 1-337. 1972. [Genera arranged alphabetically. ] 1975] ROBERTSON, OXALIDACEAE 229 Uxricu, E. B. Leaf movements in a family Oxalidaceae. Contr. Bot. Lab. Univ. Penn. 3: 211-242. pl. 3. int , J. F. A revision of Suited Bl. and Dapania Korth. (Oxalida- ae). Blumea 15: 519-543. 1967. . Oxalidaceae. Jn: C. G. G. J. van STEENIS, ed., Fl. Males. I. 7: 151-178. 197 1. [Contains much useful information. ] WarzurG, E. F. Taxonomy and relationship in the Geraniales in the light of their cytology. New Phytol. 37: 130-159, 189-210. 1938. WessTErR, G. L. A monographic study of the West Indian species of Phyllanthus (continued). Jour. Arnold Arb. 38: 51-80. 1957. [Suggests that Averrhoa is of New World origin. ] Wits, J. C. A dictionary of the flowering plants and ferns. ed. 8. (Revised by H. K. Arey SHaw.) xxii + 1245 pp. + Ixvi pp. (Key to the families of flowering plants.) Cambridge, England. 1973. [Averrhoaceae, 112, 113; Lepidobotryaceae, 655; Oxalidaceae, 836.] 1. Oxalis Linnaeus, Sp. Pl. 1: 433. 1753; Gen. Pl. ed. 5. 198. 1754. Perennial or annual, caulescent or acaulescent herbs [rarely under- shrubs], sometimes with bulbs (often with contractile roots below) or rhizomes [or tubers]. Indumentum of septate and/or nonseptate tri- chomes that vary in length, shape, density, and distribution. White or sometimes orange, red, or black calcium oxalate deposits frequent on sepal apices, bracts, bulb scales, and leaves, infrequent on petal tips and Synoecia. Leaves basal and/or cauline (often in apical clusters), tri- foliolate [to many-foliolate or rarely unifoliolate], often heteroblastic, long petiolate [to nearly sessile], the petiole with a persistent, basal artic- ulation; leaflets often with reddish or purple markings, mostly obcor- date or emarginate [or entire or deeply divided], nearly sessile, with a basal pulvinus, folding and drooping at night; stipules absent or small, paired, and adnate to the basal articulation of the petiole. Inflorescences flowered cymes or modified cymes, such as pseudoumbels. Flowers tri- Stylous, distylous, homostylous, semihomostylous, or quasihomostylous. Petals shortly clawed below, yellow, orange, white, or violet [to red], the base of the blade often with nectar guides, withering after expansion, sometimes forming a calyptra on the fruit. Filaments monadelphous be- low, alternate ones longer and sometimes with an abaxial appendage. Carpels 5, connate adaxially, free laterally; styles free, erect in long- and midstyled flowers, abaxially curved and projecting between the fila- ments in short-styled flowers; stigmas punctate, capitate, or penicillate, faintly to prominently 2- lobed, Capsules globose, oblate, or broadly to narrowly cylindric, often 5-angled or star-shaped in cross section, dehisc- ing by loculicidal slits (often appearing septicidal), the valves persistent. Seeds in the capsule each enclosed by a turgid, translucent aril that turns inside out explosively; seed flattened, elliptic with pointed ends, often with transverse and/or longitudinal ridges; endosperm present [or absent). (In- cluding Acetosella Kuntze, 1891, not Fourreau, 1869; Bolboxalis Small; Tonoxalis Small; and X oui bocalls Small.) Type species: O. Acetosella L.; 230 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 see J. K. Small, N. Am. Fl. 25(1): 25. 1907. (Name from Greek, oxys, acid, in reference to the supposed medicinal use of these plants; see Lin- naeus, Phil. Bot. ed. 1. 184. 1751. This name was used by the ancient Greeks for Rumex Acetosella and was first applied to this genus by Lin- naeus.) —- WOOD-SORREL. Estimates of the number of species range from 300 to more than 800, the latter probably being closer to the actual number. The genus is cos- mopolitan but is most diverse in South Africa and South America, and, to a lesser degree, in Central America and Mexico; relatively few species are indigenous to North America and Eurasia. In the world-wide treat- ment of the family for Das Pflanzenreich, Knuth recognized 791 species of Oxalis, grouping them primarily on variations in stem structure into 37 mostly unnatural sections and numerous subsections and series. Since that time, important taxonomic treatments include Salter’s study of the genus in South Africa, Eiten’s synopsis of sect. CoRNICULATAE, and Den- ton’s monograph of the North American species of sect. IJonoxALIs. Cur- rently, Dr. Alicia Lourteig is in the midst of a major world-wide revision of the genus (exclusive of the South African species) with particular emphasis on the poorly understood South American species Small (FI. Southeast. U. S. 1903; N. Am. Fl. 1907) placed the North American species of Oxalis in eight genera. His scheme has not been adopted generally, and, in view of the variation that occurs within Oxalis on a world-wide basis, it seems best to recognize only one inclusive genus. Section Oxatis (sect. Acetosellae Knuth) (flowers solitary from elon- gated, underground rhizomes) is represented in our area by Oxalis Ace- tosella subsp. montana (Raf.) Hultén ex D. Live (O. montana Raf.), 2 = 22, which occurs in rich, moist woods from Newfoundland and eastern Quebec to Manitoba and Saskatchewan, south to Pennsylvania, eastern Ohio, Kentucky, Michigan, Wisconsin, and Minnesota, and in the moun- tains of the Virginias, North Carolina, and Georgia. The attractive flow- ers of this plant have white or light pink petals marked with darker pink veins and basal yellow spots. Individuals with solid dark pink or purplish flowers can be referred to f. rhodantha Fern. In the chasmogamous flow- ers of this subspecies, the stigmas are either considerably above the upper whorl of anthers or slightly below them (see family discussion). Reduced, cleistogamous flowers are also produced, particularly late in the growing season. Young (1968) notes that the cleistogamous flowers of the Euro- pean populations are apetalous, but at least some of the cleistogamous flowers on North American plants have small petals (see FicurE 1, c). Oxalis Acetosella has a very broad distribution (see maps in Veldkamp, 1971, and Hultén). Subspecies Acetosella is Eurasian, occurring from Ice- land, the British Isles, and Scandinavia, south to Spain, Italy, and Anatolia, and west to the Caucasus Mountains, China, Korea, Kamchatka, and Japan. Subspecies Grifithii (Edgew. & Hooker f.) Hara, 2n = 22, is mostly of southern and western Asia, from northwestern India through China to Japan, Formosa, and the Philippine Islands. Related plants are 1975] ROBERTSON, OXALIDACEAE 231 FIGURE Oxalis sections Oxalis (a—c) and Corniculatae (d-q). i, Aree a . montana: a, plant with chasmogamous flower and en uk uy oa Ae ole tat flower — note persistent swollen leaf bases on rhizome, X 14; b, chasmogamous flower, veins of petals deep pink, basal tt ogee x 2; C, ike. flower in off-center vertical section, upper se nthers to ouching stigmas, lower set of anthers sterile, x Ma a, . ‘trite: os habit, 4; e, mature fruit before dehiscence, X 3; n, carpels free laterally, seeds enclosed by aril, dehiscence through oculcidal aie x 17. 8, Capsule during dehiscence — note seeds and arils, < 3; h, se enclosed by aril, x ed, he eG views of aril splitting away from seed, ye 12: ‘i aril after eversion, X 12; — illenii subsp. filip j androecium nd Avery from quasi-homostylous sidigs 10; n, penicillate, 2-lobed stigma, x 2 randis: androeciu and gynoecium from long-styled, o-q, O. midstyled, Sa short-styled flowers, peaecGvely. Ser aiinetatamatic. x 6, 232 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 found in the United States from the Olympic Mountains of Washington to Monterey County, California; these are treated as either subsp. oregana (Nutt. ex Torrey & Gray) D. Léve or as a distinct species, O. oregana Nutt. ex Torrey & Gray. Oxalis magellanica Forster f., 2n = 10, is a closely allied, Southern Hemisphere counterpart of O. Acetosella that is known from Andean South America (southern Peru to Patagonia), New Zealand, Tasmania, the Victorian Alps of southwestern Australia, and New Guinea. Veldkamp indicates that only long-styled flowers are found in both O. Acetosella subsp. Griffithii and O. magellanica. Section IonoxaLis (Small) Knuth (acaulescent, the flowering peduncles arising from scaly bulbs, the petals violet, purple, pink, or white) is com- posed of about 50 species of the New World, with the greatest diversity in Mexico and South America. Only Oxalis violacea L. (Jonoxalis violacea (L.) Small), 2n = 28, is indigenous in eastern North America, where it occurs in a variety of habitats, including woods, pinelands, and prairies, from southern New England to Minnesota and South Dakota, south to Georgia, upper Florida, Louisiana, and Texas. It occurs disjunctly in Arizona and New Mexico. The plant is easily recognized by its dark pink, violet, or purple (white in f. albida Fassett) flowers in several- flowered, simple umbels on unbranched peduncles that overtop the leaves, by the oblate capsules, and by the moderate-sized leaflets (8-15 mm. long and 10-23 mm. broad) with reddish markings above or a solid reddish cast below and with calcium oxalate deposits only at the apical notch. The leaflets are partly folded most of the time, seldom expanding fully. The plants are usually glabrous, but in the region from Arkansas, Mis- souri, Mississippi, and Alabama, north to Ohio, New York, and Vermont, some individuals have multicellular, often glandular, trichomes on the petioles; these may be called var. trichophora Fassett. Oxalis violacea flowers in the spring and often again in late fall following autumnal rains. The flowers are distylous with long- and short-styled forms. Several other species of this section are cultivated in the southeastern United States, and a few have become established. Oxalis corymbosa DC. (including O. martiana Zucc., Ionoxalis martiana (Zucc.) Small), 2n = 24, 28, 30, has flowers in irregularly branched cymes, nonseptate trichomes on the petioles and peduncles, large leaflets (27 to 46 mm. long and 34 to 63 mm. wide) that are mostly fully expanded during the day, randomly distributed calcium oxalate deposits in the leaflets, and usually abundant bulblets. A native of South America, it is found in scattered localities from South Carolina to Florida and Texas; it is also widespread in the West Indies. According to Denton, this species does not set seed in North America (although Small describes capsules and seeds), and Veldkamp (1971) reports the same situation in Malesia. Small recorded O. inter- media A. Rich. (as Jonoxalis intermedia (A. Rich.) Small) from ham- mocks in southern peninsular Florida, and Denton noted a variant allied to this species from Sarasota, Florida. Oxalis intermedia is readily rec- ognized by its obdeltoid leaflets. Evidently escaped from cultivation in the Carolinas and perhaps else- 1975] ROBERTSON, OXALIDACEAE 233 2. Oxalis section Ionoxalis. a—n, O. violacea: a, sowtipae - plant, x 1b; b, b, scaly bulb with contractile ig vole below, 1; c, leaflets in folded position e inva hte abaxial appendages on —. filaments, < 6; FC ececaes ‘4 stamens rem d gynoecium from long-styled flower, 10; g, longer stamen from long-styled flow - h, tip of style and stigma from long- styled fi ; 5: i, short-styled flower, petals and 2 sepals removed, J, androecium and gynoecium teas short-styled flower, X 10; k, nearly matur capsule from short-styled flow 5; 1, same in cross ection, placentation xile, deh stab through loculicial slit, carpels connate ee adaxially, seeds enclosed by with aril removed, X 12; n, seed in vertical section, ee sa gas tie pes enes aa Saray ma 1d, 234 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 where are plants superficially rather similar to O. corymbosa, but which have fleshy, more or less cylindrical rootstocks (not scaly bulbs) and densely pubescent pedicels, calyx lobes, and petals. These plants are known in the horticultural trade as O. rubra St.-Hil., 2n = 42, a native of South America, but their identity is suspect. Knuth placed O. rubra in his sect. ARTICULATAE. Oxalis Pes-caprae L. (O. cernua Thunb., Bolboxalis cernua (Thunb.) Small), 2n = 28, indigenous to South Africa, is cultivated in our area and, according to Small, has perhaps escaped at least in northern Florida. This species has showy yellow flowers in several-flowered, leafless cymes that exceed the rosette of basal leaves and has a caudex at the apex of a long contractile taproot. It reproduces mostly by bulbils. Section Cornicutatar DC. (flowers yellow, stems creeping to erect, bulbs absent) is mostly of temperate North America. The nomenclature of some of the species is particularly confusing, since several specific names have been applied differently. Small placed the North American species of this section in his segregate genus Xanthoxalis. The section was revised by Eiten (published in an abbreviated form), and his nomenclature and classification, which differ substantially from previous accounts, are used here, since both have been widely adopted. Dr. Lourteig’s studies may change the number of taxa, the ranks at which they are recognized, and some of their names. Eiten recognized 14 species and eight sub- species; five species are restricted to South America, three mostly to eastern North America, two to the Greater Antilles, two to western North America, one to eastern North America and eastern Asia (introduced elsewhere), and one is a cosmopolitan weed. Eiten divided this section into two subsections, the first of which is subsect. CorNIcuLATAE. (According to Article 22 of the 1972 edition of the International Code of Botanical Nomenclature, this becomes subsect. BoreatEs Knuth.) In species of this group, the stems are usually several from the crown of a taproot (any horizontal stems are above ground); septate trichomes are absent from stems, petioles, and pedicels (but sometimes present on capsules); the inflorescences are umbellate; and the pedicels are usually strongly reflexed in fruit with the capsules erect. Oxalis corniculata L. (Xanthoxalis corniculata (L.) Small, O. repens Thunb., X. Langloisii Small), 2n = 24, 36 (38?), 42, ca. 46, 48, is a pan- tropical weed with creeping stems rooting at the nodes, broadly au- riculate stipules, and small, mostly homostylous flowers. This species, evi- dently native to the Old World and extremely variable in Australasia, is a troublesome lawn weed in warm regions and is frequently encountered as a weed in greenhouses farther north. Several varieties have been de- scribed, but Eiten recognized only one polymorphic species. Another group of plants of this subsection, with erect flowering stems that do not root at the nodes, is taxonomically and nomenclaturally dif- ficult. Eiten grouped them into two species and five subspecies. Plants with small, mostly homostylous flowers (petals less than 13 mm. long) 1975] ROBERTSON, OXALIDACEAE 235 belong to Oxalis Dillenii Jacquin, while those with larger strongly tri- stylous flowers (petals mostly longer than 15 mm.) belong to O. Priceae Small. Two subspecies of O. Dillenii based on differences in the indumen- tum of the capsules were recognized by Eiten: subsp. Dillenii (O. stricta auct., not L. [following Eiten’s lectotypification], O. florida Salisb., O. Lyonti Pursh, O. Navieri Jordan, O. recurva var. floridana Wiegand, O. Dillenii var. radicans Shinners), 2n = 18, 20, 22, 20-24, which is com- mon nearly throughout eastern North America (locally naturalized in Europe) and subsp. filipes (Small) Eiten (O. filipes Small, O. Brittoniae Small, O. florida var. strigosifolia Wiegand), 2n = 16, which occurs from Florida to Louisiana, north to Connecticut, Tennessee, and Missouri. Oxalis Priceae (O. recurva Elliott, nom. dub. according to Eiten) is con- fined to the southeastern United States; Eiten recognized three subspecies that differ in the pubescence of the stems and pedicels. Subspecies Priceae (O. cespitosa Raf., not O. caespitosa St.-Hil., O. hirsuticaulis Small) oc- curs in Kentucky, Tennessee, Mississippi, Alabama, and Georgia; subsp. colorea (Small) Eiten (Xanthoxalis colorea Small) occurs along the coast from North Carolina to Florida and Louisiana; and subsp. texana (Small) Eiten (X. ¢texana Small, O. recurva var. texana (Small) Wiegand) occurs in eastern Texas and Louisiana and in scattered localities on the Coastal Plain to northern Florida and Georgia. Subsection Srrictar Ejiten of sect. CoRNICULATAE is characterized by the stems arising singly from underground rhizomes; the presence of sep- tate trichomes on stems, petioles, and pedicels; cymose inflorescences; and pedicels that are not reflexed in fruit. It includes Oxalis stricta L., 2n = 18, 24, 18-24, O. grandis Small, and O. Suksdorfii Trelease, the last mostly confined to western Oregon and adjacent Washington and California. Plants from eastern North America (Newfoundland to North Dakota and British Columbia, south to Florida, Arkansas, Oklahoma, New Mexico, and Arizona) and from eastern Asia (extensively naturalized in Europe) with small, mostly homostylous flowers (the petals usually less than 1 cm. long) and with leaves lacking colored margins were called O. stricta L. by Eiten. These plants have had a tortuous nomenclatural history, having been called O. corniculata by Gray, Xanthoxalis cymosa, X. Bushii, and X. rufa by Small, and O. europaea by authors of numerous twentieth-cen- tury manuals and floras; the eastern Asiatic plants are usually known as O. fontana Bunge. The name “Oxalis stricta L.” was first lectotypified by Robinson and was applied by him to those plants Eiten called O. Dillenii. Eiten rejected Robinson’s typification and used the name for the plants native to eastern North America and eastern Asia. Dr. Lourteig has indicated in conversa- tion that she thinks Robinson’s typification is correct, that the name Q. stricta should be applied to those plants Eiten called O. Dillenii, and that O. fontana is the correct name for the plants Eiten called O. stricta. Oxalis grandis Small is a very attractive species with large, red- or purple-margined leaflets and showy, strongly tristylous flowers. These 236 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 plants occur in rich woods, usually in the mountains, rarely on the Upper Piedmont, from Pennsylvania to southern Illinois, south to Georgia, Ala- bama, Tennessee, and Kentucky. The carpels of many species of Oxalis are connate only toward the floral axis, with most of the lateral walls being free and merely closely juxtapositioned (see Ficurrs 1, f, and 2,1). To the casual observer, it appears that the capsules are septicidal because of the folds (the “episeptal rimae” of Veldkamp) between the carpels. However, dehiscence takes place through a loculicidal slit on the abaxial side of each carpel. At maturity, the slits open slightly, and the abaxial carpel walls are thin and flaplike. The seeds are enclosed by a smooth, turgid aril, which splits suddenly along an abaxial suture and turns inside out. This motion ejects the seed, and often the aril, through the slit to a considerable dis- tance from the parent plant. The ejection of one seed sets off a chain reaction that results in the dispersal of most seeds in one capsule in a very short time. The seeds of some species, such as O. corniculata, are sticky and adhere to objects on which they land. REFERENCES: See family references. BANERJEE, U. C., & E. S. BARGHOORN. Scanning and transmission electron micro- scopy of exine pattern in normal and aborted pollen grains and the structure of ubish bodies and tapetal membranes in Oxalis rosea. (Abstr.) Am. Jour. Bot. 57: 741. 1970. BrUcHER, H. Poliploidia en especies sudamericanas de Oxalis. Bol. Soc. Venez. Ci. Nat. 28: 145-178. 1969. CaRNIEL, K. Licht- und electronenmikroskopische Untersuchungun der Ubisch- kdrperentwicklung in der Gattung Oxalis. (English summary.) Osterr. Bot. Zeitschr. 114: 490-501. 1967. . Beitrage zur seen geen des Antherentapetums in der Gat- tung Oxalis. I. Oxalis rosea und O. pubescens. Ibid. 116: 423-429. 1969; II. Oxalis Acetosella. Ibid. 117. 201-204. 1969. CHEVALIER, A. Révision de quelques Oxalis utiles ou nuisibles. Répartition géographique et naturalisation de ces espéces. Revue Bot. Appl. Agr. Trop. 940. 20: 656-694. Darwin, C. The different forms of flowers on plants of the same species. viii + 352 pp. New York. 1877. [Oxalis, 169-183; 211-213; 321-324.] Datta, M. Mechanical adaptations to autonomous moveme ents in Desmodium gyrans Linn. and Oxalis repens Linn. (Abstr.) Indian Sci. Congr. Assoc. Proc. 43(3): 235, 236. 1955.* Denton, M. E. A monograph of Oxalis, section Ionoxalis Ce in North America. Publ. Mus. Mich. State Univ. Biol. 4: 455-615. Eten, G. The typification of the names “Oxalis corniculata L.” a pga stricta I ni = on 4: 99-105. 1955. — y and regional variation of Oxalis section Corniculatae. 1. In- toduction, ai and synopsis of the species. Am. Midl. Nat. 69: 257-309. 1978}! ROBERTSON, OXALIDACEAE 237 FABERGE, A. C. Populations of Oxalis with floral trimorphism. (Abstr.) Genetics 44: 50 09. 1959. [O. grandis in Indiana, O. Suksdorfi in Oregon FassETT, N. C. Mass collections: Oxalis violacea. Castanea 7: 31-38. 1942. FisHER, R. A., & V. C. Martin. Genetics of style-length in Oxalis. Nature 162: 533. 1948. [O. valdiviensis. | Fyre, V. C. The genetics of tristyly in Oxalis valdiviensis. Heredity 4: 365-371. 1950 : o modes of inheritance of the short-styled form in the ‘genus’ Oxa- lis, Nature 177: 942, 943. 1956. GALIL, J. Pa gia pai a: in Oxalis cernua. Am. Jour. Bot. 55: 68-73. 1968. [= O. Pes-capra Gates, S. C., & H. W. VOGELMANN. Variation in populations of Oxalis mon- tana Raf, Bull. Torrey Bot. Club 96: 714-719. sie [Correlation noted between certain morphological characters and elevation. | Gray, A. Ord. Oxalidaceae. Gen. Pl. U. S. Ill. 2: 109-112, pl. 144. 1849. [O. stricta, O. violacea. | Hara, H. Conteivutions to the study of variations in the Japanese plants close- ly related to those of Europe or N. America. I. Jour. Fac. Sci. Univ. Tokyo Bot. 6: 29-96. 1952. [O. Acetosella, 81; O. fontana (incl. O. europaea), 82.] Herr, J. M., Jr, . L. Dowp. Development of the ovule and —— phyte ti ao nigel L. Phytomorphology 18: 43-53. Hitt, A. W. The oca and its varieties. Bull. Misc. Inf. Kew pa "169-173. 1939. [O. tuberosa.] Hopce, W. H. Three neglected Andean tubers. Jour. N. Y. Bot. Gard. 47: 214— 224. 1946. [O. tuberosa. | Hutren, E. The amphi-Atlantic plants and their phytogeographical connec- tions. Sv. Vet.-Akad. Handl. IV. 7(1): 1-340. 1958. [O. Acetosella, 146, 147; distribution map. | . The circu ae plants. II. Dicotyledons. /bid. 13(1): 1-463. 1971. [O. corniculata, is. INGRAM, J. The rae ce species of Oxalis. 1. The KP species. Baileya 6: 22-32. 1958; 2. The acaulescent species. Jbid. 7: 11-22. 1959. [With keys and illustrations. ] Jacquin, N. J. von. Oxalis. Monographia, iconibus illustrata. 120 pp. chart. 1 pls. Vienna. eee [Most plates handcolored, the tint varying some- what from copy to c LEON, J. Plantas sinwattety andinas. Inst. Interam. Ci. Agr. Zona Andina Bol. éc. 6: 1-112. 1964. [O. tuberosa, 22-29.] Love, A., & D. Love. Cytotaxonomy of the alpine vascular plants of Mount Washington: Univ. Colorado Stud. sere 24. 74 pp. 1966. [O. Acetosella, 39; see also D. Live, Taxon 17: 89. content Cleistogamia en una ious ‘ineek de Oxalis. Bol. Soc. - Bot. 10: 19, 20. 1962. patioaties extra-austroamericanae. I. Oxalis L. sectio Thamnoxys Planchon. Phytologia 29: 44-471. Marks, G. E. Chromosome numbers in the genus Oxalis. New Phytol. 55: 120-129. 1956. . The cytology of Oxalis dispar (Brown). Chromosoma 8: 650-670. 1957. 238 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Metcatre, C. R. A note on the structure of the phyllodes of A beg . Knuth and O. bupleurifolia St. Hil. Ann. Bot. 47: 355-359. Mrcwact, P. W. The identity and origin of varieties of Oxalis eee gees L. naturalized in Australia. Trans. Roy. Soc. S. Austral. 88: 167-173. 1964. [Pentaploid and tetraploid varieties Montatpo, A. Bibliografia de raices y tuberculos lagen sds chee Fac. Agr. Venez. 13: 1-595. 1967. [Oca, 497-500; many refere Mutcany, D. L. The reproductive biology of Oxalis ey “Am. Jour. Bot. 51: 1045-1050. 1964. . Interpretation of crossing diagrams. Rhodora 67: 146-154. 1965. Ornpurr, R. The breeding system of Oxalis Suksdorfi. Am. Jour. Bot. 51: 307-314. 1965. . The breakdown of “eet pa incompatibility in Oxalis section Corni- culatae. Evolution 26: 52-65. OverBEcK, F. Zur Kenntnis des Mechanisms der Samenausschleuderung von Oxalis. Jahrb. Wiss. Bot. 62: 258-282. Rickett, H. W. Wildflowers of the Lg States. Vol. 2. The Southeastern United States. “ol x + 322 pp. pls. 1-116. New York. 1966. [Oxalis, 270- 272, pls. 97, 106.] Ross, S. M. ses latifolia Kunth. New Phytol. 62: 75-79. 1963. [Morphol- ogy, anatom Rosinson, B. L. Oxalis corniculata and its allies. Jour. Bot. London 44: 386- 391. 190 06. Satter, T. M. The genus Oxalis in South Africa. Jour. S. Afr. Bot. Suppl. Vol. : 1-355. frontisp. pls. 1-10. 1944. [See notes and errata in Jour. S. Afr. Bot. 23: 103, 104. 1957.] n the process of forming contractile roots and the lowering of the first bulbils by seedlings of the South African Oxalis which produce endospermous seeds. Jour. S. Afr. Bot. 17: 189-194. 1951 [1952]. ay he Die Gattung Oxalis L. in Siidwestafrika. Bot. Jahrb. 86: 293- 1967 Sarma, A. K., & T. CHATTerRjI. Cytological studies on three species of Oxalis. Caryologia 13: 755— 765. 1960. [O. Acetosella, O. corniculata, O. pur purata. | STiRLING, J. Studies of flowering in heterostyled and allied species. III. Gen- tianaceae, Lythraceae, Oxalidaceae. Publ. Hartley Bot. Lab. Liverpool 15: 1-24, 1936. [O. cernua (= OQ. Pes-caprae), O. dispar.] , D., & A. J. Davey. Contractile roots. IJ. On the mechanism of root- contraction in Oxalis imcarnata. Ann. Bot. 46: 993-1005. pl. 40. 1932. [See also, Jbid. 40: 571-583. pl. 17. 1926. TRELEASE, W. Heterogony of Oxalis violacea. Am. Nat. 16: 13-19. 1882 WELLER, S. G. The evelution ms stad in Oxalis alpina. (Abstr.) Am. Jour. Bot. 61(5-Suppl.): 52. Wriecanp, K. M. Oxalis crite cite its relatives in North America. Rho- dora 27: 114-124, 133-139. 1925. [See also correction, /bid. 28: 67. 1926.] Younc, D. P. Oxalis in the British Isles. Watsonia 4: 51-69. 1958. [See note in Proc. Bot. Soc. Brit. Isles 4: 273. 196 . Oxalidaceae. Jn: T. G. Tuttn, V. H, Heywoop, et al., eds., Fl. Euro- paea 2: 192, 193. 1968. ZIEGLER, H. Uber die priate von Oxalisarten. Ber. Bayer. Bot. Ges. 36: 61, 62. 1 pl. 1 1975] ROBERTSON, OXALIDACEAE 239 ZuccaRINI, J. G. Nachtrag zu Monographie der amerikanischen Oxalis-Arten. Abh. Math.-Phys. Bayer. Akad. Wiss. 1: 177-276. pls. 7-9. 1832. ARNOLD ARBORETUM HARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 240 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 GAULTHERIA SWARTZII, NOM. NOV. AND THE COMBINATIONS IN RAEUSCHEL’S NOMENCLATOR Ricuarp A. Howarp Two names have been used over the years for a plant of the mountains of Guadeloupe. Swartz described the species briefly but validly as Epigaea cordifolia (Prodr. 73. 1788), citing its locality as Guadeloupe. Four years later Richard (Actes Soc. Hist. Nat. Paris 1: 109. 1792) described a plant as Gaultheria sphagnicola. When published, however, this name was illegi- timate, being superfluous, for Richard also cited E. cordifolia Sw. In 1797 Raeuschel published the binomial Gaultheria cordifolia (Nomencl. ed. 3. 124. 1797), which Urban (Symb. Ant. 3: 330. 1902) and Airy-Shaw (Kew Bull. 1940: 310. 1940) apparently regarded as a new combination. As- suming the basionym to be Epigaea cordifolia Sw., Small (N. Am. Fl. 29: 75. 1914) considered the Raeuschel name to be a nomen nudum and used the binomial Gaultheria sphagnicola Rich., as did Camp (Bull. Torrey Bot. Club 66: 19. 1939). Thus for Gaultheria two invalid names occur in recent literature and a new name is needed for this species. I propose Gaultheria swartzii nom. nov. Raeuschel’s binomial Gaultheria cordifolia is accompanied only by the name Cayenne and the classic symbol for a woody plant. There is no teference to Swartz’s publication in the introduction. The binomial is not a combination and is a nomen nudum. However, the treatment of names in Raeuschel’s Nomenclator botanicus has been inconsistent even in recent years. Steyermark’s massive treatment of the Rubiaceae in Maguire et al., Botany of the Guayana Highlands, Pt. IX (Mem. N. Y. Bot. Gard. 23: 227-832. 1972) illustrates this. In treating a comparable problem in Psy- chotria guianensis Raeuschel (loc. cit. 457), Steyermark concluded that most botanists consulted agreed that the binomial was a nomen nudum without either direct or indirect reference to any previously published name, and therefore it was illegitimate. However, for Psychotria officinalis (loc. cit. 614) Steyermark noted W. T. Stearn’s suggestion that a combi- nation be attributed not to Raeuschel (1797) but to Sandwith (1931), although Sandwith did not discuss the problem (Kew Bull. 1931: 473. 1931). Elsewhere in his publication Steyermark accepted Raeuschel’s combinations for Psychotria paniculata (Aubl.) Raeusch. (loc. cit. 500) and Psychotria racemosa (Aubl.) Raeusch. (loc. cit. 542), even though these names carried no direct or indirect reference to the Aublet binomial. For these as well as for many other combinations attributed to Raeuschel a search must be made for a later valid combination or an alternative name. 1975] HOWARD, GAULTHERIA SWARTZII 241 Gaultheria swartzii Howard, nom. nov. Brossaea coccinea L. Sp. Pl. 1190. 1753; not Gaultheria coccinea H.B.K. (1819) or Gaultheria coccinea (L.) Urb. 1902. Epigaea cordifolia Sw. Prodr,. 73. 1788; not Gaultheria cordifolia H.B.K. Gaultheria sphagnicola Rich. Actes Soc. Hist. Nat. Paris 1: 109. 1792; nomen ille git. Brossaea anastomosans Griseb. Fl. Brit. W. Ind. 142. 1859; nomen illegit. and also not Gaultheria anastomosans (L.) H.B.K. (1819). Brossaea coccinea L. is based on Plumier, Gen. 5, ¢. 17. Urban proposed the combination Gaultheria coccinea (L.) Urb. (Symb. Ant. 3: 330. 1902), at which time he added the reference Plumier, Plantarum Americanarum ed. Burm. ¢. 64, f. 2. Small (N. Am. Fl. 29: 75. 1902) lists Brossaea coccinea L. in the synonymy of Gaultheria sphagnicola with a question and the Urban name Gaultheria coccinea “in part.” Airy-Shaw (Kew Bull. 1940: 310. 1940) assigned Gaultheria coccinea (L.) Urb. to the synonymy of Gaultheria cordifolia (Sw.) Raeusch. No Plumier material has been seen, and it is possible the plant in question may have been seen in Guadeloupe and not in Hispaniola. In any case, Gaultheria coccinea H.B.K. (Nov. Gen. Sp. 3: 284. 1819) from Venezuela precludes any use of the Linnaean basionym. Brossaea anastomosans Griseb. (Fl). Brit. W. Ind. 142. 1859) is a combination for Andromeda anastomosans L., although Grisebach also cited in synonymy Epigaea cordifolia Sw. Gaultheria anastomosans (L.) H.B.K. (Nov. Gen. Sp. 3: 283. 1819) has the same basionym. Grisebach’s general description does not permit typification by any of the synonyms cited. To select a lectotype of Gaultheria swartzii is not an easy matter. In the original publication, Swartz (Prodr. 73. 1788) indicated the species to be from Guadeloupe. In the subsequent treatment, Swartz (Fl. Ind. Occ. 2: 842. 1800) cited a Du Ponthieu collection from Guadeloupe and one by Le Blond from Cayenne. I have seen neither collection. Richard (Actes Soc. Hist. Nat. Paris 1: 109. 1792) did not cite a specimen, but in the Richard herbarium (Pp) there is a specimen labeled “type” and named Gaultheria sphagnicola from the Soufriére of Guadeloupe. The label notes, however, that the plant also occurs in Martinique on Monte Calvo. If the Du Ponthieu specimen were located, this logically would be the lectotype. Small (N. Am. Fl. 29: 75. 1914) indicated the range of this species to be Guadeloupe, Trinidad, and northern South America. A. De Candolle (DC. Prodr. 7: 592. 1838), under Epigaea cordifolia, cited a collection (Sieber 346) from Trinidad. Sieber’s collections often have unreliable data, and this specimen, which I have not seen, may be from Guadeloupe or Martinique. The species has not been collected in Trinidad according to Hill & Burtt (Fl. Trin. & Tobago 2(2): 114. 1940). The Le Blond collection, also cited by De Candolle from “Cayennae seu Guianae Galli- cae,” should be re-examined for verification that it is the present species and not one of the many from South America. Modern collections are on 242 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 56 hand from Guadeloupe and Martinique, but only from elevations of 1200 to 1467 m. in altitude. The species might also be expected in Dominica. Camp (Bull. Torrey Bot. Club 66: 19. 1939) noted that Gaultheria sphagnicola (= G. swartzii) and G. domingensis are very similar. Small . Am, Fl. 29: 74. 1914) distinguished the two species on the basis of the elabrous corolla with leaf blades manifestly toothed in G. sphagnicola and the pubescent corolla with leaf blades obscurely toothed in G. domin- gensis. Recent collections from both areas substantiate Camp’s observation that a pubescence does occur on the corollas of plants from the Lesser Antilles, although none matches the abundance of hairs on material from Hispaniola. The leaf blade differences are obvious and of specific value. Material of G. swartzii from Guadeloupe and Martinique has short blunt teeth, each terminating in a fairly stout seta. Hispaniolan material has leaves with the margin inrolled or thickened but without teeth. Large setae are marginal without noticeable toothlike bases. ARNOLD ARBORETUM ARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 1975] HARTLEY & HYLAND, FLINDERSIA 243 ADDITIONAL NOTES ON THE GENUS FLINDERSIA (RUTACEAE) * T. G. HARTLEY AND B. P. M. HyLanp SINCE THE PUBLICATION of a revision of the genus Flindersia (Hartley, Jour. Arnold Arb. 50: 481-526. 1969), a new species of the genus has been discovered in northern Queensland, and the first known flowering speci- mens of F. unifoliolata Hartley have been collected. A description of this new material is given below. Specimens cited as ars are deposited at the herbarium of the Queensland Research Station, Forest Research Institute, Forestry and Timber Bureau, Atherton, Queensland. The remaining speci- mens cited are all deposited at the Herbarium Australiense, C.S.I.R.O., Canberra (CANB). Flindersia brassii Hartley & Hyland, sp. nov. Arbor usque 30 m. alta; ramulis, foliis et inflorescentiis glabris vel pub- erulis vel subtiliter adpresse pubescentibus, pilis simplicibus et basifixis vel irregulariter ramosis et centrifixis. Folia opposita vel subopposita, pari- pinnata vel imparipinnata, 2—4-juga, 7-18 cm. longa; rhachidi basin ver- sus puberula, aliter glabra; petiolulis foliolorum lateralium 2—6 mm. lon- gis, rhachidi ad apicem extensa 0.7—1.6 cm. longa foliolum terminale ferente; laminis subcoriaceis, consperse pellucido-punctatis, subtus costa saepe sparse puberulis, supra glabris, ellipticis vel elliptico-oblongis, aequi- lateribus vel parum inaequilateribus, 4-8 cm. longis, 1.5—3.7 cm. latis, basi acuta vel cuneata plerumque parum inaequilatera, venis primariis utrinse- cus costa 8—11, apice obtuso vel rotundato. Inflorescentia terminalis, usque 15 cm. longa plerumque fere lata quam longa; axibus et ramulis dense pub- erulis vel subtiliter adpresse pubescentibus. Flores bisexuales, ca. 4.5 mm. longi; pedicellis 2~3 mm. longis; sepalis puberulis, ciliolatis, late ovatis vel suborbicularibus, 1-1.5 mm. longis; petalis cremeis, in sicco pallide brun- neis, abaxialiter dense adpresse pubescentibus, adaxialiter tomentulosis, ellipticis, 3.5-4 mm. longis, basi subito contractis; staminibus declinatis, ca. 2.5 mm. longis, filamentis glabris, antheris subdorsifixis, ca. 0.5 mm. longis, mucronulatis; staminodiis ca. 0.7 mm. longis; disco ca. 1 mm. alto; Synoecio ca. 1.3 mm. alto, ca. 1.5 mm. lato, ovulis 1 in quoque latere placen- tarum. Capsula maturite secedens in valvas distinctas, elliptico-oblonga, 7-11 cm. longa; exocarpio in sicco pallide brunneo, subtiliter _adpresse pubescenti, muricato, processibus dense aggregatis, inaequilongis, usque 4.5 mm. longis; endocarpio in sicco luteo. Semina 1 in quoque latere dis- sepimentorum, utrinque alata, 5.5-7 cm. longa; hypocotylo terminali. Hototypus: Hyland 2770 (cans). Ficure 1. * This is the seventh in a series of papers on the Rutaceae of Malesia and Aus- tralasia. 244 JOURNAL OF THE ARNOLD ARBORETUM [vou. 56 beet els Flindersia brassii Ha artley & ye pea Staats of the gerne NB): a, peloneg hana ; b, three of the valves of the fruit in latera poate and adaxial views; c, p seis sae “of the fruit: d, seed. 1975] HARTLEY & HYLAND, FLINDERSIA 245 FIELD CHARACTERS. Medium to rather large tree 13-30 m. tall, 20-40 cm. d.b.h., without conspicuous buttresses. Bark thin (less than 2.5 cm. thick), bitter when chewed, pale brown, smoothish or minutely tessellated, lenticels vertically elongated, often inconspicuous; subrhytidome layer red, pink, or green; outer blaze pink to red, granular to fibrous; inner blaze red to cream, fibrous. Heartwood pale pinkish brown, with odor like that of scented maple (Flindersia laevicarpa White & Francis var. laevi- carpa). SEEDLING. (Description based on dried specimen of a 4-month-old plant grown from seed of Hyland 2737.) Plant about 25 cm. high, stem with five nodes above the cotyledons, youngest growth and petioles sparsely to densely puberulent with simple, basifixed trichomes. Cotyledons chloro- phyllous, chartaceous, oblong, about 2.5 cm. long, base sagittate, apex obtuse. Leaves opposite at the first node (i.e., the first above the cotyle- dons), otherwise alternate; simple at the first four nodes, imparipinnate and unijugate at the fifth node. Petioles of simple leaves 0.3—2 cm. long (gradually increasing in length from the first to the fourth node). Blades of simple leaves subcoriaceous, broadly elliptic, entire, equal-sided, 4.5— 8.5 cm. long (also gradually increasing in length from the first to the fourth node), base acute, main veins (in the largest leaf) 8 on each side of the midrib, apex obtuse. Imparipinnate leaf immature, 4 cm. long. Ecotocy. Dry, rocky rain forest, 60 to 360 meters. Associated species: Podocarpus neriifolius, Licuala muelleri, Grevillea pinnatifida, Xanthophyl- lum octandrum, Halfordia kendack, Quassia bidwillii, Vavaea amicorum, Euroschinus falcatus, Eugenia (Syzygium) cormiflora vel aff., Metro- sideros tetrapetala, Rhodamnia blairiana, Vitex acuminata, and Antirhea tenuiflora. Queensland. Coox District: Cape York Peninsula, Upper Claudie River, Iron Range, Hyland 2734 (CANB, QRS), 2735 (CANB, QRS), 2736 (CANB, QRS), 2737 (QRS), 2738 (CANB, QRS), 2740 (QRS), 2743 (QRS), 2770 (CANB, holotype; QRs, isotype), 6663 (CANB, QRS), Irvine 248 (CANB, QRS). This species is named in honor of Leonard J. Brass (1900-1971), one of the outstanding plant explorers of the Australasian region. Flindersia brassii is related to F. fournieri Panch. & Sebert, an endemic to New Caledonia; F. laevicarpa White & Francis, with two varieties, one endemic to northern Queensland and one restricted to New Guinea and to Misool Island; and F. brayleyana F. Muell., an endemic of northern Queensland. It shares with these species the characteristic of a terminal hypocotyl in the embryo. This is a unique (and apparently primitive) feature, the hypocotyl being lateral in the embryos of the remaining species of the genus. Other similarities and differences between these four species are summarized in Tasxe I. In having abruptly narrowed petals and muricate capsules, Flindersia TABLE 1. Characteristics of Flindersia brassii and related species. F. laevicarpa F. brassii F. fournieri TRICHOMES simple and basifixed or simple and basifixed irregularly branched and trifixed LEAVES opposite or subopposite ; alternate or (occasional PETIOLULES OF LATERAL LEAFLETS PETALS STAMINAL FILAMENTS OVULES CAPSULE EXOCARP EXNDOCARP SEEDS imparipinnate or pari- pinnate; 7-18 cm. long 2-6 mm. long abruptly narrowed at the glabrous 1 on each side of the placentae 7-11 cm. long finely appressed- pubescent; muricate yellow 1 on each side of the dissepiments; winged at both ends leaves) opposite or sub- opposite; paripinnate ; 6-13 cm. long 4-9 mm. long abruptly narrowed at sparsely to rather densely villous 2 on each side of the placentae (one of each pair is smaller and apparently aborts) 4—4.7 cm. long glabrous; muricate yellow-brown to brown 1 on each side of the dissepiments; winged at both ends simple and basifixed opposite; paripinnate ; 6-30 cm. long 2-13 mm. long gradually narrowed at the base glabrous to densely pubescent 1 or 2 on each side of the placentae Sas there are two, smaller and popavenite aborts) 2.9-5.2 cm. long glabrous; almost smooth to bluntly short-muricate pale brown and some- times flecked with orange 1 on each side of the dissepiments; winged at ends F. brayleyana simple and basifixed opposite or subopposite ; paripinnate; 27-45 (-75) cm. long 10-28 mm. long gradually narrowed at the villous subapically 1 on each side of the placentae 6-10 cm. long glabrous; almost smooth cream to reddish brown 1 on each side of the dissepiments; winged at both ends Oe WOLANOTUV GIONUV AHL JO TYNUAOf 9g “10A] 1975] HARTLEY & HYLAND, FLINDERSIA 247 brassii appears to be most closely allied to F. fournieri. This close relation- ship indicates that the New Caledonian species is of Australian ancestry, since the center of diversity of Flindersia is clearly in eastern Australia. Flindersia unifoliolata Hartley, Jour. Arnold Arb. 50: 498. 1969. Inflorescences from the axils of the upper leaves and terminal, 5—7 cm. long and about one-half as wide, upper axes and branches puberulent to finely pubescent with simple trichomes. Flowers bisexual, about 4 mm. long; pedicels puberulent, obsolete to 0.5 mm. long; sepals 5, puberulent and ciliate, ovate, 1.2 mm. long; petals deep red, rather sparsely strigose abaxially, glabrous adaxially, elliptic, 3.5 mm. long; stamens declinate, 3.5 mm. long, filaments rather stiffly pubescent subapically, anthers dorsifixed, obtuse, 0.8 mm. long; staminodes about 1 mm. long; disc 0.5-0.7 mm. high; gynoecium about 1.5 mm. high and 1.1 mm. wide, ovules 2 on each side of the placentae. ADDITIONAL COLLECTION. Queensland. Cook District: Mt. Bellenden Ker, montane rain forest, 1550 m., Hyland 6569 (CANB, QRS). T. G. Hartley B. P. M. HyLAND HERBARIUM AUSTRALIENSE QUEENSLAND RESEARCH STATION C.S.LR.O. FORESTRY AND TIMBER BUREAU Division oF PLANT INDUSTRY ATHERTON, QUEENSLAND 4883 CANBERRA, A.C.T. 2601 AUSTRALIA AUSTRALIA 248 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 THE MAYACACEAE IN THE SOUTHEASTERN UNITED STATES? Joun W. THIERET MAYACACEAE Kunth, = Akad. Wiss. Berlin Phys. 1840: 93. 1842, Mayaceae,” nom. cons (Bocmoss FAMILY) A monotypic family of herbaceous aquatic monocotyledons distinguished by “mosslike” habit; perfect, hypogynous, regular (actinomorphic) flowers with 2 perianth whorls; 3 stamens; unilocular gynoecium with three parie- tal placentae; loculicidal capsular fruit; and seeds with starchy endosperm, a minute apical embryo, and a “stopper” or “embryostegium” formed from the inner integument of the ovule. Characteristic anatomical features cited by Tomlinson include the lack of hairs except in the leaf axils; the presence of longitudinal air canals in root, stem, and leaf segmented by transverse diaphragms of stellate cells; the absence of mechanical tissues, the reduced stelar tissues being sheathed in both stem and root by an endodermis (thickened in the stem) ; and the absence of secretory elements. The Mayacaceae are of somewhat uncertain taxonomic position. Even _ their familial status has been questioned (Grisebach included them in the Xyridaceae). They share various features with one or more of several families: Centrolepidaceae, Commelinaceae, Eriocaulaceae, Rapateaceae, Restionaceae, and Xyridaceae. A convincing argument for closest relation- ship with Commelinaceae is presented by Hamann (1961). Tomlinson concluded that “it is probable that Mayaca originated from the same stock that has produced Eriocaulaceae, Commelinaceae, and Xyridaceae.” 1. Mayaca Aublet, Hist. Pl. Guiane Franc. 1: 42; 3: pl. 15. 1775. Simple or branched “‘mosslike” aquatic herbs with copiously leafy stems. *Prepared for a generic flora of the southeastern United States, a joint project of the Arnold Arboretum and the Gray Herbarium of Harvard University made possible in the first paper in the series (Jour. Arnold Arb. 39: 296-346, 1958). The area cov- ered includes North and South Carolina, Georgia, Florida, Tennessee, Alabama, Mis- sissippi, Arkansas, and Louisiana. References that I have not seen are marked wit an asterisk I am indebted to Dr. Wood for his careful review of the manuscript and for other aid and to the staff of the Lloyd gn Cincinnati, for help in bibliographic matters. The illustration was drawn by Kar Velmure, under the direction of obertson, from preserved Suet collected by J. D. Ray, C. E. Wood, Jr., C. E, Smith, Jr., and R Eaton in Seminole County, Florida, and from 4 kodathioue taken by C. E. Smith, Jr. at the same time. 1975] THIERET, MAYACACEAE 249 Transverse diaphragms in roots producing in dried specimens the appear- ance of cross-striations. Leaves alternate, spirally arranged, sessile, lanceo- late or linear-lanceolate to filiform, 1-nerved, commonly notched at the apex. Inflorescence of solitary axillary flowers [or of terminal simple um- belliform clusters]. Flowers perfect, regular, hypogynous, with 2 perianth whorls, the pedicels short to long, each bracteate at its base, the bracts (“spathes” or “hypsophylls”’) broad, membranaceous, delicate, shorter than the leaves. Calyx persistent, of 3 distinct, ovate or ovate-lanceolate to lanceolate sepals. Corolla of 3 distinct, ovate to rotund, white to pink petals. Androecium of 3 distinct stamens, these opposite the sepals; fila- ments linear, slightly widened at the base; anthers basifixed, 2(?)- or 4-sporangiate, 2- [or 4-] loculate at anthesis, opening through an apical or subapical pore or slit [or through an apical tube or cup]; pollen 1-sul- persistent; ovary unilocular, with 3 parietal placentae; ovules 6-30, ortho- tropous. Fruit a 3-valved, loculicidal capsule; seeds ovoid or globose, reticulate-scrobiculate, with an apical “stopper” or “embryostegium,” the endosperm starchy, the embryo minute and apical. TyPE species: M. fluviatilis Aublet. “Aboriginal American name,” according to Fernald; perhaps related to the Mayaca or Mahica region of Brazil, according to Lourteig, 1952.) — Bocmoss. A genus of four species (Lourteig, 1952), three of these in tropical and warm-temperate America and one (M. Baumii Giirke) in southern Africa (Angola, Zaire, Zambia). One or two (?) species are found in our area: M. fluviatilis Aublet (including M. Audletii Michx.?) occurs on the Coastal Plain of the southeastern United States (North Carolina to Florida, west to eastern Texas *), in the West Indies and Central America, and in South America, south to Bolivia, northeastern Argentina, and Uruguay. It grows submersed or floating in water or creeping on soil or moss mats at margins of ditches, streams, ponds, lakes, swamps, and b Lourteig, the most recent reviser of dhe genus, recognizes only 4 species, other workers as many as 10. Such differences in taxonomic opinion derive in part from the great phenotypic plasticity of the bogmosses in response to different 2 obi ep conditions. Like m aquatic genera, Mayaca shows great variation between emersed anid Pescered forms. Submersed plants of M. fluviatilis, for ex- *A specimen of Mayaca from Wayne Co., Georgia (W. H. Duncan 7861, GH) bears the statement “ovary usually 3 carpellate (occasionally 4 or 5 carpellate) with usu- ally 3 (occasionally 4 or 5) parietal placentae.” The — of supernumerary flowers in oo seems not to have been noted in liter “Reports of Mayaca from Virginia, dating back to ous, are ascribed by Fernald to re stiri of Lycopodium inundatum var. Bigelovit. Gleason’s report of ange of M. Aubletii may sid be ignored, as may Muenscher’s report of Penn- ng in the range of this specie 250 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Figure 1. Mayaca. a-l, M. fluviatilis (M. Aubletii): a, apical part of flower- ing plant — note ene roots, X 1; b, flower bud with subt ending bract, X 3; ¢, tip of stem with open flower, X 3; d, flower, X 6; e, flower in vertical - i, gynoecium in vertical section, one parietal placenta i in section, one uncut — note orthotropous ovules and stylar canal, 20; j, nearly abe capsule, X 5: k, dehisced cap- su —— remains of placentae on valve, seed, the micropyle up, 2 seed in vertical section, outer in eae hatched horizontally, inner intentaas: forming oe hatched vertically, endosperm evenly el a em- bryo unshaded, : 1975] THIERET, MAYACACEAE 251 ample, tend to have elongate stems with long-tapering, translucent, obviously spirally arranged leaves, while emersed plants generally have short stems with shorter, thicker, very closely imbricated leaves. Sub- mersed forms have a thicker endodermis and a greater amount of aeren- chyma than do emersed forms. Mayaca in the southeastern United States should be studied under controlled conditions to determine whether M. fluviatilis is the only representative of the genus there, as Lourteig con- cluded, or whether M. Aubletii is distinct, as claimed by some. The two taxa have been supposed to be distinguishable on the basis of weak, trail- ing, often submerged stems usually more than 40 cm. long in M. fluviatilis versus tufted or matted emersed stems only 2—20 cm. long in M. Aubletii; leaves 4-20 mm. long vs. 3-5 mm. long; pedicels shorter than the leaves vs. longer than the leaves; and capsules oblong-ellipsoid, nearly twice as long as broad, vs. subglobose or ovoid, nearly as broad as long. At least some of these characteristics are known to be environmentally influenced. Of basic taxonomic value in Mayaca is the variation in the mode of dehiscence of the anthers, which open through an apical or subapical. pore or slit (M. fluviatilis) or through an apical tube (M. longipes, M. Sello- wiana) or cup (M. Baumii). A detailed developmental study of the stamens of M. fluviatilis is needed to determine whether the anthers are indeed 2-sporangiate and thus different from the usual 4-sporangiate condi- tion in Mayaca, a claim made by Horn af Rantzien but denied by Lourteig (1952). Kenneth R. Robertson, in a series of freehand sections made for Ficure 1, found “no evidence of four locules” (C. E. Wood, in litt.). The Mayacaceae are unknown cytologically and embryologically. The broadly ovate bract subtending each pedicel splits longitudinally into halves when it is still relatively young, often even before the pedicel elongates fully. Literature reports of the pedicels of Mayaca being bibracteate at the base derive from misinterpretation. Pollination mechanisms in Mayaca have been little investigated. Uphof (1933) noted no insect visitors to the flowers of M. fluviatilis in Florida and suggested the possibility of anemophily. He reported fruit develop- ment both from aérial and from submersed cleistogamous flowers. The seeds of Mayaca are characterized by an “embryostegium” (or “stopper”) at their micropylar end (FicurE 1, k-). This structure, just distal to the embryo, is apparently developed from the inner integument, the growth of which exceeds that of the outer. The cells of the “stopper” are thinner walled than those of the testa, which is formed from the outer integument. Hamann (1961) suggests that disintegration of the “stopper” may provide a canal for emergence of the seedling, The seeds are dispersed, so far as is known, by water. In one experi- ment (Ludwig), seeds of M. fluviatilis germinated promptly in water after six weeks of drying, but seeds kept submerged had not begun to germinate even after twelve weeks. : Mayaca fluviatilis and perhaps other species of the genus fare poorly in competition with other plants. : ayaca may rarely be used as an aquarium plant. Other than this, the genus has no economic importance. 252 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 REFERENCES: Arzer, A. Leaves of the Farinosae. Bot. Gaz. 74: 80-94. 3 pls. 1922. [ Maya- caceae, 82, pl. 3. fig. 27, A-B; gross anatomy. AUBLET, F. Histoire des plantes de la Guiane Francoise. 4 vols. 392 pls. Lon- don & Paris. 1775. [M. fluviatilis, 1: 42-44; 3: pl. 15.] Barton, H. Mayacacées. Hist. Pl. 13: 230, 231. 1895. BATE- SMITH, E. C. The phenolic constituents of plants and their taxonomic gy Stone II. Monocotyledons. Jour. Linn. Soc. Bot. 60: 325-356. 1968. . Sellowiana, 334; = of leaf hydrolysates. | aS ey ., GJ. D. Hoox KER. Mayaceae. Gen. Pl. 3: 843. 1883. BOuBIER, A. M. Remarques sur Paaboue systématique des Rapateacées et des familles voisines. Bull. Herb. Boiss. 3: 115-120. 1895. [Mayacaceae, 119, 120.] Boutique, R. Mayacaceae. In: Flore du Congo, du Rwanda et du Burundi. Jard. Bot. Natl. Belg. 4 pp. 1971. [M. Baumii Giirke. Mayacaceae. Distributiones arene africanarum, Jard. Bot. Natl. Belg. 3: 90. 31 Dec. 1971. [M. Baum BruccEN, H. As E. van. Mayaca species. of ee Den Haag 28(7): 153, Costas, A. Mayacaceae. In: H. R. Descore, Gen. Sp. Pl. Argentinarum pls. 3-5. 1945. ae especies de plantas interesantes para la flora Uruguaya. Lilloa 20: 237-249. 1949. [M. Vandellii, 240, 241, new to flora of Uruguay.] CorreELL, D. S., & H. B. Corretyt. Aquatic and wetland plants of southwestern United States. xvi + 1777 pp. frontisp. Water Pollution Control Res. Ser., eis Protect. Agency. [Washington, D. C.] 1972. [Mayacaceae, 578, 8.2 ——— & M.C. Jounston. Manual of the vascular plants of Texas. xv + 1881 frontisp. 1 map. Renner, Texas. 1970. [Mayacaceae, 347, 348.] Eouicne, S. Genera plantarum. 2 vols. Vindobonae. 1836-1840. [Mayaca, > 124 ENGLER, - Mayacaceae. Nat. Pflanzenfam. II. 4: 16-18. 188 e Pflanzenwelt Afrikas. II. Charakterpflanzen frets, Vol. 9 in A. ete & O. DrupeE, Die ieee der Erde. 460 pp. Leipzig. 1908. Mayacaceae, 259, 260, fig. 1 ERDTMAN, G. Pollen n morphology ett plant taxonomy. Angiosperms. xii + 539 pp. Wa Itham, Mass. 1952. [Mayacaceae, 266. FERNALD, M. L. Additions to and subtractions from the flora of Virginia. Rho- dora 49: 85-115, 121- ee 145-159, 175-194, 1947. [“Is Mayaca in the ‘Manual Range’?, > PAR: GANDOGER, M. Sertum PTCA novarum. Pars secunda. Bull. Soc. Bot. France 66: 286-307. 1919. [M. longipes & M. caroliniana, spp. nov., 293; types from southeastern United States. ] GeEason, H. A. Notes from the Ohio State Herbarium. IV. eo Nat. 6: 397, 398. 190. [M. Aubletii reported erroneously from Ohio, 3 GRISEBACH, A. Catalogus plantarum Cubensium. iv + 301 pp. ‘ibe 1866. : [Mayaca, 224, included in Xyridaceae. pee ig Eine neue Mayaca-Art aus Afrika. Bot. Jahrb. 31(Beibl. 69): 1, 2. . [M. Baumii described from Benguela.] hae U. Merkmalsbestand und Verwandtschaftsbeziehungen der Farinosae. 1975] THIERET, MAYACACEAE 253 Willdenowia 2: 639-768. 1961. [Mayacaceae, 719, 720, passim; discussion of relationships of family. ] . Weiteres itiber Merkmalsbestand und ee der “Farinosae.” Ibid. 3: 169-207. 1962. [Mayacaceae, 180, 191, . Mayacaceae. Jn: H. Metcuior, ed., A. Engler’s Syllabus doe Pflanzen- familien. ed. 12. 2: 552. fig. 228, N-S. 1964. Harper, R. M. Botanical explorations’t in Georgia during the summer of 1901 — II. Noteworthy species. Bull. Torrey Bot. Club 30: 319-342. 1903. ae notes on differences between M. fluviatilis and M. Aubletii, 324, 325. HEGNAUER, R. Chemotaxonomie der Pflanzen. Band 2. Monocotyledoneae: 540 pp. Basel & Stuttgart. 1963. [Mayacaceae, 361, 362. Horn AF RAntzren, H. Notes on the Mayacaceae of the Regnellian Herbarium in the Riksmuseum, Stockholm. Sv. Bot. Tidskr. 40: 405-424. 1946. [ Monographic study. ] Horcuxiss, N. Underwater and floating-leaved plants of the United States and ada. . S. Dept. Interior, Fish and Wildlife Service, Bureau of Sport Fisheries and Wildlife, Resource Publ. 44. 124 pp. 1967. [Mayaca, 70. ] HuTcHINSON, J. The families of flowering plants. II. Monocotyledons. xiv + 3 = London. 1934. [Mayacaceae, 59-61, map. | Jones, S. B., Jr. Mississippi flora. I. Monocotyledon families with aquatic or wetland species. Gulf Res. Rep. 4: 357-379. 1974. [Mayacaceae, 370, 371, Keen € i Ueber Mayaca Aubl. Abh. Akad. Wiss. Berlin Phys. 1840: 91-- 94. yaceae Kth. Enumeratio Plantarum 4: 30-33. 1843 San L. A. Pollen morphology and phylogeny of the peo (In Russian.) Trudy Bot. Inst. Komarova Acad. Nauk. SSSR Syst. (Acta Inst. Bot. Acad. Sci. URSS. 1. Syst.) 7: 163-262. 1948. (Maya ceae, 239, 240; descriptions of pollen of M. fluviatilis and M. Kunthii.| Lanjouw, J. Mayacaceae. Jn: A. Putte, Fl. Suriname 1(1): sath: 1938. LINDLEY, - fy vegetable kingdom. lxviii + 908 pp. London. 1846. [Maya- ceae, LourTEIc, ws Mayacaceae. Not. Syst. Paris 14: 234-248. 1952. [Revision; 4 species recognized. Distribution géographique des Mayacacées. Compt. Rend. Soc. Bio- géogr. 323/325: 31-35. maps. Flora del Uruguay. III. Mayacaceae, Zygophyllaceae, Celastraceae, seh Primulaceae. Mus. Nac. Hist. Nat. Montevideo. 38 pp. 1963. [Mayacaceae, 3; 25 orecgp ie of M. Sellowiana and M. fluviatilis).] . Maiacaceas. Im: P. R. Retrz, ed., Fl. Illus. Catarinense. 9 pp. 1965. ur Mayaca pees ( Mayacaceae). Taxon 17: 742, 743. 1968. [No- menclatural note. ] . Mayacaceae. In: T. Lasser, ed., Fl. Venezuela 3(1): 1-7. 1971. : Lupwic, F. Ueber durch Austrocknen bedingte Keimfahigkeit der Samen einiger asserpflanzen. Biol. Centralbl. 6: 299, 300. 1886. Macsripe, J. F. Mayacaceae. Jn: Flora of Peru. Publ. Field Mus. Nat. Hist. Bot. 13: 487. 1936. [M. Endlicheri Poepp. ex Seubert. ] Martin, A. C. The comparative internal morphology of seeds. Am. Midl. Nat. 36: 513-660. 1946. [Mayacaceae, 533.] MEIssNeEr, C. Mayaca Vandellii Schott et Endl. Gartenflora 74: 169, 170. 1925. Mirset, M. Examen de la division des végétaux en endorhizes et exorhizes. 254 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 56 Ann. Mus. Hist. Nat. Paris 16: coe 1810. [Indifferent drawing of seed and embryo of M. fluviatilis, pl. 1 MUuENSCHER, W. C. Aquatic plants of the United States. x + 374 pp. Ithaca, N. Y. 1944. [Mayacaceae, 189-191, PILcER, R. “hace Nat. Pflanzenfam. - ms 15a: 33-35. 1930. Poutsen, V. A. Anatomiske studier over Mayaca Aubl. (In Danish; French s. Kongel. Danske Vidensk. Selsk. Forh. Medlemners Ar- bejder 1886(Meddel.): 85-100. pls. 3-7. 1886; 1886(Résumé): xxi-xxiv. 1887. [M. lagoensis Warming and M. Vandellii Schott & Endl. ] Ricxetr, H. W. Wildflowers of the United States. Vol. 2. The Southeastern States. Part 1. x + 322 pp. New York. 1966. [Mayaca, 64, pl. 19.] Russy, H. H. Descriptions of new genera and species of plants collected on the Mulford Biological Exploration of the Amazon Valley, 1921-1922. Mem. N. Y. Bot. Gard. 7: 205-387. 1927. [M. boliviana, sp. nov., 211, 212.] SCHLEIDEN, M. J. Grundziige der Wissenschaftlichen Botanik. ed. 4. xxiv + 710 pp. Leipzig. 1861. [M. fluviatilis, 189; reports absence of vessels. ] SCHNIZLEIN, A. Iconographia familiarum naturalium regni vegetabilis. Vol. 1: Ordines 1-75. Cryptogamae et Monocotyleae. Bonn. 1843-1846. [Maya- ceae, pl. 47*, + 2 unnumbered pages of text. | SCULTHORPE, C. D. The biology of aquatic vascular plants. xviii + 610 pp. London. 1967. [See pp. 20, 23, 280, 316, 317, 324, 372, 374. SEUBERT, M. Mayaceae. In: C. F. P. VON Martius, Fl. Brasil. 3(1): [col.]225- $32. O30. 1855. SmaLL, J. K. Flora of the southeastern United States. xii + 1370 pp. New SMITH, A. he meagre N. Am. Fl. 19: 1, 1937. SOLEREDER, H., & F. J. MEYER. Mayacaceae. a Systematische Anatomie der Monokotyledonen, Heft 4: 34-36. Berlin. 1929. STANDLEY, P, C., & J. A. STEYERMARK. Mayacaceae. In: Flora of Guatemala. Fieldiana Bot. 24(1): 369, 370. fig. 63. 1958. STepBins, G. L., & G. S. Kuusw. Variation in the organization of the stomatal ae in. the leaf epidermis of monocotyledons and its bearing on their phylogeny. Am. Jour. Bot. 48: 51-59. 1961. [Mayacaceae, 54, table g: included among families with two subsidiary cells as the predominant STELLFELD, C. Mayaca — hee Stellfeld: nova combinacao. Tribuna Farmacéut. 35(1/2): 1, 196 — J. Encyclopedia sr water cn 368 pp. T. F. H. Publications, Jer- y City, N. J. 1967. [M. Vandellii, 264, fig. 147 Chee M. P. van. Structure de la racine et disposition des radicelles dans les Centrolépidées, Eriocaulées, Joncées, Mayacées et Xyridées. Jour. Bot. Morot 1: 305-315. 1887. [Mayacaceae, a12; 313.3 ee P. B. Commelinales-Zingiberales. In: C. R. MeTCALFE, ed., Anat- y of Monocotyledons. Vol. 3. xx + 446 pp. Clarendon Press, Oxford. 1969. [ Mayacaceae, 83-91. Utericn, E. Ueber die Familie Mayacaceae. Verh. Bot. Ver. Brandenb. 71: 56, 57. 1929. [Miscellaneous notes. Upuor, J. C. T. The physiological anatomy of Mayaca fluviatilis. Ann. Bot. 38: 389-393. 1924 . Die Bliitenbiologie von Mayaca fluviatilis Aubl. Ber. Deutsch. Bot. Ges. 51: 78-85. 1933. 1975] THIERET, MAYACACEAE 255 VESTER, H. Mayacaceae. Jn: Die Areale und Arealtypen der Angiospermen- Familien. Bot. Archiv 41: 526. fig. 238 (map). 1940.* Wenpt, A. Die Aquarienpflanzen in Wort und Bild. 321 pp. in 16 parts. Alfred Kernen Verlag, Stuttgart. 1952. [Mayacaceae, 253, 254.] Woopson, R. E., Jr., & R. W. ScHEeRy. Mayacaceae. Ju: Flora of Panama. Ann. Missouri Bot. Gard. 31: 62, 63. 1944 ZIEGENSPECK, H. Das Vorkommen von 6] in den Stomata der Monocotyledonen d die Bedeutung des konstitutionalen Vorkommens fiir die Systematik derselben. Repert. Spec. Nov. 53: 151-173. 1944, [Mayacaceae, 158, 170.] DEPARTMENT OF BIOLOGICAL SCIENCES NorTHERN KENTUCKY STATE COLLEGE HIGHLAND HEIGHTS, KENTUCKY 41076 256 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 DEVELOPMENT OF THE DIGITATELY DECOMPOUND LEAF IN CUSSONIA SPICATA (ARALIACEAE) W. F. REYNEKE AND H. P. VAN DER SCHIJFF EVEN THOUGH LEAF FoRM is one of the earliest and most common char- acteristics used in descriptions of plants, the interpretation of the leaf form in most species of Cussonia has still to be clarified. These include South African Cussonia species such as C. spicata Thunb., C. sphaeroce- phala Strey, C. arenicola Strey, C. nicholsonii Strey, C. zuluensis Strey, and C. gamtoosensis Strey. In all six species the leaves have long petioles and are digitately com- pound, with 5 to 13 digits radiating from a single point, the compacted rachis. These digits are homologous to the pinnae of a pinnately compound leaf. Since each digit is further once or several times vertebrately divided, the entire leaf is thus digitately decompound. At the present time interpretations of what the parts of each digit represent vary. For example, Strey (1973) refers to an individual digit as a “vertebrate leaflet” consisting of pinnules arranged along a winged rachilla. In contrast, Van der Schijff (1971) divides each digit (pinna) into leaflets of the first, second, and third order. In order to clarify this problem, the external morphology of the leaf of Cussonia spicata was studied at progressive stages of development. Since the leaf form of C. spicata varies considerably, the form that appeared to be the most complex was examined. This would make interpretation of less complex leaf forms relatively easy. MATERIALS AND METHODS Leaves of Cussonia spicata are formed in clusters at the apex of branches during a growth flush. As a result, all stages of leaf development are present in a single actively growing shoot apex. Such shoot apices were fixed in formalin-acetic-acid-alcohol and examined under a dissection microscope. All apices were collected from one plant growing in the Loskop Dam Nature Reserve in the Northern Transvaal (W. F. Reyneke, 280), where specimens of this plant occur in quite large numbers. The leaves of these plants differ from those of other members of C. spicata in that they have a considerably more complex form and are gray-green in contrast to the dark green leaves of other plants in the same and other localities. OBSERVATIONS The leaf development of Cussonia spicata can be divided into two phases: (1) the development of the digitately decompound leaf in its entirety and (2) the development of an individual vertebrately (de-)compound digit. 1975] REYNEKE & VAN DER SCHIJFF, CUSSONIA 257 DEVELOPMENT OF THE DIGITATELY DECOMPOUND LEAF Following the initiation of the pyramidal leaf primordium (FIGURE 1A), limited apical growth occurs while the two stipular primordia differentiate laterally. At this stage the leaf primordium is approximately 230 pm. long (Ficure 1B) and comprises a median petiolar-midrib region (Fos- ter, 1936) and two lateral stipular primordia. The stipular primordia develop rapidly, so that at a very early stage they are already very much wider and longer than the petiolar-midrib region. During their development the young stipules extend toward each other behind the petiolar-midrib region, and the leaf axis then lies against the stipules (FicurE 1C—G) As in the leaf development of most Angiospermae, the apex (tip) of the petiolar-midrib region matures very early, and when the leaf axis is ap- proximately 300 um. long, the first digit primordia have already been initiated (Ficure 1C). The initiation of the digit primordia resembles that of the pinnae in most pinnately compound leaves, which arise basipet- ally as a result of localized marginal growth. Since the future rachis of the digitately decompound leaf is reduced or compacted in Cussonia spicata, the digit primordia appear to emerge at the same level (Ficure 1D). A single apical digit primordium (I), which is homologous with the apical leaflet of imparipinnate leaves, develops first. This is followed by two lateral digit primordia (IT, IJ"), and the subsequent pairs of lateral digit primordia (III, III', IV, IV}, etc.) are formed on either side of the pre- ceding pair in a similar manner. Eventually this leads to an uneven num- ber of digits in a mature leaf (FIGURE 4), with the single apical digit (1) the oldest and the most lateral pair the youngest. The apical digit (I) and the first pair of lateral digits (II and II’) usually are at maturity the most complex, while the digits most laterally situated are less complex. In some leaf forms of Cussonia spicata, the most lateral digits can even be simple. Immediately after their initiation, the first five digit primordia lie in the same vertical plane, but as the leaf matures, more digits are initiated an- teriorly on either side of the first five digit primordia. The young leaf then eventually has its digits arranged in a semicircle around the reduced rachis, with the adaxial surfaces of the digits facing one another. It is because of this arrangement that the first differentiated digit is often re- ferred to as the posterior or central digit and the last differentiated digits as the anterior or most lateral digits. ; The further development of a single digit was studied using the posterior digit from leaves of different ages. DEVELOPMENT OF THE VERTEBRATELY (DE-) COMPOUND DIGIT Once the digit primordium has reached a length of about 0.5 mm. (Ficure 1F), it elongates rapidly. Apical growth here is also of short duration, and the first pair of lateral leaflets soon appear as rod- shaped structures on the adaxial leaf surface (FicurE 1G). Their appearance is 258 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 FE Sieh ee ye A-G. Different stages in the dev tely decom- ae ae: of Cussonia spicata pele surfa che “initio “i ior gt midal leaf primordium (Ip); B, differentiation of two stipular pri os (s) on either side of the petiolar-midrib region (pe); C, initiation of digit primordia at the apex of the petiolar-midrib region. D-G. Further development of the young stipules and digit primordia @; I, II, II’, II, and IIE show the sequence in which the rife nitiate. on erent stages in ~ dkny aiging He a eee digit (adaxial ace): a, = rculat S tion n = articulation no. 3: pe = apical nat of dei raichortiaee: o re Se st ak pair of first gene = ration at articulation no. 1; pl = uae leaflet pair at articulation no. 2; pi = third leaflet pair at articulation no. 3. 1975] REYNEKE & VAN DER SCHIJFF, CUSSONIA 259 3cm Ficure 2. A-D. Different stages in the — 3 a digit of —— sieht ‘al = apical part of digit primordium; c = constri iction; p} st leaflet pair of first generation; PS = second cst pair of first generation; p, = third leaflet pair of first gecieratiins: pe = first leaflet pair of second gener- ation; a second leaflet pair of second generation; Pe = third leaflet pair of second generation. 260 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 followed by the basipetal differentiation of an additional one or two pairs of leaflet primordia (Ficure 1H). These lateral pairs of leaflets on the digit are called leaflets of the first generation and are able to subdivide by forming constrictions (FIcuRE 2D). The apical part of the digit primor- dium above the first pair of lateral leaflets gives rise to an apical leaflet which can also constrict (FIGURE 2C). Those parts where the different pairs of lateral leaflets of the first gene- ration arise basipetally are termed articulations 1, 2, and 3, i.e., leaflet pair no. I arises at articulation 1 and pair no. II arises at articulation 2, etc. (Ficure 1K). If the apical part of the digit primordium does constrict, the articulation is called no. 4 (Ficure 3) and a pair of lateral leaflets may even originate here. Although only four articulations have been observed during this study, there may be up to five in some digits (Strey, 1973). During subsequent development a rapid elongation of the rachilla and an increase in size of the apical and lateral leaflet primordia take place (Ficure 1I-K), together with a flattening of these structures. When the young leaflet reaches a length of approximately 1 cm., the lateral leaflets of the second generation appear and develop at the articulations, with the leaflets directly proximal to those of the first generation, and according to Strey (1973), leaflets of a third generation may even develop (FIGURE 2A-D). Similar to the leaflets of the first generation, these second gene- ration leaflets arise in basipetal succession at articulations 1, 2, and 3. In contrast to the leaflets of the first generation, which arise as distinctly rod-shaped primordia, those of the second generation appear to have been formed by a prominent widening of the rachilla directly below the arti- culations (Ficure 2C). At a later stage of development individual leaflets originate from these widened parts (Ficure 2D). At some articula- tions these leaflets of the second generation may not constrict at all, may constrict incompletely, or may not even develop. Leaves have also been observed on which only one of a possible pair of leaflets develops. The development of leaflets of the first and second generations is ac- companied by an elongation and broadening of -the digit axis and eventu- ally results in a winged rachilla. These wings, which extend along the entire length of the digit, are not only between articulations but are also beyond the first and below the most basal articulations (FIcuRE 3). In most cases the wings appear V-shaped, with the broadest part directly below the articulations. The wings themselves can sometimes also form constrictions (FicurRE 3). CONCLUSION AND SUMMARY According to these observations, it is apparent that the development of the digitately decompound leaf of Cussonia spicata corresponds, in general principle, to that of a pinnately compound leaf. In Cussonia, how- ever, apical growth of the petiolar-midrib region ceases at a very eatly stage. Consequently, the digits that develop on this axis emerge at the 1975] REYNEKE & VAN DER SCHIJFF, CUSSONIA 1 Ficure 3. Fully developed digit: a, = articulation no. 1; & = articulation no. 2; as = articulation no. 3; a, = articulation no. 4; al = apical leaflet; pi = first leaflet pair of first generation; P} second leaflet pair of first generation; Pp} = third leaflet pair of first generation; p? = first leaflet pair of second gen- second leaflet pair of second generation; P; = third — pair winged rachilla; wp = winged = petiolule; r = eration; Pp; = of second generation : ot ul _petiolule. 262 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 same level, thus resulting in a palmate arrangement of digits about the reduced rachis (Ficure 4). AY M - S\ a ee Wi Kf \ 24 ic) tT? ° = =o = oO be ist] Os 3 ° be Qu oO 3 ce re, i. ° S ry Q. oO = = ° a= = gg co & 3 re) bs n & 3. Cladocolea clandestina (Martius) Kuijt, comb. nov. FIGURE 6. Loranthus clandestinus Martius in Schultes & Schultes, Syst. Ms 7: 96. 1829. Phthirusa clandestina (Martius) Martius, Flora 13: 110. 1830 Type: Martius (see below). Young leafy stems quadrangular, smooth, green; older stems terete, developing longitudinal lenticels which are often in long series. Leaves regularly decussate, 2.5 1.5 cm. or slightly smaller, obovate to broadly elliptical, with rounded apex and acute base; petiole ca. 1 X 1 mm.; vena- tion pinnate but obscure, with two large lateral veins at base of blade. Inflorescence with flowers single or in threes (two laterals in axils of scale leaves beneath primary, median flower), in the axils of foliage leaves, margin and back of scale leaves covered with short hairs. Flowers x I mm., calyculus glabrous but with fringed margin, the projecting hairs mot- tled with brown; petals 4, slightly more than 1 mm. long, each with papil- late tip but otherwise glabrous; anthers on extremely short filaments, less than 1 mm. long, placed at uniform heights on the middle of the petal; petals differing only slightly in width, otherwise both petals and stamens monomorphic; anther connective projecting slightly; pollen broadly tri- angular, smooth, with very faint triradiate marking; style 1 mm. long, somewhat quadrangular, base very heavy; stigma Me conspicuously papil- late, dark-colored; nectary rather smooth. Fruit 2 x 4 mm., ellipsoid, dark-colored ( ?). This species is the type species of Phthirusa Martius, a generic name recently superseded by Phthirusa Eichler (Kuijt, in press). era are clearly with Cladocolea inconspicua, as already suggested by Eichle (1868, p. 67). There is no real evidence for the floral dimorphism described by oe the two “forms” described by Eichler may represent two stages in maturity. Brazil. Prov, Rio pE JANEIRO: Glaziou 1429 (F), Martius (m, holotype of Lo- 282 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ranthus Eke this specimen very faithfully drawn in Eichler, Flora Brasil. 68).° 5(2): pl. 18 4. Cladocolea coyucae Kuijt, sp. nov. Ficures 7 & 8. Type: Hinton 3958 (see below). Gracilis, dioecia?, parce ramosa, sympodialis; caules ut videtur sine ra- dicibus, teretes, ieveniles breviter albo-pubescentes, vetustiores lenticellis manifestis vel fissuris epidermalibus longis. Folia alterna, solum in innova- tionibus vertentibus, oblanceolata, basi longe attenuata, 35 < 8 mm. In- florescentiae singulares in axillis foliarum ad ramos novellos, subsessiles vel pedunculis ad 10 mm. longis; flores 5-7, ad apicem congesti, foliis squami- formibus parvis suffulti; ca. 3 mm. longi, tetrameri; antherae monomorphi- cae vel submonomorphicae connectivum obtusum. Stylus medio semel conspicue contortus. Fructus ca. 5 * 3 mm. Plant possibly dioecious, slender, sparsely branched, with sympodial growth; twigs straight, terete, apparently rootless, the young growth with very short, stiff, white epidermal hairs; year-old stems with longitudinal or roundish lenticels or long epidermal cracks. Leaves alternate, occurring only on current growth, up to 35 & 8 mm., oblanceolate with fairly blunt apiculate apex and long, tapering base; petiole very short or lacking; vena- tion pinnate, the midrib running into apex. Inflorescence one per leaf axil on current growth, only occasional on year-old growth, leafless, pedun- cles as long as 10 mm. but sometimes much shorter, rarely nearly lacking; flowers 5-7, crowded at apex, subtended by small scale leaves, either paired or alternate, terminal flower always present. Flowers about 3 mm. long, 4-merous; anthers monomorphic or nearly so, 4-loculate, nearly ses- sile; filament buttress thick, the free upper part continuing in an extreme- ly slender, short filament; connective blunt; ovary 1 < 1 mm., somewhat frayed at calyculus; style with a single, prominent contortion in the mid- dle; stigma well differentiated, capitate, with papillar surface, sometimes lobed, reaching above pollen sacs. Fruit 5 x 3 mm., somewhat obovate, smooth: embryo ca. 3 mm. long, clavate, cotyledons 2 mm. long. I am not completely satisfied that Hinton 4777 is the staminate plant of this species or even that the species is dioecious. Hinton 3958 is a fruit- bearing plant, and its flowers have apparently fully matured anthers; yet I have not been able to find pollen. Hinton 6688 is also fruit-bearing but has clearly degenerate anthers. As these conditions at least theoretically could coexist in one species, and as some very striking and close similari- ties exist between these specimens, they are treated together provisionally. Mexico. GUERRERO. Distr. Coyuca: Coyuca, on a chirimo, Hinton 5554 (K, * The following tie is cited in Rizzini, Rodriguésia 28-29: 130. 1956. PROV Rio DE JANEIRO: Tijuca, Brade 10461; Corrocado, Schwacke 1411; Prov. Aracoas: Maceid, Gardner jens, Two further collections, by Mikan and meas! yee from Prov. Rio de Janeiro, are cited by Eichler (loc. cit.) but have not been 1975] KUIJT, CLADOCOLEA (LORAN THACEAE) 283 FIGURE 7, Cladocolea coyucae: a, habit (Hinton 3958, kK); b, inflorescence, Same collection; c, inflorescence, pistillate (Hinton 6688, K); d, inflorescence of sessile type (Hinton 4777, G); e-g, inflorescence details of same collection. MICH, NY, Us); Santa Barbara, Hinton 6688 (K, MICH, NY, UC, US). Mexico. Distr. Temascaltepec: Bejucos, on a guaje, 610 m., Hinton 3958 (x, holotype of C. coyucae; MICH, NY, UC, US, isotypes); Bejucos, on a brazil, Hinton 4777 (r, G, K, MICH, NY, P, S, UC, US, Ww). MicHoacAN: Tancitaro region, arid slopes above Apatzingan, on Thevetia, 2000 ft., Leavenworth & Hoogstraal 1513* (x, *The Leavenworth and Hoogstraal specimen is sterile, and it is assigned to C. coyu- ae on the basis of vegetative similarity only. The Purpus collection is a broad- leaved plant with hermaphroditic flowers, and its placement here is provisional. 284 6088, ye ton bf JOURNAL OF THE eee “and § ARNOLD ARBORETUM [vou. 56 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 285 GH, MICH, MO, NY). PueBLa: Coxcatlan, on Heliocarpus, Purpus 4191 (xm, F, UC 5. Cladocolea cupulata Kuijt, sp. nov. FIGURE 9. Type: McVaugh 21127 (see below). Dioecia, pendula, sympodialis; rami vetustiores scabri. Folia decus- sata, pendula, coriacea, taeniata vel falcata, ad 140 * 10 mm., apice b-f, McVaugh 23273; eg MICH): a, habit, pistillate plant in it; b, infructescence, three fruits removed ; a same, Bess moved and lowest cupule cut aig Y (broken line) ; d, gynoecium; e, petal and abarted anther; f, mature embry URE 9. Cladocolea aoe (a, McVaugh 21127; 286 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 basique acuta. Inflorescentia pistillata brevis validaque, axis 3-5 m longa, floribus binis ad quaternis, structuris cupulatis insidentibus. Flos femineus fere 8 mm. longus; stylus rectus, 4.5 mm. longus; stigma capita- tum; staminodia magna. Fructus ovoideus, 10 & 7 mm., cupula accreta suffultus. A dioecious, pendent, rather coarse mistletoe 50—70 cm. long, with sym- es opposite, up to 140 & 10 mm., rather thick, pendent, ribbon-shaped, often somewhat falcate, tapering gradually into an acute apex and base; petiole lacking; leaf margin thickened; venation obscure except for several paral- lel veins near base. Pistillate inflorescence short and stout, 1-3 per axil of persistent leaf on year-old growth, developing only after full expansion of branches; axis 3-5 mm. long with 2—4 flowers, each flower in a cuplike structure, the cups decussate. Pistillate flowers nearly 8 mm. long, prob- ably hexamerous; petals very slender, with large staminodia which have clearly discernible filaments; ovary 2 mm. long, calyculus somewhat den- tate; style straight, 4.5 mm. long, almost as long as the petals; stigma ca- pitate, well differentiated. Fruit 10 * 7 mm., ovoid, smooth, the enlarged, subtending cupule usually rupturing in two places; embryo 4.5 mm. long, the two cotyledons 3.5 1.5 mm., very flat, rather blunt-tipped. Staminate plant unknown. Cladocolea cupulata is an extremely clearly marked species with a puzzling inflorescence morphology. The peduncle is a saddlelike structure, holding the four flowers in bays. I have not been able to identify the bracts which one would expect below the flowers; however, between the upper two cupules and alternating with them are two triangular organs which may be leaflike. The young cupules may consist of a bract. The inflorescence as a whole, therefore, is an indeterminate one. A staminate plant is unfortunately not available. C. cupulata would seem to be related to C. grahami and C. pringlei. xico. JALISCO: pine forests on rolling mountain summits 6 mi. NW 0 fe os on Pinus, 1700 m., McVaugh 21127 (micu, holotype of C. ss pine-oak forest, hills 7-8 km. NW of Cuautla, on Pinus, 1850 m., McVaug 23273 (MICH). 6. Cladocolea dimorpha Kuijt, sp. nov. Ficure 10. Type: Smith, Peterson, & Tejeda 4127. Mexico. Pursia: Tehuacan area, Leucho Diego, S of Coxcatlin on Cerro Ajuereado and in the adjacent valley, 1000-1800 m. (c, holotype; F, Ny, Us, isotypes). Sympodialis, caules ee ut videtur sine radicibus, recti, isc ca- pillis brevibus remotis. Folia alterna, primaria silun in innovation- ibus vertentibus, 20 < 30 mm. vel minora, lanceolata, se acutus, apiculo parvo; folia secundaria paulo minora, solum ad ramos anniculos. Inflorescentiae primariae permanenter orientes ad innovationes vertentes, 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 287 singulae axillares, simpliciter dichasiales; flores sessiles, laterales bracteis persistentibus; inflorescentiae secundariae ad ramos anniculos; folia bina ad quaterna ad partem inferiorem pedunculi, flores 3—5 in capitulum par- FicurE 10. Cladocolea dimorpha (Smith, Peterson, & Tejeda 4127, G): ws diagrammatic representation of the distribution of primary gages ap rent growth) and secondary inflorescences (year-old growth); b, wep a florescence and axillant leaf; c, secondary inflorescence, with leaf scar below; d, flower, longitudinal section. 288 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 vum congesti. Flos 3 & 1 mm.; petala 4; antherae petalaque monomor- phica. Stylus ipsum supra antheras acute contortus, praeterea plus minusve rectus. A branched plant at least 40 cm. long, with sympodial growth; stems terete, straight, with widely spaced, short hairs when young, but from second season smooth, light brown, and with many lenticels; apparently without roots. Leaves alternate; primary leaves only on current growth, 20 & 30 mm. or less, glabrous but with somewhat granular surface, nar- rowly lanceolate, the apex acute with small tooth and the base narrow and tapering; discrete petiole absent; secondary leaves along year-old stems, similar but smaller, more oblanceolate, and with more rounded apex. Inflorescences of two types: (1) primary, developing continuously on current growth, one in the axil of all except the first several leaves of a twig, being simple dichasia of 3 sessile flowers, the 2 lateral flowers each subtended by a slightly shorter lanceolate bract, and (2) secondary, on year-old growth only, leaving craters; 2-4 leaves on lower part, one often at very base, the 3 to 5 flowers in a small capitulum, the lowest flow- ers subtended by foliar or smaller bracts. Flowers 3 1 mm. in bud; anthers and petals monomorphic, the 4 petals seemingly sessile but attached nearly half-way up the anther by a very short and slender filament; fila- ment cushion or ridge below anther; pollen sacs 4, the inner ones half the size of the outer ones; connective not extended; pollen trilobate, lack- ing obvious triradiate groove or triangle; ovary ca. 24 mm. long, calyculus slightly dentate; style reaching to above the anthers, more or less straight up to that point but then bent sharply; stigma well developed, capitate, minutely papillate; nectary ring smooth. Although no fruits are present on the single known collection, the well differentiated style, stigma, and anthers suggest that the flowers of Clado- colea dimorpha are hermaphroditic. If this is true, a degree of affinity to C. inconspicua and C. inorna would seem to be indicated; both of these species also have 4-partite flowers with monomorphic stamens, as does C. dimorpha, The only other Cladocolea with dimorphic inflorescences is C. oligantha, where the differences are less striking than in C. dimorpha. 7. Cladocolea glauca Kuijt, sp. nov. FicureE 11. Type: Arséne 1749/2 (see below). Tenuis, volubilis, glabra, dioecia; rami vetustiores radices gerentes. Folia primaria glauca, lanceolata, ad 25 7 mm.; folia secundaria bina in inflorescentia, oblanceolata-obovata. Inflorescentia ad ramos anniculos, spicam breviter pedunculatam, vulgo solitariam efformans; bracteae cadu- cae. Flores in inflorescentia ca. 6, 5 mm. longi, hexameri; stamitea dimor- phica; stylus florum pistillatorum valde flexuosus. Fructus 4 x 5 mm. Dioecious, slender, completely glabrous plants with voluble twigs; bark light brown, smooth, later peeling off in long, gray patches revealing brown, 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 289 FIGURE 11. oe Saini a, habit, _staminate plant (Arséne 1749/2, BM); longitudina section, same b, inflorescence, same collection; c, staminate flower, antes: collection: d, style of pst flower (Nicolas s.n., BM); e, two infruct one leafless, same collection 290 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 reticulate, subdermal tissue; some stem roots on year-old and older growth; axillary cushions nearly indistinguishable, but craters on older twigs fairly conspicuous. Primary leaves apparently dropped at end of first growing season or soon after, up to < 7 mm., glaucous, lanceolate, with acute apex and base; petiole ca. 2 mm. long; venation pinnate but only mid- vein visible; secondary leaves oblanceolate to obovate, with obtuse apex and acute base; petiole 1 1 mm., usually 2 leaves per spike; both pri- mary and secondary leaves with narrow, leathery margin. Inflorescences only on year-old wood and (few) on two-year-old wood: staminate inflo- rescence a pedunculate (1-2 mm.) spike, solitary, the foliage leaves com- pletely basal and seemingly emerging from crater; pistillate inflorescence resembling staminate, but peduncles up to 5 mm. long, at least 1 mm. thick, a superposed, second spike sometimes developing; in both cases flowers ca. 6 per spike, sessile, and subtended by caducous scalelike bracts, spikes determinate. Staminate flowers: mature bud ca. 5 mm. long, obovate; petals 6, with hooded apex; anthers 1.5 mm. long, inserted 14 or 7% the distance from the base (stamens dimorphic), filament very short or lack- ing; connective not projecting, the 2 outer pollen sacs slightly longer than the 2 inner ones; the ovary 1 mm. thick and slightly longer, calyculus ir- regularly dentate to smooth; style reaching to middle of upper anthers, distal half much convoluted; stigma not differentiated. Pistillate flowers: petals 6, 3 mm. long; style doubled back upon itself for nearly its entire length; stigma capitate, well differentiated, papillate. Fruit ca. 4 5 mm., smooth, ellipsoid A rather small species related to both Cladocolea tehuacanensis and C. pedicellata, differing from the former in its fleshy, broad leaves and short spikes and flowers, and from most of the latter in its sessile, small flowers which are obtuse in bud and have a much convoluted style. The material available, as in many Cladocolea species, is unfortunately inadequate. Thus I cannot be certain that the superposed pistillate spikes have any foliar leaves; it seems to me that they are leafless. The fruits drawn are not quite mature. xico. PUEBLA: Huejotzingo, near hig on Crataegus, 2900 m., Arsene 1749(2) (us, holotype of C. glauca; BM, Gu, Nv, isotypes); vicinity of Puebla, ee Tepoxuchil, 2330 m., Ate 2268 (us); Tepoxuchil, on Acacia, Nicolas BM 8. Cladocolea gracilis Kuijt, sp. nov. FicurE 12. Type: Rzedowski 17518 (see below). Dioecia, glabra, brite rami tenues, teretes. Folia alterna, linearia, 10-20 X 1-2 mm., impetiolata. Inflorescentia determinata, ad partes anniculos vel eae basi foliis ca. 6; pistillata axi gracil- lima attenuata, fructifera ad 20 mm. longa, floribus 3-4: staminata brevior, floribus ad 6. Flos hexamerus, ca. 5 mm. longus; stylus floris pistillati valde convolutus, staminati subrectus. Staminodia floris pistillati lori- 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 291 habit, pistillate plant (Rzedowski 17518, ol scat); b, pistillate inflorescence © (Reedowst 22618, MICH); C, pistillate flower, ongitudinal section, same collection; d, staminate idence ence, same collection; €, staminate flower, same perros -£ fruit (Rzedowski 17518, MICH). 292 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 formia; antherae floris staminati planis duobus, inaequalibus. Fructus ovoideus, 6 X 4 mm Dioecious, completely glabrous mistletoe about 1 m. in size, pendent, with sympodial growth; branches rather straight, terete, brown, dotted with small lenticels above in the first season, with occasional stem roots on older growth and larger roots at base of plant; craters discernible but not striking. Leaves alternate, with primary leaves only on current growth, 10-20 & 1-2 mm., linear, with acute or somewhat rounded apex; petiole absent. Inflorescences on one-year-old growth and older, with up to half a dozen secondary leaves crowded at the base of the peduncle: pistillate inflorescence with very slender and elongated axis up to 15 mm. long at anthesis, reaching up to 20 mm. in fruit; flowers 3-4, ebracteolate, sessile in axils of acicular bracts spaced along upper half of inflorescence, except for the very prominent terminal flower, which is sessile in a small cuplike structure at the tip of a 2-4 mm. pedicel; staminate inflorescence shorter, with up to 6 flowers, the bracts larger, sometimes almost foliaceous. Stam- inate flowers yellow, hexamerous, 4.5 X 1 mm., the bud oblong; anthers ses- sile or nearly so, at two different heights, both above middle of petal but of the same shape; filament buttress prominent; pollen trilobate, smooth, with faint triradiate groove but no triangular prominence; ovary 0.5 mm. long; style more or less straight; stigma undifferentiated. Pistillate flowers greenish, hexamerous, nearly 5 mm. long, very slender; petals very narrow, ca. 3.5 mm. long, staminodia narrow, strap-shaped, reaching the petal tips, their filaments often twisted at anthesis; ovary less than 1 X 1 mm., calyculus smooth; style ca. 2.5 mm. long, strongly convoluted in upper 7; stigma capitate, somewhat pointed and lobed, with tubercular, dark sur- face reaching nearly to the petal tips. Fruit 6 < 4 mm., smooth, ovoid, but with rather blunt apex. This extraordinary species at first sight reminds one of a larch because of its very narrow leaves and its clearly separated long shoots and short shoots, the latter being reproductive. Mexico. GUERRERO: road above Canyon de Zopilote 8 km. E of Xochipala on way to Filo del Caballo from Milpillas, 850 m., Breedlove 35998 (cas); Canyon de Zopilote, near Milpillas, municipality of Zumpango del Rio, on Randia, 750 m., Rzedowski 22618 (MIcH). JALIsco: municipality of Tecalitlan, oe Gallardo, 10 km. NW of Tepalcatepec (Michoacan), on Colubrina, 500 m., Rzedowskt (F, MO); old lava flow 4 mi. NW of Apatzingén, 300 m., McVaugh 17937 (MIcH); Tepalcatepec, flat areas near settlement, on Podopterus mexicanus, 400 m., Rze- dowski 16623 (MIcH). 9. Cladocolea Fetes (Bentham) Van Tieghem, ae Soc. Bot. France 42: 167. 1895. 1cuRES 13 & 14. Loranthus grahami Bentham, Plantae Hartweg. 62, 63. 1845. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 293 Figure 13. Cladoc grahami: a, habit, staminate plant n (Pringle _ P); b, fruit and embryo crake 235, nfo 6; pollen grain (Pringle 698 294 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 — grahami (Bentham) Standley, Contr. U. S. Natl. Herb. 20(6): — grahami — Engler in Engler & Prantl, Nat. Pflan- zenfam. ed. 2. 16b: 174. 1935. Typr: Graham 235 (see below). Large, coarse, dioecious plants, glabrous throughout, with possibly sym- podial growth; stems terete, chestnut brown, straight or voluble, with stem roots on year-old growth and older; young, voluble shoots originat- ing subterminally or laterally, growing out for 40—50 cm., not immediately producing stem roots or inflorescences; stem epidermis first smooth, in second year and later exfoliating in irregular, long strips, revealing a fine, brown, honeycomblike subdermal cellular structure; older stems some- times with low ridges and with round lenticels; craters extremely conspicu- ous at base of innovations and inflorescences. Leaves irregularly decus- sate to quite irregular, yellow-green when fresh, 7 x 2(-4) to 14 X 3 cm., leathery, lanceolate, usually with attenuate apex and base; petiole ca. 5 X 2 mm.; margin distinct; venation pinnate, midrib reaching apex or nearly so, often multiple at base. Staminate inflorescence up to 20 mm. long, peduncle 5 mm., first solitary in leaf axils, later in crowded groups of 4—6 per leaf axil; inflorescence bracts mostly caducous but persistent above, very small; 10-12 flowers per spike, the lowest paired, the upper ones alternate, and one flower in a terminal position, subtended by one or sometimes 2 unequal bracts, the other flowers oblique; pistillate inflores- cence up to 15 mm. long, peduncle 1-2 mm., basic structure as in stami- nate, flowers 7-11, usually paired. Staminate flowers sessile, 4-7 < 2-3 mm., 6-merous, the buds ovate; calyculus with smooth edge: stamens strongly dimorphic; anthers at middle or near apex of petals, with 4 ap- proximately equal pollen sacs; connective terminating in a very short cone; pollen with triradiate groove and included triangular prominence (FIGURE 13c); style somewhat undulate; stigma undifferentiated, reaching to base of upper anthers. Pistillate flowers ca. 5 mm. long; petals 6, with strap- shaped aborted anthers; ovary 1 & 1 mm.: style much contorted in mid- portion; stigma capitate, well differentiated, somewhat lobed. Fruit ca. 12 X 6 mm., dark-colored, ellipsoid, calyculus prominent; embryo clavate, ca. 7 mm. long, dicotyledonous, the cotyledons 24 the length of the embryo. A striking species which can be confused only with Cladocolea pringlei or C. mcvaughii, and with these only superficially. There seems to be a certain amount of variation in some floral features. Commonly, the tips of petals are held together in the bud by a papillate crest. In one instance (FIGURE 14f), a remarkable tuft of long hairs was observed just above the anthers, a tuft very similar to that in santalaceous flowers (Kuijt, 1969). Mexico. Graham 235 (x, holotype of Loranthus grahami). GUERRERO. ae cus, 2500-2700 m., McVaugh 10143 (micu). Mexico. Distr. Temascaltepec: Nanchititla, on oak, Hinton 3107 (GH, K, MICH, NY, US); Pantoja, on oak, 1500 1975] KUIJT, CLADOCOLEA (LORAN THACEAE) 295 m., Hinton 3550 (GH, K, MICH, US); Cumbre-Trojas, Hinton 9021 (GH, K, MICH, us). MIcHOACAN: 8-10 mi. NW of Ciudad Hidalgo, a few mi. N of village of San Pedro Aguaro, on Quercus, 2500-2700 m., McVaugh 9999 (micH). Moretos: Ficure 14. Cladocolea grahami: a, staminate inflorescence ges ie <); b, terminal flower of another inflorescence, same collection; c, pistillate in ‘ d, pistillate flower, longitudinal section, same co 296 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Sierra de Tepoxtlan, on oak, 7500 ft., Pringle 6987 (BR, C, F, G, GH, GOET, K, M, NY, P, PR, S, UC, US). 10. Cladocolea harlingii Kuijt, sp. nov. FicureE 15. Type: Harling 6094 (see below). Scandens, flexuosa, ramosissima, glabra, haud sympodialis; caules quad- rangulares, virides. Folia juvenilia prehensilia, matura 3 < 1 cm., obova- ta; petiolus 4-5 mm., canaliculatus. Inflorescentiae pro axilla 1-4; axis tenuis, quadrangularis; flores ca. 15 pro inflorescentia, singulares, pedi- cellis ca. 1 mm. insidentes, unus terminalis, reliqui laterales, omnes bractea caduca sub pedicello subtenti. Flores bisexuales; petala 4, 2.5 mm. longa; antherae petalaque monomorphica; stylus rectus, planum antherarum su- perans. Fructus 4 2 mm., ovoideus. A sinuous, scandent, profusely branching plant, superficially very similar to, but much smaller than, Struthanthus orbicularis, completely glabrous, branching not sympodial; stems somewhat quadrangular, green; young leaves on slender branches stiffly recurved, prehensile as in S. orbicularis, i.e., the petioles swelling upon contact, allowing the leaf to grasp other objects; epicortical stem roots produced near such grasping leaves and elsewhere. Leaves 3 X 1 cm., blade lanceolate with acute base and apex; leaves occasionally up to 5 X 3 cm., then obovate; petiole 4-5 mm. long, canaliculate; venation pinnate, the single midvein running into apex, very prominent below. Inflorescences 1—4 per axil, one primary, 2 lateral, and one superposed, lacking basal scale leaves or evident craters; axis rather slender, ca. 0.5 mm. thick, quadrangular; flowers single, on 1 mm. long pedicels, in about 7 decussate pairs, and with one terminal, short-stalked flower (inflorescence development acropetal), equally spaced along axis, each lateral flower subtended by a caducous bract, the scar remaining evi- dent below the pedicel. Flowers hermaphroditic, said to be yellowish- green or orange; petals 4, 2.5 mm. long, monomorphic, pointed; anthers also monomorphic, 14 as long as petals, on very slight filament buttress, apparently lacking filament; pollen sacs 4, the inner 2 smaller than the outer 2; pollen with obvious triradiate groove; ovary slightly more than 1 mm. long, less than 1 mm. wide, calyculus smooth; style straight and rather stout; stigma well differentiated, capitate, papillate, reaching to just above the anthers; nectary fleshy, glabrous. Fruit at least 4 x 2 mm., ovate, apparently dark in color, the nectary ring forming a conspicuous “button” at apex. This remarkable, geographically isolated species must undoubtedly be counted to Cladocolea, as indicated by inflorescence morphology, herma- phroditic 4-merous flowers, and monomorphic anthers. Paradoxically, its nearest relative (possibly its derivative) would seem to be Struthanthus orbicularis, as shown partly by general appearance, but particularly by the unique mode of parasitism in both mistletoes, where young leaves are used as grappling hooks to capture new host branches. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 297 Ecuador. Prov. Loja: road from Loja to La Tuna, km. 13-34, 1600-2600 m., Dodson & Thien 1507 (usc, uc, us); 16 km. S$ of Loja, lower than Cajanuma, 2000-2200 m., Espinosa 16366 (Ny); Cariamanga, road to Gonzanama, 1700 m., Harling 6015 (s); San Pedro, 2200 m., Harling 6094 (s, holotype of C. harlingii): ingii ; ‘ bit, showing prehen- Ficure 15. Cladocolea harlingii (Harling 6094, s): a, ha , Show sile petiole (arrow), epicortical stem roots, and flowering eon b, inflorescence with young fruits; c, flower, longitudinal section; d, mature fruit. 298 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Cerro Villonaco, 7-12 km. W of Loja, 8000-9000 ft., Sparre 16295 (s); Caria- manga, 7210 ft., Townsend a-27 (us); 46 km. SE of Cariamanga, 1750 m Wiens 3800 (ur); 70 km. SE of Pinas, 1500 m., Wiens 3781 (uT); 28 km. S of Catamayo on road to Macara, on Compositae, 2020 m., Wiens 3792 (ut); Cer- ro Villonaco, 7-12 km. W of Loja, 8000-9000 ft., W igpins 10964 (uT). 11. Cladocolea hintonii Kuijt, sp. nov. FicureE 16. Type: Hinton 10148 (see below). Dioecia, sympodialis ; rami teretes, recti, puberuli. Folia decussata vel alterna: folia primaria secundariaque ad 20 X 12 mm., late lanceolata vel obovata, puberula. Inflorescentia pistillata spica pedunculata ad 2 mm. longa; flores 3-5, ad apicem sessiles; folia secundaria nulla vel 1-3, alterna, parte inferiore pedunculi; inflorescentiae solum ad partes an- niculos. Flores dense puberuli, 4 x 1 mm., hexameri; petala anguste linea- ria; stylus tenuis, 3 mm. longus, parte exteriore convolutus. A dioecious, relatively small mistletoe with sympodial growth, straight, terete, puberulent branches, and puberulent leaves; innovations subter- minal, slender; craters fairly obvious; no stem roots seen. Leaves decus- sate to alternate; primary and secondary leaves approximately the same, the former perhaps somewhat narrower, up to 20 12 mm., broadly lan- ceolate to obovate, the apex usually acute and the base tapering into a petiole ca. 2 X 1 mm.; venation pinnate but obscure. Pistillate inflores- cence a spike up to 25 mm. long with 3-5 sessile flowers on distal portion, usually alternate but sometimes subopposite, always with terminal flower; spikes only on year-old growth where primary leaves no longer persist, some spikes lacking foliage leaves, but nearly all with 1-3 alternate leaves on lower half of peduncle. Pistillate flowers densely puberulent, mature bud 4 X 1 mm.; the 6 petals 3 mm. long, narrowly linear, bearing a small, aborted anther shave the middle; ovary ca. 1.5 & 1 mm. or narrower, style slender, 3 mm. long, convoluted in distal half; stigma clearly differ- entiated, somewhat lobed and tubercular; nectary with short hairs. Stam- inate plant unknown. It is a pleasure to honor Mr. G. B. Hinton, who seems to have had a special eye for mistletoes in his collecting i in southern Mexico. The major set of his mistletoe collections is deposited at Kew and forms the most significant single source, by far, in the present monograph. Although Cladocolea hintonii has clear affinities with C. loniceroides and C. microphylla, the distinctions are very considerable. C. hintonii is sym- podial and lacks the involucral leaves or bracts of C. loniceroides, while the latter difference also separates it consistently from C. microphylla. The fruit and male plant of C. Aintonii await description. Mexico. GUERRERO: Distr. Mina, Laguna, on oak, ba m., Hinton 10148 (&, holotype of C. hintonii), 1800 m., Hinton 10151 (NY 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 299 FIcuRE 16. Cladocolea hintonii, pistillate plant (Hinton 10148, x): habit, in- florescence, and sectioned flower. 300 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 FicurE 17. Cladocolea hondurensis: a, habit (Yuncker, Dawson, & You. 7 K); b, very young fruit on nearly se sessile inflorescence, same auction: same, showing circumscissile calyculus; d, staminate flower and bud (Molina & Molina 13922, ¥); e, inflorescence axis, same collection. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 301 12. Cladocolea hondurensis Kuijt, sp. nov. Ficure 17, TypPE: Vuncker, Dawson, & Youse 6220 (see below). Dioecia, glabra, sympodialis. Folia irregulariter decussata vel al- terna, subcoriacea, obovata vel lanceolata, rotundata, basi acuta; lamina 4 25 mm. Inflorescentia pistillata axillaris, subsessilis, solitaria, flori- bus ca. 4 sessilibus geminatis. Inflorescentia staminata ad 15 mm. longa, floribus sessilibus, decussatis, paribus ca. 4; flos 6 mm. longus; petala 5; antherae biseriatae, sacculi polliniferi quaterni; stylus fere rectus. Plant dioecious, leafy, and glabrous, with sympodial growth; young stems straight, somewhat grooved or ridged; craters conspicuous around seen. Leaves irregularly decussate to alternate, rather leathery, the leaf blade ca. 40 & 25 mm., obovate to lanceolate, the apex rounded and the acute base tapering into a petiole 4-5 mm. long and at least 1 mm. thick; venation pinnate but rather obscure. Staminate inflorescence up to 15 mm. long, with about 4 pairs of decussate, sessile flowers, lacking terminal flower(?). Pistillate inflorescence axillary, on year-old wood only, vir- tually sessile, solitary, with apparently 4 sessile flowers arranged in two decussate pairs, the flowers in axils of caducous scale leaves. Staminate nective scarcely protruding; pollen smooth, trilobate, with faint triradiate groove; ovary 1 mm.; calyculus smooth; style more or less straight; stig- ma undifferentiated, nearly reaching the upper anthers. Pistillate flowers: ovary slightly longer than 1 mm., the flaring, dentate calyculus apparent- ly deciduous in circumscissile fashion, leaving a rough, circular scar; no other pistillate flower or fruit details known. This species, although very imperfectly known, may be rather distant- ly related to Cladocolea mcvaughii. In superficial appearance it reminds one of an Antidaphne, or even C. andrieuxii, but the few inflorescences seen leave no doubt that we are concerned with a distinct species of Clado- colea. pee me spikes are also known from C. cupulata, C. mcvaughii, and C. pringl Honduras. Dept. La Paz: Cordillera Guajiquiro, 5 km. from Sabanetas, on Quercus, 2100 m., Molina & Molina 13922 (F). Dept. ComAyacua: hills above plains of Siguatepeque, near El Achote, 1350 m., Yuncker, Dawson, & Youse 6220 (cH, holotype of C. hondurensis; F, K, isotypes). 13. Cladocolea inconspicua (Bentham) Kuijt, comb. nov FIGURES la, 18, 19. Loranthus inconspicuus Bentham, Bot. Voy. Sulphur. 102. 1844 [1845]. rrr inconspicua (Bentham) Eichler in Martius, Fl. Brasil. 5(2): 67. 1868. 302 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 rahe oa inconspicuus (Bentham) Standley, Contr. U. S. Natl. Herb. 20: Zi2. Type: Hinds 346 (see below). E}e ae ; Elo Se ie b FiGuRE 18. Cladocolea inom a ie Hinds 346, K); b, flower, longitu- dinal section Nag O32, &); ushion, bracts, and flower scars (Palmer 531, BM); d, lateral branes wi © fe leaves and single, terminal flow- er (Wiens 2494, WwTuU 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 303 Plant a small, much branched, stiff mistletoe with simple graftlike haus- toria lacking any sign of other roots (Ficure 1a), with sympodial growth, each twig with up to 12 internodes, more commonly with about 6, the lateral branches paired; stems somewhat compressed ancipitally when young, becoming terete in age, then with irregular, longitudinal cracks; young stems greenish-gray, essentially glabrous but for papillar bulges of epidermal cells; stomata (and other epidermal cells) in regular longitudinal files, the guard cells transversely oriented; axillary cushions distinct (F1c- URE 18c), triangular, light brown and somewhat hairy, on young twigs only, but craters scarcely discernible. Leaves decussate, up to 22 X 9 mm., usually much smaller, glabrous, oblanceolate to obovate, with rounded to acute or mucronate apex, often with callose “nail,” the latter a remnant of the densely hairy scalelike tip visible in young, expanding leaves, tapering at base into a petiole 2-3 mm. long; midvein running into the apex, sometimes with 2 additional veins standing out. Flowers hermaphroditic, occurring singly in the axils of foliage leaves, sometimes followed by 2 more developing in the axils of the paired scale leaves of the first flower; each flower sessile but subtended by 2 minute scale leaves with white- hairy margins and papillate dorsal surfaces; some older nodes showing evidence of further flower production. Mature bud 2.5 mm. long; petals 4, rarely 3; anthers 1 mm. long, monomorphic on very short filaments at- tached at the middle of the petal with conspicuous buttresses below, con- nective projecting well above the 4 pollen sacs; pollen smooth, with three rather bulbous lobes, each with a circular, shallow depression; ovary 1 mm.; style straight; stigma just above anthers, well differentiated, papil- late; nectary smooth. Fruit 2 x 3 mm., red, smooth, broadly ellipsoid; embryo nearly spherical but for the 2 cotyledons, 1.5 K 1 mm. It is indeed tempting to compare Cladocolea inconspicua with the Te- markable Jxocactus (Kuijt, Brittonia 19: 62-67. 1967), which is similar in general appearance, though leafless. Jxocactus, however, has a pollen grain which is unique not only in Loranthaceae but also in the Santalales in general; it also has dimorphic anthers, each of which has only 2 pollen sacs, and a conical, short style. The closest relatives of C. inconspicua are C. inorna and C. clandestina. It is of some interest that an occasional flower develops in a terminal position, between two normal foliage leaves, on a small lateral branch one internode long (Ficure 18d). The occurrence of such “inflorescences lends support to the contention that single, axillary flowers represent the final stage in reduction from a several-flowered, determinate inflorescence. Mexico. Between Tepic and Mazatlan, Gregg 1116 (mo). GUERRERO: Acapul- : uc, us). NAYARIT: near Mexcaltitlan, Ortega 6162 (GH, UC, US). SINALOA: vicinity of Culiacan, Yerba Buena, Brandegee (uc) ; Culiacan, Brandegee (uc) ; above Cofradia, NE of Imala, 450 m., Breedlove 35588 (cas); vicinity of Labradas, on Croton miveus, Ferris & Mexia 5166 (cas); Imala, on Zanthoxylum, Gentry 4996 (GH, MICH, ny); Capa- dero, Sierra Tacuichamona, on Mimosa palmeri, Gentry 5636 (GH, NY); Culia- can and vicinity, 150-500 ft., Gentry 7056 (CAS, F, GH, MICH, NY, UC, us); San 304 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 FicurE 19. Cladocolea inconspicua: a, flower with two lateral flower buds (Ortega 632, K); b, mature fruit (Palmer 531, Bm); c, embryo, same collection. Blas, Hinds 346 (x, holotype of Loranthus inconspicuus); “La Noria” foothills, wooded N slope S of village, 800 ft., Mexia 321 (c, cas, MO, UC); trail from Los Labrados to Marisma, 5 m., Mexia 970 (cas, F, GH, MO, NY, UC, US); San Tgna- cio, San Agustin, 185 m., Ortega 632 (F, K); Culiacan, Palmer 1796 (cH, US); vicinity of Mazatlan, on Randia, Rose, Standley, & Russell 13746 (us); ca. 40 mi. N of Mazatlan on Mex. route 15, thorn forest, sea level, Wiens 2494 (CAS, UC, US, UT; voucher, m = 8). 14. Cladocolea inorna (Robins. & Greenm.) Kuijt, comb. nov. IGURE 20. Loranthus inornus Robinson & Greenman, Am. Jour. Sci. 50: 163, 164. 1895. Struthanthus inornus (Robins. & Greenm.) Standley, Contr. U. S. Natl. Herb. 20(6): 212. 1919 Type: L. C. Smith 122 (see below). Extremely slender, brittle, profusely branching mistletoe, 56-60 cm. in size, with sympodial branching (no lateral branches formed within each season); stems terete, glabrous, gray-green, with fine longitudinal ridges when dry, apparently lacking both stem roots and basal roots. Leaves irregularly alternate-decussate, the former arrangement predominating, gray-green, the largest leaves up to 15 X 3 mm., oblanceolate, with acute 1975] KUIJT, CLADOCOLEA (LORAN THACEAE) 305 FIcuRE 20. Cladoc inorna: a, habit, b, flower with two petals removed, la and c, axillary flower bad (all tom Smith 122, cx); d, fruit and embryo (Mc- Va ugh & Koelz 1019, mich). 306 JOURNAL OF THE ARNOLD ARBORETUM [ VoL. 56 base and acute, sclerotic, and papillate apex; petiole indistinct or absent; most leaves, however, acicular and about 5 & 1 mm.; youngest leaves, at least on lower portion of each branch, with a fringe of brownish hairs, as on scale leaves; the scale leaves several at very base of laterals, 1 mm. long or less, sclerotic and with reddish-brown laciniate margins. Flowers hermaphroditic, sessile in axils of leaves, commonly single, sometimes fol- lowed by later flowers, either in axils of subtending scale leaves or in a superposed position, often flanking the base of lateral branches. Mature buds acute, 3 mm. long, of which ca. % is ovary; calyculus more or less smooth; petals 4; both petals and stamens monomorphic; filament short, slender, attached about 14 the distance from the base of the petal; anther 1 mm. long, with 4 elongate pollen sacs which reach beyond the connective; pollen either of two types or with two faces, one with 3 obscure, circular depressions, the other with faint triradiate line; style straight, 2-2.5 mm. long; stigma small, capitate, just above anther tips; nectary smooth, in- conspicuous. Fruit 5 & 3.5 mm., ovoid, smooth and black at maturity, calyculus not prominent; endosperm nearly spherical, embryo dicotyledon- ous, 1.5 mm. long, both endosperm and cotyledons pink. Cladocolea inorna is undoubtedly closely related to C. inconspicua, as Robinson and Greenman recognized. At the same time there cannot be any question as to the distinctness of the two. C. inorna has predominantly alternate leaves that are lanceolate to acicular; terete, smooth stems; and pressed stems with a papillate epidermis; and a projecting connective. Sev- eral other minor differences could be added. Another close relative is C. clandestina, which, surprisingly, grows in Brazil. Mexico. JALIscO: mountainsides 6.5 mi. NE of Autlan, near highway pass, on legumes, 925 m., McVaugh & Koelz 1019 (MICH); N-facing slope 2 mi. W of Autlan, Wilbur & Wilbur 1666 (mic); 8 mi. § of Autlan aan La Reso- lana, on Cassia, Wilbur & Wilbur 2400 (mic). MicHoacAn: between Rio Tepalcatepec and Arteaga, along highway S from “Cuatro Caminos,” 3 km. 5 of Nueva Italia and 30 km. E of Apatzingan, 225 m., McVaugh 22521‘ (aricH). Oaxaca: Cuicatlan, 2000 ft., Smith 122 (cu, holotype of Loranthus inornus). 15. Cladocolea loniceroides (Van Tieghem) Kuijt, comb. FIGURES tb, 21, dy oxania loniceroides Van Tieghem, Bull. Soc. Bot. France 42: 387. 895. Struthanthus loniceroides — Tieghem) Engler in Engler & Poa Nat. Pflanzenfam. ed. 2. 16b: 1935. he collection McVaugh 22521 is added provisionally only, as it shows some seni Saeco (densely poner leaves cr vate, up to 10 mm. wide, wit ith t cronat runcate, e apex; fruit red at maturi ty) and may, when further material be- comes availabe warrant nomenclatural pie tion. also Calderén & Rzedowski, Cact. y Sucul. Mex. 17: fig. 59. 1972. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 307 co oie a FicurRE 21. Cladocolea loniceroides: a, pistillate Oe oti i eed ton 3796, G); b, pistillate inflorescence, large-bracted «ae d ‘ga : C, pistillate inflorescence, ee ha ed ‘type (P stamina ( eicatads 10458, K omp lack dots = flowers, onal rcles bryo (Hinton 3152, K); : séaciinaté ey een Poems mab bracted type “(Hinton 3840, K), ? 308 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Struthanthus hunnewellii 1. M. Johnston, Contr. Gray Herb. 95: 53, 54. 1931. Struthanthus mexicanus Calderon, Cact. y. Sucul. Mex. 17: 99-102. 1972. Type: Pavén (see below). Dioecious, leafy, profusely branching plants reaching 2 to several m. in size, pubescent or finely puberulent throughout, with growth percurrent and continuously branching, only exceptionally tending to sympodial habit; stems slender, terete, light tan-colored, not exfoliating even when older; plants lacking stem roots or basal roots; craters inconspicuous. Leaves de- cussate to alternate, soft and thin, up to 35 15 mm. (more usually 25 x 10 mm.), broadly lanceolate with acute (sometimes slightly attenuate) apex and acute base; petiole very short or lacking; venation pinnate, mid- vein running into apex. Inflorescences sometimes in compound groups (Ficure 21d), where they show transitions between larger lateral branches and individual inflorescences. Staminate inflorescences one or 2, some- times more per axil, superposed and/or lateral, or flanking vegetative laterals; peduncle 1-several mm. long, topped by an involucre of bracts mm. long or less, each one with one axillary flower, terminal flower al- 15 mm. long, slender; involucral bracts extremely variable, ranging from squamate organs or linear 4 mm. bracts to foliaceous organs more than 10 X 5 mm. (outer bracts), decreasing in size inwardly; numbers of flowers same as in staminate. Staminate flowers said to be yellow, 4 mm. long; petals more than 3 mm. long, 6 (rarely 5) per flower; anthers less than 1 mm. long, at two different heights on the petals, dorsifixed more or less in middle of anther by slender, short filament; the inner 2 pol- len sacs lower but not smaller than the outer 2; pollen smooth, with a faint central, triangular prominence; ovary less than 1 mm. long; style 3 mm. long, straight except for slight undulation near anthers; stigma little differentiated; base of style invested by pubescent nectary. Pistillate flowers said to be white, at least 3 mm. long; staminodia strap-shaped; ovary less than 1 mm.; style contorted in middle or upper 24, reaching to tip of petals; stigma fairly well differentiated; nectary pubescent. Fruit ¢ mm., obovoid, glabrous, turning red at maturity; embryo dark green, clavate, the 2 cotyledons linear. This seems to be the most commonly collected species of Cladocolea, even though its geographic range is limited. The holotype at Paris is 4 small pistillate specimen with rather small bracts (FicureE 21c). C. loni- ceroides is the type species of Loxania Van Tieghem. Several of the collections at micu from Jalisco are very delicate in all structural details and have only squamate floral bracts. The main char- acteristics of Cladocolea loniceroides apply, however, and the specimens are here included. Also unusual is the Guerrero collection McVaugh 150, which, besides having squamate bracts, has leaves that are nearly orbicular. further questionable specimen is Rzedowski 16372. It has extremely fine branches and foliage, squamate inflorescence bracts, and, in apparent 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 309 contrast to other collections of C. loniceroides, secondary haustoria from a thick basal root. “Attracts large numbers of bees” (Wilbur & Wilbur 1838). 0, il ie of pistillate flower aon Jc, © fruits on staminate plant (Hinton 10689, K 310 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Mexico. Pavén (P, sel of Loxania loniceroides); Sessé, Mocino, Castillo, & Maldonado 927, 4957 (F). GUERRERO. Distr. Mina: Manchon, on oak, Hinton 10458 (K, MO, NY, US); Aguazarca-Filo, on oak, Hinton 10500 (cH, kK, us); Pilas, 1600 m., Hinton 10689 (K, wru); 2 km. NE of Campamento El Gallo, estribaciones suroccidentales del Cerro Teotepec, on Alnus, 2650 m., McVaugh 150 (micu); Chichihualco, near Camotla, Campo de Aviacion, 2250 m., Rzedowski 16372 (micH); Chichihualco, Cerro de la Pastilla, near Camotla, on Quercus, 2300 m., Rzedowski 16437 (MICH); same, on Ostrya virginiana, eee ae 16451 (st1cxt): Puerto Chico, Chichihualco, 10 km. W of Camotla, nm Alnus, 2500 m., Rzedowski 18000 (micH); 16 km. E of Aserradero Aqua Fria, Tlacotepec, on road to Chilpancingo, on Populus, 2400 m., Rzedowski & McVaugh 270 (cAs, MICH); below Omiltemi, on Ostrya, 6400 ft. , Sharp 441572 m., Tillett 637-153 (GH, US). JALIsco: mountains N of Autlan, 3-5 mi. above Min na San Francisco, on Malvaceae, 1500-1650 m., McVaugh 19918 (MICH); Sierra de Manantlan, 25-30 km. SE of Autlan, 8-10 km. E of La Cumbre be- tween El Chante and Cuzalapa, on Eupatorium mairetianum, 2000-2250 m., McVaugh 23159 (micu); Sierra de Halo, 7 mi. SSW of Tecalitlan, on lumber road to San Isidro, on Baccharis, 2000-2200 m., McVaugh & Koelz 1129 (MIcH); wooded slopes S of road above pass 10 mi. S of Autlan toward La Resolana, on Compositae, Wilbur & Wilbur 1420 (mMicH); mountains E of Mamantlan ca. 15 km. SSE of Autlan by way of Chante, on Alnus, 8300 ft., Wilbur & Wilbur 1838 (MIcH); Pacific slopes 10 mi. § of Autlan, 5200 ft., Wilbur & Wilbur 2162 (micH). Mexico: Tiloxtoc, below Valle de Bravo, edge of river, on Salix, Con- Mori, & Rzedowski (ut); Distr. Temascaltepec: Temascaltepec, 1750 m., Hin- ton 636 (K, US); Bejucos, 610 m., on brazil, Hinton 930 (K, MICH, NY, US); Acatitlan, on a cirian, Hinton 3152 (K, MIcH, ny, Us); Calera, 770 m., Hinton 3796 (G, GH, K, MICH, NY, S, UC, US); Rincén, 1960 m., on peach, Hinton 3840 (x, N Y, US); Nanchititla, on oak, Hinton 4112 (kK, MICH, NY, UC, US); same on Paine i 8-10(-16) mm., lanceolate to oblanceolate, acute to rounded at apex, long-tapering at base into a petiole 2-4 mm. long and 0.5-2 mm. thick; midvein running into the apex, other veins often obscure, pinnate except for two large, basal lateral veins running half-way down the length of the blade. Inflorescences of two types: (1) primary, on current year’s growth, being mostly single (rarely with a superposed inflorescence), axillary, simple dichasia on peduncles 4-5(-10) 1 mm.; bracts of 2 lateral flowers caducous; the 3 flowers in one plane, and (2) secondary, developing on year-old growth, bearing one or 2 smallish but normal foliage leaves at the very base, deceptively like primary leaves; flowers 4-6, one of which is terminal, the others crowded nearby, spirally arranged. Flowers said to be reddish, ca. 5 xX 2 mm. when in (clavate) bud, tetramerous; anthers 1.5 mm. long, inserted in the middle of the petals, with projecting connective and 4 pollen sacs; stamens and petals monomorphic; style straight or nearly so, at least 4 mm. long; stis- ma inconspicuous. Fruit red, becoming black, 7 X 5 mm., ovoid, smooth; embryo dicotyledonous, nearly 4 mm. long, clavate. This is one of two Cladocolea species with dimorphic inflorescences, the other being C. dimorpha. In the present species the two inflorescences are deceptively alike except, of course, for the position of the associated leaves or leaflike organs. Occasionally, leafless inflorescences identical to primary ones may be found in superposed positions above secondary ~~. The staminate and pistillate flowers are also remarkably similar. T “ aborted stamens in the pistillate flower, for example, are unusually we differentiated. Cladocolea oligantha is further noteworthy for being the only Cladocolea which occurs both north and south of the Isthmus of Tehuantepec. Guatemala. Dept. HUEHUETENANGO: rocky dry slopes above San Ildefonso 318 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 mas FicurE 26. Cladocolea oligantha: a, habit, showing primary inflorescences (erect portion) ioe grr inflorescences (lower, oblique portion) (Himton 8146, K); b, staminate flower, same collection; c, ieee howe (Hinton 4730, K); d, fruit’ and si (Breatives 35995, CAS 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 319 Ixtahuacan, 1600-1700 m., Steyermark 50672 (r, holotype of Struthanthus oli- ganthus; isotype at us); NW of Cuilco, Cerro Chiquihui above Carrizal, on copal, 1350-2300 m., Steyermark 50824 (F, us). Mexico. Cottma: Rancho Guer- ro, Jones 423 (US). GUERRERO: road above Canyon del Zopilote, 8 km. E of Xochipala on way to Filo del Caballo from Milpillas, on Lysiloma, 850 m., Breed- love 35991 (cas); 5 km. E of Xochipala, on Bursera, 1100 m., Rzedowski 18649 (cas); E of Cerro Alquitran, near Mazatlan, municipality of Chilpancingo, on Bursera bipinnata, 1500 m., Rzedowski 22674 (CAS, MICH); Distr. Coyuca, Pungarabato, on a copal, Hinton 3146 (x, us). JaLtsco: near Chapala, Rose & Hinton 4730 (K, MICH, Ny, Uc, US). Oaxaca: Pan-Am. Highway between Oaxaca and Tuxtla Gutierrez, 12.5 km. E of Juchitan, on Bursera, 0-50 m., Mc- Vaugh 21853 (MIcH). PuEBLA: 12 km. NW of Petlalcingo along Pan-Am. High- way on road to Acatlan, 1350 m., Jltis & Koeppen 1116 (micu, us); 7 mi. SE of Izticar de Matamoros, on Bursera, 4950 ft., Webster, Miller, & Miller 11446 (GH). Panama. Prov. PANAMA: vicinity of Las Lajas bridge, Panama National Highway, Bartlett & Lasser 16645 (mo); near beach at Nueva Gorgona, on Bursera tomentosa, Duke 4504 (cH, vs). 19. Cladocolea pedicellata Kuijt, sp. nov. Ficures 27 & 28. TYPE: Hinton 4091 (see below). Dioecia, glabra, sympodialis; caules sat validi; cortex badia, deinde cinereo-brunnea. Folia opposita vel decussata, oblanceolata vel obovata, nga; pars inferior foliis 2-6 geminatis vel sparsis. Flores in racemo determinato, 7—9, pedicellis 4-7 mm. insidentes, saepe gracillimi; alabastra acuta, 6 mm. longa vel ultra, hexamera, calyculus extus expansus. Stylus gracilis, parte superiore valde contortus; stigma bene efformatum. Stamina dimorphica; antherae ad 2 mm. : Plant dioecious, glabrous, with sympodial growth, the leafy long shoots developing during late summer, primary leaves being dropped before ee staying on during anthesis; stems terete, stout, the bark shredding into strips later, becoming gray and smooth in age; craters evident; stem roots seen only on Rzedowski 24020 (cas). Leaves alternate to decussate, up to 60 * 23 mm., lanceolate to oblanceolate or obovate, acute to rounded at apex, at base tapering into flat, short petiole. Inflorescences determinate, only on second season and older stems, one or rarely 2 per axil, consisting of 7-9 flowers on a stout or slender axis; secondary leaves somewhat smaller than primary ones, one or 2 pairs, the lateral flowers in the leaf axils (or slightly above) and in a terminal raceme; flowers with pedicels ranging from extremely slender, 4-7 mm. long, to stout and very short or occasionally (Rzedowski 16373) absent. Staminate flowers hexamerous, apparently variable in size, 6-12 mm. in length, narrowly acute bse somewhat oblong and blunt; buds acute; stamens strongly dimorphic; anthers up to 2 mm. long, attached at or above middle of petals; poree sacs 4, more or less equal; style straight or slightly undulating at tp; 320 JOURNAL OF THE ARNOLD ARBORETUM [VOL. 56 Ficure 27. Cladocolea pedicellata: a, habit, probably staminate plant, primary leaves persisting (Rzedowski 16373, micn); b, habit, staminate plant, eine re | } bu ’ and longitudinal section of flower; f, fruit and embryo (Rzedowski 22359, MICH). j Hinton i isti long-pedicelled form (Hint lea pedicellata, pistillate, Pe yt dee at b, rare triad at base of otherwise n florescence. 322 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 stigma scarcely differentiated. Pistillate flowers hexamerous, 6 mm. long in bud; bud acute; petals acicular, greenish, with dimorphic staminodia above middle: ovary 1.5 mm. long, only slightly thicker than supporting pedicel, expanding into a flaring, dentate calyculus above; style slender, undulating slightly below, greatly contorted in upper half; stigma clearly differentiated. Fruit ca. 12 6 mm., smooth, ovoid; embryo 8.5 mm. long, the 2 cotyledons 6.5 mm. long, very flat, the haustorium scarcely dif- ferentiated. The specimens cited below are placed together with a certain amount of trepidation, as much variation exists, particularly in various inflo- rescence characters. The type specimen, in particular, has an unusually slender and graceful inflorescence, which is probably unique in the fam- ily. Only more extensive collecting can demonstrate whether all the cited specimens may be retained in one species. Cladocolea pedicellata is one of the two or three species with pedicellate flowers, the others being C. harlingii and (perhaps) C. cupulata. These species, nevertheless, are scarcely related to one another except at the generic level. A closer affinity may exist with C. glauca, which differs in having stem roots, more slender, scandent stems, sessile flowers, and smaller leaves. It is interesting, never- theless, that one of the three known collections of C. glauca was made by the same person, in the same locality, and on the same host as one col- lection of the present species. xico. GUERRERO: Campo de Aviacién, sppediaes are near Camotla, on oer 2250 m., Rzedowski 16373 (MicH). MExIco: Cerro Sacremonte, near Amecameca, Rzedowski 22359 (MICH); E of Cerro del Pino, near Ayotla, on Quercus, 2600 m., Rzedowski 24020 (cas, MicH); 5 km. E of Zoquipan, on road to Puebla, on Quercus, 2500 m., Rzedowski 27330 (F, MIcH); Distr. Temascalte- pec, Nanchititla, on oak, ‘Hanton 4091 (x, holotype of Cladocolea aber! isotypes at G, MICH, NY, UC, US). MicHoacAN: wooded slopes 8-10 m f Ciudad Hidalgo, a few mi. 'N of village of San Pedro Aguaro, 2500-2700 m., on Quercus, McVaugh 10000 (micH). Pursia: Tepoxuchil, near Puebla, on Acacia, Nicolas 5158/4 (sm, us); Cerro del Gavilan, on Quercus, 7000-8000 ft. , Purpus 4063 (8, UC, US). 20. Cladocolea pringlei Kuijt, sp. nov. Ficures Ic, 29, 30. Type: Pringle 4697 (see below). Dioecia, scandens vel volubilis, glabra, sympodialiter ramosa; rami badii, deinde cinerei. Radices ad partes vetustiores. Folia irregulariter alterno- decussata; ad annuum secundum persistentia, coriacea, lanceolata vel obo- vata, 50-110 > 7-15 mm., apice basique acuta, margine squamosa. In- dorescentine singulae vel paucae congregatae, axillares, ad partes vertentes vel juniores; seer determinatae; bracteae caducae: flores 6-13. Alabastra ca. 5 & 2 mm.; petala 6; stamina petalaque dimorphica; an- therae sessiles. — parte superiore paulum vel multum flexus. Fructus ovoideus, 5 & 3.5 mm. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 323 7, G): a, habit; flowers removed showing scar of ter- FicurE 29. Cladocolea pringlei, staminate plant (Pringle ~ b, flower, with three petals removed; c, inflorescence, os to show terminal wedge; d, tip of a second inflorescenc minal flower (arrow). 324 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 Plants dioecious, scandent to somewhat voluble, often 2 m. or more in size, completely glabrous, with apparently sympodial branching; branches first chestnut-brown, becoming grayish; craters conspicuous; stem roots on older stems only. Leaves sometimes paired, with their arrangement al- ways quite irregular, leathery, 50-110 x 7-15 mm., lanceolate to obo- vate, with an acute to rounded apex and an acute base often tapering into a petiole 3-8 mm. long; leaf margin brown, of scaly texture; the basal portion of the midrib multiple; venation pinnate. Inflorescences single or in small clusters, in axils of foliage leaves on current or very re- cent growth; mature infructescences on year-old growth, where leaves persist. Staminate inflorescence a spike with 6-13 flowers, the apex often aborting to form a terminal wedge of sterile tissue, but at other times spike terminated by a bracteate flower; all bracts caducous, leaving a swollen, crescent-shaped scar. Staminate flowers 5.5 X 2 mm. in mature bud which is obovate in shape; petals 6, dimorphic, as are the stamens; filaments very short; upper anthers above, lower anthers at middle of petals; anthers 4-locular, inner pollen sacs slightly shorter than outer ones, connectival horn short and blunt or lacking; pollen with triradiate line and included triangular prominence; ovary ca. 1 1 mm., calyculus somewhat dentate; style slightly to considerably bent in upper portion; stigma undifferentiated. Pistillate inflorescence in fruit ca. 13 mm. long, lowest fruits paired, others irregular, 5-8 fruits per spike, at least 5 X 3.5 mm., ovoid, orange-red. This species is superficially similar to Cladocolea grahami, but it is consistently smaller and has fruits and buds of a different form. The papil- late petal tips of C. grahami have not been seen in C. pringlei, while spikes in the former species are always determinate. The two species are never- theless closely related. Much confusion has existed between C. pringlei and the recently described Struthanthus palmeri Kuijt (1975), both of which have frequently been misidentified as Struthanthus “spirostylis” or S. haenkei (Presl) Engler, a synonym of S. venetus (H.B.K.) Blume. As with some other Cladocolea species, this similarity with a Struthanthus species might indicate true affinity. The Rzedowski specimen cited below has lanceolate, distinctly petiolate leaves and is, therefore, placed here provisionally. The same is true for the McVaugh & Koelz specimen, which has extraordinarily large leaves and may well belong to an un- described species. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 325 gustin toward Natividad, on Quercus, 7550 ft., Carlson 1385 (¥, MIcH); Teco- matlan, Pueblo Viejo, Camino Montelobos, 3000 m., Conzatti 1898 (Fr); Cuicat- lan, Coyula a Cuyamecalco, 1800 m., Conzatti & Gomez 2381 (2081?) (r); Canada de San Gabriel, Etla., 2900 m., Conzatti & Gonzalez 294 (GH); mon- tanas de Mitla, Tlacolula, Cerro de Xaaga, 1850 m., Conzatti & Ostlund 5178 (kK); upper SW slopes of Cerro San Felipe, above San Felipe, 12-14 km of Oaxaca, on Quercus, 2400-2800 m., Koeppen & Iltis 1242 (utc) : Felipe, Liebmann 3117 (c); foothills above Oaxaca, on oaks, 7000 ft., peer 4697 (us, rte of Cladocolea sai isotypes at BR, G, ae GOET, kK, NY, P, Pee tc t. Jayacatlan, Smith 32 (cH); Distr. Nochixtlan, W of Huandilla, 2000 m., hasiaiie 1899 (¥); Distr. Inguila, Plan de Minas, 1380 m., Conzatti 4544 (us). with nearly mature fruit (Con- IGURE 30. Cladocolea pringlei: inflorescence Zatti & ‘Ostlund 5178, K). 326 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 21. Cladocolea roraimensis (Steyermark) Kuijt, comb. nov. Ficure 31. Phthirusa roraimensis Steyermark, Fieldiana Bot. 28: 224, 225. 1956. Type: Steyermark 58943 (see below). A rigid, glabrous, sympodial plant; stems somewhat succulent, 2-5 mm. thick, bark smooth, internodes rather short (1-3 cm.); no stem roots seen. Leaves decussate, olive-green to bronze, very coriaceous, 40-50 x 10-25 mm., elliptic to ovate or obovate, with apex obtuse or more commonly FicurE 31. Cladocolea roraimensis (Steyermark 58965, us): a, habit, recon- structed; b, immature inflorescence, leaf scar below; c, mature flower, one petal removed to show central cushion and absence of style. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 327 emarginate through loss of a caducous brown nail-like tip ca. 1 < 1 mm., and base obtuse to acute; petiole ca. 10 mm. long, strongly canaliculate; venation obscure. Much of the mesophyll differentiated into sclereids with many, bulbous arms. Inflorescences one per axil, subtended by sev- eral pairs of acute, chartaceous bracts 1-2 mm. long; flowers paired, sessile, ebracteolate, inflorescence terminated by a single, sessile flower; floral bracts caducous; flowers 7 or 9 per inflorescence, yellowish; calyculus prominently 2-dentate; petals 4, 4 mm. long, with a sessile anther above the middle in dimorphic arrangement; pollen smooth, rounded-triangular, with little or no evidence of triradiate grooves; style not seen. Fruit said to be dull blue-green, oblong-ovoid, 7 < 5 mm., the fruiting axis elongat- ing to ca. 12 mm. Although only two rather inadequate collections exist of this species, the Cladocolea-like inflorescence of the material fully warrants transferal of this species to the genus treated here. It is of some interest that Steyer- mark indicated “Phthirusa” clandestina as a possible relative, since that species is presently also included in Cladocolea. However, C. archeri would seem to be much nearer to C. roraimensis, as is indicated by the chartaceous inflorescence bracts which, in Cladocolea, are known only from the latter two species. All flowers seen, in contrast to Steyermark’s state- ments, are tetramerous. The apparent absence of a style, even in young, unopened flowers, is very surprising. In its place is found a minute cushion with a small central depression. The “‘floribus. . . . dioicis” in the original description is presumed to indicate unisexual flowers. As in all other Loranthaceae with unisexual flowers, the sexes are likely to be segregated on separate individuals. If this is so, the type is staminate and the other collection pistillate. Unfortunately, no flowers are present on the latter. Venezuela. Botivar: Mount Roraima, SW slopes between Rondén ie! and base of sandstone bluffs, 2040-2255 m., Steyermark 58943 (¥, holotype o Phthirusa roraimensis); same, Steyermark 58965 (8, US). 22. Cladocolea stricta Kuijt, sp. nov. FicurE 32. Type: Hinton 10176 (see below). Dioecia, sympodialis, folia et rami puberuli, rami teretes. sg cag solum in innovationibus vertentibus, 15 7 mm. vel minora, . oes ceolata. Inflorescentiae staminatae singulae in axillis foliarum, p ss% ad 2 mm. longis; flores 5-6 ad apicem congesti, foliis squamiformibus. Stylus rectus, stamina dimorphica. Plant dioecious, short-pubescent, with sympodial — mara terete, straight, up to 25 cm. long for one seasons growth, leaves ra den mm. or smaller, broadly ce i alternate 15 x 7 : nces. Leaves consistently , petiole 1 mm. or lanceolate, with acute apex and base, slightly apiculate; 328 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 _ Ficure 32. Cladocolea stricta, staminate plant (Hinton 10176, «): habit and inflorescence. 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 329 less; blade rather fleshy, with only the midvein visible, running into apex. Staminate inflorescence solitary in the axils of leaves, being a small, deter- minate 5—6-flowered capitulum with squamate, persistent bracts and a peduncle ca. 2 mm. long, both bracts and peduncle short-pubescent. Staminate flowers 4 mm. long in bud, including the ovary, commonly 5- merous, sometimes 4-merous or very rarely 6-merous; calyculus and tips of petals short-pubescent; petals and stamens dimorphic; anthers 1 mm. long, attached at or above the middle of the petal; filament 0.5 mm., basi- fixed, with elongate filament buttress; pollen smooth, without evident grooves; ovary 1 & 1 mm.; style straight, reaching to middle of upper anthers; stigma completely undifferentiated; nectary somewhat pubescent. Pistillate plants not known. It is with some hesitation that I give this single collection specific status. However, the differences from Cladocolea microphylla and C. loniceroides, its closest relatives, seem to be such as to make it impos- sible to do otherwise. C. stricta differs from C. microphylla in its ab- sence of foliar bracts; its single inflorescence, which, furthermore, is borne in the axil of a persistent leaf; the fact that it flowers along cur- rent growth; its 4—5-partite flowers; and by its straight style, at least in the staminate flower. From C. loniceroides it differs in the same fea- tures (except the flowering along current growth) and, additionally, in its sympodial branching and very rigid, sparse habit. Mexico. GUERRERO: Distr. Mina, Armenia, on Salix, 2340 m., Hinton 10176 (kK, holotype of Cladocolea stricta). 23. Cladocolea tehuacanensis (Oliver) Van Tieghem, Bull. Soc. Bot. France 42: 167. 1895. Ficure 33. Loranthus tehuacanensis Oliver, Naturhist. Foren. Kjoeb., Vidensk. Meddel. 1864: 171. 1865. Oryctanthus tehuacanensis (Oliver) Engler in Engler & Prantl, Nat. Pflanzen- fam., Nachtr. zu III: 135. 1897. Type: Liebmann 3129 (see below). Plant dioecious, slender, sparsely branched, completely glabrous through- out, sympodial, without branching in a single season; youngest wee = attenuate and whiplike, bearing narrowly lanceolate (immature? ) leaves; stems somewhat sinuous, terete, light brown, with fine longitudinal lines, later with small, rounded lenticels; craters rather conspicuous, stem aig abundant locally but seen only on fruiting twigs. Leaves alternate vapieg out, secondary leaves one (rarely 2) per spike, at the very base Ss a spike, seemingly emerging from the crater, rather thin, up to 35 xX ng lanceolate-oblanceolate, with rounded apex and tapering at sages +n : 1X 5 mm. petiole; venation pinnate, midrib not reaching apex. Fisti an inflorescences on year-old wood, not on current growth, one or 2 a et : up to 30 mm. long, axis somewhat compressed in dried plants pete a less above crater, the flowers subtended by “shoulders” on which tea OURNAL OF THE ARNOLD ARBORETUM [VOL. 56 330 Dt Va“ y, if W \Z same collection; d, infructescence (Lie n S.N., ceca’? 3129, 7) e, em- bryo, same collection; f, roots growing 8 stem (Liebmann 3130, Cc 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) 331 scales are not recognizable; flowers 5-8 per spike, one of which is terminal, in Veo paired to alternate arrangements. Pistillate flowers: mature bud 5 X 1 mm., somewhat clavate in shape; calyculus smooth except for one or more teeth: petals 5 or 6, very narrow, slightly more than 3 mm. long, with very small staminodia — tip of petal, showing a slight but distinct dimorphism; ovary 1.5 mm. long; style highly convoluted in upper %; stigma just below petal tips, capitate, well differentiated, with papillar surface; nectary smooth. Fruit at least 7 x 3 mm., ellipsoid, dark-colored ; embryo dicotyledonous, slightly more than 5 m mm. long, % of which is cotyledons, the radicular end rather blunt. Staminate plant unknown. There is some unfortunate confusion in the very sparse collections of this species. In Copenhagen three sheets exist, each labelled “6. Loran- thus Tehuacanensis Oliv.” Two of these sheets bear the Liebmann number 3129 but have different collection dates (May and December, 1841; the latter is considered the holotype). The third sheet bears the number 3130 and was also collected in December, 1841, in Tehuacan. The two unnum- bered Liebmann sheets at Paris, dated Dec. 1841, are presumed to be 3129 Mexico. “In monte Felipe, prope Oaxacam Julio. Parasitica,” Andrieux 344 M; at K and Pp this number is C. andrieuxii); Tehuacan, Liebmann 3129 (c, holotype of Loranthus tehuacanensis; isotype at P); same, Liebmann 3130 (c). LITERATURE CITED Bartow, B. A., & D. WiENs. 1973. The classification of the generic a a a of Phrygilanthus (Notanthera) of the Loranthaceae. agate 2: EICHLER, A. W. 1875. Bliithendiagramme. viii + 575 pp. Leipz Kuyyr, J. 1967. The genus /xocactus (Loranthaceae, s.s.): esctbicn of its first species. Brittonia 19: 62-67. is . 1969. The biology of agit — plants. 246 pp. Univ. Califor- nia Beng Berkeley & Los i The identity of Strath haenkei (Spirostylis haenkei) (Lor- aa Canad. Jour. Bot. 53: 255. Van TrecHEM, P. 1895a. Sur le vin el Cladocolea. Bull, Soc. Bot. France 42: 166-168. . 1895b. Sur le genre nouveau Loxania. Ibid. 386-389. INDEX TO COLLECTIONS CITED Numbers in parentheses refer to species as treated in the text. Acosta Solis 12200 (2) Bartlett & Lasser 16645 (18) Andrieux 344 (1, 23), 345 (1) Bonpland s.n. (17) Archer 1058 (2), 1521 (2) Brade a Aye é Brandegee 13) — ee Breckon & ckcs 803 (20 Barr & Barr 64-553 (15) Breedlove 35588 (13), oa (18), Barr & Dennis 64—304A (15) 35998 (8) 332 Camp 2365 (20), 2550 (20), 2609 (1) Carlson 1385 (20) Converse 83 (15) Conzatti 1898 (20), 1899 (20), 4544 20 Conzatti & Gomez 2381 (2081?) (20) Conzatti & Gonzalez 294 (20) Conzatti & Ostlund 5178 (20) Cuatrecasas 15244 (2), 18430 (2), 20506 (2) Dodson & Thien 1507 (10), 1852 (2) Dudley 13450 (2) Duke 4504 (18) Espinosa 16366 (10) Ferris & Mexia 5166 (13) Frye & Frye 2600 (20), 2601 (17) Gardner 1322 (3) Gentry 4996 (13), 5636 (13), 7056 (1 Gimate Leyva s.n. (15) Glaziou 1429 (3) Graham 235 (9) Gregg 722b (16), 1116 (13) Harling 6015 (10), 6094 (10) Hinds 346 (13) Hinton 636 (15), 930 (15), 3107 (9), 3152 (15), 3550 (9), 3796 (15), 3840 (15), 3958 (4), 4091 (19), 4112 (15), 4115 (15), 4255 (15), 4730 (18), 4777 (4), 5554 (4), 6688 (4), 7689 (17), 8146 (18), 9021 (9), 10148 (11), 10149 (9), 10151 (11), 10176 (22), 10458 (15), 10500 (15), 10689 (15), 15022 (15 Hodge 6842 (2 Hunnewell 11854 (15) Iltis, Iltis, & Koeppen 318 (15) Iltis & Koeppen 1116 (18) Jones 423 (18) Kenoyer A-501 (15) King & Soderstrom 5105 (15), 5196 (17) Koeppen & IItis 1242 (20) JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Leavenworth 340 (17) Leavenworth & Hoogstraal 1410 (8), 1513 (4) Liebmann 3117 (20), 3120 (23), 3129 Lundell & Lundell 12328 (15) Martius s.7. (3) McVaugh 150 (15), 9999 (9), 10000 (19), 10143 (9), 10146 (17), 12193 (16), 14353 (16), 15008 (16), 17839 (17), 17937 (8), 19918 (15), 21127 (5), 21853 (18), 22521 (14), 22732 (15), 22791 (15), 23159 (15), 23273 (5), 24492 (17), 24662 (15), 24681 (1 McVaugh & Koelz 1019 (14), 1129 (15), 1211 (16) Mexia 321 (13), 970 (13) Mickel 1678 (15) Mikan s.n. (3) Molina & Molina 13922 (12) Moreno 164 (15) Moricand s.n. (17) Nelson 2421 (15) Nicolas s.n. (7), 5158/4 (19) Ortega 632 (13), 6162 (13) Palmer 531 (13), 1796 (13) Pavon s.n. (15 Pringle 4369 (17), 4697 (20), 5058 (20), 6987 (9), 7362 (15), 10244 Purpus 4063 (19), 4191 (4) Riedel s.n. (3) Roe, Roe, Mori, & Rzedowski s.n. (15) Rose & Painter 7662 (18) Rose, Standley, & Russell 13746 (13) Rzedowski 16359 (20), 16372 (15), 16373 (19), 16436 (1), 16437 (15), 16451 (15), 16623 (8), 16635 (16), 17404 (16), 17518 (8), 17914 (16), 18000 (15), 18481 (15), 18649 (18), 22120 (16), 22359 (19), 22618 (8); 22674 (18), 24020 (19), 27330 (19): 28122 (15), 28123 (15), 28125 (17); 28126 (17), 30389 (17), 30390 (17) Rzedowski & McVaugh 270 (15), 652 1975] Schwacke 1411 (3) KUIJT, CLADOCOLEA (LORANTHACEAE) 333 Troll 593 (17) Sessé, Mocifio, Castillo, & Maldonado 926 (17), 927 (18), 4957 (15) Sharp 441572 (15 Smith 32 (20), 122 (14) Smith, Peterson, ee 4127 (6) Sparre 16295 (10 Steyermark 50672 (18), 50824 (18), 58943 (21), 58965 (21) Tillett 637-146 (20), 637-153 (15) Townsend a-27 (10) Webster, Miller, & Miller 11446 (18) Wiens 2494 (13), 3781 (10), 3792 (10), 3800 (10), 4415 (16) Wiggins 10964 (10) Wilbur & Wilbur 1420 (15), 1666 (14), 1838 (15), 2162 (15), 2400 (14) Williams 3820 (17) Yuncker, Dawson, & Youse 6220 (12) RECORDED HOSTS OF CLADOCOLEA Number of records in parentheses oO . andrieuxii: archeri: clandestina: coyucae: cupulata: dimorpha: glauca: epee 66.6 gracilis: ami: harlingii: hintonii: hondurensis: . inconspicua: eNoNoNene) i} is) inorna: C. loniceroides: Alnus jorullensis (1) Alnus (1) Quercus (2) Tournefortia fuliginosa (1) Melastomataceae (1) Pe) ? Thevetia (1) Heliocarpus (1) Pinus (2) ? Acacia (1) Crataegus (1) Colubrina (1) Podo pterus mexicanus (1) 1 Croton niveus (1) 4 imosa palmeri (1) andia (1) Taahaiiae (1) Baccharis (3) Eupatorium mairetianum (1) Ligustrum (1 Ostrya gna (1) Ostrya Populus r( ) Prunus persica (2) Quercus (4) Rumfordia (1) 334 JOURNAL OF THE ARNOLD ARBORETUM C. mcvaughii: C. microphylla: C. oligantha: C. pedicellata: C. pringlei: . Stricta C. tehuacanensis: Salix (1) Solanum re Asien (1) ia Quercus (13 Bursera bipinnata (2) Bursera tomentosa (1) Bursera ( Lysiloma (1) Acacia (1) Quercus (4) Quercus (9) Salix (1) >? INDEX TO ACCEPTED NAMES AND TO SYNONYMS The numbers refer to the corresponding species in the text. in = 14 loniceroides = 15 mcva ae et = gt microphylla oerstedii = "Sirhan oligant, posticelian: = eF pringlei = 20 roraimensis = 21 stricta = 22 tehuacanensis = 23 Loranthus clandestinus = 3 grahami = 9 eases = 13 inornus = ai microphl 17 oerstedit = _Strathanths tehuacanensis = Loxania loniceroides = 15 microphylla = grahami = oerstedii = pon be tehuacanensis = 23 Phthirusa clandestina = = 3 inconspicua = : microphylla = oligantha = Dendropomon roraimensis = grahami = 9 [voL. 56 1975] KUIJT, CLADOCOLEA (LORANTHACEAE) Struthanthus (cont’d) hunnewellii = 15 mexicanus = 15 inconspicuus = 13 microphyllus = 17 imornus = 14 oliganthus = 18 loniceroides = 15 Dept. BIOLOGICAL SCIENCES UNIVERSITY OF LETHBRIDGE LETHBRIDGE, ALBERTA, CANADA 335 336 JOURNAL OF THE ARNOLD ARBORETUM [ vou. 56 HYBRIDIZATION AND INTROGRESSION IN QUERCUS ALBA * James W. HARDIN THE MosT oBVIoUS and most frequent variability in Quercus alba L., white oak, is intrinsic; that is, it occurs as random genetic variance, eco- typic or ecophenic variation, as discussed by Baranski (1975). In addition, a significant, although relatively minor, component of the variation is due to hybridization and localized introgression with eleven other white oaks of the subgenus Quercus (Lepidobalanus) which are sympatric with Q. alba in various parts of its range. During the 27 years since Palmer (1948) summarized the history of American hybrid oaks, there has been continued interest in various crosses or introgressed populations. Most of the studies have been based on gross morphology of natural populations or seedling progeny, and there is still a need for analyses of other characteristics, as well as for experimental work. One of the most perplexing gaps in our knowledge is the need for an understanding of the barriers that either effectively maintain the indi- vidual species or are at times weaker and allow limited hybridization and introgression. The intent of this paper is to summarize the information now available and to answer the basic question of just how important hybridization and introgression are as contributors to the total variation in Quercus alba. Field studies were made from southeastern Canada and New England to Illinois and south to Florida and Texas from 1965 to 1973. Herbarium material was examined from A, DUKE, FSU, GA, GH, HAM, IA, ILL, IND, KANU, KY, MICH, MIN, MISSA, MO, NCU, NCSC, OS, PAC, PH, SMU, UARK, US, WISC, and wva. Acorns from numerous labeled hybrid trees from the Arnold Arboretum and from natural populations were planted in the North Carolina State University greenhouse and the seedlings analyzed. The collections made by M. J. Baranski during 1969 and 1972, as well as his intimate knowledge of the species, have been invaluable to this study. Voucher specimens for the research are the annotated specimens in the herbaria indicated above plus my collections and those of M. J. Baranski deposited in Ncsc. THE WHITE OAK SYNGAMEON OF EASTERN NORTH AMERICA Gene exchange occurs or at least has the potential for taking place among nearly all species of subg. QuERcus in eastern North America (al- beit to a very limited extent in most cases), and the species can be *Paper number 4477 of the Journal Seri ; ies of the North Carolina Agricultural Ex- periment Station, Raleigh, North Carolina. 1975] HARDIN, QUERCUS ALBA 337 Ficure 1. The white oak syngameon of eastern North America (shaded areas). thought of as comprising the most inclusive breeding group or screens (Grant, 1971). The syngameon pictured here (FicuRE 1) is _ i sete limited to the indigenous white oaks that occur east of lou — Texas. In actuality it is more inclusive because of crosses wi “aso robur, which is cultivated in the East, and Q. gambelii and Q. hava lii, which are more western. Various crosses with these more > pe form a connecting link between the eastern and western white Tucker, 1961). : : Only the ene involving Quercus alba have been sae ek 30 study. The other crosses indicated (FicurE 1) are _ - epee (Palmer, 1948; Correll & Johnston, 1970), from my collec , herbarium specimens examined. : It is fitcreating to note that Quercus alba and Q. “agp more species than does any other member of this at co Hiade of sibly reflect the relatively broad distribution and ecologic Pp. 338 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 these species, which permit them to be sympatric with so many others. The lack of certain hybrids is equally interesting. No crosses involving either Q. chapmanii or Q. oglethorpensis are known, and for this reason they cannot at present be considered part of the syngameon. In addition, there are a number of species pairs which are frequently sympatric, but between which hybrids have not been found, such as Q. bicolor—michauxit, Q. macrocarpa—prinus, and Q. michauxii-prinus. The reason for the lack of hybrids may be either the presence of strong intrinsic barriers or mere- ly the fact that hybrids have not yet been found or identified. In view of the extensive crossing of other species, the latter explanation appears to be the more likely. The pattern of crossing within the subgenus substantiates the inclusion of the evergreen species, such as Q. virginiana, in this subgenus, but it does not lend support to the sections recognized by either Trelease (1924), Camus (1936-39), or Rehder (1940). RECOGNITION OF WHITE OAK HYBRIDS The basic prerequisite for recognizing hybrids is a thorough knowledge of the intrinsic variation within each of the parental species, particularly that due to ecophenic and ecotypic differences, stump sprouting, and ju- venility, as well as to stress morphology created by extreme climatic con- ditions or insect damage (Muller, 1941). Once a total species concept is acquired, hybrid forms can then be recognized with some degree of as- surance. However, the designation of hybridity and attribution of paren- tage are still only opinions based on comparative morphology, often with circumstantial evidence from associated species, ecology, and geography. There is seldom any real proof of the proposed hybridity in nature. It may be assumed that a first generation hybrid will be more or less intermediate between the parent species in nearly all features — leaves, twigs, acorns, bark, phenology, fall coloration, and ecology. It must be remembered, however, that all of the species are variable and the differ- ent forms of the parental types could yield hybrids with slightly differ- ent characteristics. There is also the possibility of dominance or epistasis, morphological irregularities, or transgressive segregates. Continued generations (Fo, etc.) tend to segregate somewhat, and the segregates are often similar to and difficult to distinguish from the parental species. Oaks, in general, have been thought to be rather self-incompatible (Irgens-Moller, 1955; Piatnitsky, 1960), so that selfing would be rare. On the other hand, there is evidence that indicates considerable selfing, at least within Quercus alba and hybrids. Isolated trees beyond the effective pollination range of other trees seem regularly to bear large numbers of acorns. Although the effective pollination range for oaks is not pre- cisely known, such normal fruit production would indicate selfing, assum- ing, of course, that the acorns were not all of hybrid or apomictic origin. The pollen of oaks is small (ca. 35 < 40 pm.), and judging from work done with pines (Colwell, 1951), the effective pollination range would 1975] HARDIN, QUERCUS ALBA 339 probably not exceed 200 meters. In addition, the various progeny tests (Allard, 1932, 1949; Bartlett, 1951; and the analysis of Q. alba x bi- color reported here) also tend to substantiate selfing and segregation. owever, since all of the trees used in these various studies were open grown, one could argue that the individual progeny considered to be “segregates” were in fact the result of backcrosses to the parental species. Without definitive information on the relative degree of self-incompatibility in white oaks, I am assuming that at least some selfing and segregation occurs regularly in the natural populations of the eastern white oaks. When introgression occurs, there is developed a more or less complete bridge across the morphological and ecological gaps between the two parents, depending upon whether the backcrossing is unilateral or recipro- cal. It may then be impossible, at least locally, to recognize any discon- tinuity between parents and hybrids or to identify correctly certain indi- viduals as backcrosses. All features seem to vary independently, and techniques such as the use of a hybrid index or pictorialized scatter dia- grams (Anderson, 1949; Goodman, 1966, 1967) or a discriminant analy- sis (Ledig et al., 1969) must be employed to analyze complex hybrid populations and detect the subtle “trickle” of genes from one species into another. Differential survival of introgressed genes that affect nonmorpho- logical traits may be nearly impossible to demonstrate. In fact, some of the breadth in ecological amplitude in many species could possibly be due to introgression rather than to something entirely inherent within the species. Therefore it is quite likely that the ecological effects of in- trogression extend beyond the range for which there is morphological evidence of hybridization. This brings up an interesting and unanswered question. Is the very broad ecological amplitude of white oak a result of introgression with eleven other species, or is it an intrinsic feature which allows such widespread crossing? This needs to be investigated. White oak hybrids exist at various levels of frequency and importance in the natural populations. The lowest level is represented by a single tree, presumably an F,, which is fairly easily recognized and whose — is readily surmised. Such obvious hybrids often attract local interest, an a herbarium will sometimes contain specimens from one tree that have been collected over many years by many botanists. These — herbarium specimens often give a false impression of the frequency : the hybrids in nature. A higher level is represented by a few Fi et 2 hybrids, some segregation products, backcross types, oF all of se These again are very local trees, which may have very little or no ellec on the variation of white oak in the immediate area. At the other “gen is the hybrid swarm which is a complex mixture of parental cage J hybrids, or successive generations, including segregation products, intro- gressants, or crosses between any of these; or it may be an resite introgressive population developed through repeated potas eae brid one or both parental species. I think the distinction cesar : = swarm” and “introgressive population” is mainly academic and generally impossible to make in nature. Either situation may be quite local or 340 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 may cover rather extensive areas and heighten the variability of white oak in the area. The obvious hybrids in such a population may have been identified and represented in herbaria, but the subtle segregates or introgressants have normally passed as one of the parental species. The nature of the differences between the parental species increases the difficulty of recognizing or analyzing hybrids. Most differences are quan- titative, and in some cases the species are already quite similar. As Palmer (1948) indicated, “the facility and certainty with which any natural hybrid can be identified is in inverse ratio to the similarity of the parent species.” This is less of a problem when dealing with hybrids of Quercus alba, for the presence of rather loose or appressed branched hairs on the abaxial surface of the leaves is an almost certain clue to hybridiza- tion. Nine of the eleven species with which it crosses are rather densely pubescent, and the hybrids maintain a certain number of these hairs. Distinguishing which one of the nine possible parents is involved often becomes more difficult. Since the form and density of hairs on the abaxial leaf surface is so important, a brief explanation is needed regarding the two main types of trichomes on mature leaves. The more conspicuous (at 10-15 x) is a branched type (‘‘non-glandular,” according to Dyal, 1936). This type may be erect and “loose” or appressed, sessile, or pedicellate, and it may consist of 2 to 15 branches. The size, color, form, and number of branches are often quite characteristic of certain species. This is the more important trichome type in the recognition of hybrids, since it is com- mon on all species under consideration here except Quercus alba, Q. austri- na, and Q. robur. The second type is a stellate hair which is minute; gen- erally appressed, and much less conspicuous except at a magnification of about 40. These hairs, which give the impression of being some- what viscid, were designated as ‘glandular hairs” by Dyal (1936). They are of little diagnostic value. There is a need for new criteria in the study of eastern white oak hy- brids. The chromosome number of n = 12 (Duffield, 1940) is the same for all species, and only slight differences in size and morphology of chromosomes (Stebbins, 1950) occur. Although no intensive cytological studies have been conducted on eastern white oak hybrids, this technique is not expected to be of great help. Sax (1930) found no significant differ- ences in pollen sterility between different species and hybrids, but SEM studies of pollen grains may be worth investigating. Chemical analyses I d a new dimension, as indicated by Li and Hsiao (1974), to the investigation of hybrids and introgressed populations and should be made. ECOLOGICAL CONDITIONS OF HYBRIDITY Hybrids are found primarily in (1) marginal, (2) intermediate, or (3) disturbed or open habitats. The conditions of these three habitats may, and often do, occur in combination. The disturbed, intermediate habitat is certainly the most frequent site for white oak hybrids. 1975] HARDIN, QUERCUS ALBA 341 Palmer (1948) observed that “hybrids are most likely to occur in nature along the margins of the range of one of the parent species where one is locally rare and the other abundant.” His general principle stated that “other factors being equal, the chance for the production of natural hybrids between compatible species increases in proportion to the numerical inequality of the parent species in the immediate vicinity.” This is generally true if “range” is interpreted to be “ecological” in local physiographic situations as well as “geographical” in terms of total dis- tribution. Hybrids may be found at the margins of the geographical range (FicurEs 15, 16), but they are more frequently found at the mar- gins of the ecological range. Palmer’s explanation for this marginal posi- tion was based on relative pollen frequencies; i.e., “the chance of the rare parent being pollinated by one of its own kind” is less than “the chance of its pistillate flowers being fertilized by the wind-borne pollen of the dominant species.” This assumes some degree of self-incom- patibility as well as only weak incompatibility of foreign pollen. There is obviously a balance between these two mechanisms which allows the hybrids to form in these marginal situations. In addition to this differential pollination, another possible explanation for the marginal location of hybrids may be the greater ability of the hybrid to compete in an area of stress for one of the parents. Theoretically, in an area where both parents are common in a closed community, there would be maximum competition or other interactions from the two species upon the establishment and development of the hybrid. Under such con- ditions hybrids are rare. However, a species at the edge of its range 1s not only less frequent, but under stress conditions its seedlings are at a selective disadvantage and it is not able to exert maximum competition against hybrids. The hybrids, presumably more like the dominant parent, are adaptively superior to the marginal species and can compete more favorably in such a situation. : The concept of the “hybridized habitat” has been thoroughly discussed by Anderson (1948, 1949) and by Grant (1971). It Is interpreted here to mean “intermediate” or an “array of intermediate conditions” between the optimal habitats for the two parental species. In the case of Quercus alba and related species, the intermediacy is primarily in soil moisture or total moisture balance, soil texture, and soil pH. Relative shade tolerance may also be a factor. In certain habitats and regions, related sari seemingly co-exist with white oak. But as pointed out above, bo a ental species exert maximum competition against the hybrid in a 08 apparently sympatric situation. Examples of apparent ecologica i “eg patry are infrequent, however, since most related species that a tk “ ically sympatric with white oak align themselves along the agen + sf cal gradient, with the optimum for each species at a slightly differen Se and with either no overlap or varying degrees of ssisiond taaguicies my ecological ranges of each. Anemophilous species can easily 7 . fective pollination range and yet be ecologically aapainanngeague sal relatively short effective pollination range. The more narrow the og} 342 JOURNAL OF THE ARNOLD ARBORETUM [ VoL. 56 amplitude and the greater the difference between the ecological require- ments of the parental species, the greater the likelihood is for a rather broad intermediate habitat in which neither parental species is very com- mon. This concept also assumes that no other species is dominant in this intermediate habitat to the exclusion of both parents and hybrids. In such instances of ecological allopatry, an intermediate habitat is ideal and most often necessary for the survival of the F;. Backcrosses and segre- gates have a better chance of occupying either the same habitat as the more similar parent or one of the various niches in the “hybridized” habi- tat sensu Anderson (1948, 1949). In limited areas of overlap between the ranges of the species along the ecological gradient, the hybrid is likely to compete favorably, not only because of the intermediacy of its genotype and ecological requirements, but also because one or both of the parental types are on the margin of their ecological ranges and are therefore less competitive, as discussed above. Although hybrid acorns are probably formed occasionally throughout the area of geographical sympatry between species, undisturbed, closed forests contain the parental species, with only a rare surviving hybrid or none at all except in the marginal or intermediate situations described above. In contrast, disturbed or open habitats are frequent locations for the survival of white oak hybrids. The survival of seedlings is obviously greater in areas where there is less interspecific competition and weaker habitat selection. Certainly as long as the eastern white oaks have existed there have been habitats repeatedly disturbed by natural agencies, and man probably has contributed to these during the past few thousand years. As modern man continues at an even faster pace to clear and develop the land, to overgraze, and to overcut, open as well as hybridized habitats will continue to increase. On the other hand, there is no strong evidence to indicate that white oak hybrids are now any more frequent than they were when first described (Engelmann, 1877; Trelease, 1924; Palmer, 1948). In very few populations is there evidence that hybrids are in greater relative abundance in the seedling and sapling class than in the older canopy class. WHITE OAK HYBRIDS Quercus alba crosses naturally with eleven other species of the subg. Quercus (Lepidobalanus) (Ficure 2). The arrangement of the species in FicuRE 2 is not meant to indicate relationships, but rather to show a trend from the fewest crosses (3) at the top to the most (8) at the botton. Within the twelve species, Q. alba crosses with the most. It is placed at the center merely for emphasis. Quercus durandii is included here with Q. austrina, as will be discussed later. Seven of the eleven crosses with Quercus alba have been given binary names by such authors as Schneider, Trelease, and Palmer. The others have been designated by formula only. Since there is no unanimity of 1975 343 HARDIN, QUERCUS ALBA rod "ichay ii seproulsd Ves a stellata FIGURE 2. Natural hybridization between the eastern white oaks that cross with Quercus alba. opinion regarding the preferable nomenclatural method for naming hy- brids (Little, 1960; Rowley, 1961, 1964; Grassl, 1963), I prefer to be consistent throughout and to designate all hybrids by formula with the epithets in alphabetical order. None of the hybrids form large distinct Populations or in any way resemble natural species. Without direct proof of hybridity, the best evidence of hybridization is (1) a demonstration of morphological intermediacy and recombination in nearly all characters analyzed, (2) progeny tests, and (3) a comparison between the natural putative hybrids and those made artificially. Relying Primarily on the first of these, analyses of populations (using the hybrid index or pictorialized scatter diagram methods of Anderson, 1949) were made based on various features of the leaf, acorn, twig, bark, and ecology, depending upon the particular cross and the character differences between the putative parents. Foliar features alone were used to analyze the prog- eny grown in the greenhouse. The leaf offers the most obvious clue to hybridity, but features of the 344 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 B Q oc °o x fal 5 S ° 8 oNNNANNN! macrocarpa trees of number 2 4 6 index values TERM. BUD L. 6-7mm. 41-5. oO fo) =14 oo 3-4 4 : - - - > SEC. LOBING absent O . i = o present fof he ev © ae “ rinus O 2 es | -e + > 2 oa oD 7] » alba » ° ih : bas erica! + ¥ ¥ PUBESCENCE dense O ° ¥ interm. © g 6 ¥ » " ‘% = z yw a glabrous O- > La 2 alba 4 > wth we KY n ee 1 2 3 4 6 INDENTATION INDEX TI IcURE 3. Analysis of variation. A, Measurements taken of leaf form (a = length of blade ; b = length of petiole; c = width of 1 i int intersinus width nearest widest point; j = length of longest lobe from base of AICI . alba and Q. from southeastern Michigan (hatched bars). D, Hybrid population (Q. alba X 1975] HARDIN, QUERCUS ALBA 345 acorn, twig, and bark are of great diagnostic value and should always be used when available. The type and relative density of trichomes on the abaxial leaf surface are one of the most important characters. The following variables were used for analysis of leaf form (Ficure 3A): . Length of blade (a). . Length of petiole (b). . Width of leaf at widest point (c). Length/width ratio (a/c). Intersinus width nearest widest point (e). Position of widest point: below, above, or at the middle. Number of primary lobes on the right edge of the abaxial side, not including the apex. Number of primary lobes above the middle. Presence of secondary lobes. Length of longest lobe from base of vein (j) and from line between sinuses (k). NAM HPWNDNY _ he vas i c—e . Indentation index I — Cc — — is bo k Indentation index IIT — 7 Leaf silhouettes (FicurEs 4-14) represent only a few examples of each cross. The single white oak leaf is more or less typical for the species, but it obviously may not represent the correct parental type for all crosses. Also, the silhouettes represent only leaf form and should never be taken alone to indicate hybridity. The following castabies were used for acorn analysis: (A) nut —. and diameter, (B) cup depth, (C) ratio of A/B, and (D) features o ¥HH alba hybrids austrina ] arents. Ficure 4. Representative leaf forms of Quercus alba X austrina and p 346 JOURNAL OF THE ARNOLD ARBORETUM [voL, 56 the scales. In some cases the acorn was scored as being like one or the other parent or intermediate, taking all features into consideration. Twig features such as color, pubescence, form, and size of buds were used as a basis for scoring the twig as being either like one or the other parent or intermediate. Bark of mature trees was scored in a similar man- ner. Where there was an obvious ecological differentiation between parents in nature, the location of the hybrid was also given a score. The distribution maps (FicurEs 15, 16) show the location of hybrids identified in the field or from herbarium material. The ranges of the species have been generalized from the detailed maps by Little (1971) in most cases, or very general ranges have been interpreted from various floristic manuals. 1. Quercus alba austrina The entire complex involving Quercus austrina Small, Q. durandii Buckl., and Q. sinuata Walt. is in need of a critical re-evaluation and field study before definitive judgments can be made regarding hybridization with white oak. Until the taxonomy of this complex is settled, I am for con- venience considering only Q. austrina, since most of the hybrids in- volving Q. alba are with this segment of the complex. Rehder (1940) included “Q. a. X Durandii” in his list of white oak hybrids, but Palmer (1945, 1948) did not mention it. I have found a few examples that may be Q. alba durandii, on the basis of intermediate lobing and pubescence, but I prefer to withhold judgment until the complex is better understood. The differences between Quercus alba and typical bluff oak (Q. austri- na) are so subtle that hybrids are difficult to detect. A few herbarium specimens from Mississippi and Florida are tentatively identified as Q. alba < austrina (FicurEs 4, 15) on the basis of intermediacy of leaf form, color, acorn features, and habitat. There are also populations in lower South Carolina, northern Florida, and central Louisiana that seem to be mixtures of Q. austrina—durandii, Q. alba, and Q. margaretta, but most have not been analyzed critically. One population in South Carolina is discussed under Q. margaretta. All such hybrid and introgressed popula- tions are very local. I am tempted to suggest that what we know as Q. austrina may have arisen as a result of the past influence of Q. alba on Q. durandii. The apparent cline from west to east in this complex ap- proaches Q. alba in the southeastern United States. This pattern of varia- tion could, however, reflect strong selection and merely a homoplastic similarity with , alba. 2. Quercus alba & bicolor Quercus X jackiana Schneider, Ill. Handb. Laubholzk. 1: 202. 1904. Jack’s oak is scattered in distribution (Ficure 15) and generally occurs as isolated trees in disturbed or intermediate habitats within populations 1975] HARDIN, QUERCUS ALBA 347 ¥ ¥ie HF hybrids bicolor Ficure 5. Representative leaf forms of Quercus alba < bicolor and parents, containing both parental species. It is also quite frequent at the margin of the geographical range of swamp white oak (Q. bicolor Willd.). The leaf outline is more or less intermediate between the leaf outlines of the parental species and is often quite irregular (FicurE 5). The most distinctive feature is the presence of a mixture of two sizes of branched hairs, a large loose type and a small appressed type (Dyal, 1936), both in less abundance than in typical Quercus bicolor. Acorns collected from a hybrid tree in the Arnold Arboretum were grown in the North Carolina State University greenhouse. The leaves from the seedlings, as well as the parent tree and the typical parental species in the Arboretum, were analyzed with a hybrid index based on number of lobes, indentation index II, general shape, and pubescence; each was scored on a scale from 0 (Q. alba) to 4 (Q. bicolor). Although the tree was open grown and the pollen parent is unknown, both parental types were in the vicinity. The seedling variation (FicuRE 2B) shows either segregation toward both parents or backcross progeny. The progeny do tend to confirm the parentage of Jack’s oak. This hybrid is infrequent, and gene exchange between the two species seems to be quite limited. Very few populations show more than very limited backcrossing to the more abundant parent species. 3. Quercus alba x lyrata Evidence for this cross of Quercus alba with Q. lyrata Walt., overcup oak, is limited to a very few scattered locations (F1cuRE 15). Palmer (1948) merely listed it among other crosses suspected on the basis of a few specimens at that time. The hybrids are recognized on the basis of somewhat intermediate leaf shapes, pubescence, and acorns. Leaf lobing appears to be extremely variable but usually shows the broad sinus below the middle of the blade, in addition to a tendency toward having the three relatively large (al- though more deeply dissected) upper lobes (FIGURE 6). Sparse snort on the young twigs and lower leaf surface is characteristic of the wh rids. The thin acorn cup covers half to two thirds of the nut, and the fringe may either be present or not. Hybrids Sic in bottomlands or low woods where the parents are very 348 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ¥ 44¢ alba hybrids lyrata Ficure 6. Representative leaf forms of Quercus alba X lyrata and parents. close to one another and generally where there has been extensive dis- turbance by past lumbering operations. The hybrids are local, and most backcrossing seems to be with Quercus lyrata. Some of the variability of Q. lyrata in leaf shape, in pubescence of leaf, twig, and bud, and in depth of acorn cup may reflect a “trickle” of genes from white oak into overcup oak. The influence of overcup oak on the morphology of white oak ap- pears to be very local and negligible. 4. Quercus alba * macrocarpa Quercus X bebbiana Schneider, Ill. Handb. Laubholzk. 1: 201. 1904. Bebb oak is one of the most frequent of the white oak hybrids, and it is also one of the good examples of introgression. It occurs in scattered locations (Ficurr 15) within the area of sympatry of white and bur oak (Q. macrocarpa Michx.). aye Although there are “various degrees of transition between parent species (Palmer, 1948), the hybrids are fairly easily recognized by the inter- mediacy of features or the mixture of parental characters. Leaf shapes (Ficure 7) form a continuum between the parental types, but they usu- ally show at least a tendency toward the broad sinus below the middle of the blade and the massive portion above. The hybrids consistently have some degree of pubescence on the lower leaf surface, and the petiole may be pubescent or glabrous. The acorn cup is generally deeper than in white oak, but the marginal fringe, so characteristic of bur oak, may oF may not be present. The bark may be intermediate or more like that of one of the parents. Although the ecological ranges of the parental species are somewhat different, the two plants are frequently close associates and appear to occupy similar sites. : A rather large population near Brighton, Livingston County, Michigan, was analyzed in detail. Samples were taken from 56 trees scattered over 1975] HARDIN, QUERCUS ALBA 349 7 ¥ macrocarpa 5 IGURE 7. Representative leaf forms of Quercus alba X macrocarpa and par- ents. alba hybrids an area of about one square mile. The area was at that time (before construction of two dual-lane highways and a sprawling intersection) covered by an open mixed hardwood forest in small to medium-sized woodlots dissected by pastures and cultivated fields. Some large trees remained along roadsides and in pastures. Much of the area showed signs of extensive disturbance by logging and grazing. Only mature trees greater than 4 inches dbh were sampled. Ten trees of each parental species were sampled from scattered locations in Lapeer and Oakland counties, Michigan. Hybrid indices were constructed using a scale of 0 (Q. alba) to 2 (Q. macrocarpa) for the following eight diagnostic features: bark (light ashy gray to darker gray and more distinctly ridged), twigs (glabrous to pubescent), acorns (less than 3/4 inches to greater than 3/4 inches, cup less than 1/2 to greater than 1/2 length of acorn, without or with fringe), leaf pubescence (glabrous to densely hairy), and leaf form (oblong to obovate, without and with wide central sinus and massive upper portion). This hybrid population (F1curE 3C), in contrast to the typical species, is composed of both parental types plus various hybrid forms. There may be some limited segregation toward both parents, but there is probably more backcrossing, particularly to Q. macrocarpa, which is the more fre- quent parent in the immediate area. This pattern seems rather typical of a number of populations that exhibit limited gene exchange between species. The predominance of forms closer to bur oak is probably due to differential pollination rather than differential selection of seedlings. Pre- sumably any hybrid seedling could compete well in this open, disturbed habitat in which both parental species are well adapted. Hybrids are nearly always associated with both species. However, a population of hybrids more like bur oak was found near Mora, Kanabec 350 JOURNAL OF THE ARNOLD ARBORETUM [voL, 56 County, Minnesota. No white oaks were found in the area. The hybrids are large trees, possibly 50 to 75 years old, and white oak has undoubtedly been selectively cut from the area since the hybrids were formed. Bebb oak exists either as single trees, probably F, hybrids, or in mixed populations, which could be either hybrid swarms or introgressed popula- tions. Hybrids are localized, and introgression seems to have rather limited influence on the variability of the parent species in the region. Li and Hsiao (1974) have shown that the phenolic compounds in a hybrid tree growing at the Morris Arboretum substantiate the suspected parentage of Quercus alba and Q. macrocarpa. 5. Q. alba x margaretta The hybrid with Quercus margaretta Ashe, sand post oak, is found in- frequently in the lower Coastal Plain (FicurE 15). The habitat of sand post oak is fairly restrictive (Muller, 1952), and white oak generally does not occupy the same sites. Undoubtedly the ecological barrier is very effective where the parental species are close enough for cross-pollination, and an intermediate habitat is necessary for the survival of the hybrid. This hybrid was included under Quercus X fernowii (Q. alba X stellata) by Palmer (1948). The collections from Nansemond County, Virginia, which Fernald (1942) considered to be Q. alba x stellata var. margaretta were cited by Palmer under QO. x fernowii. I consider Q. margaretta to be a distinct species, and likewise the hybrid with white oak is distinct from Q. X fernowii. The hybrid between Quercus alba and Q. margaretta is recognized by the more or less shrubby or small tree habit, smaller leaves, large pedicellate branched hairs (in contrast to the sessile branched hairs in Q. alba X stellata), and glabrous twigs. Leaf shapes (FicurE 8) are variable but generally indicate the large lobes of the upper half. In most cases, these hybrids occur as single individuals or small clones. However, there are populations, particularly in the southwestern part of the range, where presumably reciprocal or unilateral introgression has occurred and heightened the variability of both parental species in the immediate area. A hybrid index for a population in Harrison County, alba hybrids margaretta Ficure 8. Representative leaf forms of Quercus alba < margaretta and pat- ents. 1975] HARDIN, QUERCUS ALBA 351 Texas would appear quite similar to that in Ficurr 3C, owing to the greater backcrossing to Quercus margaretta., As mentioned under Quercus alba x austrina, there are populations that appear to be mixtures of Q. alba, Q. austrina, and Q. margaretta. One such population near Bluffton, South Carolina is a mixture of a few large white oaks, infrequent sand post oak, and fairly common bluff oak and hybrids. The hybrid forms are either small single trees (more nearly Q. alba & austrina) or clones of stoloniferous small trees to eight feet tall. The leaves are mostly like Q. alba X austrina in shape and texture but have scat- tered pedicellate branched hairs and occasional larger lobes at the apex typical of Q. margaretta. The habitat is a low, sandy, pine flatwood, which has been heavily disturbed in the past by lumbering operations. The in- fluence of this mixture appears to be very local. 6. Quercus alba X michauxii Quercus < beadlei Trelease ex Palmer, Jour. Arnold Arb. 29: 16. 1948. Beadle oak is found rather infrequently in scattered geographical loca- tions (FicurE 15) and in low woods, on the lower slopes adjacent to floodplains, or in swamps where the ecological ranges of white oak and swamp chestnut oak (Quercus michauxii Nutt.) overlap. This hybrid is fairly easily recognized by the light gray, flaky bark, the more or less intermediate leaf form (FicuRE 9), the sparse pubescence of loose branched hairs, and acorns of more or less intermediate size, the cups with rather coarse, thick, and loosely imbricated scales. The leaf form (FicurE 9) appears very similar to Quercus alba bicolor (F ae 5), Q. alba & prinus (FicuRE 12), or Q. alba & muehlenbergti (FIGURE 10), and distinction between these four has to be based on other features, such as bark, pubescence, acorns, and ecology. A number of herbarium specimens were found to be mistakenly identified as Q. alba X prinus : . : . . . cma seem to exist as individuals in disturbed, intermediate — tats, and there is no evidence thus far of either extensive hybrid swarms i opulations. tne ae oh ike eee Quercus prinus L. continues to be a source of con- alba hybrids michauxii } ii arents. Ficure 9, Representative leaf forms of Quercus alba X michauxii and p 352 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 + Hi alba hybrids muehlenbergii Ficure 10. Representative leaf forms of Quercus alba X muehlenbergii and parents. fusion, and it may be a good candidate for rejection under Article 69 of the Code. Standardization of the use of Q. prinus for chestnut oak and Q. michauxii for swamp chestnut oak did not follow the publication of Little’s Check list (1953) as was hoped, for many recent publications use Q. prinus for swamp chestnut and Q. montana Willd. for chestnut oak. C. H. Muller considers the Linnaean type specimen to be the swamp chest- nut (Bernard & Fairbrothers, 1967). At this time, no one can be certain of the meaning of the name Q. prinus unless it is accompanied by a syno- nym, common name, habitat, or distribution. However, I prefer, at least for the present, to continue to follow Little (1953) and to use Q. michauxu for the swamp chestnut oak and Q. prinus for the chestnut oak. 7. Quercus alba X muehlenbergii Quercus < deamii of some authors; not Trelease, Natl. Acad. Sci. Mem. 20: 14. 1924. White oak and chinkapin oak (Quercus muehlenbergii Engelm.) are frequent associates on calcareous soils, and hybrids between them have been found at the edge of fields or in heavily disturbed woods in scattered locations (FicurE 16). There is no evidence of extensive introgression, for most hybrids seem to exist either as single trees or at most as a le individuals together in a small area. This hybrid is recognized primarily by the leaf, which is more OF less intermediate in lobing (Ficure 10), often with the rather sharp points and glandular mucros more characteristic of chinkapin oak, and always with some given density of appressed branched hairs. It can be distin- guished from Quercus alba X bicolor by the lack of the two sizes of hairs mentioned under that cross. It is questionably distinct from Q. X faxont, as will be discussed later. 1975] HARDIN, QUERCUS ALBA 353 The name Deam oak (Quercus x deamii Trel.) has often been mis- takenly associated with this hybrid cross, since a tree from near Bluffton, Indiana, which was later named Q. x deamii by Trelease, was originally determined by Sudworth to be Q. alba x muehlenbergii (cf. Palmer, 1948). Palmer, although he used this binomial for this cross, questioned the parentage of the tree, since seedlings raised from acorns from the type tree included individuals with leaves similar to those of Q. bicolor. I col- lected acorns from Q. < deamii growing at the Arnold Arboretum and grew them in the North Carolina State University greenhouse for two years. Some leaves had the general shape of Q. bicolor, but they all lacked the two sizes of hairs, the lobes were more pointed (like those of Q. muehlen- bergii), and many had the shape indicative of Q. macrocarpa. Bartlett (1951) showed from progeny tests from the type tree that 0. x deamii represented the cross Q. macrocarpa « muehlenbergii. The progeny which I grew confirm this, and many herbarium specimens originally identified as Q. < deamii indicate Q. macrocarpa and Q. muehlenbergii rather than Q. alba. Thus Q. X deamii applies to Q. macrocarpa < muehlenbergii, and the cross between Q. alba and Q. muehlenbergii has no binary name. 8. Quercus alba x prinoides Quercus X faxonii Trelease, Natl. Acad. Sci. Mem. 20: 14. 1924. Faxon oak has been identified infrequently from scattered locations (Ficure 16). Except for generally smaller leaves (Ficure 11) and a shrubby or smaller tree habit, it is doubtful whether Q. alba x prinoides can always be distinguished from Q. alba < muehlenbergii. The leaf often has fewer and shallower lobes, but these features are quite variable. Much of the variation would seem to be due to the intrinsic variation in the parental species, and it is questionable whether the chinkapin oaks repr t two distinct species. , ee There hess indication that this cross leads to any increased variability in the parental species. Hybrids occur rarely, and then usually as indi- 8 cm. alba hybrids prinoides inoi d par- FicurE 11. Representative leaf forms of Quercus alba X prinoides and p ents. 354 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ¥ Yan alba hybrids prinus Ficure 12. Representative leaf forms of Quercus alba X prinus and parents. viduals or infrequent backcrosses to the dwarf chinkapin oak (Quercus prinoides Willd.). The map (Ficure 16) for dwarf chinkapin oak is very general and is probably quite incomplete in some areas. 9. Quercus alba < prinus (montana) Quercus saulit Schneider, Ill. Handb. Laubholzk. 1: 203. 1904. Saul oak is not only one of the most commonly found hybrids (FIGURE 16) but is also one of the best examples of introgression among the white oak hybrids. In addition, it is the best known through progeny tests (Allard, 1932, 1949; Ledig ef al., 1969) and population analysis of mature trees (Silliman & Leisner, 1958). This hybrid is easily recognized by the leaf, which has more lobes than white oak but deeper sinuses than chestnut oak (FicureE 12), by the vary- ing numbers of branched hairs on the abaxial leaf surface, by the inter- mediate terminal bud sizes, by the more or less intermediate acorn size and nature of the cup scales, by the intermediate bark, and by its occurrence generally in an intermediate and disturbed habitat where the parental species overlap in their ecological ranges. The various studies cited above indicate a limited amount of selfing and segregation and a significant amount of backcrossing. The population analyzed by Silliman and Leisner (1958) showed predominant back- crossing with Quercus prinus or possibly a selection for these types by the particular habitat. The analysis of hybrid progeny by Ledig ef al. (1969) indicated backcrossing to both parental species, which may be the expected situation when both parental types are in about equal frequency in the area and when natural selection of the seedlings has not yet occurred. Any deviation from equal backcrossing, as shown by the progeny, would normally be a function of the relative frequency of the paren species in the vicinity. Further deviation from equal numbers of surviving seedlings and mature trees would be a function of natural selection. This model assumes no differential intrinsic barrier to backcrossing. 1975] HARDIN, QUERCUS ALBA 355 A population of Saul oak in Reedy Creek Park, west of Raleigh, North Carolina, was analyzed, since it appeared to have hybrids that approached both parental species. The habitat is a rocky northeast- to northwest- facing slope, with Quercus alba in the ravine and lower part of the slope and Q. prinus on the ridge and upper part of the slope. The hybrids occur throughout the slope, but they are more abundant in the mid-section. Both parental species are present in large numbers, and the habitat appears intermediate and open enough to accommodate all hybrid forms. Forty trees from a transect perpendicular to the contours were selected as probable hybrids on the basis of morphology. For a comparison, samples were taken from eight white oaks from the North Carolina State University Schenck Forest, northwest of Raleigh, and eight chestnut oaks from Hem- lock Bluff, southwest of Raleigh. Saul oak is not found in these two loca- tions. The pictorialized scatter diagram of these populations (Ficure 3E) probably indicates a more or less equal backcrossing to both parental species, although there may also be some segregation products included. This location is obviously capable of maintaining various products from reciprocal introgression. This introgressant population at Reedy Creek covers an area of about 70 acres, and the major influence from the gene exchange seems fairly well restricted to that immediate area. A subtle “trickle” of genes from one species into another would be very difficult to detect, although it un- doubtedly is occurring. There is certainly no obvious heightened morpho- logical variation in either Q. alba or Q. prinus in the region asa result of the scattered populations of Saul oak. The heightened ecological variation, although difficult to analyze, may be more extensive. Several populations of Saul oak in other areas show introgression with the predominant tendency toward backcrossing to the more abundant parental species. In all cases the hybrids are found in intermediate habi- tats that have been opened up by fire, logging, grazing, highways, or powerline construction. : i The name Quercus prinus L. is at present meaningless without alba hybrids stellata Ficure 14. Representative leaf forms of Quercus alba X stellata and parents. The hybrids generally occur in open, cut-over areas where the parental species are rather closely associated. Intermediate soil conditions are necessary in less disturbed areas. The hybrids are few in number in southeastern Oklahoma that show rather extensive introgression of Quercus alba into Q. stellata Wang. This is at the margin of the white oak range, so backcrossing could be expected to be to Q. stellata. Samples were taken from a population of 25 mature trees over 4 inches dbh along the eastern edge of Bland Lake, San Augustine County, Texas. A hybrid index was constructed using a scale of 0 (Quercus alba) to 2 (OQ. stellata) for the following four diagnostic features: bark (light ashy gray and flaky — intermediate — reddish brown and longitudinally ridged) , twig pubescence (glabrous — scattered hairs — pale and canescent), leaf pube- scence (glabrous — scattered branched hairs — densely hairy), and leaf form (even lobing — intermediate — large, wide lobe above middle). All features seemed to vary independently, and from the pattern of variation shown by the population (Ficurr 3D), I suspect a predominance of back- crossing to post oak and possibly some segregation. This pattern seems fairly typical of a number of populations in the southwestern part of the range of Q. alba. The white oak of the region shows little influence from this gene exchange away from the local sites of introgression. Additional crosses — expected and artificial. = Some three-way hybrids among the eastern white oaks undoubtedly exist, but since there are few qualitative characters by which the parent species can be recognized, it is difficult to detect such crosses. pet hybrids in Aesculus (Hardin, 1957) were easily identified _ a distinct qualitative parental features. Tucker (1961) recognizes hs Rae ters of three or more species in the Quercus undulata complex. - ss ample in the east is the Q. alba—austrina—margaretta complex po _ earlier. A specimen from Ashley County, Arkansas, with leaves mee of Q. alba X lyrata, but with acorns (attached to the twig) more 358 JOURNAL OF THE ARNOLD ARBORETUM [ VOL. 56 Le 4 = ataer ma ts CF tk ss eer Seo nte! | ian So ey a = p 4 ae Bees = ete Kaw & age: Bes Uees=, SA A Oss Re A het to Bae asta PG e scien ee leer acoceeeBe® Be dele asteces’ shi: <4 pes) , 4 oe ‘ ES gr XS rd é irs 1 age Sein elses \\ =" or an ty ri pie a < yi 2 ‘j oe ory) by gn, (Se tieware j: ee ee ee TT USES i Suga. gees of FASE eect Y ag ‘ ay 2 gees be ats ] mens’ Wee) gaseepzeats Soe etary cen ane 1 Se, 4; Raseaee WP ase SEs, aie PF } WG X margaretta Deas a sd ‘ iy Oe ed eee: eZ Ress ea & : ‘% Ko 4 iN ay 3 Sates < alba X michauxii alba X lyrata Ficure 15. Distribution of hybrids (dots) between Quercus alba (heavy line) Q. austrina, Q. bicolor, Q. lyrata, Q. macrocarpa, Q. margaretta, and Q michauxii (shading). of Q. michauxii, may also indicate a mixture of these three species in a low woods. In addition, progeny grown in the North Carolina State University greenhouse from acorns collected at the Arnold Arboretum from a Q. X bimundorum (Q. alba X robur) showed a distinct tendency toward Q. bicolor in leaf form and pubescence. This could be either the result of crossing there at the Arboretum or a reflection of a three-way parentage of that particular tree. Since a number of oaks are more or less sympatric in many areas, I would certainly suspect that there must be other examples of some limited amount of crossing between three or more parental species. Within the range of Quercus alba, there are four other species of subg. Quercus that may be expected to cross with it (FicurE 1). They are Q. chapmanii Sarg., Q. oglethorpensis Duncan, Q. virginiana Mill., and Q. HARDIN, QUERCUS ALBA SAE ater ol s eae fivereRegaat tenes ae PHT fame naneyhens cna: ad T71 pee, res eet eH ‘eo iin "i a ry a L bar ee Te Tip) ae ayes: 2 Sk ti alba X prinus \ gnc ER eo a 3 ae Be Be ae i efe oesm i+ - a Laepeet alba X prinoides FIGURE 16. Distribution of hybrids (dots) between Quercus alba (heavy line) and Q. muehlenbergii, Q. prinoides, Q. prinus, and Q. stellata (shading). minima (Sarg.) Small. Hybrids with Oglethorpe oak in particular should € sought, since it is so closely sympatric with white oak. Piatnitsky (1960) reports the artificial crosses Quercus alba suber - alba X macranthera. Both species are European members of subg. QUERCUS DISCUSSION The oaks have long had a reputation for being a taxonomically difficult e hybrids are generally quite local single trees and are infrequent in com- Parison to the abundance of the species in the deciduous forests of eastern North America, Rather extensive hybrid swarms or introgressed popula- 360 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 tions occur only with Q. macrocarpa, Q. prinus (montana), and Q. stellata, and even these are generally localized. The great variability in Q. alba is most often due to ecophenic, ecotypic, and random genetic variances (Baranski, 1975). Neither Baranski nor I agree with Minckler (1965), who thinks that hybridization may mask evidence of races within white oak. As pointed out by Irgens-Moller (1955), “hybridity {in oaks] ap- parently seldom affects the distinctness of the species.” My use of the term “syngameon” in FicuRE 1 does not imply unlimited and wide- spread gene exchange between the species. To the contrary, the gene “flow” is but a “trickle” in most cases. Even where hybrid swarms or introgressed populations exist, the effect is still fairly localized, and there is no widespread influence, for example, on the morphology of white oak by genes from the other eleven species with which it crosses. Although in certain cases new genes and gene combinations are slowly being added to the genetic architecture of the introgressed species, the essential integrity is not destroyed. All species have maintained their distinctness in face of this local ‘‘contamination,” and I see no justification for considering the entities anything less than good taxonomic species. In terms of their biology, they can be considered ‘“semi-species” composing a syngameon (Grant, 1971). The highly localized gene flow appears to be characteristic of most instances of introgression (Heiser, 1973), and it is in marked contrast to the pattern of dispersed introgression found in Aesculus (Hardin, 1957) or Aronia (Hardin, 1973), where the morphological influence of one species is detected sometimes hundreds of miles from the site of original hybridization. It appears that in white oak the greatest effect of introgression may be on the ecology of the species. The broad ecological amplitude may be due to some extent to “ecological genes” acquired from other species. If it is assumed that the morphological features used in distinguishing species are governed by relatively few genes (Stebbins, 1950), while ecological adap- tation is controlled by numerous genes, this differential flow of “ecological” versus “morphological” genes may be entirely plausible. The question raised earlier of whether the broad ecological amplitude is a cause or 4 result of introgression is still unanswered, and without knowledge of the original geographical and ecological ranges of the species, we can only speculate on the significance and origin of the broad ecological diversity seen today in Quercus alba. Also unanswered is the question of the identity of the isolating mech- anisms which are so effective among the white oaks. The various barriers have been discussed by Stebbins e¢ al. (1947), Muller (1952), Tucker (1963), and others, and actually several mechanisms may act together or in sequence. Without definite information on possible incompatibilities, I suspect that ecological isolation is one of the most important means which so many related white oak species can co-exist in eastern North America in spite of genetic compatibility. I also suspect that strong 1975] HARDIN, QUERCUS ALBA 361 natural selection limits the extent of the introgressants that are produced. In recent years introgression as an explanation of certain patterns of variation has been called into question (Heiser, 1973). In view of (1) the geographical and ecological locations of the putative hybrids, (2) their close association with the parental species, (3) the nature of the associ- ation of characters within the hybrid populations, (4) study of the progeny from hybrid trees, and (5) the close similarity between artificially produced and natural hybrids, I am satisfied that localized introgression does occur among the eastern white oaks. LITERATURE CITED ALLARD, H. A. 1932. A progeny study of the so-called oak species Quercus saulii, with notes on other probable hybrids found in or near the District of Columbia. Bull. Torrey Bot. Club 59: 267-277. y . 1949. An analysis of seedling progeny of an individual of Quercus saulii compared with seedlings of a typical individual of white oak (Quercus alba) and a typical rock chestnut oak (Quercus montana). Castanea ANDERSON, E. 1948. Hybridization of the habitat. Evolution 2: 1-9. ———. 1949. Introgressive hybridization. ix + 109 pp. John Wiley, New York. BaRANSKI, M. J. 1975. An analysis of variation within white oak (Quercus alba L.). North Carolina Agr. Exp. Sta. Tech. Bull. No. 236. Raleigh. BarTLett, H. H. 1951. Regression of X Quercus deamii toward Quercus macrocarpa and Quercus muhlenbergii. Rhodora 53: 249-264. — BERNARD, J. M., & D. E. FAtRBROTHERS. 1967. Ecologic and taxonomic infor- mation about Quercus michauxii Nutt. (swamp chestnut oak) in New Jersey. Bull. Torrey Bot. Club 94: 433-438. Camus, A. 1936-1939, Les Chénes. Monographie du Genre Quercus, Vols. 1 & 2. Académie des Sciences, Paris. - CotweELL, R. N. 1951. The use of radioactive isotopes in determining spore distribution patterns. Am. Jour. Bot. 38: 511-5 Corre, D. S., & M. C. JonnsTon. 1970. Manual of the vascular plants of Texas. xv + 1881 pp. Texas Research Foundation, Renner. DvrFIELD, J. W. 1940. Chromosome counts in Quercus. Am. Jour. Bot. 27: 87 : : hus S. A. 1936. A key to the species of oaks of eastern North America based on foliage and twig characters. Rhodora 38: 53-63. ca ENGELMANN, G. 1877. About the oaks of the United States. Trans. Acad. Sci. t. Louis 3: 372-400, 539-543. : enki, M. L. 1942. The seventh century of additions to the flora of Vir- ini : 341-405. uke ropa Correlation and the structure of introgressive popula- tions. Evolution 20: 191-203 7. The identification 196 ot hybrid plants in segregating populations. Ibid. 21: 334-340. 362 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Grant, V. 1971. Plant speciation. x + 435 pp. Columbia University Press, ork. GrassL, C. O. 1963. Proposals for modernizing the International Rules of No- menclature for hybrids. Taxon 12: 337-347. Harpin, J. W. 1957. Studies in the Hippocastanaceae, IV. Hybridization in Aesculus. Rhodora 59: 185-203. : 73. The ns chokeberries (Aronia, Rosaceae). Bull. Torrey Bot. Club. 100: 184. Hetser, C. B., Jr. ie Introgression re-examined. Bot. Rev. 39: 347-366. IRGENS-MOLLER, H. 1955. Forest-tree genetics research: Quercus L. Econ. Bot. —71. Lepic, F. T., R. W. Witson, J. W. Durrietp, & G. MAxweELL. 1969. A dis- criminant analysis of introgression between — prinus L. and Quercus alba L. Bull. Torrey Bot. Club 96: 156-1 Li, Hur-Lin, & Ju-Yinc Hsiao. 1974. A nd study of the chemosyste- matics of American oaks: phenolic characters of leaves. Bartonia 42: 5-13 Litt ie, E. L., Jr. 1953. Check list of native and naturalized trees of the United States Cnchuding Alaska). 472 pp. U.S.D.A. Agr. Handb. No. 41. . 1960. Designating hybrid forest trees. Taxon 9: 225-231. . 1971. Atlas of United States trees. Vol. 1. U.S.D.A. Misc. Publ. No. 1146. MINCKLER, L. S. 1965. White oak (Quercus alba L.). In: Silvics of forest trees of the United States. U.S.D.A. Agr. Handb. No. 271: 631-637 Mutter, C. H. 1941. Hybridism, ecotypes, and peripheral race variants in Quercus. Am. Jour. Bot. 28(suppl.): 17s (abstract). 1952. Ecological control of ee in Quercus: a factor in the mechanism of evolution. Evolution 6: 61. Patmer, E. J. 1945. Quercus durandii and its allies. Am. Midl. Nat. 33: 514—- 519. . 1948. Hybrid oaks of North America. Jour. Arnold Arb. 29: 1-48. PrATNITsky, S. S. 1960. Evolving new forms of oak by A amiaaa Pp. 815- 818 in Fifth World Forestry Congress, Vol. 2. Seattle RENDER, A. 1940. Manual of cultivated trees and shrubs, xxx + 996 pp. Mac- willan Co., New York. Rowley, G. D. 1961. The naming of hybrids. A reply to Dr. E. L. Little, Jr. Taxon 10; 211, 212 , _ The naming of hybrids (2). A reply to Dr. C. O. Grassl. Ibid. 13: 64, Sax, H. J. ee Chromosome numbers in Quercus. Jour. Arnold Arb. 11: 787, 788 SCHREINER, E. £24. ee DUFFIELD. 1942. Metaxenia in an oak species cross. Jour. Hered. 33: 97, 9 SILLIMAN, E. E., & R. : Larsxen 1958. An analysis of a colony of hybrid aks. Am. pine Bot. 45: 730-736. SteBBiIns, G. L., Jr. 1950. Sl and evolution in plants. xix + 643 pp. Columbia Laren es New York. TZKE, & C. Nc. 1947. Hybridization in a population of Quercus sna Nie and — ilicifolia. Evolution 1: 79-88. 1975] HARDIN, QUERCUS ALBA 363 TRELEASE, W. 1924. The American oaks. Mem. Natl. Acad. Sci. 20: 1-255. TucKkER, J. M. 1961. Studies in the Quercus undulata complex. I. A pre- liminary statement. Am. Jour. Bot. 48: 202-208 1963. Studies in the Quercus undulata connie: Ill. The contribu- tion of Q. arizonica. Ibid. 50: 699-708. DEPARTMENT OF BOTANY NortH CAROLINA STATE UNIVERSITY RALEIGH, NorTH CAROLINA 27607 364 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 THE GENUS ANETANTHUS (GESNERIACEAE) Ricuarp A. HowArD THE GENUS Anetanthus was described in Bentham and Hooker’s Genera Plantarum (2: 1025. 1876), where it was attributed to Hiern with the ref- erence “Pl. Bras. Warm. ined.” Species were reported to be four or five from Brazil, Peru, and Mexico, with a numbered but unnamed collection, Lechler 2723, cited from Peru. No specific names or combinations were used, although three additional taxa, Dicyrta parviflora, Russelia alata, and Tapina villosa, were said to be included in the new genus : The following year Hiern published a comparable generic description for Anetanthus (Warming, Symb. Fl. Bras. 23: 93. 1877) and cited the reference to Genera Plantarum. He described a single species as Anetan- thus gracilis and referred to a Warming collection, without number, from Lagoa Santa, Brazil. In addition, Hiern noted the fact that Bentham and Hooker assioned three other species to the genus, but he also did not use the specific names in combination with Ametanthus. Jackson (Ind. Kew. 1: 133. 1893) attributed Anetanthus gracilis to Hiern and the bi- nomials Anetanthus parviflorus, Anetanthus alatus, and Anetanthus villosus to Bentham and Hooker. The fifth supplement to Jndex Kewensis also listed Anetanthus pusillus Glaziou as a nomen nudum The four validly published species of “Anetanthus” should be assigned to three genera in two families, as the following notes will indicate. Anetanthus alatus pre org : ooo Bentham & Hooker ex Jackson, Ind. Kew. 1: 133. Russelia alata Chamisso & rier —— 3: 3, 4, 1828; J. A. Schmidt in Martius, Fl. Bras. 8: 269. t. 44. I have seen but one specimen of this taxon, that in the herbarium at Kew. A single flower, previously dissected, was in a packet; however, pollen could be obtained from the single anther present for the accompany- ing SEM photograph. The illustration in Flora Brasiliensis must have been drawn from an additional specimen. The type is a Sellow collection, without number, from Brazil. Carlson, when considering this taxon in her monograph of Russelia (Fieldiana Bot. 29: 285. 1957), correctly rejected it as a Russelia but re- ferred it to Anetanthus without comment. Few morphological details are available in the material on hand for an adequate comparison with Ane- tanthus gracilis except the larger stature, alate stems, and longer calyx. Chamisso and Schlechtendal (1828) referred Russelia alata to the Scrophulariaceae, as did Schmidt (1862). Bentham (in DC. Prodr. 10: 332. 1846) listed Russelia alata as a species dubia in the Scrophulariaceae be- 1975] HOWARD, ANETANTHUS (GES) CEAE) 365 fore associating it with Anetanthus in the Gesneriaceae in Genera Plan- tarum (1876). Anetanthus gracilis Hiern in Warming, Symb. Fl. Bras. 23: 93. 1877. The type collection, made by Warming in Lagoa Santa, Brazil, is repre- sented by three unnumbered sheets in the herbarium at Copenhagen. A drawing of a dissected flower accompanies one of these sheets and a single flower is in a packet. This specimen has been designated as the lectotype, for the other specimens are in fruit. Other specimens of Anetanthus gracilis have been seen from Brazil (Lagoa Santa, Minas Gerais, and Distrito Federal); Colombia (Dept. El Cauca and Meta); Peru (San Martin and Cusco); and Bolivia (San Carlos). Anetanthus parviflorus (Hooker & Arnott) Bentham & Hooker ex Jack- son, Ind. Kew 1: 133. 1893. (Cited as Anetanthus parviflora.) Trevirania parviflora Hooker & Arnott, Bot. Beech. Voy. 302. 1840. Dicyrta parviflora (Hooker & Arnott) Seemann, Bot. Voy. Herald 326. t. 69. 1856. This species was originally described from material collected by Lay and Collie in Mexico. The genus Trevirania Willd. was considered a synonym of Achimenes P. Br. by Bentham and Hooker (Gen. PI. 2: 998. 1876). The genus Dicyrta Regel was recognized as related to Achimenes by Bentham and Hooker (Gen. Pl. 2: 1000. 1876), and it is listed as a genus of two species in the Gesneriaceae by Willis (Dict. Fl. Plants & Ferns, 8th. ed. 361. 1973). In the treatment of the Scrophulariaceae for the Flora of Guatemala (Fieldiana Bot. 24(Part IX): 406. 1973), Standley and Williams list Anetanthus parviflorus in the synonymy of Stemodia peduncularis Bentham in DC. (Prodr. 10: 382. 1846). Dr. L. O. Williams reported (pers. comm.) supported. Anetanthus pusillus Glaziou, Bull. Soc. Bot. Fr. 58(Mem. 3f): 515. 1911. i i i i iated this name with a col- A published list of Glaziou collections associat eck numbered 19586 from Alto Macahé of Nova Friburgo. A very 66 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 1975] HOWARD, ANETANTHUS (GESNERIACEAE) 367 brief description of the plant as herbaceous with violet flowers has led subsequent workers to consider this name as a nomen nudum (Ind. Kew. Suppl. 5: 16. 1921). In spite of the discordant reference to the flower color, I believe the Glaziou collection to be a depauperate specimen of Anetanthus gracilis. Anetanthus villosus (Gardner in Hooker) Bentham & Hooker ex Jack- son, Ind. Kew. 1: 133. 1893. (Cited as Anetanthus villosa.) Tapina villosa Gardner in Hooker, Icon. t. 469. 1842. The genus Tapina Martius was placed in the synonymy of Sinningia (Gesneriaceae) by Bentham and Hooker (Gen. Pl. 2: 1004. 1876), but the species Tapina villosa was associated with the new genus Anetanthus. I have seen two sheets of the original collection (Gardner 3875). Data on a sheet in the British Museum indicated that the collection was made from dry cliffs of the rocky summit of the Serra de Natividade, Goyaz Province, Brazil, in February, 1840. The specimens examined differed from Anetanthus gracilis in the shape and lobing of the corolla, the ad- herence of all four anthers, the pubescent ovary, and the scaly rhizomes. The genus Goyazia, described by Taubert (Engler, Bot. Jahrb. 21: 451, 452. f. B. 1896) with a single species, G. rupicola, was based on a collec- tion (Ule 3180) from Serra Dourado, Brazil. Anetanthus villosus shares with it the characteristics of calyx, corolla, adhering anthers, pubescent ovary, and scaly rhizomes and should be transferred to this formerly mono- typic genus as Goyazia villosa (Gardner in Hooker) Howard, comb. nov. (BastionyM: Tapina villosa Gardner in Hooker, Icon. t. 469. 1842.) Neither Anetanthus nor Goyazia were mentioned by Ivanina in her pa- per “Applications of the carpological method to the taxonomy of 7 Gesneriaceae” (Notes Roy. Bot. Gard. Edinb. 26: 383-403. 1965). Al- though Goyazia is not known in fruit or with mature seeds, the aurea type, stomata, and scaly rhizomes suggest that it is a member ° “e Gesneriaceae. The familial association of Anetanthus is more difficult. Fritsch, in a treatment of the Gesneriaceae (Engler & Prantl, Nat. Pflan- zenfam. IV. 3b: 156, 157. 1895), placed the genus alone in his Cyrtan- droideae-Anetantheae, distinguishing the section from the Beslerieae - the basis of the dry two-lobed or two-valved capsule. The fruits an seeds of Anetanthus gracilis are unlike any illustrated by Ivanina. Ficure 1. a, Anetanthus al eo the pattern of collapsed cells of the top hair; type, Sellow s.n. (Zz). b, se ype of Tapina v: , 1 : g, Stemodia peduncularis, pollen grain from “Anetanthus parviflorus,” 2500; type of Trevirania parviflora, Beechey s.n. 368 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Dr. Umesh Banerjee kindly prepared pollen grains for the accompany- ing SEM photographs and compiled the descriptions which follow. The distinctness of “Anetanthus parviflorus” is evident and the similarity of Anetanthus gracilis, A. alatus, and Goyazia villosa is equally apparent. Anetanthus gracilis (FIGURE 1d). Pollen grains spheroidal or prolate, tri- colpate, colpi long tapering, colpus membrane with warty structures, pores absent, exine sculpture foveolate to reticulate, exine thickness 1.0 pm. Anetanthus alatus (Ficure 1b). Pollen grains prolate, tricolpate, colpi narrow and tapering toward the polar region, pores absent, exine sculpture typically reticulate, occasionally luminar areas consisting of small spheri- cal structures, exine thickness 1.0 pm. Goyazia villosa (FicureE 1f). Pollen grains prolate to prolate-spheroidal, tricolpate, colpi long tapering, colpus membrane showing distinct spherical warty projections in the pore region of the equatorial plane, pores absent, exine sculpture distinctly reticulate, exine thickness 1.0 pm. “Anetanthus parviflorus” (Ficure 1g). Pollen grains oblate, tricol- porate, colpi short with weakly defined pores in the equatorial plane, colpus membrane with warty structures, exine sculpture foveolate, exine thickness 1.5 um. The pubescence of these taxa consists of uniseriate multicellular hairs. Upon drying, adjacent cells commonly collapse at right angles to each other (Ficure la). This characteristic hair type and method of drying has been seen in a great many oe of the Gesneriaceae. In the Scro- phulariaceae the same hair type is common, but numerous other types of hairs from simple unicellular to Sti iislar-stellate or multicellular-uni- seriate hairs are found. On the basis of the material available to me, both Ametanthus and Goyazia seem appropriately placed in the Gesneriaceae if this family is to be considered as distinct from the Scrophulariaceae. ARNOLD ARBORETUM HARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 1975] HARTLEY, ZANTHOXYLUM (RUTACEAE) 369 A NEW SPECIES OF ZANTHOXYLUM (RUTACEAE) FROM NEW GUINEA * Tuomas G. Hartley SINCE THE PUBLICATION of my revision of the Malesian species of Zan- thoxylum (1966) and my additional notes (1970), a new species of the genus, collected in eastern New Guinea, has come to my attention. A description of this plant follows. ecimens were provided for this study by the C.S.I.R.O. Herbarium Australiense, Canberra (cans) and the herbarium of the Department of Forests, Lae, Papua New Guinea (Laz). Thanks are extended to the curators of those institutions. Zanthoxylum novoguineense Hartley, sp. nov. Arbor parva usque 5 m. alta, dioica, sempervirens. Ramuli novelli glabri vel sparse hirtelli. Folia imparipinnata; 34-70 cm. longa; rhachidi glabra vel sparse hirtella, anguste vel late alata (3-11 mm. utrinsecus) ; foliolis in paribus 2—3(—4), oppositis, sessilibus, chartaceis vel subcoria- ceis, pellucido-punctatis, subtus glabris vel sparse _hirtellis; foliolis la- teralibus anguste vel late ellipticis vel sublanceolatis vel ovatis, 10-34 cm. longis, 5—10 cm. latis, basi acuta vel obtusa vel rotundata, plerumque inaequilatera, venis primariis utrinsecus costa 8-12, margine integra vel interdum parcissime glanduloso-crenata, apice acuminato, acumine 1-3 cm. longo; foliolo terminali oblanceolato, 14-31 cm. longo, 5-12 cm. lato, basi attenuata, aequilatera, venis primariis et margine et apice ut in foliolis lateralibus. Infructescentia terminalis, 4.5-8 cm. longa, paniculata, ramulis patentibus; axe et ramulis glabris vel sparse hirtellis; pedicellis 2.5—4 mm. longis; sepalis persistentibus 4, triangularibus, 0.4-0.9 mm. longis; cicatrici- bus petalorum delapsorum 4; staminodiis 4. Folliculi subglobosi, 6-9 mm. lati, in pares vel interdum singuli cum carpello abortivo. Flores non visi. Hototypus: Pullen 5757 (CANB). Ficure 1. DistRIBuTION. Territory of New Guinea and Papua; lowland and foot- hill rain forests; sea level to 720 meters. See Map 1. man, April 26, 1972 (LAE). Papua. NORTHERN DISTRI Pongani Falls [about 25 miles SE of Popondetta], Pullen 5757 9 (cans, holo- type). : : e There are some rather minor differences between the material from th * This is the eighth in a series of papers on the Rutaceae of Malesia and Australasia. 370 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ATA ABS Sys” LOZ MS GURE 1. Zanthoxylum novoguineense Hartley. Fruiting branchlet, X %, lower surface of one leaflet shown (drawn from Pullen 575 a7, 1975] HARTLEY, ZANTHOXYLUM (RUTACEAE) $71 Buso River area and the single collection from Pongani Falls, the former being entirely glabrous, as opposed to sparsely hirtellous, and also having shorter pedicels and smaller sepals. Although the two localities are about 140 miles apart, they are connected by continuous lowland and foothill rain forest, so it seems possible that the two populations overlap and that these variants intergrade. Edaphic factors may have something to do with the differences at hand, since the Buso River is in an area of ultra- basic bedrock and Pongani Falls is in an area of volcanic rock and soil. Zanthoxylum novoguineense appears to be closely related to Z. megis- tophyllum (Burtt) Hartley, known from Papua and the Solomon Islands, and Z. forbesii Hartley, known from West Java and Sumatra. It has in common with these species a 2-carpellate gynoecium, a 4-parted perianth and androecium, and a similar habit. In addition, the general appearance of the branchlets, leaves, and infructescences is very similar in the three. The only other species of Zanthoxylum in Malesia with 2-carpellate gynoe- cia and 4-parted perianths and androecia, Z. backeri (Bakh. f.) Hartley and Z. retroflexum Hartley, are climbers with retrorse prickles and are obviously not closely related to the three species in question. The distant geographic isolation of Zanthoxylum forbesii from Z. no- voguineense and Z. megistophyllum (see Map 11) may suggest to some that its apparent close relationship is only superficial. While there is no evidence that would definitely refute this, I think it is more likely that climatic change. Van Steenis (1961) has put forward the idea that low ocean levels, and consequently greater land area, during glacial periods of the Pleistocene resulted in an expansion of monsoonal conditions in Malesia, especially in the regions of Central and East Java and the Lesser Sunda Islands. This is perhaps the best explanation for the discontinuity in question. On the other hand, of course, there are the possibilities that connecting populations remain to be discovered or that they have been destroyed by man’s activity. The most noticeable feature that distinguishes Zanthoxylum novo- guineense from Z. megistophyllum and Z. forbesii is its winged leaf rachis. This and other differences between the three species are given in the fol- lowing key, which also includes the changes required to accommodate Z. novoguineense in the key to species that was presented in my revision (pp. 175-177). The first couplet (p. 175) should be reworded as follows: . Branchlets armed, the prickles mostly flattened and predominantly pseudo- stipular; leaf rachises usually with conspicuous wings extending to as much as 6 mm. on either side; leaves less than 30 cm. long; perianth uniseriate or irregularly biseriate, of 6-8 segments. ........--.-----+--sseeeeees 2 — *A previously unpublished station for Zanthoxylum megistophyllum is included here: Papua, Gulf District, junction of the Kapau and Tauri rivers, Schodde & Craven 4614 (CANB). [vov. 56 JOURNAL OF THE ARNOLD ARBORETUM 372 * (sapsuei}) Aaplep asuaaumsoaou *7 pur ‘(sjop) Aapaey (yang) wnydyd -oysisau “7 ‘(sarenbs) Aap}1ey “‘nsaqaof wmnjtxoyunz JO SUOTINGIIYSIG “1 dvjAl 1975] HARTLEY, ZANTHOXYLUM (RUTACEAE) 373 1. Branchlets armed or unarmed, the prickles terete and cesses scattered ; leaf rachises terete or with narrow wings extending to not m on either side, or, if more broadly winged (to 11 mm. on st side), then the leaves more than 30 cm. long; perianth biseriate, of 4-5 sepals and 4-5 TAB oc ac os RO ee a The twelfth couplet (p. 176) should be reworded as follows and an ad- ditional couplet, 12a, added: 2. Leaves more than 30 cm. Mie: leaflets 2-5 pairs; leaf rachises winged or terete; wynoecium :2-carpellate.. 5 6 ee Se 12a. 12a. Leaf rachises winged; jects 2-3(—~4) pairs, eeesile. 0... ee PEs eran ce bois eri oes ee ee 6a. Z. novoguineense. 12a. Leaf rachises terete; leaflets 3-5 pairs, sessile or petiolulate. .... 13. 13. Leaves more than 70 cm. long; leaflets 4-5 pairs, the petiolules obsolete to 5 mm. Itee. 3.6 6. Z. megistophyllum. 13. Leaves less than 70 cm. long; leaflets 3-4 pairs, the petiolules —10 th OR ee 7. Z. forbesii. Leaves less than 40 cm. ‘long or with more than 5 pairs of leaflets; leaf rachises terete; gynoecium 1-carpellate. .. uc. 5 5 ok oasis 14. —_ bt = LITERATURE CITED Hart.ey, T. G. A revision of the Malesian species of Zanthoxylum (Rutaceae). Jour. Arnold Arb. 47: 171-221. 1966. . Additional notes on the Malesian species of Zanthoxylum (Rutaceae). Ibid. 51: 423-426. 1970 STEENIs, C. G. G. - VAN. Introduction iz M. S. van MEEUWEN, H. P. Noote- G. J. vAN STEENIS, Preliminary revisions of some genera of Malaysian Papilionaceae EL Reiesacdha 5: 420-429. 1961. HERBARIUM AUSTRALIENSE CS.ER.0. Division OF PLANT INDUSTRY CANBERRA, A.C.T. 2601 AUSTRALIA OURNAL © ARNOLD ARBORETUM should i. sent to Ms, Kathicen Clagett, 2 Divinity Avenue, Cambridge, Massachusetts 02138, ccepted after six months from the date of , and some bak numbers of couanes 46-50 print Corporation, Route 100, Millwood, - JOURNAL OF THE ARNOLD ARBORETUM Vou. 56 OCTOBER 1975 NUMBER 4 THE GENERA OF BROMELIACEAE IN THE SOUTHEASTERN UNITED STATES 1 LYMAN B. SMITH AND CarroLu E, Woop, Jr. BROMELIACEAE A. L. de Jussieu, Gen. Pl. 49. 1789, ““Bromeliae,” nom. cons. (BROMELIA FAMILy) Perennial, stemless or sometimes caulescent herbs, [terrestrial to] opti- ing from narrowly and regularly triangular (with a dense indument) to *Prepared for the Generic Flora of the Southeastern United States, a joint proj- ect of the Arnold Arboretum and the Gray Herbarium of Harvard University made nnessee, Alabama, Mississippi, Arkansas, and Louisiana. The descriptions apply primarily to the plants of this area, with ie. aera information in brackets. References not seen by either author are marked with a In this collaborative effort the senior author has saab to bear his monographic interest and experience in the Bromeliaceae and the junior author has added ob- servations applicable especially to the southeastern United States. The literature references are intended to sample both the taxonomic and general biological literature, well as some of the pertinent horticultural references on this fascinating family. We are indebted to Julien Marnier-Lapostille for preserved material of Guzmania; to Richard A. Howard for living material of Catopsis, Guzmania, and i illandsia ; Avery for their generosity in sharing their field knowledge of Florida bromeliads at various times nu the plants used in the illustrations, all of which were prepared from living material, were grown to flower or fruit in Boston, Massachu- setts, in the greenhouse of Theodore J. Schultz. The illustrations were drawn b Dorothy H. Marsh, in Savage, Karen S. Velmure, and Sydney B. DeVore under the direction of the junior author, who prepared the dissections. © President and ain of Harvard College, 1975. 376 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 liguliform (with an inconspicuous indument), the indument consisting of peltate scales, the leaf margin entire or spinose-serrate. Inflorescence terminal or lateral or pseudolateral by the elongation of the stem (sym- podial), usually scapose, indeterminate, branched or simple, rarely one- flowered, usually bearing brightly colored conspicuous distichous or poly- stichous bracts, each with an axillary flower. Flowers perfect, 3-merous, regular. Perianth of 2 differentiated whorls, the sepals and petals free or connate. Stamens 6, in 2 series of 3; filaments free or agglutinated or adnate to the petals; anthers basifixed or dorsifixed, introrse, dehiscing by vertical slits; pollen ellipsoid or globose, 1-sulcate or 2- [3- or 4-]porate [or polyporate]. Gynoecium 3-carpellate, syncarpous; style 3-parted; stigmas 3, often spirally twisted; ovary superior or inferior, 3-locular; pla- centae axile, extending the length of the locule or variously reduced (e.g., apical in Ananas) ; ovules usually numerous, anatropous, the 2 integuments nearly equal. Fruit a capsule Jor berry]. Seeds plumose [or winged or naked]. Embryo small, situated at the base of the abundant mealy endo- sperm. TYPE GENUS: Bromelia L. An almost exclusively neotropical family of about 45 genera with some 2000 species, but including two genera of temperate latitudes in Chile and one species (Pitcairnia Feliciana (A. Chev.) Harms & Milbraed) na- tive to westernmost Africa. Three native genera and one introduced genus occur in our area The family is delimited by its mealy endosperm, regular (actinomorphic) or subregular trimerous flowers with contrasting sepals and petals (hetero- chlamydeous), and trilocular ovary usually with numerous ovules. How- ever, Bromeliaceae are identifiable even when sterile, by the curious indu- ment of peltate scales. The flowers are relatively simple, showing scarcely any reduction of parts in the direction of the Eriocaulaceae or any ten- dency toward zygomorphy in the direction of the higher Commelinaceae and Pontederiaceae. In fact, the Bromeliaceae would seem to be the most primitive family of the order Farinosae, and some recent authors have emphasized this by placing the family in an order of its own Division into three nearly equal subfamilies is primarily on the basis of fruit and seed characters, along with some good vegetative correlations. In the Pitcairnioideae * the fruit is dry and usually dehiscent, with the t the rank of subfamily, the name Navioideae Harms (1929) has priority over pee Harms (1930) when both Navia and Pitcairnia are included i same subfamily, as in the present classification. The first use of the rank subfamily in the Bromeliaceae appears to have been by Harms, who in 1930 raised the con- ventional tribes Pitcairnieae Meisner (84a), Tillandsieae Dumortier (1829), and Bromelieae Dumortier (1829) to subfamilial rank and recognized Navioideae Harms (1929) as a fourth subfamily. In his treatment in Das Pflanzenreich (1934), however, Mez used only three subfamilies, Pitcairnioideae, Tillandsioideae, and Bromelioideae, in his classification, reducing Navioideae to the rank of tribe under Pitcairnioideae. These three subfamilial names, which have ni used in all of the subsequent me 3 o n of the name Navioideae for the subfamily that includes both Navia and Pit- 1975] SMITH & WOOD, BROMELIACEAE 377 carpels always distinguishable and the seed with entire appendages or rarely with none. The leaves are almost always spinose-serrate, and the arrangement of cells in their scales is quite irregular. With rare ex- ceptions the plants are terrestrial or saxicolous. The Pitcairnioideae do not occur in our area but approach it closely in Cuba and in Texas. The Tillandsioideae resemble the Pitcairnioideae in the always dry, de- hiscent fruit, but the seeds have plumose appendages, and the leaves are invariably entire. The cells of the leaf scales are arranged in a bicied geometric pattern with four equal ones in the center (cf. Ficure 2, 1). The plants generally are epiphytic. All three of our indigenous genera belong to this subfamily. The Bromelioideae are unique in the family in their baccate fruit with wholly united carpels and are almost unique in their unappendaged seeds. The leaves with their marginal spines and unorganized scales are very similar to those of the Pitcairnioideae and have led some students to con- sider these subfamilies to be much more closely related to each other than to the Tillandsioideae. The trend toward epiphytism in the Bromelioideae is about midway between the two other subfamilies. Ananas, which has some record of persistence in southern Florida but which is included here only tentatively as naturalized, is strictly terrestrial. he leaf in the Bromeliaceae is considered by some to be a phyllode, but the evidence is not wholly convincing and must be adjusted to the for- mation of a new sheath, blade, and petiole in the case of a number of spe- cies. There is always some distinction between sheath and blade, and usu- ally it is quite marked. The blade usually varies from narrowly triangular to liguliform, with no contraction at base in either form, but occasionally it can be broadly elliptic, with a slender petiole. In at least the Tillandsioideae and Bromelioideae, the leaf scales have evolved into very effective organs for absorbing water and transmitting it to the interior of the leaf. In the epiphytic species the scales have taken over the function of the roots and absorb organic compounds as well. Their distribution on the leaf surface correlates with the habit and habitat of the two common epiphytic types. In the more or less caulescent xero- phytic type with narrow leaf blades, the scales completely cover the blades, protecting them from the sun and giving an even supply of water that is wholly taken up by the leaf tissue. In the rosette mesophytic type, the broad leaf blades carry the water to the tanks formed by the sheaths, and the scales of the blades are reduced, while those of the sheaths become more important in the absorption of both organic and inorganic com- cairnia would cause — confusion, it is proposed that the provisions of Article 1 of the International de of Bot nee Nomenclature (1972), which allows for o gen enus inclusive,” be invoked, and that 102. 19 0, nom. cons. prop. TyPE: Pitcairnia L’Heritier. Subfam. Navioidene Harms, Notizbl. Bot. Gart. Mus. Berlin-Dahlem 10: 575. 1929, nom. rejic. prop. Type: Navia Martius ex Schultes f. 378 JOURNAL OF THE ARNOLD ARBORETUM [VoOL. 56 This second type of habit, with water stored in the rosette, allows a sym- biotic relationship with many more or less aquatic species of plants and animals, furnishing shelter and receiving materials from waste products. In our area this relationship is confined to southern Florida and, to date, has not involved any insects that are carriers of disease, although in a few more tropical areas bromeliads have harbored malaria-carrying mosquitoes, to the detriment of public health. The possibility of the host plant’s being directly insectivorous has been explored and disproved. The primitive type of inflorescence appears to be a many-flowered ter- minal panicle, which has evolved by reduction to such extremes as the one-flowered pseudolateral (actually terminal) inflorescences of Tilland- sia usneoides and the spicate compound fruit of Ananas. The family is almost unique in its flowering response to chemical stimuli such as car- bide, rocket fuel, and even ripening apples. Pollination is by insects and birds, especially hummingbirds, and by bats in the case of some night-blooming species. Erdtman & Praglowski divide the family into two groups on the basis of pollen morphology (ca. 125 spp. in ca. 40 genera), the first with 1-colpate pollen grains, the second with 2-, 3-, 4-porate to polyporate grains. The pollen of all of the Pitcairnioideae and Tillandsioideae is of the 1-colpate type, but in the Bromelioideae both types occur and both are found in the genus Aechmea. Chromosome counts made for 21 genera and about six pei cent of the known species are 2n = 32, 34, 36, 42, 46, 48, 50, 52, 54, 56, 57, 64, 72, 75, 96, 98, 100, 108, 126, and 150. These counts show little relation to subfamily grouping, except in the Pitcairnioideae, where the base number appears to be 25, and they vary within genera so that little can as yet be inferred from them. In addition, the identification of the plants from which many of these counts were obtained is suspect, and four of six principal papers on chromosome numbers apparently are not backed by voucher specimens. (See McWilliams in Smith & Downs for a review.) Economically, the family is most noted for the pineapple, Amanas co- mosus, but Tillandsia usneoides has been used for pillow and mattress stuffing, especially in our area, and several species furnish strong fibers for cordage. Horticulturally, the Bromeliaceae are enjoying considerable popularity, and some exotic species have been recorded as spontaneous in Florida, although it remains to be seen if they will persist. For a fuller summary of general information about the family see Bromeliales in Encyclopedia Britannica, ed. 15, 1974, and Smith & Downs (1974, introduction). REFERENCES: In addition to those listed below, see L. B. SmitH, Studies in the Bromelia- ceae, I-XIII, published in Contr. Gray Herb. 89-154, 1930-1945, and Notes on Bromeliaceae, I-XXXVII, published in Phytologia 4-30, 1953-1975. Nu- merous notes and articles on bromeliads and their cultivation will be found in The Bromeliad Society Bulletin, 1-20, 1951-1970, continued as Journal of the Bromeliad Society, 21-, 1 1975] SMITH & WOOD, BROMELIACEAE 379 BAILLON, H. Broméliacées. Hist, Pl. 13: 86-118. 1895. BAKER, J. G. Handbook of the Bromeliaceae. xi + 243 pp. London. 1889. BENTHAM, G., & J. D. Hooker. Bromeliaceae. Gen. Pl. 3: 657-670. 1883. BENZING, D. H. Significance of patterns of CO, exchange to ecology and phylo- geny a Tillandsioideae (Bromeliaceae). Bull. Torrey Bot. Club 98: 322- S27 1977. ———. Monocotyledons: their evolution and comparative biology. I. Mineral nutrition and related phenomena in Bromeliaceae and Orchidaceae. Quart. Rev. Biol. 48: 277-290. 2. & A. RENFROW. Significance of photosynthetic efficiency to habitat preference and phylogeny among tillandsioid bromeliads. Bot. Gaz. 132: 19-30. 1971. [Includes Tillandsia (14 spp.), Catopsis (3 spp.), Guzmania 2 spp.), Vriesea (2 spp. BEUTELSPACHER, C. R. Some observations on Lepidoptera of bromeliads. Lepidopterists Soc. Jour. 26: 133-137. 1972. Bonny, G. Contribution a l’étude anatomique des Broméliacées. Adansonia II. 8: 551— 1968. Broapway, W. E., & L. B. SmirH. The Bromeliaceae of Trinidad and Tobago. Proc. Am. Acad. Sci. 68: 152-188. 2 pls. 1933. (Reprinted as Contr. Gray Herb. 102(2).) BUDNOWSKI, ae _" Septaldriisen der Bromeliaceen. Bot. Arch. 1: 47-80, 101- 105. Carasi, J. P. Oe Bromeliaceas de Cuba. I-IV. Mem. Soc. Hist. Nat. 14: 329-347. 1940; 15: 245-258, 265-279, 359-374. CASTELLANOS, A. Bromeliacese: we H. R. DEscoLe, ed., il et species plantarum argentinarum. Vol. 3. 383 pp. pls. 1-133. Bonariae [Buenos Aires]. 1945. Bromeliaccae, pee pls. 22-133.] CuHapmMan, A. W. Flora of the southern United States. ed. 3. xxxix + 655 pp. Cambridge, Mass. 1897. [ Bromeliaceae, 497-499. | CHEADLE, V. I. Conducting elements in the xylem of the Bromeliaceae. Bro- meliad Soc. Bull. 5: 3-7. 1955. CHEVALIER, C. On the reciprocal action of the parents among the Bromeliaceae. Bromeliad Soc. Bull. 2: 39-41, 48. CoRNELISON, F. Tragedy in the Everglades. Jour. Bromeliad Soc. 21: 117. 1971. [Destruction by fire of bromeliads (including a variegated form of Guzmania monostachia) in the Big Cypress Swamp in a CraIcHEAD, F. C. Orchids and other air plants of the Everglades National Park. 127 pp. + color pls. 12-19. Univ. Miami Press, Coral Gables, Florida. 1963. [Bromeliaceae, 52-71, color pls. 13, 14B, 15C, D; treats all of our indigenous species, including Tillandsia Bartramii (as T. simula- ta), which does not occur in southern Florida. Includes the best biological notes available for most of our species. | Cutak, L. Micro-organisms found in bromel water-cups at the Missouri Botanical Garden. Bromeliad Soc. Bull. 3: 15-18. 1953. DOUTRELIGNE, J. Les divers “types” de structure nucléaire et de mitose so- matique chez les phanérogames. Cellule 48: 191-212. pls. 1-3. 1939. [Includes Ananas microcephala, Billbergia < Windii, Lindmannia penduli- flora, Nidularium latifolium, Pitcairnia pulverulenta, Vriesea splendens. | Downs, R. J. Photocontrol of germination of seeds of the Bromeliaceae. Phy- ton Buenos Aires 21: 1-6. 1964. ErptMAN, G. Pollen morphology and plant taxonomy. Angiosperms. xii + 380 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 539 pp. frontisp. Stockholm; Waltham, Mass. 1952. [Bromeliaceae, 81, 8 ——. On the pollen morphology in the ee Bromeliad Soc. Bull. 8: 70. 1958. [See also ErpTMAN & PRAGLOWSKI in SMITH & Downs. |} Foster, M. B. The bromeliads of pes: sis Smithson. Inst. 1949: 351- 365. 10 pls. 1943 . Bromeliads, a cultural handbook. By Mutrorp B. Foster and other members of the Bromeliad Society. 64 pp. Orlando, Florida. 1953. Re- issued, 1974. GatTin, C. L. Premiéres observations sur l’embryon et la germination des Broméliacées. Revue Gén. Bot. 23: 49-66. 1911. GAUTHE, J. Contribution 4 l'étude caryologique des Tillandsiées. Mem. Mus. Natl. Hist. Nat. Paris Bot. 16: 39-59. 1965. [Undocumented counts; see ] GrtmartTin, A. J. Trichomes of some Ecuadorian Bromeliaceae. Morris Arb. Bull. 23(2): 19-23. 1972 . Variance of phenetic affinities with different randomly selected char- acter sets in an alpha-numerical taxonomic study of the Bromeliaceae. (Abstr.) Am. Jour. Bot. 54: 655. 1967. ———. Transandean distributions of Bromeliaceae in Ecuador. Ecology 54: 1389-1393. 1973. Grar, A. B. Exotica 3. Pictorial cyclopedia of exotic plants. 1834 pp. Roehrs Co., Rutherford, N. J. 1968. arco . Bromeliaceae on pp. 39 466, including Catopsis floribunda, C. berteroniana, C, nutans, Guzmania monostachia, Tillandsia Balbisiana, T. cabaaey ¥; ‘fasciculata, T. flexuosa, T. pruinosa, T. polystachia, T. recurvata, T. usneoides, T. utriculata, T. Valenzuelana. See also short descriptions: Catopsis, 1569; Guzmania, 1622; Tillandsia, 1725-1727 HALL, J. How the native bromeliads took the cold in Florida. Bromeliad Soc. Bull. 8: 6, 7. 1958. [Exposure to 24°-15° F. in various parts of Florida; Tillandsia spp., Catopsis, Guzmania. | Harms, H. Bromeliaceae. Nat. Pflanzenfam. ed. 2. 15a: 65-159. 1930. HEGNAUER, R. Chemotaxonomie der Pflanzen. Band 2. Monocotyledoneae. 540 pp. Basel & Stuttgart. 1963. coe erat 99-109. HutcuHinson, J. Bromeliaceae. Fam. Fl. Pl. ed. 2. 2: 576-581. 1959. MER, J. Bromeliads, the colorful house ao Drawings and photos by A. R. AppKIson. x + 113 pp. Princeton, N. 965. eae H. “Raphidenpollen’” bei iroeliaceery: Bestach: Bot. Ges. Ber. ; 388-393. 1942. KUPRIANOVA, L. A. Pollen morphology and phylogeny of the monocotyledons. (In Russian.) Trudy Bot. Inst. Komarova Acad. Nauk SSSR. 1. Syst. (Acta Inst. Bot. Acad. Sci. URSS. 1. Syst.) a. 163-262. 1948. [Bromelia- ceae, 235, 236.] Linpscuavu, M. Beitrage zur Zytologie der Bromeliaceae. Planta 20: 506- 530. 1933. [Undocumented chromosome counts for 47 spp.]| Luspock, J. A contribution to our knowledge of seedlings. 2 vols. London & New York. 1892. [Bromeliaceae, 2: 569-571. McWILIiams, E. Comparative rates of dark CO, uptake and acidification in the Bromeliaceae, Orchidaceae and Euphorbiaceae. Bot. Gaz. 131: 2 290. 1970. MarcHANT, C. J. Chromosome evolution in the Bromeliaceae. Kew Bull. 21: 1975] SMITH & WOOD, BROMELIACEAE 381 161-168. 1967. (See also GAUTHE, LinpscHAU, McWILLIAMs in SMITH & Downs, SHaRMa & GosH, and WEIss Martin, A. C. The comparative internal morphology of seeds. Am. Midl. Nat. 36: 513-660. 1946. [Bromeliaceae, Meyer, L. Zur Anatomie und Entwicklungsgeschichte an Bromeliaceenwurzeln. Planta 31: 492-522. 1940. Merz, C. Bromeliaceae. Im: C. F. P. von Martius, FI. — — 173-280. 1891; 281-424. pls. 51-62. 1892; 425-634. pls. 63-8 Bromeliaceac. In: C. DE CANDOLLE, Monogr. ipo 9: Ixxvii, 1- 990. 1896. Bromeliaceae. Pflanzenreich IV. 32(Heft 100): 1-160. 1934; 161- 667. 1935. [Latest complete monograph. ] Naytor, E. E. Air plants and their problems of survival; how specialized roots and leaves = them live above the ground. Jour. New York Bot. Gard. : 55-64. NEILL, Ww. A Fos’ s air-plants | Bromeliaceae] and their inhabitants. Florida Nat. 24: 61-66. 1951. Noxan, G. C. Bibliography of Bromeliaceae. Bromeliad Soc. Bull. 4: 31-34. 1954. [See also R. Foster, More about the literature on the Bromeliaceae. Ibid. 10: 61, 62, 72, 73. 1960. Orre: fF. & A. Drerricn. Bemerkungen uber die Familie der Bromeliaceen und "Beschreibung der noch wenig bekannten schonbliihenden Ananassa bracteata Lindl. Allg. Gartenz. 12: 377-379. 1844. PADILLA, V. Bromeliads in color and their culture. A compilation from the bulletins of the Bromeliad Society. vi + 125 pp. Los Angeles. 1966. [In- cludes a key to subfamilies and genera, 11-13; Guzmania monostachia, 47.] . Bromeliads, a descriptive listing of the various genera and the species most often found in cultivation. x + 134 pp. New York. 1973. Picapo, C. Les Broméliacées épiphytes, considérées comme milieu biologique. Bull. Sci. France Belg. VII. 47: 215-360. pls. 6-24. 1913 PITTENDRIGH, C. S. The bromeliad-Anopheles-malaria complex in Trinidad. I. The bromeliad flora. Evolution 2: 58-89. RavuH, W. Bromelien fiir Zimmer und Gewachshaus. “Band 1. Die Tillandsioi- colored pictures, 141 half-tones, 44 line drawings). Stuttgart. 1973. Rickxett, H. W. Wild flowers of the United States. Vol. 2. The Southeastern States. Part 1. x + 322 pp. New York. 1966. [Bromeliaceae, 84-88, pls. 27, 28, 29; includes excellent color photographs of species of Catopsis, Guzmania, and T: illandsia. RoHWEDER, O. Die Farinosae in der Vegetation von El Salvador. Univ. Ham- burg Abhandl. Gebiet Auslandskunde Band 61. Reihe C. Naturwiss. Band 18. xvi + 199 pp. 36 pls. 1956. [Bromeliaceae, 18-97 ScHuiz, E. Beitrage zur physiologischen und phylogenetischen Anatomie der vegetativen Organe der Bromeliaceen. Bot. Arch. 29: 122-209. 1930. SHARMA, A. K., . GosH. Cytotaxonomy of the family Bromeliaceae. Cy- tologia 36: 237-247. 1971. [Undocumented counts for 15 spp. in 7 gen- era; not included in McWrttiaMs im SMITH & Downs SMALL, J. K. Cypress trees and air-plants. a. New York Bot. Gard. 33: 117-123. 1932. [Abundance of Tillandsia on Taxodium ascendens (up to 382 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 6 spp. on a single tree) in contrast with its paucity on Taxodium distichum. | . Bromeliads and pinetrees. /bid. 34: 165-170. 1933. [Tillandsia spp. on various spp. of Pinus in Florida. ] SmitH, L. B. Geographical evidence on = lines of evolution in the Bromelia- ceae. Bot. Jahrb. 66: 446-468. . Bromeliaceae. N. Am. Fl. 19: pe 228. 1938. . Bromeliaceae. Jn: C. L. LUNDELL et al., Fl. Texas 3: 200-207. 1945. . Bromeliaceae. Jn: R. E. Woopson, Jr., & R. W. ScHery, Fl. Panama. Ann. Missouri Bot. Gard. 31: 73-137. 1944. . The subfamilies and genera of the Bromeliaceae. Pl. Life 1: 40-44. 47. Bromeliad malaria. Rep. Smithson. Inst. 1952: 385-398. pls. 1, 2. _ The Bromeliaceae of Brazil. Smithson. Misc. Coll. 126(1): vii + 290 pp. 1955. e Bromeliaceae of Colombia. Contr. U. S. Natl. Herb. 33: 1-311. 1957. With keys, descriptions, enumeration of specimens, and 88 illustra- peal by R. J. Downs. e oriental of the bromeliads. Bromeliad Soc. Bull. 8: 19, 20. 1958. [Pitcairnia Feliciana in West Africa (Guinea). ] . Bromeliaceae. Jn: T. Lasser, Fl. Venezuela 12(1): 1-361. 1971. Bromeliales. Jn: Encyclopedia Britannica. ed. 15. 2: 323-327. 1974. & R. J. Downs. Bromeliaceae subfamily Pitcairnioideae. Flora Neo- tropica Monogr. 14. ii + 658 + ii pp. Hafner Press, New York. 1974. [First part of a monograph of the family. Introduction by L. B. S. e¢ al. includes: R. J. Downs, Anatomy and physiology, 2-28; G. ErRpTMAN & J. PRacLowsk1, Note on pollen morphology, 28-33; E. L. MCWILLIAMS, Chromosome numbers and evolution, 33-40; E. L. McWr1ams, Evolu- tionary ecology, 40-55; L. B. Smiru, Hybridization, fossils, geographical distribution, 5 5-5 7; extensive bibliography, 58-64. | _ LUNDELL. The Bromeliaceae of the Yucatan Peninsula. Car- negie Inst. Publ. 522: 103-136. 1940. [Botany of the Maya Area Misc. Paper 16.] & C. S. PIrTenprIcH. Realignments in the Bromeliaceae iat Tillandsioideae. Jour. Washington Acad. Sci. 43: 401-404. 1953. a P. B. Scales in Bromeliaceae. Bull. Fairchild Trop. hie 21(2): 3. 1966 ——. Co hee ve 6: S. Metcatre, ed., Anatomy of Monocotyledons. Vol. 3. xx + 446 pp. en Press, Oxford. 1969. anise ons 193- sib detailed, illustrated account; includes most of Spp. WEIsS, HL E. Etude caryologique et cyto-taxonomique de quelques Broméli- acées. Mem. Mus. Natl. Hist. Nat. Paris. Bot. 16: 9-38. 1965. Undocu- mented counts; see also GavTHe, ] WETZEL, K. Beitrag zur Anatomie der Sanghaare von Bromeliaceen. Flora 117: 133-143. 1924. Witson, R. G., & C. Witson. Bromeliads in cultivation. Vol. 1. 126 pp. Coconut Grove, Florida. 1964. [Includes genera “A” to “G”; Catone 63, 64. WirrMack, L. Bromeliaceae. Nat. Pflanzenfam. II. 4: 32-48. 1887; 49-59. 1888. Supplement in Nachtrage z. II-IV. 61-69. 1897 1975] SMITH & WOOD, BROMELIACEAE 383 ZIEGENSPECK, H. Ueber einen starkeahnlichen léslichen Stoff im Fruchtknoten von Bromeliaceen. Bot. Arch. 8: 303, Analyse des belebten Kohasionsmechanismus der Wasserspeicher in den Bromeliaceenblattern. Ein Beitrag zur physikalischen Chemie der Quellungs- und Kohasionsmechanismen. Ibid. 37: 267-327. 1935. [In- vestigations on Billbergia. ZIMMER, K. Germination of Bromeliaceae. e German; English summary.) Gartenbauwissenschaft 38: 171-177. 1973.* Key To THE GENERA OF BROMELIACEAE IN THE SOUTHEASTERN UNITED STATES A. Fruit dry, capsular; seeds plumose; ovary usually superior; leaves always entire. Subfam. TILLANDSIOIDEAE B. Principal seed appendage basal, not outgrowing es capsule and there- fore straight; stamens usually equal or nearly s C. Petals free; flowers eee distichously (in two rows) or solitary [rarely solvsticluius in a single spike, but the plant with nar- rowly triangular: teal binds fo . : Tillandsia. C. Petals closely agglutinated in a tube at least to the cos of the sepals (when weakly so, the inflorescence simple and the leaf blades een). flowers always arranged polystichously. .. 2. Guzmania. B. Principal seed appendage apical, growing eae than the capsule and therefore folded over; stamens strongly unequal. ....... 3. Catopsis. A. Fruit fleshy, baccate; seeds naked at maturity aouh the ovules often appendaged); ovary inferior or nearly so; leaves nearly always spinose- Berens, “Uta, PIBOMELICUOEAR. aa we 4. Ananas. Subfam. TILLANDSIOIDEAE Harms 1. Tillandsia Linnaeus, Sp. Pl. 1: 286. 1753; Gen. Pl. ed. 5. 138. 1754. Mostly epiphytic, caulescent or acaulescent plants of very diverse hab- it; roots reduced to wirelike holdfasts or completely lost. Leaves rosu- late or fasciculate or distributed along a stem, polystichous or distichous, entire; blades liguliform or triangular or filiform. Scape usually distinct. Inflorescence terminal or rarely lateral or pseudolateral by the elonga- tion of the stem, usually of distichous-flowered spikes [or sometimes a single polystichous- flowered spike formed by the reduction of the spikes to single flowers], or rarely the whole inflorescence reduced to a single flower. Sepals usually symmetrical, free or equally joined or only the two posterior ones joined. Petals free, naked. Stamens mostly equal or subequal, of various lengths relative to the petals and gynoecium; pollen l-sulcate. Ovary superior, glabrous; ovules usually many, apically cau- date. Capsule septicidal. Seeds erect, narrowly cylindric or fusiform; the short apical appendage undivided, the large plumose basal appendage straight, white. (Renealmia L., 1753, not Renealmia L. f., 1781, nom. cons.; Caraguata [Plumier] Adanson, 1763; Dendropogon Raf., 1825; Strepsia Nutt. ex Steudel, 1841; Diaphoranthema Beer, 1854; Phytar- rhiza Vis., 1855.) Lectotype species: T. utriculata L.; see Britton & Ficure 1. Tillandsia subgenus Tillandsia. a—j, T. utriculata: a, plan with flowers and fruit, ; b, cross section of flower — note three ante pained free petals, six staminal filaments free from petals, sap gatos ovary Wi axile Lenieis ge < 6; ¢, anther, adaxial side, X 6; d, upper part of syle with s oN 17 ovule at time of anthesis, the apex caudate, the micro- oie helow a right), x 25; f, part of inflorescence branch with possi nearly mature fruits, X 14; rtly mature seed oriented as in “e.” < 6; h, mature see x pla AE with developing nt, x % Eh, sim ulata) : 1, ar salle on plant, X 4; m, sneoreecenee with open flower, X 1; n, flower, showing tubular eels ee imbricate sepals, X 1%. 1975] SMITH & WOOD, BROMELIACEAE 385 Millspaugh, Bahama Fl. 64. 1920. (Name in honor of Elias Tillands, professor in Abo [Turku], Finland, 1640-1693; also a play on words, since the name means “by land,” in reference to the professor’s abhor- rence of travel by water and Linnaeus’s mistaken idea that the scales of Tillandsia served to shed water.) — WILD PINE. A genus of over 400 species in seven subgenera, ranging from coastal Virginia, through the West Indies and Mexico, to central Argentina and Chile; represented in our area by 12 native species in two subgenera and a single introduced species in a third subgenus. The three subgenera of Tillandsia in our flora are all widely divergent from the ancestral type of the northern Andes, subg. ALLARDTIA, and presumably have arrived by different routes. Subgenus TILLANDSIA ex- Small’s Manual of the Southeastern Flora, disregarding the complete pic- ture, divides Tillandsia into three separate genera. While there may be some grounds for separating Dendropogon and Diaphoranthema from Tillandsia on the floral characters, to take Diaphoranthema from Dendro- pogon on a purely habital basis would logically require a genus for each species of Tillandsia. Subgenus TILLANDsIA, with petals erect and forming a long tube, sta- mens exserted, and style elongate, includes over 100 species distributed from southern Georgia and southern Texas to central Brazil and Bolivia, with the greatest concentration in Mexico. The subgenus is represented in our area by ten species that range in size from Tillandsia utriculata L.., which may form rosettes 1.2 m. across and paniculate inflorescences 2 m. tall, to T. pruinosa Sw., which may be only 7.5—15 cm. tall, with the inflorescence reduced to a 2—5-flowered spike. Other representatives are zuelana A. Rich., T. circinnata Schlecht., T. polystachia (L.) L., fasciculata Sw. (T. hystricina Small), T. setacea Sw. (T. tenuifolia : authors, not L.; see Smith, 1962), and T. Bartramii Ell. (T. juncea of authors, not (Ruiz & Pavon) Poiret, T. myriophylla Small, T. simulata Small; see Smith, 1966). All except the last species are well known in the West Indies, and some have more extensive distributions. Tillandsia Bartramii is the most northern species of the subgenus, its range extending from midpeninsular Florida northward well into Georgia (Ben Hill and Liberty counties) and apparently at least formerly into southeastern South Carolina (cf. Leavenworth [cH]). Tillandsia utricu- lata reaches southern Georgia, but all of the others, with the possible ex- ception of T. fasciculata (see Brooks), are limited to Florida. At the southern edge of its range in central Florida (e.g., in Polk Coun- ty), Tillandsia Bartramii can be found growing on the same tree with T. setacea, there near its northern limit. Although the two are frequently 386 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 FIGURE 2. Tillandsia La Diaphoranthema. a, b, T. rec rie baie a, fruit- ing plant on branchlet, X 14; b, single stem mith ‘open capsule and seeds — note sympodial growth by axillary shoot at left, x %. c-l, T. usneoides: ¢, stem with flower and open fruit, x 4; d, flower, x 25 «, flower with 2 sepals, 2 petals, and 5 stamens removed to show gynoecium, X 2; f, cross section of ovary, diagrammatic, X 15; g, gynoecium in vertical section to show placenta- tion and stylar canal, diagrammatic, x 15; placenta and ovules from one a X 20; i, open capsule with seeds, X 2; j, seed with sg appendage of hairs, X 2; k, seedling, & 4; 1, small scale from leaf, x 5 confused, they are quite distinct (see Smith, 1966), and hybrids between them are unlikely, since T. Bartramii flowers in spring, while T. setacea flowers in August and September. Another spring flowering species, T. 1975] SMITH & WOOD, BROMELIACEAE 387 fasciculata, in the northern part of its range in Florida, occurs with T. Bartramii, which is extremely variable in this area, strongly suggesting a hybrid swarm. The chromosome number of T. Bartramii has not yet been reported, but counts of 2n = 64 and 2m = 56 have been recorded for T. fasciculata and T. setacea, respectively. Subgenus PHYTARRHIZA (Vis.) Baker, members of which have large and showy, broadly elliptic to orbicular petal blades and stamens that are deeply included but exceed the very short style, comprises 35 species native from Uruguay and northern Argentina to Trinidad and Central America. Tillandsia Lindenii Regel, 2n = 64, of Peru, is widely culti- vated and is apparently established in Florida in the Tampa region. Subgenus D1aPHORANTHEMA (Beer) Baker includes some 26 species of relatively small plants with simple inflorescences; small, narrow, in- conspicuous petal blades; and stamens that are deeply included but ex- ceed the very short style. Its species cover the whole American range of the family, and the two in our area, T. recurvata (L.) L. (Diaphoran- thema recurvata (L.) Beer) and T. usneoides (L.) L. (Dendropogon usneoides (L.) Raf.), are the most widely distributed members of the family. Tillandsia usneoides, Spanish moss, long moss, Florida-moss, wood-crape, or crape-moss, 27 = 16, extends along the Coastal Plain from Virginia to Florida and Texas (rarely entering the Piedmont south- ward), on into Mexico, and is scattered southward through Central America and the West Indies to central Argentina and Chile, always in relatively humid habitats. Growing on trees in weird-looking, long, gray festoons and often very abundant, it attracts attention in the south- eastern United States in a way no other plant does. In 1969 a mysterious blight was reported to be destroying Spanish moss in ten counties in Florida and later on more extensively in Florida, as well as in south- eastern Georgia, South Carolina, and Mississippi. Insects, viruses, and air pollution were suspected variously, but Roberts, Jensen, & Weber showed that the blight was caused by a fungus, Fusarium solani (Mart.) Appel & Wr. The plant now appears to be recovering in most areas. For details of the structure, life history, and ecology of T. usneoides, see es- pecially Billings; Garth; Guard & Henry; Penfound & Deiler; and Tom- linson. Tillandsia recurvata, ball moss, occurs in more xeric habitats than those of T. usneoides in Florida, Louisiana, and Texas, and is the only bromeliad in Arizona. It is widely distributed through the West Indies, Mexico, and Central America to northern Argentina and Chile. Considerable eco- typic differentiation must be involved, since it occupies a variety of habi- tats from tropical lowland to upland semidesert areas. REFERENCES : For a key to all of the species of Tillandsia, see SMITH, 1970, below. Most of the family references include Tillandsia in one way or another, but see CRAIGHEAD for the best biological notes on most of our species. Beecuer, H. A., & L. Duncan. An unusual distribution of Tillandsia simulata 388 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 frie Florida Sci. 36: 91, 92. 1973. [T. Bartramii, westernmost locality, OO Se along the lower Apalachicola River, Liberty-Franklin counties, BENNETT, “s B. Spanish moss and some aspects of its commercial possibilities. Engineer. Progr. Univ. Florida 8(12): 1-11. 1954.* Benzinc, D. H. The nutritional status of Encyclia tampense and Tillandsia circinnata on cypress [Taxodium] and the availability of nutrients on this host in South Florida. (Abstr.) Am. Jour. Bot. 61(5—Suppl.): 53. 1974. HLE. The vegetative morphology, habitat preference and water balance mechanisms of the bromeliad Tillandsia ionantha Planch. Am. Midl. Nat. 85: 11-21. 1971. . Renrrow. The biology of the epiphytic bromeliad Tillandsia eesate Schlecht. I. The eee) status of populations in South Florida. . Bot. 58: 867-873. BIEBL, R con Wasserhaushalt von ae illandsia recurvata L. und Tillandsia usneoides L. auf Puerto Rico. Protoplasma 58: 345-367. 1964. Briuines, F. H. A study of Tillandsia ee. L. .Bot:..Gazn. 38: 99-121; 1904. [Includes embryo sac, fertilization, seed germination, flower, leaves, chloroplasts, scales, stomata, al Birce, W. The anatomy and some biological aspects of the oe we aL) Wondsia recurvata L. Bull. Univ. Texas 194(Sci. Ser. 20): oe 1-10. 1911. Brooxs, J. C. Range extensions of two southeastern Bromeliads. Bromeliad Soc. Bull. 18: 116, 117. 1968. [Records “J. setacea” (undoubtedly T. Bartramii) from Ben Hill and Laurens counties, Georgia; T. fasciculata from Camden County, Georgia. | Burt, K. M., & J. F. Uriey. Uptake and translocation of Calcium-45 in Til- ees Balblsionk Schult. (Liliatae: Bromeliales). (Abstr.) ASB Bull. 17: 34, 35. 1970. CorFIELD, G. S. Spanish moss (Tillandsia usneoides): forest by-product of e South. Jour. Geogr. 42: 308-317. 1943.* DJ eeioiy C., & R. McCrinpte. Terpenoids. LI. The isolation of some new cyclopropane- ~ontaining triterpenes from Spanish moss (Tillandsia Jou Duncan, W. H. Pr wliiens reports on the flora of Georgia— 4. Notes on the distribution of flowering plants including species new to the state. Castanea 15: 145-159. 1950. [T. usmeoides, 150, 151; records from the Piedmont, one at 630 ft. above sea level.] Feurt, S. D., . E. Fox. A report on the waxy constituents of Spanish moss, Tillandsic usneoides L. Science 117: 600, 601. 1953. Foster, M. B. New varieties in the Bromeliaceae. Bromeliad Soc. Bull. 3: 29, 30, 1953. [T. fasciculata var. alba M. B. Foster, with greenish-white floral bracts and white petals described from Collier County, Florida.] GarTH, R. E. The ecology of Spanish moss (Tillandsia usneoides): its growth and distribution. Ecology 45: 470-481. 1964. Guarp, A. T., & M. Henry. Reproduction of Spanish moss, Tillandsia usneoides L., by seeds: Bull. Torrey Bot. Club 95: 327-330. 1968 HAywarp, W. Spanish moss as an economic plant. Pl. Life 1: 97, 98. 1947. Howe Lt, J. O. A new species of Aclerda from Spanish moss in Georgia (Ho- moptera: Coccoidea; Aclerdidae). Ann. Entomol. Soc. Am. 65(6): 1261- 1264. 1972. [A. tillandsiae from Tillandsia usneoides.] 1975] SMITH & WOOD, BROMELIACEAE 389 Jounson, J. D., & R. 5S. HALLIWELL. Compounds for control of ball moss. Pl. Disease Rep. 57(1): 81-83. 1973. [T. recurvata on shade trees. | LeContTe, J. E. On the North American plants of the genus Tillandsia, with descriptions of three new species. Ann. Lyceum Nat. Hist. New York 2: 129-132. : MacIntTireE, W. H., M. A. Harpison, & D. R. McKenzie. Atmospheric pol- lution: Spanish moss and filter paper exposures for detection of air-borne fluorides. Jour. Agr. Food Chem. 4: 613-620. 1956.* McIntyre, R. T., & E. W. Berc. Mineral content of Spanish moss. Ecology 37: 605, 606. 1956. [T. usneoides MarTINEZ, J. D., M. NatHany, & V. DHaxiapayan. Spanish moss, a sensor for lead. Nature 233: 564, 565. 1971. [Tests in Louisiana. ] Mez, C. Physiologische Bromeliaceen-studien I. Die Wasserdkonomie der ex- trem atmosphirischen Tillandsien. Jahrb. Wiss. Bot. 40: 157-229. 1904. Miter, A. C. Observations on Chironomidae (Diptera) inhabiting leaf axils of two species of Bromeliaceae on St. John, U. S. Virgin Islands. Canad. Entomol. 103: 391-396. 1971. [T. utriculata, Aechmea lingulata; see also Jour. Bromeliad Soc. 21: 112-114. 1971.] Mozinco, H. N., P. Kiern, Y. Zeevi, & E. R. Lewis. Scanning electron micro- scope observations on Tillandsia usneoides. Trans. Am. Microscop. Soc. 89: 259-263. OESER, R. Culi@vation. of Tillandsia from seeds. Bromeliad Soc. Bull. 6: 3-5. 1956. Pater, T. C. The ash of Tillandsia usneoides. Am. Nat. 22: 458, 459. 1888. PENFOUND, W. T., & F. G. Detter. On the ecology of Spanish moss. Ecology 28: 455-458. 1947. [T. usneoides. | Roserts, D. A., A. S. JENSEN, & G. F. Weer. Blight of Spanish moss. PI. Disease Rep. 55: 390-392. 1971. [Blight caused by Fusarium solani.] Rosrnson, B. B. Minor fiber industries. Econ. Bot. 1: 47-56. 1947. [Includes T. usneoides. | SAFForD, W. E. Natural history of Paradise Key and the nearby Everglades of Florida. Ann. Rep. Smithson. Inst. 1917: 377-434. 64 pls. 1919. [T. usneoides, T. utriculata, pls. 20, 21.] ScHRoper, H. H. Vegetable hair (Spanish moss). Nat. Hist. 55: 469-471. 1946 Smiru, L. B. Notes on Bromeliaceae, XVIII. Phytologia 8: 219. 1962. [T. setacea. tes on Bromeliaceae, XXIV. bid. 13: 454-465. 1966. [T. Bar- trami Ell. replaces T. simulata Small; illustration included of cross section of ete gs T. Bartramii and T. setacea; T. “incurva.”] siete,” INGE n Bromeliaceae, XXXI. Jbid. 20: 121-183. 1970. [Key to Tillandsia Be simulators. | SMITHSONIAN INSTITUTION CENTER FOR SHORT-LIVED PHENOMENA. Florida Spanish moss mortality. Event 143-69. 22 Dec. 1969. [Dying T. usneoides reported from 10 counties in Florida; cf. ROBERTS et al. above. ] Sustts, R. Poliembronia en las especies argentinas de Tillandsia (Bromelia- ceae). Kurtziana 7: 266, 267. 1973. ary found in 8 of 22 spp. of subg. Diaphoranthema in central Argenti SwaLtey, B. Variation of growth on T Jlentsio. oe. Jour. Bromeliad 73. Soc, 232 215-217: [voL. 56 JOURNAL OF THE ARNOLD ARBORETUM X Ss AS VN \\ M\ I, SN WW ZZ e fruit — a-m, G. monostachia: a, plant with matur i flower with , flower in vertical section, 3; e, anther (pollen shed) and upper part of filament, x 5; f, anthers in cross section after anthesis, anthers agglutinated but not connate, X 8; g-i, petals FIGURE 3 i note new shoot from near base 6; orescen V : ce, X subtending bract seen from adaxial side, Vp and staminal filaments (h, i) in cross section at levels indicated on “d” ‘— note agglutination of petal margins to each other and of stamens to petals, vascular 1975] SMITH & WOOD, BROMELIACEAE 391 THIERET, J. W. Twenty-five species of vascular plants new to Louisiana. Proc. Louisiana Acad. Sci. 32: 78-82. 1969. [T. recurvata.] ToMLINSsON, P. B. Monocotyledons— towards an understanding of their morphology and anatomy. Pp. 207-292 in R. D. Preston, ed., Advances in Botanical Research. Vol. 3. xii + 309 pp. Academic Press, London & New York. 1970. [Evolutionary morphology of “Spanish moss,” 224- 229, figs. 6-8.] Upnor, J. C. T. Tillandsia usneoides als Pflanzenschadling. Zeitschr. Pflan- zenkr. 41: 593-607. VASCONSELLES, P. W. C. DE. Como combater a Tillandsia usneoides. Anais Esc. Super. Agr. “Luiz de Queiroz’ 4: 95-99. 2 pls. 1947.* VoLuT, R. Tillandsia usneoides L. Revue Hort. 110: 166. 1938. WELbD, J. T. The antibiotic action of Tillandsia usneoides (Spanish moss). Proc. Soc. Exper. Biol. Med. 59: 40, 41. 1945.* Wuerry, E. T., & R. BUCHANAN. Composition of the ash of Spanish-moss. Ecology 7: 303-306. 1926. [T. usneoides.] ——— & R. G. Capen. Mineral constituents of Spanish-moss and ballmoss. Ecology 9: 501-504. 1928. [T. usneoides, T. recurvata.] Wise, L. E., & A. Meer. The cellulose of Spanish moss. Proc. Florida Acad. Sci. 1: 131-144. 1937. WRINKLE, G. A method for aseptic cultures of Tillandsia seed. Jour. Bromeliad Soc. 23: 117, 118. 1973. 2. Guzmania Ruiz & Pavon, Fl. Peru. Chile. 3: 37. 1802. Acaulescent [or rarely long-caulescent] mostly epiphytic plants. Leaves polystichous, entire; sheaths usually conspicuous; blades mostly ligulate in shape, with inconspicuous scales. Inflorescence simple [or compound], the bracts usually conspicuous and often brightly colored; flowers always polystichously arranged. Sepals usually somewhat connate. Petals with edges overlapping and closely agglutinated, but not truly connate (see Figure 3, g-i), naked, white [or yellow]. Stamens usually included; filaments more or less agglutinated to the petals but not truly adnate (see Ficure 3, g-i); pollen 1-sulcate. Ovary wholly superior, pyramidal, ellipsoid, or ovoid, glabrous; ovules many, densely glomerate. Capsule septicidal:; seeds with a long, straight, usually brownish basal coma. (Caraguata Lindley, 1827, not Adanson, 1763; Massangea E. Morren, 1877; Sodiroa André, 1877; Schlumbergera E. Morren, 1883, not Lem., 1858.) Type species: G. tricolor Ruiz & Pavon = G. monostachia (L.) Rusby ex Mez. (Named in honor of Anastasio Guzman, 18th-century Spanish naturalist and apothecary.) A genus of more than 120 species extending from southern Florida and southern Mexico to central Brazil and Bolivia, with its main con- bundles not shown, X 4; j, diagrammatic cross section of ovary to show pla- centation, 8; k, nearly mature capsule capped by marcescent corolla and persistent style, X 114; 1, opening capsule with seed being extruded by drying and expanding basal appendages, X 1; m, seed with partially expanded basal appendage, X 3. [voL, 56 JOURNAL OF THE ARNOLD ARBORETUM FIGURE 4. Catopsis. C. Bert at base, X 4%; b, flower ork subtending bract, x 3; at base, m4: d, antesepalous stamen with dehisced anther, x 4 teroniana: a, esa in fruit — note new shoot c, petal with _— adnate right, eh , two views of three ovules, showing elongated integument below a distal tuft of hairs that grows into terminal appendage of seed (1), X 12 1975] SMITH & WOOD, BROMELIACEAE 393 centration in the northern Andes and Central America; one species in our area. Guzmania monostachia.is native to the hammocks and Taxodium swamps of southern Florida, extending thence to the West Indies and Nicaragua, northern Brazil, and Peru. In Florida the plant flowers from late May through July (Craighead). The inflorescence is very con- spicuous, the upper bracts being pink to salmon [or red], the lower ones pale with dark stripes (see FicurE 3, b). Each white-petaled flower is open for a single day and, in cultivation at least, is self-pollinated. The plumose seeds are an effective means of dispersal. As the capsules dry and open at maturity, the filamentous basal appendages of the seeds spread out as they dry, and the whole cloudlike mass expands out of the capsule, the inside walls of which are dark brown, shiny, and very smooth (see FicurE 3, 1). The incredibly light seeds are carried even by very weak air currents in the forest interior. The filaments of the appendage catch on almost anything they touch, effectively anchoring the seed. (Obs. C. E The most important generic character in Guzmania is the pseudo-fusion between the petals and filaments, which simulates a sympetalous corolla with adnate stamens. Although there is no real connation or adnation, the agglutination of petals and stamens is by an adhesive so strong that fresh petals will rupture irregularly under tension, rather than at the lines of meetin Harms divided Guzmania into five genera and Mez split it into two, largely on the basis of habital characters. These, although striking in the extremes, have so much intergradation that they are quite unusable. The only floral character is the degree of fusion of the sepals, but again there is no firm line of demarcation. In any event, G. monostachia, being the type species, would be unaffected. The chromosome number of Guzmania monostachia has been reported as m = ca. 25 and 2m = 48. Other counts in the genus are 2m = 48, 50, and 56 (see McWilliams in Smith & Downs, 1974). REFERENCES: Under family references see especially BENzING & RENFROW, CRAIGHEAD, Grar, Harms, Mez, PapItta, RAUH, RicKetT, and SMITH (1947 Ariza-JuuiA, L. An albino Guzmania from Hispaniola. Bromeliad big Bull. 9: 38, 39. 1959. [G. monostachia var. alba Ariza-Julia described from Puerto Plata Prov., Dominican Republic; upper bracts of inflorescence white, lower bracts light green, lacking stripes. Foster, M. B. New varieties in the Bromeliaceae. Bromeliad Soc. Bull. 3: 29, 30. 1953. [G. monostachia var. variegata M. B. Foster described from Big Cypress Swamp near Deep Lake, Collier County, Florida. ] , Mature capsule beeinning to open, X 2; j, same after dehiscence, seeds being velensed, x 2; k, empty capsule, x 2. 4, seed with long ee psagit idage of hairs, x 3 m-q, & aporeree m, plant with fruit, X 1; n, flower with sub- tending bract; & 3: tal with stamen adnate at “ol “3 is p, anther and Nag part of lnireitt antesepalous stamen, X 12; q, mature unopened fruit, X 2. 394 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Hooker, W. J. Guzmannia tricolor. Bot. Mag. 86: pl. 5220. 1860. [G. monostachia.] [Papitta, V.] Guzmania monostachia. Bromeliad Soc. Bull. 17 (5): cover, 102. 1967. [Cover with excellent picture of a form more brilliantly col- ored than that in Florida. } Smirn, L. B. Notes on Bromeliaceae, XXXII. Phytologia 21: 73-96. 1971. [Key to Guzmania and simulators, 73-90; most recent revision of the genus. 3. Catopsis Grisebach, Fl. Brit. W. Indian Islands 599. 1864. Epiphytic acaulescent herbs. Leaves densely rosulate, entire, minutely appressed-lepidote, often cretaceous-coated, green; sheath large; blade narrowly triangular or liguliform. Scape conspicuous, the paniculate in- florescence usually bipinnate, rarely simple (cf. C. mutans) or tripinnate, equaling or exceeding the leaves. Flowers always polystichously arranged, small or minute, mostly sessile or subsessile, uniform and perfect [or dimorphic with some functionally staminate plants]. Sepals free, usually rounded and strongly asymmetric, glabrous. Petals free, naked. Stamens included; filaments unequal; anthers ovate or elliptic. Ovary superior, broadly ovoid or ellipsoid; style shorter than the ovary or lacking; ovules few to several, with an apical tuft of hairs and a potential but normally undivided coma appearing as a spur on the laterally attached funiculus (Ficure 4, g, h). Capsule septicidal; seeds with principal coma apical and folded over (Ficure 4, 1). Lectotype sPEcIES: C. nutans (Sw.) Griseb.; see Britton & Millspaugh, Bahama Fl. 66. 1920. (Name from Greek katoptos, a view or a place from which a view may be obtained, not explained, but probably in reference to the epiphytism of the plant.) A genus of some 19 species extending from southern Florida and south- ern Mexico to Peru and eastern Brazil; three species in our area. Catopsis Berteroniana (Schult. f.) Mez, distinctive in its chalky- coated yellowish-green leaves, is locally abundant in hammocks in sub- tropical Florida, where it grows high up in the trees in full or nearly full sunlight. It occurs through the Greater Antilles and Central America to Brazil. Catopsis floribunda L. B. Smith (C. nutans of authors, in- cluding Small) and true C. mutans (Sw.) Griseb. (C. fulgens Griseb.) are both plants of shadier habitats. The former occurs in scattered ham- mock locations in southern Florida, southward through the West Indies and Central America to Venezuela. The latter, notable for its slender, usually decurved simple inflorescence, in contrast with the paniculate inflorescences of the preceding two, is found sparingly in the Big Cypress Swamp area of Collier County, Florida, and it occurs in the Greater Antilles, Mexico, and Central America, southward to Venezuela and Ecuador. Catopsis floribunda flowers in early summer in Florida, while both C. Berteroniana and C. nutans are fall-flowering (September, October) (see 1975] SMITH & WOOD, BROMELIACEAE 395 Craighead). The conspicuous liguliform, bright yellow petals of C. nutans contrast strongly with the inconspicuous white petals (hardly longer than the sepals) that characterize most other members of the genus, in- cluding the two other species of our area. Because of its conspicuous petals, C. mutans can be presumed to be outcrossing, but C. Berteroniana and C. floribunda are both self-compatible and self-pollinated, at least under greenhouse conditions (obs. C. E. W.). Catopsis nutans has dimorphic flowers (staminate-flowered plants and either perfect [?] or functionally carpellate-flowered ones [?]) in Mexico and Central Ameri- ca, but only perfect flowers elsewhere. The geographical limits of floral dimorphism in Catopsis are one of the most interesting features of the genus. The species that are normally di- morphic are limited to Mexico and Central America, but the species that are both perfect-flowered and dimorphic are dimorphic only within that same area. The northern part of this area overlaps that of Hechtia, which is the only completely dimorphic genus in the family. So far no explanation of this situation has been found. An unusual character for many species is a chalky coating on the leaves that is easily brushed off (cf. C. Berteroniana). Its exact nature is not understood, but it may be an epidermal excretion similar to the waxy coat in some other families. In contrast with the large basal appendage of the seeds of Tillandsia and Guzmania, which is derived from the splitting of the outer layer of the outer seed coat, the principal one of Catopsis is composed of apical hairs that increase greatly in length as the ovule matures into seed, while the basal one appears as a spur on the funicle (see Ficure 4, e-g, 1) Chromosome counts of 2” = 50 have been recorded for two species of the genus. REFERENCES: Under family references see especially BENzING & RENFROW, CRAIGHEAD, CorNELISON, Grar, HALL, HARMS, KRAMER, MCWILLIAMS in SMITH & Downs MEz (1934-35), PapILLA, RauH, RIcKETT, SMiTH & Downs (Introduction), and TOMLINSON. SmitH, L. B. Notes on Bromeliaceae, XXVII. Phytologia 16: 62-86. 1968. [Catopsis, 64-69; most recent revision of the genus. Witson, R. G., & C. Wuson. Bromeliads in cultivation. Vol. 1. 126 pp. Coconut Grove, Florida. 1964. [Includes genera “A” to “G”; Catopsis, 63, 64.] Subfam. BROMELIOIDEAE [Harms] 4. Ananas Miller, Gard. Dict. Abr. ed. 4. ord. alph. 1754. Coarse acaulescent herbs, not producing stolons but short upright shoots or slips. Leaves densely rosulate, scarcely enlarged at base; blades usually spinose-serrate. Scape evident, mostly erect. Tuikaceatesicn densely strobiliform, usually terminated by a series of sterile foliaceous 396 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 bracts, often producing slips at the base. Flowers sessile. Calyx lobes free above the epigynous tube, obtuse, slightly asymmetric. Petals free, erect, violet or red, each bearing two slenderly funnelform scales. Stamens included; pollen grains ellipsoid, with two pores. Ovaries coalescing with each other and with the bracts and axis to form a fleshy compound fruit; epigynous tube short; placentae apical; ovules caudate. Seeds naked, completely aborted in the cultivated species. LECTOTYPE SPECIES: Bromelia Ananas L. = A. comosus (L.) Merrill (Ananas Ananas (L.) Voss). (Name from that used by the Indians of the Antilles.) —- PINE- APPLE. A genus of some eight species and numerous varieties and forms, probably native to interior South America from the Amazon Basin to Paraguay but now pantropical in cultivation. Ananas comosus (A. sati- vus Schult. f.), 22 = 50, 75, the commonly cultivated species, is re- portedly persistent and may possibly be spontaneous in southern Florida. It is included here tentatively. Like many other cultivated plants, the pineapple is of obscure and controversial origin. There is good evidence that the Indians brought it to the Antilles before the arrival of Columbus, and probably the Por- tuguese introduced it into the East Indies, although some authors believe it to be native there. REFERENCES: The enormous horticultural literature is omitted here; see CoLLINs for many references. Baker, K. F., & J. L. Cottins. Notes on the distribution and ecology of Ananas and Pseudananas in South America. Am. Jour. Bot. 26: 697-702. map. 1939. [See also Tech. Pap. Pineapple Exper. Sta. Univ. Hawaii 124.] Camaroo, F. C., & L. B. SmirH. A new species of Ananas from Venezuela. Phytologia 16: 464. 1968. Cottins, J. L. The pineapple; botany, cultivation, and utilization. 294 pp. ill, eae 1960. [An encyclopedic treatise . Cooper, W. C. Effect of growth Spee on flowering of the eee under Florida Psa Am. Soc. Hort. Sci. Proc. 41: 93-98. 1942 Cas Menta, of ay in pineapple plants. Bull. Bromeliad HEILBorN, QO. wate es on the cytology of Sime sativus Lindl. and the origin of its parthenocarpy. Ark. Bot. 17(11): 1-7. 1921. Grrrorp, E. M., Jr. Initiation and early aes of the inflorescence in pineapple (Ananas comosus, ‘Smooth Cayenne’) treated with acetylene. Am. Jour. Bot. 56: 892-897. 1969. MatHews, W. H. Pineapples in Florida. Univ. Florida Agr. Extension Circ. 195. 14 p pp. 1959. MERRILL, E. D. An interpretation of Rumphius’s Herbarium Amboinense. pp. 2 maps. Manila. 1917. [A. comosus, 133. Rosinson, E. L. Failure of witchweed [Striga asiatica] to parasitize smooth Cayenne pineapple. Weeds 10: 334, 335. 1962. 1975] SMITH & WOOD, BROMELIACEAE 397 SmitTH, L. B. Notes on the taxonomy of Amanas and Pseudananas. Harvard Univ. Bot. Mus. Leafl. 7: 73-81. 1939. ; e Bromeliaceae of Brazil. Smithson. Misc. Coll. 126(1): vii + 290 pp. 1955. [Pseudananas & Ananas, 251-255.] . Bromeliaceae. Jn: T. Lasser, Fl. Venezuela 12(1): 1-361. 1971. [Ananas, 338-343. ] Tuomas, E. N. M., & L. E. Hotmes. The development and structure of the seedling and young plant of the pineapple (Amanas sativus). New Phytol. 29: 199-226. 1930. A oath p C. BE. W. DEPARTMENT OF BOTANY ARNOLD ARBORETUM NATIONAL MUSEUM OF HARVARD UNIVERSITY NATURAL HISTORY CAMBRIDGE, MASSACHUSETTS 02138 SMITHSONIAN INSTITUTION WasuinctTon, D. C. 20560 398 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 ISOZYME VARIATION IN SPECIES OF PROSOPIS (LEGUMINOSAE)* Otto T. SoLBric AND KAMALyit S. BAWA THE GENUS Prosopis — mesquite, algarrobo, screwbean — is comprised of about 40 species (Burkart, in press). They are found primarily in North and South America, but three species grow in East Africa and Asia Minor. The genus Prosopis consists mostly of small to large trees, al- though a few species of shrubs and woody perennial herbs are also known. They inhabit primarily subtropical areas with rainfall regimes of 200— 800 mm. and a pronounced dry period. In areas with less than 250 mm. the species are restricted to washes or places with a high water table. Some species (e.g., P. ruscifolia, P. glandulosa) become obnoxious weedy trees, particularly where man is trying to preserve a grass cover in spite heavy grazing by his own domestic animals (Morello e¢ al., 1971; Fisher, 1973). Other species (e.g., P. tamarugo) are being grown in dif- ferent parts of the world (India, Chile) as forest species adapted to semi- arid conditions. Several species of Prosopis (P. alba, P. nigra, P. chilensis, P. velutina, etc.) are the principal riparian trees in the semidesert regions of the “Monte” (Morello, 1958) in Argentina, and the Sonoran Desert (Shreve, 1951) in the United States and Mexico. In conjunction with a comparative ecological study of these areas (Solbrig, 1972a), the genus Prosopis was singled out for an in-depth ecological and evolutionary study (Carman, 1973; Solbrig & Cantino, 1975). One of the objectives of the study was to investigate the genetic structure of populations of species of Prosopis. Specifically, we asked the following questions: (1) what is the level of genetic variation in species of Prosopis and (2) what is the extent of genetic differentiation among species and among populations of the same species? In this paper we attempt to answer these questions by presenting data on variation in isozymes of several species of Prosopis. MATERIALS AND METHODS Sampling. Twenty to 50 fruits of a tree selected at random were gath- ered at maturity before they dropped to the ground. Up to ten trees per population were sampled, although only one to three trees per population were used in the assays. The fruits of each tree were kept separate for most species, but they were mixed in a few cases. In the laboratory the * Contribution of the Structure of Ecosystem Program of the U.S./I.BP. 1975] SOLBRIG & BAWA, ISOZYME VARIATION 399 seeds from the fruits were extracted by hand and 80 undamaged and well- developed seeds were selected for germination. The species sampled and the number of seedlings assayed are listed in TABLE 1. The samples com- prise 13 of the 20-25 species in section ALGAROBIA as well as the two species of section CavENICARPA. In most cases more than one locality was sampled. Altogether, 2145 seedlings belonging to 15 species from 48 localities were analyzed. Experimental techniques. Seeds were germinated on plastic trays in loamy soil at field capacity at 20° C. The cotyledons of 8—10-day-old seedlings were used for electrophoretic analysis on starch gels. The meth- ods used are those described in Brewer (1970) and modified by Solbrig (1972b). For each seedling, the following six enzymatic systems were assayed: a-esterase, LAP (lucine-amino-peptidase), ADH (alcohol-dehy- drogenase), MDH (malic-acid-dehydrogenase), G6DH (glucose-6-phos- phate-dehydrogenase), and catalase. The data from the last two systems were ambiguous and are not presented here. Analysis of data. The isozyme data were analyzed in two ways. In the first method, we obtained the frequency of each isozyme band in the population being analyzed (all seedlings from a tree, or all seedlings from a locality, etc.) and calculated the diversity of the population using the Shanon-Weiner information measure: H’ = — = PlogsP; This formula measures the “evenness” of the distribution of the bands in the population. So, for example, if two alleles produce alternate bands, the highest value of H’ in the population is obtained when the bands have a 50:50 distribution, and the lowest value is obtained when the frequency of one of the bands approaches zero. In addition, the larger the number of bands, the higher the value of H’ is. In our context, a high value of H’ therefore signifies populations with many bands, each with a relatively high frequency. Since different samples possess different numbers of bands (and pre- sumably alleles), the ratio of H’ to H’max (H’/H’max) was calculated (where H’nax = logsP;). This expresses how close the sample is to a perfectly even distribution. Unfortunately, populations formed entirely by identical homozygous individuals will also have a H’/H’max ratio of 1. Consequently, a second method of analysis was also used. In this case we scored the frequencies of all the possible combinations of bands (which we will call the “zymogram phenotypes”) to get a measure of the number of genotypes in the population. Only the zymogram phenotype data are presented (TABLE 3), since they are representative of the results obtained with the other enzymes. : The number of segregating loci and the allelic frequencies in popula- tions were not calculated, because the sample size was not large enough to produce accurate estimates and such a calculation would be misleading. TABLE 1. Species and populations of Prosopis sampled. S NO, OF SEEDLINGS SPECIES CoLLecTOR & SAMPLE NO. LOCALITY ANALYZED P. alba Solbrig 4238 Argentina, Prov. Formosa, Bartolomé de las Casas 41 Solbrig 4272 Argentina, Prov. Santiago del Estero, Quimilo 15 oS P. algarobilla Naranjo 355 Argentina, Prov. Entre Rios 19 S| Naranjo 369 Argentina, Prov. Entre Rios 44 Zz Naranjo 365 Argentina, Prov. Entre Rios 31 ei Naranjo 364 Argentina, Prov. Entre Rios 5 ro) = P. alpataco Simon 449 Chile, Prov. Santiago, Cuesta de Chacabuco 58 ia Simon 440 Chile, Prov. Aconcagua, Los Andes 25 jee} Simon 445 Chile, Prov. Aconcagua, La Rinconada 25 Simon 461 Chile, Prov. Santiago, Polpaico 7 ps P. caldenia Simpson 1001 Argentina, Prov. La pha Santa Rosa 39 z Hunziker 9055 Argentina, Prov. La P. 63 5 Hunziker 9052 Argentina, Prov. La Sal 62 Re P. chilensis Simon 456 Chile, Prov. Santiago, Los Andes 26 a Simon 429 Chile, Prov. Santiago, Cuesta de Chacabuco 20 S P. ferox Hunziker $n, Argentina, Prov. Salta, road to Antofagasta 20 pe P. flexuosa Simpson 1022 Argentina, Prov. La Rioja, Arauco 43 S Hunziker 9199 Argentina, Prov. Catamarca, Andalgala 44 Hunziker 9107 Argentina, Prov. Catamarca, Andalgala 50 Simpson 1025 Argentina, Prov. Catamarca, Andalgala 48 P. glandulosa Simpson 2218 Texas, Hudspeth Co., McNary 142 ‘3 Simpson 2217 Texas, El Paso Co., Faben ns 106 r Simpson 2215 New Mexico, Luna Co., Las Cruces 45 on S P. juliflora Hunziker 4716 Colombia, Dept. Tolima, Honda 36 a Hunziker 4715 Venezuela, Mérida 24 Solbrig 4708 Venezuela, Mérida, Lagunillas 20 P. laevigata Penalosa 3427 Mexico, San Luis Potosi, Ciudad del Maiz 32 Penalosa 3433 Mexico, San Luis Potosi, Tula 30 nm Penalosa 3423 Mexico, San Luis Potosi, Ciudad del Maiz 29 iS Penalosa 3422 Mexico, San Luis Potosi, Ciudad del Maiz 54 3 P. nigra Solbrig 4292 Argentina, Prov: Cérdoba, Monteros 26 a Solbrig 4267 Argentina, Prov. Formosa, Bartolomé de las Casas 90 Re Solbrig 4248 Argentina, Prov. — yoni de las Casas 66 x Solbrig 4263 Argentina, Prov. Formosa, Baz 45 z Simpson 1024 Argentina, Prov. peasy AndalgalA 41 > P. ruscifolia Solbrig 4252 Argentina, Prov. Formosa, Estanislao del Campo 68 re Solbrig 4240 Argentina, Prov. Formosa, Bartolomé de las Casas 37 S Solbrig 4236 Argentina, Prov. Formosa, Bartolomé de las Casas 46 re Solbrig 4235 Argentina, Prov. Formosa, Bartolomé de. las Casas 32 is Solbrig 4249 Argentina, Prov. Formosa, Bartolomé de las Casas 44 : P. sericantha Simpson 1015 Argentina, Prov. La Rioja, Chamical 56 a P. tamarugo Simon 171 Chile, Prov. Tarapaca, Tarapaca 15 > Simon 183 Chile, Prov. Tarapaca, Tarapaca 15 z Simon 173 Chile, Prov. Tarapaca, Tarapaca 29 3 P. velutina Simpson 2200 Arizona, Pima Co., Tucson a5 Simpson 2211 Mexico, Sonora, Km. 557, Santa Ana 122 Simpson 2227 Arizona, Pima Co., Ajo Way near Tucson 107 Simpson 2304 Arizona, Maricopa Co., Gila Bend 84 cOv TABLE 2, H’ and H’/H’ max values for all populations of Prosopis studied. a-ESTERASE LAP ADH MDH SPECIES CoLLEcTOR & SAMPLE NO. H’ H’/H' nex n.. Wate, A ie | a» gd = fren P. alba Solbrig 4238 2.003 0.870 1715 0.745 1.573 0.878 1.386 1.000 vr Solbrig 4272 1.753 0.761 1.098 0.476 i484 =~ 0772 1.386 1.000 S P. algarobilla Naranjo 355 0.892 0.910 — — 1.482 0.827 1.386 1.000 S Naranjo 369 1.870 0.899 ~~ te 1.562 0.872 1.386 1.000 = Naranjo 365 1.899 0.913 — — 1.386 0.773 1.386 1.000 Naranjo 364 1.777 (0.854 — — 1.386 0.773 1.386 1.000 ie P. alpataco Simon 449 1.904 0.866 1.486 0.676 1.386 1.000 1.197 0.863 = Simon 440 2.027. 0.922 1.776 0.808 1.386 1.000 1.377. 0.993 f Simon 445 2.133 0.970 1.573 0.719 1.386 1.000 1.299 0.937 > Simon 461 1.863 0.847 1.361 0.619 1.386 1.000 1231 |. D888 z P. caldenia Simpson 1001 1.954 0.889 1.350 0.753 1.859 0.955 1.386 1.000 eS) Hunziker 9055 1.998 0.903 1.337 0.746 1.890 0.971 1.386 1.000 ns) Hunziker 9052 1.986 0.909 L358) ace 1.890 0.971 1.386 1.000 > P. chilensis Simon 456 1.881 0.817 1.374 0.767 1.386 0.773 1.098 0.792 es Simon 429 2.199 0.955 1.289 0.719 1.530 0.854 1.098 0.792 Ss) P. flexuosa Simpson 1022 2.019 0.877 1.475 0.823 1386 «0773 1.076 0.776 a Hunziker 9199 2.089 0.871 1.264 0.705 1.863 0.957 1.098 0.792 2 Hunziker 9107 2.353 0.981 1.599 0.892 1.887 0.970 1.095 0.790 Simpson 1025 1.686 0.703 1.597 0.891 —_ — P27 52-0917 P. glandulosa Simpson 2218 2.000 0.869 — — 1.406 0.873 1.386 ‘1.000 pe Simpson 2217 1.949 0.847 _ — 1.410 0.876 1.386 1.000 s Simpson 2215 1.997 0.847 — — 1.386 0.861 1.386 1.000 m wm [oa S P. juliflora Hunziker 4716 1.834 0.796 1.679 0,937 1.386 1.000 1.386 1.000 a Hunziker 4715 1.791 0.778 1.098 0.613 1.386 1.000 1.386 1,000 P. laevigata Pefialosa 3423 2.035 0.884 1.098 1.000 1.386 1.000 1.386 1.000 Pefialosa 3422 2.049 0,890 1.098 1.000 1.386 1,000 1.386 1.000 Pefialosa 3427 oe ae 1.098 1,000 _ we 1.386 1,000 - Pesialosa 3433 os a 1.098 1,000 oe a 1.386 1.000 2 P. nigra Simpson 1024 ae fs 1.530 0.664 ons a 1.098 0.792 5 Solbrig 4292 ee ae 1335 0.579 =< a es ae a Solbrig 4263 2.096 0,954 1.918 0.833 1.644 0.845 1.307 0.943 Re Solbrig 4267 1.951 0.847 1661 0.721 1.670 0.858 1.133 0.817 bw lbrig 424 — — 1.743 0.679 oe —< ee se z P. ruscifolia Solbrig 4252 1.634 0.785 1.098 0.428 1.527 0.785 1.098 1,000 P Sol, 4240 1.484 0.712 1.728 0.673 1.479 0.760 1.098 1.000 rm Solbrig 4236 1.564 0.752 1.859 0.739 1.386 0.712 1.098 1.000 2) Solbrig 4235 1.690 0,812 1.369 0.533 1.386 0.712 ie Solbrig 42 ies ne 1.554 0.606 os ae 1.098 1.000 3 P. sericantha Simpson 1015 2.044 0.930 0.864 0.786 1.857 0.845 1.098 1.000 ad P. tamarugo Simon 171 1.096 1.000 1.098 1.000 1.386 1.000 0.693 —-1.000 m Simon 183 1.096 1.000 1.098 1,000 1.386 1.000 0.693 —-1,000 > Simon 173 1.096 1.000 1.098 1.000 1.386 1.000 0.693 ‘1.000 a P. velutina Simpson 2200 2.047 0.934 1.381 0.858 1.786 0.918 0.693 1.000 4 Simpson 2211 2.053 0.937 1.385 0.860 1.782 0.916 0.693 ‘1,000 Simpson 2227 2.038 0.931 1.374 0.853 1.788 0.919 0.693 —-1,000 Simpson 2204 9121. 6065 1.355 0.842 1.883 0.911 0.693 ‘1,000 404 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 RESULTS DIVERSITY AND VARIATION WITHIN SAMPLES a-esterase. The number of isozyme bands varied from three to 11 in dif- ferent species. In most species, two zones of activity can be distin- guished: zone 1, with two to four bands, and zone 2, with four to six bands. Bands of zone 1 are thicker and more intensely stained than bands of zone 2. The exception is band 5 of zone 2, which in some species is as intensely stained as the bands of zone 1. The expression of zone 2 bands appears to be modified by minor variations in experimental tech- niques; occasionally, seedlings from the same sample showed different numbers of zone 2 bands with no consistent pattern from one day to the next. Although such samples were excluded from the data presented here, we are uncertain about the reliability of data on the frequency of zone 2 bands as a whole. Consequently, we have not used such data to make intra- or interspecific comparisons. Samples of all species showed high H’/H’max ratios (TABLE 2). How- ever, samples of some species had higher ratios than others. For example, in Prosopis ruscifolia the H’/H’max ratio ranged from 0.712 to 0.812, whereas in P. velutina the range was from 0.931 to 0.965 (TABLE 2). Samples of all species except Prosopis juliflora and P. tamarugo showed a large number of zymogram phenotypes (TaBLE 3). The frequency of the common classes differed from one species to another. For example, in P. juliflora 85% of the individuals sampled belong to one phenotype (TaBLE 3). In the other extreme, not more than 35% of the individuals of P. velutina belong to one given class. LAP. The LAP isozymes also appear in two different zones. Zone 1 has one to four bands, which are intensely stained. Most species have one or two bands in this region. The zone 2 bands, which are thin and faintly stained, can be further subdivided into two groups: the slow migrating subgroup @ and the fast migrating subgroup 6, with one or two bands in each. In all species, the samples had a high H’/H’,,,; ratio. There was much variation within samples with respect to the number and frequency of various zymogram phenotypes. ADH. The ADH isozymes separate into three zones. Most species show only two zones of activity. The number of bands in zone 1 and zone 2 vary from two to three, in zone 3 from two to five. The diversity measures for ADH bands were generally higher than those for a-esterase and LAP bands (TaBLE 2). Again, samples of some species had higher H’/H’,,,x values than other species. For example, the H’/H’max ratio for Prosopis algarobilla ranges from 0.773 to 0.872, while for P. alpataco, P. laevigata, and P. tamarugo the ratio is 1.00, indicating that these last species are probably homozygous for various ADH loci. In contrast to the situation in a-esterase and LAP, the number of band 1975] SOLBRIG & BAWA, ISOZYME VARIATION 405 phenotypes obtained for ADH isozymes within each sample was remark- ably uniform throughout. The total number of bands considered for phe- notypes was greater than the total for a-esterase isozymes, and almost equal to the total for LAP. Samples of species such as Prosopis alpataco, P. juliflora, P. laevigata, and P. tamarugo had only one class of pheno- types for all samples. In P. algarobilla, P. chilensis, P. glandulosa, P. nigra, and P. ruscifolia, 70 to 90% of the individuals within samples be- longed to one class. Only in P. alba, P. flexuosa, and P. velutina did the individuals within samples occur in two or more classes in almost equal proportions. MDH. All MDH isozymes separate in the same zone and their numbers vary from two to four in different species. Except for Prosopis alpataco, P. chilensis, P. flexuosa, and P. nigra, the H’/H’max ratio in samples of all species was 1.00 (TABLE 2). The level of variation displayed by the distribution of different zymo- gram phenotypes within the samples was extremely low. The number of phenotypes was rarely more than two in most species and, furthermore, a majority of phenotypes belonged to one class. DIVERSITY AND VARIATION BETWEEN SAMPLES OF THE SAME SPECIES a-esterase. None of the species investigated showed significant differ- ences between samples with respect to H’/H’max ratios. However, in re- gard to the zymogram phenotypes of the first four bands, some differences were observed among samples in a few species. For example, one sample of Prosopis alpataco (445) showed about one-fourth of its individuals with bands 1 and 2, which were completely lacking in the three other samples of the species. In P. caldenia, sample 9055 showed a high frequency of individuals with bands 1, 2, 3, and 4. However, population samples 9052 and 1001 had such individuals in low frequency. Instead, they had a large number of individuals with bands 3 and 4 (TasBLeE 3). Other species showing such differences between population samples were P. algarobilla (with bands 2, 3, and 4) and P. chilensis (with bands 1, 2, 3, and 4) (TaBLE 3). LAP. In contrast to the situation in a-esterase, there was considerable variation among samples of several species with respect to H’/H’ max Yra- tios. Such species include Prosopis alba, P. alpataco, P. juliflora, P. nigra, and P. ruscifolia (TaBLE 2). Similarly, many species showed much variation among samples with respect to zymogram phenotypes. Because of a possibility that some of the observed variation is the result of ex- perimental techniques, none of these cases are described in detail. ADH. The H’/H’max ratios were remarkably uniform among samples of all species. However, with respect to phenotypes based on zymograms, samples in several species differed in the frequency of various phenotypes. For example, in Prosopis chilensis only population sample 429 had more TABLE 3, Frequency of various a-esterase patterns in Prosopis species (in %). PATTERNS OF BANDS SPECIES COLLECTOR & SAMPLE NO. N 4 Ty 3,4 2,3,4 1,2,3,4 OTHER P. alba Solbrig 4238 41 0.243 ~ 0.487 —_— 0.048 0.222 Solbrig 4272 15 Sth < 1.000 an — — ToTaL 56 0.178 — 0.660 -- 0.035 0.127 P. algarobilla Naranjo 369 44 — -— 0.022 0.159 —_ 0.819 Naranjo 364 5 — — — 0.400 —_ 0.600 Naranjo 355 19 —_ a= ae 0.894 — 0.105 Naranjo 36 31 “= — — 0.258 — 0.741 TOTAL 99 -—— —- 0.009 0.343 — 0.646 P. alpataco Simon 449 58 — —_— 0.775 0.019 0.206 — Simon 440 25 — — 0.200 0.520 0.040 0.240 Simon 445 25 — 0.240 0.480 _ 0.200 0.080 Simon 461 Hs — —- 0.428 _- -- 0.572 TOTAL 115 = 0.052 0.565 0.121 0.156 0.106 P. caldenia Hunziker 9052 62 — — 0.580 0.370 — — Hunziker 9055 63 — a= 0.822 0.177 — —_ Simpson 1001 39 —_— — 0.743 0.179 —_ —_ TOTAL 164 — o- 0.711 0.250 a — P. chilensis Simon 456 26 0.076 — 0.730 0155 — 0.038 Simon 429 20 == 0.050 0.400 = 0.250 0.300 TOTAL 46 0.043 0.022 0.587 0.081 0.109 0.152 90F WOALANOTUY GIONUY AHL AO TYNUNOL apn! < ° F wa! QO P. glandulosa P. juliflora P. laevigata P. nigra P. ruscifolia P. sericantha P. velutina Simpson 2218 Simpson 2217 Simpson 2215 TOTAL Hunziker 4716 Hunziker 4715 TOTAL Penalosa 3423 Penalosa 3422 TOTAL Solbrig 4263 Solbrig 4267 TOTAL Solbrig 4252 Solbrig 4240 Solbrig 4236 Solbrig 4235 Solbrig 4249 TOTAL Simpson 1015 Simpson 2200 Simpson 2211 Simpson peed TOTAL oo9 9 Bom st tl) oo & 0.259 NOLLVIUVA AWNAZOSI ‘VMVE 8 OTAATIOS [S261 LOv 408 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 than 25% of its individuals with bands 6, 7, 9, and 11. In P. velutina, population sample 2227 had about 25% of its individuals with bands 7, 8, 11, and 12, and about 65% with bands 6, 7, 9, 10, and 11. On the other hand, population samples 2211 and 2204 had more than 50% of their indi- viduals with bands 7, 8, 11, and 12 and about 30% with bands 6, 7, 10, and 11. MDH. There were no appreciable differences between population sam- ples either with respect to H’/H’max ratios or with respect to zymogram phenotypes. DIVERSITY AND VARIATION BETWEEN DIFFERENT SPECIES The various species differed from each other in two respects: (a) fre- quency and electrophoretic mobility of isozyme bands and (b) levels of variation. a-esterase. Prosopis tamarugo is different from all other species because it has only three isozyme bands. Although these are numbered 4, 5, and 6 in TABLE 2, they migrated at a slightly faster rate than the equivalent bands of other species. Prosopis ruscifolia differs from other species in that bands 1, 2, and 3 either occur in very low frequency (less than 10%) or are completely absent. The zymograms of P. juliflora lack bands 1, 5, and 7, and instead appear to be fixed for bands 2, 3, 4, 6, 8, and 9. Among the closely related South American species P. alpataco, P. chilensis, P. caldenia, P. algarobilla, P. alba, and P. nigra no appreciable differences were observed. However, among the closely related North American species P. glandulosa and P. velutina there are notable differences in the frequency of certain bands. In P. glandulosa bands 1 and 2 occur in low frequency (less than 25%), while in P. velutina they occur in high fre- quency (more than 50%). In terms of levels of variation, two groups of species can be distin- guished. One, comprised of Prosopis tamarugo, P. juliflora, and P. rusci- folia, shows very little variation. The other, involving the rest of the species, is highly variable. LAP. Except for Prosopis alba, P. nigra, P. glandulosa, and P. velutina, which had similar zymograms, all species showed differences in the location and frequency of one or more bands. Most species were quite variable in terms of H’, with the sole exception of P. tamarugo (TABLE 2). DH. Prosopis sericantha has zymograms that are quite distinct from the remainder of the species. Prosopis tamarugo, which differs from all the other species investigated in the patterns of a-esterase, LAP, and MDH bands, does not differ with respect to the patterns of ADH bands. Pro- sopis ruscifolia, a species quite distinct from the others analyzed in respect to the patterns of a-esterase and LAP bands, also shows a characteristic species-specific ADH zymogram, with band 8 in almost 100% frequency 1975] SOLBRIG & BAWA, ISOZYME VARIATION 409 in all samples studied. In the other South American species this band, if it is present at all, occurs in very low frequency (3% or less). Excep- tions are P. caldenia and P. flexuosa, where the frequency of band 8 may vary from 25% in the former to 50% in the latter. Among other closely related South American species, P. caldenia and P. flexuosa differ from the remainder in having not only band 8, but also bands 11 and 12 in relatively high frequencies (TaBLE 2). Among the three closely related North American species analyzed, P. velutina differs from P. glandulosa and P. laevigata in having bands 6, 9, and 10 in very high frequencies (more than 50%). These bands are totally absent in the other two species. On the basis of levels of variation, the species can be included in one of two groups. The first includes Prosopis tamarugo, P. ruscifolia, P. chi- lensis, P. juliflora, P. algarobilla, P. nigra, P. alba, P. laevigata, and P. glandulosa. All or more than 95% of the individuals have the same pheno- type. The second group, containing P. sericantha, P. caldenia, P. flexuosa, and P. velutina, is more variable than the first; most of the individuals in these species are more or less evenly distributed among two or three pheno- types. MDH. Prosopis tamarugo again has very distinct zymograms. These dif- fer from other species in having bands 5 and 6, which are totally absent in all other species. Prosopis sericantha, with bands 1, 2, and 3, also has zymograms which appear to be species-specific. Prosopis ruscifolia and P. chilensis differ from the other South American species in lacking band 1. Along the same lines, P. alpataco and P. flexuosa can be distinguished from the rest, since they have band 1 in very low frequency. The North American species, P. glandulosa, P. velutina, and P. laevigata, are all alike, but they differ from the South American species in having bands 1 and 2 very faintly stained. All species are remarkably uniform in their MDH isozyme patterns and show no differences with respect to levels of variation. DISCUSSION Although only four enzyme systems were analyzed, we believe the number of loci controlling the expression of various isozyme bands for the four systems to be more than ten. Thus the number of loci examined in the present study is fairly large for studies of this kind, and on the basis of data already presented, it is reasonable to suggest that the species of Prosopis are genetically quite diverse. The progeny of all species of Pro- sopis investigated segregated for one or more enzymatic loci, indicating the existence of heterozygous individuals. The level of genetic diversity observed in various species is higher than that of some species of inbreed- ing herbs, such as Avena barbata (Jain, 1969) and species of Leavenwor- thia (Solbrig, 1972b). This is to be expected, for although precise infor- mation about breeding systems of Prosopis species 1s lacking, the taxa 410 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 analyzed are considered to be widely outcrossed (Simpson, in prepara- tion). One could argue that the observed levels of variation are overestimates of the actual levels of variation in populations, since the analyzed seed- lings were not subjected to selection. This might be true. However, it should be pointed out that the estimates presented here take into account not only the diversity of zymogram phenotypes, but also the number of segregating bands. The allelic diversity at a locus among the seedlings cannot arise unless such a diversity is also present in the population of adults. In regard to differences among species with respect to isozyme variability, two points deserve attention. It should first be noted that species which belong to a different section of the genus, e.g., Prosopis sericantha and P. alpataco, have vastly different zymograms for various enzyme systems; furthermore, within a section (as already discussed), some closely re- lated species show minor differences in zymograms. The second and per- haps more important point is that some of the species and populations showed less variation than others. Three species in particular can be singled out: P. juliflora, P. tamarugo, and P. ruscifolia. Three populations of Prosopis juliflora were investigated, one from western Colombia and two from western Venezuela. They are remarkably similar, particularly if one considers that they are separated from each other by several hundred kilometers, and more importantly, that they are separated by areas of high mountains and tropical vegetation, where Prosopis does not grow. Most of the plants investigated showed a re- markably uniform pattern of several (more than three) nonsegregating bands. So, for example, all 56 plants showed the same six bands for a- esterase (bands 2, 3, 4, 6, 8, and 9), although bands 10 and 11 also ap- peared at low frequencies in population 4716 from Colombia. Population 4715 from Venezuela showed no variability in the LAP pattern and all plants had bands 2, 3, and 5. All plants of the Colombian population were fixed for bands 5, 6, and 8, but segregated for bands 2 and 3. For MDH both populations showed the same invariable pattern of four bands, and a similar situation was also found for ADH. The genetics of the ADH locus were investigated in more detail, and we were able to show that P. juliflora is a permanent heterozygote for ADH, with the genetic constitution S*S?, F2F2/S8S%, F°F%, possibly due to gene duplication. Although the patterns for a-esterase, LAP, and MDH cannot be analyzed with the same precision as the ADH locus, the similar- ity in the zymograms suggests that there may be some fixed heterozygosity in these systems as well (Bawa & Solbrig, in preparation). Prosopis juliflora grows in isolated, arid, rain-shadow valleys in Co- lombia and Venezuela (and in the Caribbean and Mexico). These val- leys are surrounded by very high mountains (3,000 m. and higher) and are separated from each other by several hundred kilometers. There is evidence that some, if not most, of these dry pockets are post-Pleistocene in origin, and most of these populations are around 10,000 years old or 1975] SOLBRIG & BAWA, ISOZYME VARIATION 411 less. Given the large size of Prosopis seeds, gene flow between populations is a very rare event indeed. Seeds are carried in the digestive tracts of animals (Solbrig & Cantino, 1975), and there is anecdotal evidence that the species has spread in Colombia with the development of the cattle industry. This special ecological circumstance (with populations being started by one or a few seeds) subjects the species to repeated events of severe genetic depletion. Under these conditions, mechanisms such as gene duplication that can create permanent heterozygotes may be fa- vored. Prosopis tamarugo is a species of the very dry coastal areas of the province of Tarapaca in northern Chile. Of all the species investigated, it grows in the most extreme environment. Three population samples were investigated. They were characterized by the lowest total number of isozyme bands of any species investigated and the lowest within-sample variation. A single sample of a related species, P. ferox (from an equally extreme environment in the high Puna of Argentina), was analyzed and was also found to be invariable and to have very few bands. It is our con- tention that in extreme environments selection may favor certain particu- lar superior genotypes, and this may help to explain the lowered vari- ability of these species. Finally, we would like to mention Prosopis ruscifolia, the “vinal” from Argentina, and P. glandulosa, the “honey mesquite” from Texas. Both of these species (Morello e¢ al., 1971; Fisher, 1973) have become ob- noxious agricultural pests in grassland areas. In both, but particularly in P. ruscifolia, we detected a slightly lower degree of genetic variability than the mean for all species. This could be attributed to the fact that these are expanding populations (Morello e¢ al., 1971; Fisher, 1973). The significance of observed differences in variation patterns among samples of Prosopis alpataco, P. caldenia, P. algarobilla, and P. chilensis for a-esterase isozymes and those of P. chilensis and P. velutina for ADH isozymes is obscured by the fact that only a few samples, consisting of a small number of trees, were analyzed. Interpopulation differences with respect to isozymes have been observed as well in some coniferous trees (Clarkson & Fairbrothers, 1970). However, because of differences in techniques of different investigators, it is not possible to say whether the differences reported here are comparable to those reported for conifers. In summary, then, species of Prosopis are characterized by a high de- gree of genetic variability. Within the genus two species show significantly lower levels of variability. This can be attributed to severe genetic de- pletion because of extreme reduction of the population in one case, and to extreme directional selection in the other. ACKNOWLEDGMENTS We should like to acknowledge the assistance of Juan Hunziker, Jorge Morello, Carlos Naranjo, Javier Pefialosa, J. P. Simon, and Beryl Simp- son, who gathered seed for us and/or assisted in the field. Joseph Pettaway 412 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 also provided able laboratory assistance. To all we express our gratitude. The research was supported by grant GB—27150 from the National Science Foundation (principal investigator, Otto T. Solbrig), and this is also grate- fully acknowledged. LITERATURE CITED Brewer, G. J. 1970. An introduction to isozyme techniques. 186 pp. Aca- demic Press, New York & London. Burxart, A. A monograph of the genus Prosopis (Leguminosae, Mimosoideae). Jour. Arnold Arb. (in press). CARMAN, N. S. 1973. Systematic and ecological investigations in the genus Prosopis (Mimosaceae). 200 pp. Unpublished Ph.D. thesis, Univ. of Texas CLARKSON, R. B., & D. E. FatrprorHers. 1970. A serological and electrophoretic investigation of eastern North American Abies (Pinaceae). Taxon 19: 720- 2 FisHER, C. E. 1973. oars 68 pp. Texas A. & M. University Research Monograph No. AIN, 8. K. 1969. caine ecogenetics of two Avena species occurring in central California. Evol. Biol. 3: 73-118. MoreELLo, J. H. 1958. La provincia fitogeografica del monte. Opera Lilloana 2: 1-155. , N. E. Crupe ui, & M. Saraceno. 1971. Los vinalares de Formosa. Jn: La Eageetine de la Republica Argentina. No. 11. 111 pp. INTA, Buenos Aire SHREVE, ¥. 1951. Vegetation of the Sonoran Desert. Vol. 1. 192 pp. Car- negie Inst. Wash. Publ. 591. Washington Sotsric, O. T. 1972a. New approaches to the study of disjunctions with special emphasis on the American amphitropical desert disjunctions. Pp. 85-100 in D. VALENTINE, om Taxonomy, phytogeography and evolution. Aca- use Press, Lon 972b. Breeding system and genetic variation in Leavenworthia. Evo- sea: 26: 155-16 — &P.D. cae 1975. Reproductive a coe in Prosopis (Legu- minosae, Mimosoideae). Jour. Arnold Arb. 56: 185—2 Ores. ES. DEPARTMENT OF BIOLOGY DEPARTMENT OF BIOLOGY AND UNIVERSITY oF MASSACHUSETTS Gray HERBARIUM Boston, MAssacHusEtTs 02125 HARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 1975] WOOD, BALSAMINACEAE 413 THE BALSAMINACEAE IN THE SOUTHEASTERN UNITED STATES? CaRROLL E. Woop, Jr. BALSAMINACEAE A. Richard, Dict. Class. Hist. Nat. 2: 173. 1822, “Balsamineae,” nom. cons. (ToucH-ME-NOT FAMILy) Annual [or perennial] herbs [sometimes epiphytic, or subshrubs] with saccate and [usually] spurred, the spur nectariferous, the 2 lateral sepals free [or connate]. Petals 5 [free] or by connation of the lateral petals in pairs appearing to be 3. Stamens 5, alternate with the petals; filaments short, free or + connate, in ours with a scalelike appendage on the inner side, the scales partly united over the gynoecium; anthers 2-locular [co- herent or] connivent, opening by a slit or pore. Gynoecium [4- or] 5- carpellate, syncarpous; stigmas 5, minute, sessile [or style short, subu- late, stigma 1]; ovary superior [4- or] 5-loculate, each locule with 2 to many anatropous, 2-integumented ovules, the placentation axile. Fruit a + fleshy [4- or] 5-valved capsule, usually opening elastically, or (in Tytonia) drupaceous or a fleshy capsule(?). Seeds with a straight embryo and without endosperm. Type GENus: Balsamina P. Miller, nom. illegit. = Impatiens L. A family of three genera and some 500 described species. T ytonia G. Don (Hydrocera Blume ex Wight & Arnott) comprises only a single species, T. triflora (L.) C. E. Wood (Hydrocera triflora (L.) Wight & ‘Prepared for the Generic Flora of the Southeastern United States, a joint proj- ect of the Arnold Arboretum and the Gray Herbarium of Harvard University made possible through the support of the National Science Foundation, currently under Grant BMS74-21469 (Carroll E. Wood, Jr., principal investigator). This treat- paper (Jour. Arnold Arb. 39: 296-346. 1958) and continued to the present. The area covered by the Generic Flora includes North and South Carolina, Georgia, Florida, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana. The descrip- y paper o alsaminaceae written by Dr A. Wilson for va Generic Flora project has been consulted in the preparation of this treatment. lagi Vince ail i e preparation of the bibliography and the typing of the : pman under direction of manuscript. The illustration was drawn by A. D. Cla : dby R.B the author. The material for the drawing of Impatiens pallida was collected by R. B. Channell and H. F. L. Rock 414 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Arnott),? 2m = 16, of marshes from India to Java. Semeiocardium Zoll. is also monotypic, including only S. Arriensii Zoll., known solely from Madura and Kangean islands off the northeast coast of Java. Impatiens L. comprises the remainder of the species The family is a distinct one, characterized by the simple, exstipulate leaves, watery sap, resupinate zygomorphic flowers with a usually spurred often saccate sepal, stamens that are coherent around the gynoecium, and (in Impatiens and Semeiocardium) elastic dehiscence of the capsule. The fruit of Tytonia has been variously described as a berry; or as suc- culent, drupaceous, 5-angled, 5-furrowed, 5-loculate, the endocarp hard and bony, the seeds solitary (Wight & Arnott, p. 140); or as a 5- pyrenous drupe, “‘the stones 3-4 celled; only 1-2 cells seed-containing; the other ones empty and serving as a floating apparatus” (Backer & Bakhuizen, Fl. Java); or most recently as a purplish-red capsular berry dehiscing septicidally from the top leaving the seed attached to the col- umn (Venkateswarlu & Dutt). In Tytonia the perianth consists of five sepals (one spurred) and five petals, the lowermost largest. In /mpatiens there are usually only three sepals (one saccate and usually spurred and two smaller lateral ones), but some species (cf. Hooker) have five, the two additional ones smaller than the others. The uppermost petal is free (and is often carinate or bifid), and the four others are connate in pairs, the pairs free from each other, each usually giving the appearance of a single two-lobed petal, but in J. Wallerana free nearly to the base and equal in size. An earlier interpre- tation of the perianth as composed of four sepals (the fourth [the upper- most petal in the above interpretation] being petaloid and often notched, presumably representing two sepals) and four petals (united in pairs) seems unlikely in view of the 10 perianth segments of Tytonia and the five sepals of some species of Jmpatiens. The perianth of Semeiocardium is composed of three sepals and five petals as in Impatiens, but the two fused petal-pairs have become connate into a bifid two-clawed liplike structure. Semeiocardium differs further from Tytonia and Impatiens in the largely connate lateral sepals, the 4-locular ovary, and the short, subulate style with a single stigma. Although it was originally described by Zollinger as a member of the Balsaminaceae, first Hasskarl and then Chodat mistakenly assigned it to the Polygalaceae. However, Backer’s observations on living plants show that it is closely allied with ‘Impatiens (cf. Miller, Jour. Arnold Arb. 52: 273. Li * As Backer & Bakhuizen van den Brink (Fl. Java 1: 251. 1963) pointed out a dozen years ago, Blume (Bijdr. Fl. Nederl. Indié 241. 1825) did not publish the generic name H ydrocera validly, since he gave only a family description (Hydro- yst. G 749. 1831) in synonymy, making Hydrocera superfluous and illegitimate. The single species in this genus should be known as ah re giro (L.) C. E. Wood, comb. nov., basionym, Impatiens triflora L. Sp. L2:9 1975] WOOD, BALSAMINACEAE 415 The Balsaminaceae have been considered to be allied with the Ger- aniales, and they have even been included in the Geraniaceae, but neither position is supported by recent studies. Most recent students have placed the family with the Sapindales, but this association is also uncertain. Erdtman notes that “an affinity with Celastrales, Geraniaceae, Oxalida- ceae, Simaroubaceae, a Violaceae has been suggested but is not supported by pollen morphology.’ REFERENCES: ae C. A. Semeiocardium Zoll., a misinterpreted genus of Balsaminaceae. Gard. Bull. ee 9: 70-72. pl. 2. 1935. [Emended description based on living plants. | & R. C. BAKHUIZEN VAN DEN BRINK, Jr. Flora of Java. Vol. 1. xxiii + 648 pp. frontisp. [Balsaminaceae, 248-251.] BAILLon, H. Geraniacées. VI. Serie des Balsamines. Hist. Pl. 5: 17-19. 1874. BENTHAM, G., & J. D. Hooker. Geraniaceae. Tribus VII. Balsamineae. Gen. Pl. 1: 277, 278. 1862. CANDOLLE, A. P. pe. Balsamineae. Prodr. 1: 685-688. 1824. Davis, G. L. Systematic embryology of the angiosperms. viii + 528 pp. New York, London, & Sydney. 1966. [Balsaminaceae, 54; numerous refer- es. Salat, R. Chemotaxonomie der Pflanzen. Band 3. Dicotyledoneae: Acanthaceae~Cyrillaceae 473 pp. Basel & Stuttgart. 1964. [Balsamina- ceae, 229-234. ] Hooker, J. D., & T. THomson. Praecursores ad Floram Indicam.— Balsa- mineae. Jour. Linn. Soc. Bot. 4: 106-157. 1860. Huynu, K. L. Morphologie du pollen des Tropaeolacées et des Balsamina- cées II. (English summary.) Grana Palyn. 8: 277-516. 1968. [Includes about 450 spp. of Jmpatiens and Tytonia triflora (as Hydrocera).]| Lusgock, J. A contribution to our knowledge of seedlings. 2 vols. London & New York. 1892. [Balsaminaceae, as “Geraniaceae,” 1: 314-316.] ‘ Martin, A. C. The comparative internal morphology of seeds. Am. Midl. Nat. 36: 513-660. 1946. [Balsaminaceae, 626.] Narayana, L. L. Contributions to the embryology of Balsaminaceae. Jour. Indian Bot. Soc. 42: 102-109. 1963 . Contributions to the embryology of Balsaminaceae. 2. Jour. Jap. Bot. 40(4): 8-2 1965. e et (be to the floral anatomy of Balsaminaceae. bid. 49: 315-320. 1974 Posepimova, E. G. “Balsaminaceae. In: B. K. SHisHxin & E. G. Bosrov, eds., FT, URSS. 14: 624-634. 1949. [English translation, Fl. USSR. Israel Program for Sci. Transl. 14: 478-485. 1974. Includes 8 spp. of Impatiens. | Rypperc, P. A. Balsaminaceae. N. Am. Flora 25: 93-96. 1910. Scriirnorr, P. N. Die Haploidgeneration der Balsaminaceen und ihre Ver- wertung fiir die Systematik. Bot. Jahrb. 64: 324-356. pls. 14-18. 1931. TiecHeM, P. van. Structure de quelques ovules et parti qu’on eu peut tirer pour améliorer la classification. Jour. Bot. t 12: 197-220. 1898. [210, some integuments concrescent nearly oughout. | : TRELEASE, W. A study of North American Geraniaceae. “Mem. a oc. Nat. Hist. 4: 71-104. pls. 9-12. 1888. [Balsamineae, 98100; literature, 102, 103 416 JOURNAL OF THE ARNOLD ARBORETUM [ VoL. 56 VENKATESWARLU, J., & L. LAKSHMINARAYANA. A contribution to the embryol- of Hydrocera triflora W. & A. Phytomorphology 7: 194-203. 1957. [Allium-type megagametophyte; includes a list of references with some on decay a s.] 5. Dutt. Amended description of ages triflora Wt. & Arn. fae Bombay Nat. Hist. Soc. 58: 544-546. 1 pl. 1 Warsurc, E. F. Taxonomy and relationship in the ed vei in the light of their cytology. New Phytol. 37: 130-159, 189-210. 1938. WARBURG, Pe & K. REIcHE. Balsaminaceae. Nat. Pflanzenfam. III. 5: 383- 392. 895. Wanen, F. Weitere Untersuchungen zur Morphologie des Unterblattes i den Dikotylen. Beitr. Biol. der Pflanzen 33(1): 17-32. 1957. [I. Si seas II. Plumbaginaceae. | Witczex, R., & M. ScHutze. Balsaminaceae. Fl. Congo Belge 9: 396-428. 1960. [Jmpatiens. | 1. Impatiens Linnaeus, Sp. Pl. 2: 937. 1753; Gen. Pl. ed. 5. 403. 1754. Annual [or perennial] herbs [to subshrubs, sometimes acaulescent, sometimes epiphytic], usually with succulent stems and alternate [oppo- site, or pseudoverticillate], simple, exstipulate leaves [but sometimes with a nectary at each side of the leaf base]. Flowers axillary, solitary, in clusters of 2 or 3 [or in panicles]. Sepals 3 [5], the two lateral ones small, the posterior one large (in ours), petaloid, [usually] saccate [or funnel-shaped| and spurred. Petals 5, appearing to be 3, each of the 2-lobed laterals representing a fused pair, the single upper petal free, often carinate and/or more or less bifid. Stamens 5, the filaments short and flat, each bearing a scalelike appendage on the inner side, the scales partly or completely united over the ovary and stigma, the filaments partly connate; anthers introrse, often connate; pollen strongly flat- tened [3- or] 4-colpate, reticulate [rarely spinulose]. Gynoecium of 5 ; style short or absent; ovary 5-locular, the valves elastic, in ours coiling violently from base to apex in dehiscence, scattering the seeds. Seeds with a straight embryo; cotyledons plump, hypocotyl and epicotyl short; endosperm none. LECTOTYPE SPECIES: I l (Name Latin, impatiens, in reference to the sudden bursting of the ripe fruit when ‘touched, ) — ToucH-ME-NOT. A genus of about 500 described species in 14 sections (see Warburg & Reiche), primarily of tropical and subtropical Asia (about half of the species in India and Burma) and Africa (about 150 species), with a few in temperate Eurasia and North America and none in either South America or Australia. Five indigenous species, all annuals of sect. Im- PATIENS (§ Brachycentron Warb.), and two naturalized species occur in the United States and Canada; two of the indigenous species occur in our area. 1975] WOOD, BALSAMINACEAE 417 FIGuRE 1. Impatiens. a-I, /. capensis: a, tip of flowering shoot, X %; mewer <2. ¢, spurred sepal wand petal- esa esi surface), eS d, ree cium inclosing gynoecium, e oe oe 4 : androecium and oe- I = eae Ge = fe) len from herbarium specimen (after Khoshoo, 1 oe : m, flower, X 2; n, spurred sepal and petal-pair (inner surface), X 1 I ante capensis Meerburg (J. biflora Walter, J. fulva Nutt.), im weed, 2m = 20, is widely distributed in wet places, on stream b 5; in clit from Newfoundland to Alberta, south to Florida, Alabama, Arkansas, and Oklahoma. The saccate part of the spurred sepal is oon than broad and the sepal spur is usually strongly incurved. The flower = is orange with red spotting, but it is very variable, and numerous color forms have been named (cf. Weatherby). Disjunct populations occur in northwestern Oregon and in extreme northwestern Washington an southwestern British Columbia. Ornduff, who has studied the Oregon 418 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 populations, thinks that J. capensis may be introduced in Oregon but indigenous in Washington and British Columbia. This species is wide- ly naturalized in Great Britain and in France. Impatiens pallida Nutt. (J. aurea Muhl.), 2n = 20, with yellow, un- spotted or sparingly spotted flowers, with the sac of the spurred sepal broader than long and the spur at a right angle to the sac, occurs in wet places or on stream banks in rich, shaded areas, most often on calcareous soils. It is distributed from Newfoundland to Saskatchewan, south through Nova Scotia and New England to Georgia, Tennessee, Missouri, and Kan- as. Impatiens pallida and I. capensis, vegetatively similar, often grow to- gether, but there seems to be no evidence of hybridization anywhere in protandrous (as are those of other species of Jmpatiens), and the ap- pendages of the filaments form a cover over the stigmas preventing pol- len from falling on them. The stamens fall off as a unit, exposing the receptive stigmas. Unpollinated chasmogamous flowers of J. pallida and I, capensis do not set fruit. The effective pollinators of the two seem to be different, the rather small sepal sac and orange-and-red color of J. ca- pensis favoring the ruby-throated hummingbird (Archilochus colubris), which seems to be the only “legitimate” visitor to the flowers both before and after the stamens fall. (Various bees collect pollen, and bees and wasps bite holes in the nectariferous spur, robbing the flowers illegitimate- ly.) Impatiens pallida, with its yellow flowers and larger saccate sepal, is visited by species of Bombus, which Robertson noted were more con- stant in their visits to flowers of this species than to those of J. capensis. He did not see hummingbirds visiting the flowers of J. pallida. A relatively small proportion of the chasmogamous flowers of either species set fruits, and the bulk of seed production appears to be from cleistogamous flowers. These are much smaller but bear all of the parts present in open ones except for the staminal appendages that cover the stigmas, pollen thus coming directly into contact with the stigmas. The floral parts never expand, but are forced off by the developing fruit. (See Bennett, Carroll, and Gray.) Ornduff has pointed out that the center of diversity for the genus in North America is in the Pacific Northwest (Oregon, Washington, Idaho, western Montana, and southern British Columbia), where four species d the ranges of several overlap. In the northern extreme of its distribution in Oregon on the lower Columbia River, Impatiens capensis forms large hybrid swarms with J. ecalcarata Blankinship, which has un- spotted yellow or orange spurless flowers. The Eurasian J. noli-tangere L. (J. occidentalis Rydb.), 2n = 20, which occurs in North America from southern Alaska through British Columbia to northwestern Washington, overlaps the range of /. ecalcarata and that of J. aurella Rydb., which has relatively small, spurred, unspotted orange flowers. Puzzling plants combining in various ways the morphological features of these four species led Ornduff to hypothesize that “in the Pacific Northwest J. capensis was 1975] WOOD, BALSAMINACEAE 419 once widespread, but subsequently the species has largely been extermin- ated in the region as a result of extensive and widespread hybridization with various other species. Vestiges of the floral morphology and pigment pattern of /. capensis still occur, but they are mostly in combination with features derived from J. noli-tangere, I. ecalcarata, or I. aurella. The last species in turn combines characters of J. ecalcarata and J. noli-tangere and may have originated by means of hybridization between these two species, followed by additional local hybridization with J. capensis.” Impatiens glandulifera Royle (I. Roylei Walpers) (sect. SALPINGO- CHILON Warb.), 2” = 18, 20, of the Himalayan region, is naturalized in the cooler, moister areas of Nova Scotia, New England, and Quebec, and appears to be spreading in western British Columbia, Washington, and Oregon. It is extensively naturalized in Great Britain, and is spreading in western and central Europe. It is distinctive in its opposite to pseudo- verticillate leaves and clusters of large dark magenta-red to rose, pink, or white flowers. Impatiens parviflora DC. (sect. IMpATIENS), 2m = 20, 24, 26, a na- tive of central Asia, is now widely naturalized in northern, central, and eastern Europe and in Great Britain, and it is introduced in Prince Edward Island and Quebec and on Vancouver Island, British Columbia. This very small-flowered species apparently is quite variable in its native area, but all of the naturalized plants apparently are descendants from a single seed lot planted in Geneva, Switzerland, about 1830, and are notably uniform. The five-sepaled flowers of J. parviflora apparently are largely self-pollinated. (See Coombe for a very complete account of this species in Britain.) The very variable Impatiens Balsamina L. (sect. MICROCENTRON Warb.), 2m = 14, from India, Malaya, and China, is cultivated in many parts of the world as an ornamental garden plant. This and the African I. Wallerana Hooker f. (J. Sultani Hook. f., J. Holstu Engler & Warb.) (sect. Lonctcornes Warb.), 2n = 16, notable for a wide range of colors and nearly equal lobing of the paired petals, are probably the — most widely cultivated species of Jmpatiens. Their range of flower colors and ease of cultivation have made them the subject of many physiologi- cal, chemical, and genetic studies (see references). Although both are naturalized in various warmer areas, they are only occasional waifs in our region. : : Bitbeye sac development of the Polygonum type (e.g., In as capensis, I. pallida, I. Balsamina) and of the Allium type pasts = Wallerana, I. glandulifera) has been reported in the genus. te a hile Impatiens are unique in that the strongly flattened pollen z she hed the generative nucleus is in prometaphase of the division 7 heaps a the two sperm nuclei; hence the chromosome number can be determin i e persists in the pollen of herbarium at this stage. This nuclear stage P ee cm 16, 20, 26, 32, 34, 36 (+ 2f), 40, and 66 have been recorded in various 420 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 species of the genus. These ae fall into groups based on x = 7, 8, 10, and 11 (cf. Jones & Sm Huynh (1968), who wacisd the pollen of about 450 species of /m- patiens but who apparently was unaware of the numerous relationships between the floras of North America and Asia, remarked with some sur- prise that the species of /mpatiens of North America have pollen which recalls curiously that of the group of J. noli-tangere, which includes about 20 species of southern China. REFERENCES: Under family references /mpatiens is included in all references to Balsamina- ceae. Space limitations have dictated that much of the voluminous literature on physiological and chemical studies of Jmpatiens species be omitted. How- ever, some references on each of the general topics are among those below. AtsTon, R. E., & C. W. HAcEN. Chemical aspects of the inheritance of flower color in Jongotiens Balsamina L. Genetics 43: 35-47. ANnprEws, F. M. An unusual /mpatiens biflora. Proc. Indiana Acad. Sci. 34: e71,.272;.1925. An individual with dark red leaves with a green border, Monroe County, Indiana. See also ibid. 35: 179. 1926; seedlings from cleistogamous flowers were like the parent plant. | ArIsuMI, T. Chromosome numbers and _ interspecific rae among New Guinea Impatiens species. Jour. Hered. 64: 77-79. 1973. . Morphology and Lenin: behavior of colchicine- induced ethine Impatiens spp. L. Jour. Am. Soc. Hort. Sci. 98: 599-601. ARNOLD, A., & R. E. Atston. Certain properties of hypocotyl ee sae Balsamina reflecting physiological complexity. Pl. Physiol. 36: 650-656. 1961 BEAL, W. J. Fertilization of flowers by hummingbirds. Am. Nat. 14: 126, 127. 1880. [Observations by WM. Snyper that the ruby-throated humming- bird is an effective pollinator of J. capensis, while bees are not. ‘Impatiens fulva is cross-fertilized mainly, if not wholly, by hummingbirds.” Beck, A. R., J. L. Wetcle, & E. W. Krucer. Breeding behavior and chromo- some numbers among New Guinea and Java Impatiens species, cultivated varieties, and their interspecific hybrids. Canad. Jour. Bot. 52(5): 923- 925. 1974. BENNETT, A. W. On the floral structure of Impatiens fulva, Nuttall, with es- pecial reference to the imperfect self-fertilized flowers. Jour. Linn. Soc. Bot. 13: 147-153. pl. 3. 1873. [J. capensis; also cleistogamous flowers in I. noli-tangere. | . Notes on cleistogamic flowers; chiefly of Viola, Oxalis, and Impatiens. Ibid. 17: 269-280. 1880. [J. noli- -tangere, fi parviflora, 276-2 78. . E. Woop. Observations on the anatomy of teratological seed- The anatomy of some oes seedlings of Impatiens Roylei, Walp. Ann. Bot. 44: 297-309. BuaskKar, V. A new kind of exine a ge in Tusutont L. (Balsaminaceae) from south India. Curr. Sci. Bangalore 42: 510-512. 1973.* Biss, P. C. Studies on the regulation of developmental sequences of an- thocyanin pigmentation in cultured petals of Impatiens Balsamina L. Diss. Abstr. B. 28(9): 3596B. 1968. 1975] WOOD, BALSAMINACEAE 421 Boum, B. A., & G. H. N. Towers. A study of phenolic compounds in /mpatiens. Canad. a Bot. 40(5): 677-683. 1962. [In 16 s BoyLen, C. W., & C. W. Hacen. Partial purification and characterization of a flavonoid- 3- beta D-glucoside fc petals of Jmpatiens Balsamina. Phyto- chemistry 8: 2311-2315. 1969. BuntTInG, G. A. Jewel weed vs. poison ivy. Am. For. & For. Life 30: 495, 496. 1924. (Illustr.) [Tincture of J. capensis used in treating dermatitis caused by Rhus radicans CAMPBELL, I. M. Roles of alanine, aspartate and glutamate in lawsone bio- synthesis in Impatiens Balsamina. Tetrahedron Lett. 54: 4777-4780. 1969.* CARROLL, F. B. The development of the chasmogamous and the cleistogamous flowers of Impatiens ee Contr. Bot. Lab. Univ. Penn. 4: 144-183. pls. J5—57. 1919. [7. cap CHADEFAUD, M. Le Fe ne impatiences et la theorie de Wodehouse. Bull. Soc. Bot. France 99: 182, 183. 1952. CHAPELLE, J. P. 2-Met thoxy-1, 4-naphthoquinone in -iciasaidied glandulifera and related species. Phytochemistry 13: 662. 1974. Cuaunan, K. P. S., & W. O. ABEL. Evidence for the association of homologous chromosomes during premeiotic stages of /mpatiens and Salvia. Chromo- soma 25: 297-302. 1968 CLEVENGER, S. The flavonols of Impatiens Balsamina L. Arch. Biochem. & Biophys. 76: 131-138. fhe ee of some Jmpatiens species. XI Int. Bot. Congr. Abstr. 34. Coomse, D. E. Medel flora of the British Isles. clas parviflora DC. Jour. Ecol. 44: 701-713. [A very complete acco CurTIs, S, Impatiens glanduligera. Bot. Mag. 49: pl. ee 1843. [J. glandu- lifera. dee K. V. O. Die Embryologie von Impatiens Roylei. Sv. Bot. Tidskr. 28: 103-125. 1934. [J. glandulifera. ] Davis, D. W., L. A. Taytor, & R. P. AsH. Impatiens Balsamina L. — the inheritance of floral colors. Genetics 43: 16-34. 1958. ENGLEMAN, E. M. Sieve element of Impatiens Sultan. 1. Wound reaction. 2. Developmental aspects. Ann. Bot. II. 29: 83-118. pls. 1-9. 1965. [J. Walleran FERNALD, M. ze & B. G. Scuusert. Studies of American types in British herbaria. Rhodora 50: 149-176, 181-208, 217-233. pls. 1097-1117. 1948. [Note on Impatiens biflora Walt., 203-205; = J. capensis Meerb. Ficter, J. Infrastructural study of petiolary glands of Impatiens Holstit. ae French: English summary.) Botaniste 55(1/6): 71-79. OT UE. er lera eer FLynn, J. ma Jr. Impatiens. Pollen development, maturity, and ——— Diss., Univ. Massachusetts, 1969. Diss. Dig. May 1970: 14. ee. [Order No. 70-13, 209B.] Fourcroy, M., & J. BOULANGER. Ontogénie et anatomie Impatiens Balfouri H.: Echantillons normaux et hétéroco Bot. France 1963: 154-186. 1964. Fucus, H. P. Nomenklatorische Erganzungen zu der Arbeit Nicholas Meer- erfassten botanischen Tafelwerke. Acta Bot. ; me for Neerl. 12: 12-16. 1963. L. — Meerb., 1775; the correct * the de la plantule chez tylés. Mém. Soc 422 JOURNAL OF THE ARNOLD ARBORETUM [VvoL. 56 Bot. Gart. Berlin 13: 665. 1937; B. L. Burtt, Bull. Misc. Inf. Kew 1938: 161-163. 1938; M. L. FerNAtp, Rhodora 50: 203-205. pl. 1108. 1948.] Gitc, E. Balsaminaceae africanae. Bot. Jahrb. 43: 97-128. 1909. [85 spp. in Africa; pp. 118-120, discussion of Jmpatiens Wallerana Hook. f., J. Sultani Hook. f., 7. Holstii Engler & Warb., of sect. Longicornes Warb.; combines all under I. Wallerana. | Gray, A. Ord. Balsaminaceae. Gen. Pl. U. S. 2: 131-136. pls. 152, 153. 1849. [Z. fulva (= I. capensis), pls. 152, 153; pacpengiantee flowers, pl. 153.] GroNER, M. G. Sugar excretion in Teshotions Sultani. Am. Jour. Bot. 26: 464- 467. 1939. [Excretion of sucrose by petiolar hairs in plants of J. Waller- ana. GROTZINGER, E., & I. CAMPBELL, Intermediate symmetry in sages bio- synthesis. becca mae 11: 481-488. 1972.* [J. Balsam HAcEN, C. W. The production of pigments in flowers of Yoietins Balsamina. (Abstr.) Proc. Indiana Acad. Sci. 66: 61. 195 Hecarty, T. W. Seedling growth in controlled- ee conditions. Jour. Exper. Bot. 24: 130-137. 1973.* [J. parviflora. ] Hom, T. Stiaphilous _ -types. Beih. Bot. Centralbl. 44: 1-89. 1927. [J. fulva, $6, 7; capens Hooker, J. D. Impatiens Sele var. pallidiflora. Bot. Mag. 125: pl. 7647. 1899. Fe ‘glandulifera Royle f. pallidiflora (Hook. f.) Weatherby. | n epitome of the British Indian species of Impatiens. a Bot. Surv. India 4: 1-10. 1904; 11-35. 1905; 37-58 + iii (index). 190 Huane, T. C. A revision of Formosan Impatiens (Balsaminaceae). ee 18: 49-54. 1973. [3 species. ] Hucues, A. P. The importance of light compared with other factors affecting plant growth. Brit. Ecol. Soc. Symp. 6: 121-146. 1966. [Review of the literature; chiefly 7. parviflora. ] Huynu, K. L. Cinq espéces d’/mpatiens au pollen insolite. (English summary.) Pollen Spores 8: 455-460. 1966. [5 Asiatic spp. of 440 spp. surveyed have “spinulate” ~~ others have reticulate. | Le minisme de l’emplacement des apertures sur le pollen d’une espbce a sic apertures: Impatiens scabrida DC. Grana Palyn. 7: 37-45. 1967 IwaNnaMI, Y. Physiological researches of pollen VII. The starch grain in the pollen of Impatiens Balsamina L. (In Japanese; Esperanto summary. Bot. Mag. 67: 134-137. 1954 & N. Nakamura. Storage in an organic solvent as a means for preserv- ing viability of pollen grains. Stain Technol. 47: 136-139. 1972. [Lilium, Camellia, Impatiens. | —— M. Impatiens Roylei Walpers, a new forest meadow plant in oland. (In Polish; German summary.) Polska Akad. Nauk. Inst. Bot. ce Florystyczne Geobot. 7(1): 77-80. 1961.* JENNINGS, O. E. Impatiens pallida forma speciosa f. nov. Ohio Jour. Sci. 20: 204. 1920. Jones, K., & J. B. SmirH. The cytogeography of Impatiens L. (Balsaminaceae). Kew Bull. 20: 63-72. 1966. [Includes counts on 25 spp., 2m = 14, 16, 18, 20, 34, 36 (+ 2f), 66.] KuosHoo, T. N. Cytology of Impatiens. Cur. Sci. Bangalore 24: 423, 424. 1955.* ————. Chromosomes from herbarium sheets of Impatiens. Stain Technol. 1975] WOOD, BALSAMINACEAE 423 31: 31-33. 1956. [Counts obtainable from generative nucleus in prome- taphase in pollen grains. ] ytology of some Jmpatiens species. Caryologia 10: 55-74. see id. 1957. [Includes table listing known chromosome counts in Jmpatiens.] . Cytology of pollen with particular reference to Impatiens and “Allieae. Proc. Indian Acad. Sci. B. 63: 35-45. 1966.* Kietn, A. O., & C. W. Hacen. Anthocyanin entree in detached petals of Impat iens Balsamina L. Pl. Physiol. 36: 1-9 KRISHNAMOORTHY, H. N., & K. K. NANDA. a ne reversion in — Balsamina under non-inductive photoperiods. Planta 80: 43-51. Kroecer, G. S. Dormancy in seeds of Impatiens Balsamina L. So ae Thompson Inst. 12: 203-212. 1941. LaunerT, E. Balsaminaceae. Jn: A. W. EXELL, A. FERNANDES, & H. WILD, eds., Fl. Zambesiaca 2(1): 162-180. 1963. [22 spp. of Jmpatiens; I. Wallerana, 166. ] Legon, E. Sur la formation de l’albumen chez Jmpatiens Sultani. Comp. Rend. Soc. Biol. Paris 101: 1168-1170. 1929. [J. Wallerana Le SAINT-QUERVEL, A. M. Etude anatomique de quelques plantules anormales d’Impatiens Roylei W. Revue Gén. Bot. 62: 373-391. -¥ LotsEau, J. E. Observations et expérimentation sur la phyllotaxie et le fonc- tionnement du sommet végétatif chez quelques Balsaminacées. Ann. Sci. Nat. Bot. XI. 20: 1-214. pls. 41-60. 1959. [Republished as Thése, Fac. Sci. Univ. Paris Ser. A, No. 3229. 1959. Includes /. capensis and 1. glandulifera (as I. Roylei)]. Low, E. Der Bliitenbau und die eg natee goer eg von Impatiens Roylei Walp. Bot. Jahrb. 14: 166-182. pls. 1 892. MANSELL, R. L., & V. L. KEMERER. Qualitative and quantitative comparisons of hydroxycinnamic acid derivatives in petals of red (IIHHPrPr), white (IIhhpp) and purple CUBR genotypes of Impatiens Balsamina. Phytochemistry 9: 1751-1755. 1970.* . A. SEDER. O-methyltransferase activity — young flower petals of Impatiens Balsamina. Ibid. 10: 2043-2045. 1971. Menra, K. L., N. Risut, & H. KESHORE. eeu between Impatiens racemosa, Impatiens laxiflora, and Impatiens scabrida. Proc. Indian Acad. Sci. B. 71: 1970. Movie, R. Ky . ee piu The vegetative anatomy of Jmpatiens pallida. feu c. 50: 1-19. 1931. MILEs, OD se eres W. hee The differentiation of pigmentation in set parts. IV. Flavonoid elaborating enzymes from petals of Impatiens Bal- 1354. 1968. am, 2. 205 i pe ba cats germination at various stages of pga of flower buds of balsam (Impatiens Balsamina). Jour. P alynol. 9: 29-33. 1973, Narayana, L. L., & M. SaveepuppIN. A study of the gametophytes . Im- patiens Leschenaultii Wall. Jour. Indian Bot. Soc. eee ape t. Ornvurr, R. Impatiens capensis in Oregon: native or neceeiet: Lea . = Bot. 10: 317-319. 1966. [Evidence inconclusive; apparently indigendut Mp a small area of northwestern Washington and southwestern British Co si and regional variation in Pacific northwestern Impatiens (Balsaminaceae). Brittonia 19: 122-128. 1967. 424 JOURNAL OF THE ARNOLD ARBORETUM [VoL. 56 Orrtey, A. M. A contribution to the life history of Jmpatiens Sultani. Bot. Gaz. 66: 289-317. pls. 14, 15.1918. [/. Wallerana Panpey, K. K., & G. W. Btaypes. Cytoplasmic inheritance of plastids in Impatiens Sultanii Hook. f., Petunia violacea Lindl. and Chlorophytum elatum R. Br. Ohio Jour. Sci. 57: 135-147. 1957. PHoupnHas, C. Nouvelles a embryogéniques sur les /mpatiens. Bull. Soc. Bot. France 98: 238-241. RackHAm, QO. Radiation, as and growth in a woodland annual. Brit. Ecol, Soc. Symp. 6: 167-185. 1966. [J. parviflora and solar radiation. | RacHavan, T. S., K. R. VENKATASUBBAAN, & H. D. Wutrr. Division of the generative cell in /mpatiens Balsamina L. Cytologia 9: 389-392. 1939. RAGHUVANSHI, S. S., & S. JosHrI. Investigation on the frequency of B-chromo- somes in Impatiens Balsamina and the appearance of single flowers on double varieties. Genetica 39: 544-552. 1968. Raitt, A. H. Development of the ovule of Jmpatiens pallida Nutt. Pl. World 19: 195-203. 1916. RICHTER-LANDMANN, W. Der Befruchtungsvorgang bei /mpatiens glandulifera Royle unter Beriicksichtigung der plasmatischen Organelle von Spermazelle, Eizelle und Zygote. Planta 53: 162-177. 1959. RicKETt, H. W. Wildflowers of the United States. Vol. 2: The Southeastern States. Part 2. Pp. i-vi + 323-688. New York. 1966. [/mpatiens, 366, pl. 131.) Rosertson, C. Flowers and insects. III. Bot. Gaz. 14: 297-304. 1889. [Pol- lination of J. capensis & I. pallida, 301; see also Flowers and Insects. 221 pp. en — 1928; Impatiens, 36, 37.] SAWHNEY, S., N. Saw y, & K. K. NAnpbA. Partial substitution by long days of short days iat for floral induction in Impatiens Balsamina. Pl. Cell Physiol. 13: 1123-1127. 1972. SCHLECHTER, R. Die Scie Papuasiens. Bot. Jahrb. 55: 114-120. 1917. [8s SENAY, P. Impatiens fulva Nutt. sur les rives de la basse Seine. Bull. Soc. Bot. France 77: 257-259. 1930. [J. capensis.] SuIMizu, T. Contributions to the flora “ hes Asia. II. Impatiens of Thailand and Malaya. Tonan Ajia Kenkyu (Southeast Asian Studies) 8: 187-217. 1970. [47 spp.] SHIVANNA, K. R. Inhibition of gamete formation by cycloheximide in pollen tubes of Jmpatiens Balsamina. Planta 117: 173-177. 1974. SINGH, T. C. N., & S. PonnrIAH. On the response of structure of the leaves of balsam (Impatiens Balsamina) and mimosa (Mimosa pudica) to the musical sounds of violin. Indian Sci. Cong. Assoc. Proc. 42(3, abstr.): 254. 1955.* SMITH, F. H. Prochromosomes and chromosome structure in Impatiens. Proc. Am. Philos. Soc. 74: 193-214. pls. 1-3. 1934. ————. Anomalous spindles in /mpatiens pallida. Cytologia 6: 165-176. 1935. Reduction divisions in triploid Jmpatiens. Am. Jour. Bot. 25: 651-654. 1938. SonMA, K. Pollen morphology of Japanese species of Impatiens, with notes on first fossil record of genus in Japan. Tohoku Univ. Sci. Rep. 4. (Biol.) 35: 259-262. 1971.* SovEces, R. Embryogénie des Balsaminacées. Développement de l’embryon 1975] WOOD, BALSAMINACEAE 425 chez separ Balfourit Hook. Compt. Rend. Acad. Sci. Paris 220: 837- 840. STEFFEN, = ‘ter Kenntnis des Befruchtungsvorganges bei /mpatiens glanduli- gera Lindl. Cytologische studien am Embryosack der Balsamineen. Planta 39: 175-244. 1951. [J. glandulifera. | . Die Embryoentwicklung von /mpatiens cipro — Flora 139: 394-461. 1952. [Detailed account of embryo develop & W. LANDMANN. Enteicktise aeh kui und fits he Unter- uchungen am Balkentapetum von Gentiana cruciata L. und /mpatiens glandulifera Royle. Planta 50: 423-460. 1958. STEWART, S. E. Breaking male sterility in Jmpatiens Sultani Hook. f. by hy- bridization (Malvales: Balsaminaceae). (Abstr.) ASB Bull. 18: 57. 1971. [Z. Wallerana. ] es as nae L., & F. WEBER. beter bei Jmpatiens. Phyton Austria 5: 34- _ 1953. (J. Holstii = I. Waller Takao, S. “ study on the Se of chew sac in Impatiens textori. Bot. Mag. Tokyo 81: 310- 968. Tara, C. P. Aberrant ics and sterility in /mpatiens Sultam (Balsarminacese). Am. Jour. Bot. 61: 585-591. 1974 Taytor, L. A. Plants used as curatives by certain southeastern tribes. Part I. Plants used medicinally. xi + 88 pp. Bot. Mus., Harvard Univ., Cam- bridge, Mass. 1940. [Impatiens capensis, 40.] Toxy, K. L., & K. K. Nanpa. Hastening effect of intercalated long days on short- ~day induction in /mpatiens Balsamina, a qualitative short day plant. Planta 89: 198-202. 1969. TRELEASE, “ Impatiens fulva, action of bees toward. Bull. Torrey Bot. Club 7: 20, 21. 1880. [Honeybees visiting flowers of /. capensis with perforated and pe nectaries. VALENTINE, D. H. Flower-colour polymorphism in Impatiens glandulifera Royle. Boissiera 19: 339-343. 1971. Vazart, J. Etude cytologique du genre Impatiens. II. Premiers stades du développement de V’ovule et prophase heterotypique ¢ chez J. Balfourit. Revue Cytol. Biol. Vég. 19: 311-336. WeaTHersy, C. A. apes forms of Impatiens biflora. Rhodora 19: 115-118. 1917. (I. capensis. | Further pie on Impatiens biflora. Ibid. 21: 98-100. 1919. [Z. ca- pensis. | Impatiens Roylei versus I. glandulifera. Ibid. 48: 412-414. 1946. ECorrect name is J. glandulifera. | es WEBER, F. — nektar. Phyton Austria 3: 110, 111. 1959. [J. Holsti 7 Wa llerana. | flower qT ti Balsamina L. I. The inheritance of Tae Stu oe non of cumulative linked isomery. Genetica 29: 358-384. 1959; II. The inheritance of flower doubleness a its dependence on gibberellic acid, indoleacetic acid and related compounds Ibid. 30: 70-107. 1959; III. The inheritance of dilute and very dilute flower colours. Canad. ‘Jour. Genet. Cytol. 2: oe WEIssenBock, G., & H. REzNICK. Changes in flavonoid pattern eg" is mination of Impatiens Balsamina L. seeds. (In German.) Zeitschr n- zenphysiol. 63: 114-130. 1970.* 426 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 WILLE, W. Labelling experiments in relation to the kinetics of leucoanthocyanin and anthocyanin synthesis in the hypocotyls of Impatiens Balsamina L. In German; English summary.) Zeitschr. Pflanzenphysiol. 57: 134-150. 1967.* ARNOLD ARBORETUM HARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 1975] FRODIN, STUDIES IN SCHEFFLERA 427 STUDIES IN SCHEFFLERA (ARALIACEAE) : THE CEPHALOSCHEFFLERA COMPLEX D. G. FRopIN IN RECENT YEARS there has been a renewal of interest in the mor- phology, anatomy, and systematics of the Araliaceae, beginning with the work of Baumann (1946) and continuing to the present (Baumann- Bodenheim, 1955; Rodriguez, 1957; Hoo & Tseng, 1965; Hutchinson, 1967; Smith & Stone, 1968; Eyde & Tseng, 1969, 1971; Grushvitzky & Skvortsova, 1970; Hladik, 1970; Philipson, 1970; Grushvitzky et al., 1971; Tseng, 1973; Bamps, 1974b). This paper, a preliminary report on the complex of sect. CEPHALOSCHEFFLERA Harms and some related topics, represents the first of a series aimed at elucidating the systematics of Schefflera J. R. & G. Forst., the largest and geographically most wide- spread genus in the family, and one which is conspicuous in many trop- ical vegetation formations. Although there are several recent regional revisions (Backer & Bakhuizen, 1965; Bamps, 1974a, 1974b; Bernardi, 1969; Grushvitzky & Skvortsova, 1969; Hoo & Tseng, 1965; Li, 1942; Macbride, 1959; Smith, 1944; Smith & Stone, 1968; Tennant, 1968), the latest general revision on a world-wide basis is an incomplete and un- critical compilation by Viguier (1909). In addition, the limits of Schef- flera, like those of various other genera in the Araliaceae, have been sub- ject to many differences of opinion, which a perusal of even some of the above-cited references will show. THE CEPHALOSCHEFFLERA COMPLEX The first part of this paper is primarily a reconsideration of sect. CEPHALOSCHEFFLERA Harms (1894), which, for convenience, I shall here call “the Cephaloschefflera complex.” It is a partial summary of an as yet unpublished dissertation (Frodin, 1970), which is in turn based on research toward a world-wide revision of Scheflera and allied genera. Associated with this question is the status of Brassaia Endl., included by Harms within his sect. CEPHALOSCHEFFLERA but still kept separate from Schefflera by a number of authors, both botanical (Burbidge, 1963; ong ham, 1964; Hutchinson, 1967; Smith & Stone, 1968; Stone, 1970; Clif- ford & Ludlow, 1972) and horticultural (Neal, 1965). This may be in part due to tradition (Brassaia was recognized as distinct by Bentham (1867)) or convenience. It may be noted that the type species of Bepseis, B. actinophylla Endl. (= S. actinophylla (Endl.) Harms), has long been : well known staple of ornamental horticulture, both indoors and out, anc in some countries or regions it is adventive or naturalized (e.g., Fiji, 428 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Singapore, southern Queensland). The question as to whether Brassaia should be kept separate or should be merged with Schefflera in a way highlights the whole problem of the Cephaloschefflera complex: is it or is it not a natural grouping? Schefflera is presently considered to have ca. 200 species (Willis, 1973). These species are found in most of the tropical and subtropical regions of the earth, but they are especially numerous in certain mountainous belts, such as the Andes and the mountains of Southeast Asia and Male- sia (notably the central cordillera of New Guinea); the other main concentrations are found in the Guayana Highlands, Madagascar, and New Caledonia. The genus is typified by the single species in New Zealand, Schefflera digitata J. R. & G. Forst. As delimited by Harms (1894-97), Schefflera comprises trees, shrubs, epiphytes, hemi-epiphytes (sometimes strangling), and climbers. The genus is largely characterized by the following: a) an absence of prickles on vegetative parts; b) once palmately compound leaves with fused stipules extending into an ap- pendage of greater or lesser length at the base of the petiole; and c) inflorescences in panicles with a main axis and a varying number of branches along which the flowers are arranged in more or less numerous, usually stalked umbellules, capitula, racemules or spicules. Less common- ly, the entire inflorescence forms a compound umbel recalling those pres- ent in the vast majority of the Umbelliferae. The flowers lack an ar- ticulation at the base of the pedicel and are most often characterized by an ovary with five (or more) locules. Associated with Scheflera are a number of related genera: Crepinella E. March., Didymopanax Decne. & Planchon, Dizygotheca N. E. Br., Enochoria Baker {., Geopanax Hemsley, Neocussonia (Harms) Hutch- inson, Octotheca R. Vig., Plerandra A. Gray, Scheffleropsis Ridley, and Tupidanthus Hook. f. & Thomson. Agalma Migq. and Brassaia Endl. are maintained as segregates of Schefflera by Hutchinson (1967), while sev- eral authors, past and present, have merely segregated Brassaia. In the Philippines, Merrill (1923) added a further segregate, emengge (Harms) Merr. (based on sect. CEPHALOSCHEFFLERA Harms). All of these taxa are distinguished from one another by essentially small dif- ferences in inflorescence morphology and in the absolute and relative numbers of floral parts. More distantly related are 2 onaeta Am Decne. & Planchon, Macropanax Miq., and Pseudopanax C. Harms (1894) proposed the division of Scheflera he inte by him) into two sections: Sect. CEPHALOSCHEFFLERA. Flowers sessile, in more or less densely aggregated capitula, these mostly pedunculate and arranged in racemes [including Brassaia]. (Piate III-A.) ect. EUSCHEFFLERA. Flowers pedicellate, in racemes or umbels. (Prate III-B.) The geographical distribution of both sections was shown to be more or less pantropical, although sect. CEPHALOSCHEFFLERA was not re- 1975] FRODIN, STUDIES IN SCHEFFLERA 429 corded for the islands east of New Guinea. Harms intended his de- limitation of sections and subsections to be practical; to him, attempting a natural arrangement at that time was not advisable, since available herbarium material and field data were too often imperfect. Unfortunately, he never made a new overall revision of Schefflera before his death in 1942, although in the intervening 48 years he described numerous new species and made various regional revisions, of which the most important was that forming part of his treatment of the Papuasian Araliaceae (Harms, 1920-21). Harms’s arrangement came into wide use, its outlines (although some- times modified) being used for treatments of Scheflera and other Araliaceae in many floras and regional revisions. Initial acceptance of his arrangement may have been consolidated by the wide influence of Engler and Prantl’s Die natiirlichen Pflanzenfamilien and other German works of the pre-World War I era. Since then, the most significant modi- fication of Harms’s system has been that of Hoo and Tseng (1965), in which that part of the Agalma group characterized by entirely racemose inflorescences was elevated to sectional rank, along with their sect. BRASSAIA (= sect. CEPHALOSCHEFFLERA Harms) and sect. SCHEFFLERA = sect. EUSCHEFFLERA of Harms, except for the racemosely flowered species in the Agalma group); this arrangement has also been adopted by Grushvitzky and Skvortsova (1969). An alternative arrangement of Schefflera was proposed by Viguier (1909). In his compilation he showed that a few species were inter- mediate in so far as pedicel development was concerned. In other words, the flowers appeared to be in capitula, although in fact they were pedi- cellate. This interpretation cut across the primary division in Harms's scheme, thus rendering it open to question. For the sake of comparison, Viguier’s scheme is given below in synoptic form (no formal nomenclature was applied to his groups): capitula). [Only one capituliferous species, Schefflera schumanniana ae from New Guinea, was included here; the other members are the Agalma group of species of sect. EUSCHEFFLERA Harms.] (Piates I-A, I-B. Styles none and stigmata sessile on the disk, or styles free or united ap! at the base, radiating outward in fruit; flowers in racemosely arranged um- bellules or capitula. ape Flowers in capitula. [Most members of sect. CEPHALOSCHEFFLERA Harms, including Brassaia, were listed here. ] (Prate III-A.) is Flowers in umbellules. [This group included the greater part o Ley ; EUSCHEFFLERA, except for the Agalma group of species.} (Piates H-A, III-B.) ; Styles variously developed; flowers umbellulate, arranged in a umbels. [This group included miscellaneous members of sect. aires E ; mostly from northern South America, Madagascar, and New Caledonia. (Pate II-B.) ~ ag a = 430 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Viguier regarded the form of the inflorescence and the nature and degree of fusion of the styles as more important attributes than the presence or absence of capitula, a characteristic which was, so to speak, relegated to third place. Apparently, whether or not a given species was considered capituliferous depended, in his view, on the overall appearance of the cluster of radiating flowers; whereas Harms maintained a more exact outlook, basing his delimitation on the presence or absence of pedicels. (At a later date, however, Harms appears to have made the delimitation in Viguier’s sense; see his treatment of Papuasian Schefflera (1920-21, p. 385).) As already noted, the Philippine species of the Cephaloschefera complex were the first to be elevated to generic rank (Merrill, 1923). However, Hutchinson (1967) proposed that all of the capituliferous spe- posed to umbellules, without qualification. In an appendix (1967, pp. 622-624), he listed 45 species as belonging to his expanded concept of Brassaia; even then, a great many more published species which should logically have been accounted for were left out. In a similar manner, Hutch- inson reinstated Miquel’s old genus Agalma to include those species of Schefflera with flowers racemosely arranged throughout, notwithstanding their other relationships. Hutchinson’s proposals provided the lead which stimulated my studies in the direction of the Cephaloschefflera complex. During field work in New Guinea and New Britain in 1965-66, there first arose the suspicion that the complex as it stood might be an artificial grouping; the relation- ships of the various species of Schefflera observed, and the groups into which they seemed to fall, appeared not to correspond to the divisions proposed in the literature for the Papuasian species (Harms, 1920-21, 1938 ; Philipson, 1951). A satisfactory explanation appeared to be that series of capituliferous species were, as groups, more closely related to otherwise similar series of umbelluliferous species in the Papuasian re- gion than they were to other series of capituliferous species in that region or elsewhere. Subsequent research in herbarium and library, covering all 123 described species that should logically be assigned to the Cephalo- schefflera complex because of their inflorescence type, has shown that this preliminary hypothesis is correct when applied on a world-wide basis. There are examples of close relationships between umbelluliferous and capituliferous species in the Neotropics, the African region, and mainland Asia, as well as throughout Malesia. In fact, the similarity in the pat- terns of evolutionary radiation, both in Papuasia and the Andes, each involving umbelluliferous and capituliferous species, is especially strik- ing and merits closer study. A detailed discussion of all observed pro- gressions is beyond the scope of this paper and the cases enumerated below are merely representative. In the Neotropics, the umbelluliferous species Scheflera ternata Cuatr. of Colombia is closely related to the capituliferous S. kerthae Harms of 1975] FRODIN, STUDIES IN SCHEFFLERA 431 Ecuador by virtue of its 3—5-foliolate leaves, slender 2—3-branched inflo- rescences, capitula/umbellules with few flowers, and conical corollas. An example of a gradual transition is that from S. sphaerocoma (Bentham) Harms (an umbelluliferous species with moderately long pedicels grow- ing from Costa Rica to Colombia) through S. sciadophyllum (Swartz) Harms (an umbelluliferous species with rather short pedicels growing in Jamaica) to the capituliferous S. robusta (A. C. Sm.) A. C. Sm. of Costa Rica. The common features of these three species include large leaves with many leaflets, inflorescences with many radiating branches bearing numerous racemosely arranged few-flowered capitula/umbellules, and small flowers with elevated disks and short, partially free styles. In the African region, the capituliferous Geopanax procumbens Hems- ley 1 of the Seychelles is more closely related to the umbelluliferous species S. barteri (Seem.) Harms and S. goetzenii Harms from mainland Africa, all three having similar leaf venation, calyptrate corollas with minute sutures, and a 5—10-locular ovary, than to the capituliferous S. mannii (Hooker f.) Harms, S. stolzii Harms, and S. volkensii Harms, all of which have discrete petals and a 5-locular ovary. In Asia, the umbelluliferous species Schefflera wallichiana (Wight & Arnott) Harms of South India and S. khasiana (C. B. Cl.) Viguier of eastern India to China are very closely related to the capituliferous S. capitata (Wight & Arnott) Harms by virtue of their nearly identical leaflet form and venation, short stipular ligules, sutured calyptrate corollas, inflorescences with a moderate number of branches, stylar col- umn absent or nearly so, and ovary 5—9(—10)-locular. However, S. capi- tata differs from S. actinophylla by the presence in the latter of four large bracts per flower (in contrast to three in S. capitata), a 10-12- locular ovary, elongated anthers, and much longer stipular ligules. The apparent similarity between the two (noted by earlier workers) is due to convergence and is not necessarily indicative of close relationship, al- though there is evidence that the group of species associated with S. actinophylla are more closely related to this S. wallichiana/S. capitata group than to any other in the Old World. In New Guinea, the capituliferous species Scheflera schumanniana Harms is more closely related to the umbelluliferous S. hellwigiana Harms (the two species having similar habitats in the understory of damp mon- tane forests, shrubby habits, 5-foliolate leaves with strongly reticulate leaflets, slender, few-branched inflorescences, and long-styled globose fruits) than to large, canopy-dwelling, sun-loving capituliferous species such as S. carrii Harms, S. lasiosphaera Harms, S. stolleana Harms, Mr S. morobeana Harms. Similarly, the capituliferous 5. chaetorrhachis Harms is more closely related to the umbelluliferous S. bougainvilleana Harms, both having small green flowers in 60-100-branched energie than to the capituliferous S. actinophylla or the capituliferous 5. pachystyla 1TH: Scheffera. Availability of better material has Hey pa ge Paxton sent sah by Hemsley (1906) to segregate Geopanax do not hold. 432 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Harms, both of which have large red or pink flowers and 5—12-branched inflorescences. Reference should also be made to those “intermediate” species which were first noted by Viguier as not readily fitting into either the capituli- ferous or umbelluliferous assemblages. His list included the following Malesian species: S. cephalotes (C. B. Cl.) Harms, S. tomentosa (B1.) Harms, S. scortechinii (King) Viguier, and S. apiculata (Miq.) Viguier. In addition, he considered the neotropical S. heterotricha (Planchon & Linden ex E. March.) Harms ex Viguier, placed by Harms in his sect. EUSCHEFFLERA, to be capituliferous and grouped it with S. trianae (Planchon & Lindley ex E. March.) Harms and S. euryphylla Harms, mentioning that (translated) ‘in this case it is impossible to trace the limit between the two sections which he [Harms] proposes.” He also noted that “for example, S. cephalotes of Malaya, of his [Harms’s] sec- tion CEPHALOSCHEFFLERA, has distinctly pedicellate flowers.” Since Viguier’s time, more “intermediate” species have come to light, among them S. angiensis Gibbs of New Guinea, S. merrillii Elmer of the Philip- pines, and S. chinensis (Dunn) Li of western China. In addition, it has become evident that the flowers in the immature inflorescences of many species that are umbelluliferous when mature appear to be in capitula, since evident pedicel elongation has not yet taken place. Furthermore, there are a number of examples of both capituliferous and umbelluliferous species in which further pedicel development can take place after an- thesis; e.g., S. cephalotes, S. barteri, and S. versteegii Harms of New Guinea. In some species the flowers, although forming capitula, are found to be distinctly pedicellate ‘en the capitula are bisected; this is seen in S. cephalotes, as noted by Viguier, and in S. lasiosphaera of New Guinea. A further list of “intermediate” species has been given by Jacques-Felix (1970). While recognizing that the existence of these ‘intermediates’? cast doubt on the validity of Harms’s primary divisions in Schefflera, Viguier did not attempt a more thorough analysis of relationships at the species level. However, the evidence now available has made possible the “link- ing” of most of the intermediates with other species. Scheflera cephalotes is in leaf, inflorescence, and fruit characters most closely linked with the umbelluliferous S. havilandii Merr. of Borneo and S. latifoliolata (King) Viguier of Malaya; S. tomentosa appears to be close to the um- belluliferous S. yatesii Merr. of Sumatra and Malaya and S. petiolosa (Miq.) Viguier of Borneo in leaflet, inflorescence, and fruit characters; S. apiculata seems quite close to the umbelluliferous Moluccan species of Schefflera now known as Brassaia littorea Seem.; and S. scortechinii is but a phase of the umbelluliferous S. hullettii (King) Viguier of Malaya and Sumatra, with immature inflorescences. These umbelluli- ferous species do not on any account belong to the same series or even the same section. The affinities of S. heterotricha are more obscure. Related taxa may include Didymopanax allocotanthus Harms of Bolivia and Schefflera rubiginosa (Decne. & Planchon ex Harms) Steyerm. [non 1975] FRODIN, STUDIES IN SCHEFFLERA 433 Ridley] of Colombia and Venezuela; all have elongated styles with five (or two) radiating stigmata and a 5-toothed calyx. Schefflera chinensis is closer to the umbelluliferous S$. Aypoleucoides Harms of northern Viet Nam and S. hypoleuca (Kurz) Harms of eastern India to China than to any other capituliferous species, the three taxa having relatively simi- lar leaf form, inflorescence, and fruit; collectively, however, the three are amply distinct from species such as S. cephalotes, with which Hoo and Tseng (1965) tried to link S. chinensis. Section CEPHALOSCHEFFLERA (including Brassaia), as proposed by Harms and more or less modified by him and later authors, is thus mani- festly an evolutionary grade (Huxley, 1958; Simpson, 1961). The prob- able direction of evolution has been in the gradual reduction and sup- pression of pedicels in different series of species, perhaps by successive retardations of pedicel growth during development of the inflorescence before and after anthesis. Whether or not this is associated with changes in pollination and/or dispersal mechanisms and, if so, what kinds of mechanisms are involved, I am unable to determine at present.? It may be noted here that the occurrence of capitula in the Araliaceae (apart from Schefflera) is generally relatively uncommon. Only the neotropical Oreopanax, the Pacific-insular Meryta, and the essentially eastern Male- sian/Melanesian Boerlagiodendron and Osmoxylon are wholly or partially made up of species with capituliferous inflorescences. Within Schefflera the only series of capituliferous species without close relatives amongst umbelluliferous species is the Brassaia group (in the strict sense), the type species of which is S. actinophylla. The geographical range of these species is centered in Papuasia. As a group, the species are very distinctive, with fruits black at maturity and brilliantly-hued red or pink flowers and young fruits. (An exception is S. kraemert Harms, which has fruits green when unripe and white flowers. ) However, the only important “attribute state” (cf. Jardine & Sibson, 1971, pp. 3, 4) characterizing the Brassaia group and not appearing elsewhere in Schef- flera is the presence of four large, winglike, imbricated basal floral bracts. (In other Schefflera species such bracts are absent or only one to three in number and are virtually always otherwise shaped.) In addition, some species have an exceptionally large number of carpels (ovary-locules), reaching 25 to 30 in S. thaumasiantha Harms of southeastern New Guinea. However, in habit, gross morphology, overall inflorescence structure, ee . ” i of paradise feeding on ferous species in New Guinea act as “perches” for some birds of p : Croft, pers. comm.). On a 1973 issue of Papua New . ban . ing birds of paradise, the 21-cent stamp illustrates a Bird iwihiguges Astrapia mayeri, perching on a yet-to-be-described species of Sc efiera ni ate Giluwe area. All these birds of paradise are at least sometimes frug: ( Gilliard, 1969). 434 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 flowers, and fruits, the Brassaia group is very similar to the rest of the pantropical “central nexus” of Schefflera (as exemplified by such species as S. sciadophyllum (Swartz) Harms of Jamaica, S. tomentosa (Bl.) Harms of West Malesia, S. venulosa (Wight & Arnott) Harms of South India, and S. volkensii Harms of East Africa). I do not consider differences such as the presence of four large floral bracts (in contrast to three or fewer smaller bracts in other Schefflera species) and a relative- ly large carpel number (8 to 30) to be sufficient grounds for separation at the generic level, particularly when the strong overall resemblances with other groups of Schefflera, both in the field and on closer examina- tion in the herbarium, are considered. The Brassaia group seems best regarded as a section of Schefflera in a wider sense, although it is perhaps somewhat isolated. The series of species within Schefflera most closely related to the Brassaia group is that centering on S. wallichiana (Wight & Arnott) Harms, S. capitata, and S. khasiana, all of which are in mainland Asia; other sections of Schefflera within Papuasia are not as closely related to the Brassaia group. Together with the unusual features of the high average carpel number (considered a “primitive” feature by Eyde and Tseng (1971)) and the presence of the large floral bracteoles (which I believe also to be a “primitive” feature), the geographical isolation of the Brassaia group from its nearest relatives suggests that it is relictual in the Papuasian context. The very close, partly reticulate relationships of the known species also suggest that the group is presently undergoing a secondary evolutionary cycle. In the second part of this paper I have given an annotated list of pub- lished taxa which are correctly referable to the Brassaia group. This ex- cludes the great majority of the Brassaia combinations proposed by Hutchinson (1967). Some other Brassaia combinations of longer stand- ing must also be excluded from the group, i.e. B. capitata (Wight & Ar- nott) C. B. Cl. (= Schefiera capitata (Wight & Arnott) Harms); B. esi (Miq.) Seem. (= S. sessilis ates Harms); and B. littorea Seem. (= S. littorea (Seem.) comb. e ry I propose to regard the group as stb here at the sectional level, the correct formal name appears to be Schefflera sect. BRASSAIA (Endl.) Tseng & Hoo. When Hoo and Tseng (1965) recognized sect. Brassata (Endl.) Tseng & Hoo, they included two subsections, subsect. CEPHALOSCHEFFLERA (Harms) Tseng & Hoo and subsect. ACTINOPHYLLAE (Endl.) Tseng & Hoo, the former being lectotypified by S. cephalotes (C. B. Cl.) Harms. This was the first lectotypification of the name Cephaloschefflera; Harms did not designate a type for his section CEPHALOSCHEFFLERA, and when Merrill (1923) raised section CEPHALO- SCHEFFLERA to generic rank, he did not transfer any species which Harms had originally included in that section. Although Viguier (1909) indicated that the flowers of S. cephalotes were shortly pedicellate, they *Basionym: Brassaia orate Seem. Jour. Bot. London 2: 244. 1864 (Papaja pte oh dl Herb. Amb. 151. t. 52. 1741). The species has an involved nonymy, which will be ri “with elsewhere. 1975] FRODIN, STUDIES IN SCHEFFLERA 435 are clearly aggregated into capitula, agreeing with the original descrip- tion of the section, and hence S. cephalotes is a not unreasonable lectotype for section CEPHALOSCHEFFLERA. Although Hoo and Tseng (1965) should have used the sectional name CEPHALOSCHEFFLERA for a section includ- ing both S. cephalotes and S. actinophylla (Article 63 of the International Code, Stafleu et al., 1972), Brassata (Endl.) Tseng & Hoo is now the correct name to use for a section which includes S. actinophylia, but not S. cephalotes. The name Brassaia has been widely used in various con- texts for S. actinophyila and its allies, and it is fortunate that it can continue to be used for these plants. What of the name Cephaloschefflera? As presently typified, it ap- pears that it will become synonymous with Blume’s Aralia sect. PARA- TROPIA (1826), based partly on the umbelluliferous A. rigida Bl. (= Scheflera rigida (Bl.) Harms, presently included in S. lucescens (BI.) Viguier), to which S. cephalotes is closely related, along with S. havilandit, S. latifoliolata, and S. hullettii. This question will be considered more fully elsewhere. The necessary break-up of the Cephaloscheflera complex has led to preliminary research toward a revision of the whole of Schefflera, to- gether with the several segregates and closely related taxa listed else- where in this paper. A detailed discussion of this work is outside the scope of the present contribution. However, it is my opinion that most of the attributes used to distinguish these taxa appear to be as trivial of umbelluliferous species. PRELIMINARY SYNOPSIS OF SCHEFFLERA SECT. BRASSAIA (AS EMENDED) Schefflera sect. Brassaia (Endl.) Tseng & Hoo, Acta Phytotax. iss Addit. 1: 133. 1965, quoad subsect. Actinophyllae; Grushvitzky ¢ Skvortsova, Adansonia (n. s.) 9: 386. 1969. BASIONYM: = Endl. Nov. Stirp. Dec. 89. 1839; Bentham, Fi. Austral. 3: 385. ed Bailey, Queensl. Fl. 2: 735. 1900; Hutchinson, Gen. Fl. Pl. 2: ‘ . 1967, sensu lato; Smith & Stone, Jour. Arnold Arb. 49: 489. 1968. TyPE spectss: S. actinophylla (Endl.) Harms (B. actinop hylla ndl.). 436 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Schefflera sect. Cephaloscheflera Harms in Engler & Prantl, Nat. Pflanzen- fam. III. 8: 36. 1894, p.p. quoad spp. actinophylla et macrostachya, Bot. Jahrb. 56: 385. 1920; Philipson, Bull. Brit. Mus. Nat. Hist. Bot. 1: 14, 15. 1951; Hutchinson, Gen. Fl. Pl. 2: 73. 1967, ut syn. Brassaiae. DistrisuTion. Aru Islands; New Guinea (mainland) and Geelvink Bay Islands (except Biak); Bismarck Archipelago (except the Admiralty Is- lands); Solomon Islands (including Rennell); Torres Strait Islands; northern and northeastern Australia. Also in the Caroline Islands (Truk group). ENUMERATION OF SPECIES Studies to date have shown that some of the species assigned to the section must or are likely to be relegated to synonymy. As far as is practicable, these reductions are indicated below. In addition, one or two additional species have yet to be described, but consideration of these is deferred until a later paper. 1. Schefflera actinophylla (Endl.) Harms in Engler & Prantl, Nat. Pflanzenfam. III. 8: 36. 1894. PiaTE IV-A. Brassaia actinophylla Endl. Nov. Stirp. Dec. 89. 1839. Brassaia singaporensis Ridley, Jour. Asiatic Soc. Straits Settlements 75: 38. 1917. DistRIBuTION. Australia: northeastern Queensland and _ northern Northern Territory; Aru Islands; New Guinea: southern and southeastern parts south of the central cordillera; Torres Strait Islands. Now escaped and naturalized in several other parts of the tropics (and subtropics). Widely cultivated as an ornamental and street tree or as a pot plant, both indoors and out. The species is not native to the Hawaiian Islands, although otherwise indicated by Hutchinson (1967, p. 73). Brassaia singaporensis was based on escaped plants occurring on Singapore Island. 2. Schefflera brassaiella Ridley, Trans. Linn. Soc. II. Bot. 9: 65. 1916 Schefflera pullei Harms, Bot. Jahrb. 56: 388. 1920. rassaia brassaiella (Ridley) Hutchinson, oe Ri, Ft. 2: 627. 1967. Brassaia pullei (Harms) Hutchinson, Ibid. DIsTRIBUTION. New Guinea: Carstensz Range east to the Hindenburg Range near Telefolmin. The stamens of Schefflera brassaiella usually exceed the ovary-locules in number. 3. Schefflera corallinocarpa Harms, Bot. Jahrb. 56: 388. 1920. Brassaia corallinocarpa (Harms) Hutchinson, Gen. Fl. Pl. 2: 622. 1967. 1975] FRODIN, STUDIES IN SCHEFFLERA 437 DisTRIBUTION. New Guinea: lowlands of the middle Sepik valley, near the junction of the Sepik and May rivers. The type (Ledermann 7211) was destroyed at Berlin and no iso- types have yet been located. However, from the description it appears that the plant may be only a form of S. macrostachya. 4. Schefflera kraemeri Harms, Notizbl. Kénigl. Bot. Gart. Berlin 5: 73. 1908; Kanehira, Jour. Coll. Agric. Kyushu Imp. Univ. 4(6): 434. 1935. Schefflera pachyclada Kanehira, Bot. Mag. Tokyo 46: 670. 1932; Fl. Micrones. 294, fig. 148. 1933 DIsTRIBUTION. Caroline Islands: Truk group. Distinctive in the section for its white flowers and green (in unripe Stage) fruits; otherwise closely related to Schefflera waterhousei of the Bismarck Archipelago and the Solomon Islands. S. pachyclada was re- duced by its author a few years after being described. 5. Schefflera macrostachya (Bentham) Harms in Engler & Prantl, Nat. Pflanzenfam. III. 8: 36. 1894. Sciadophyllum macrostachyum Bentham, London Jour. Bot. 2: 222. 1843. (As “Sciodaphyllum.”) Paratropia macrostachya (Bentham) Mig. Fl. Ind. Bat. 1(1): 760. 1856. Brassaia macrostachya (Bentham) Seem. Jour. Bot. 2: 244. 1864; Hutch- inson, Gen. FI. Pl. 2: 623. 1967. DistRIBUTION. New Guinea: Japen Island in Geelvink Bay and the mainland lowlands north of the central cordillera from the Meervlakte east to the Markham-Ramu Valley near Dumpu, including the foothills of the Adalbert, Prince Alexander, Torricelli, and Van Rees ranges (so far as known). A variant form with sutures extending only part way from the apex of the corolla occurs in the Vogelkop, where it apparently replaces the more easterly form. Schefflera macrostachya is closely related to S. actinophylla, and the two species may be considered as a vicariant pair with mutually exclusive ranges largely separated by the central cordillera. The inflorescences of e two are very similar in gross structure, but on the other hand there are some more or less constant differences in leaflet shape and venation. The status of the Vogelkop variants remains to be determined. 6. Schefflera megalantha Harms, Bot. Jahrb. 56: 386. 1920. Brassaia megalantha (Harms) Hutchinson, Gen. Fi. Pl. 2: 623. 1967. Distrpution. New Guinea: in the central cordillera from the Baliem- Meervlakte divide east to the Kratke Range, and on the Ramu-Astrolabe Bay dividing range west of the Finisterre Range. 438 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 The flower buds of Schefflera megalantha are distinctly cone-shaped. The species is occasionally cultivated locally (Mt. Hagen). 7. Schefflera ovalis J. J. Sm. ex Dakkus, Bull. Jard. Bot. Buitenzorg III. Suppl. 1: 262. 1930, nomen nudum. DistRIBUTION. Aru Islands; New Guinea: southwestern coast along the Arafura Sea from the Lorentz River to the Uta River below the Car- stensz Range. Cultivated in Hortus Bogoriensis. The name Schefflera ovalis first appears in print in Dakkus’s alphabeti- cal list of plants cultivated in Hortus Bogoriensis. It also appears on a few herbarium specimens distributed from Bogor. No description has ever been published. The plants concerned represent a form of S. actino- phylla differing in its leaflets, which are coarsely toothed at the apex, and in its flower buds, which are more elongated. In addition, the leaflet venation is suggestive of S. macrostachya. The distribution of this form, as far as it is known, is just west of that of S. actinophylla in New Guinea. 8. Schefflera pachystyla Harms, Bot. Jahrb. 72: 205. 1942. PLATE IV—B. Schefflera gigantea Philipson, Bull. Brit. Mus. Nat. Hist. Bot. 1: 14. 1951. DistriBuTION. New Guinea: central cordillera from just east of Wau through the Bulolo-Watut basin to the Kratke Range, as well as in the mountains of the Huon Peninsula and the Saruwaged Range. Both Scheflera pachystyla and S. gigantea were based on the same collection (Clemens 5386). The species is intermediate between S. megalantha and S. thaumasiantha. 9. Schefflera pseudobrassaia Harms, Bot. Jahrb. 56: 388. 1920. Brassaia pseudobrassaia (Harms) Hutchinson, Gen. Fl. Pl. 2: 623. 1967. DistRIBUTION. New Guinea: foothills of the central cordillera in the es April River watershed, southwest of Ambunti (middle Sepik re- gion). The type (Ledermann 9977) was destroyed at Berlin and no iso- types have yet been located. However, the difference between the num- bers of stamens and ovary-locules as described is also found in Scheflera brassaiella, as are the relatively small leaflets and short inflorescence- branches. Harms himself noted that this taxon was very close to his S. pullei, here united with S. brassaiella. It is probable that the differ- ences given are insufficient to maintain S$. pseudobrassaia as a species distinct from S. brassaiella. 10. Schefflera secunda Philipson, Bull. Brit. Mus. Nat. Hist. Bot. 1: 14. 1951. 1975] FRODIN, STUDIES IN SCHEFFLERA 439 DistRIBUTION. New Guinea: mountains of the Vogelkop. The inflorescences of this very distinct species consist of a few spread- ing branches which bear numerous very small, few-flowered heads on long peduncles, all oriented upward. Another striking character is that the fruit at maturity may be as much as two-thirds superior (cf. Eyde & Tseng, 1969). 11. Schefflera stenopetala Harms, Bot. Jahrb. 56: 390. 1920. Brassaia stenopetala (Harms) Hutchinson, Gen. Fl. Pl. 2: 623. 1967. DIsTRIBUTION. New Guinea: lowlands of the middle Sepik valley near Ambunti The type (Ledermann 8146) was destroyed at Berlin and no isotypes have yet been located. However, the differences indicated by Harms ap- pear to fall within the range of variation of Schefflera macrostachya; in addition, a recent collection from the Ambunti region agrees well with the description of this latter species. Consequently, it is unlikely that S. stenopetala can be maintained as distinct. 12. Schefflera thaumasiantha Harms, Bot. Jahrb. 69: 278. 1938. PLATE V-A. DIsTRIBUTION. New Guinea: in the foothill and lower montane zones of the Wharton and Owen Stanley Ranges from Tapini (north of Port Moresby) through the Sogeri Plateau to Nowata (northwest of Amazon Bay). This spectacular species is characterized by its fruits, which have 25 to 30 or more locules, and by its inflorescence-branches, which are up to a meter or more long. It is sometimes cultivated locally (Sogeri, Brown River, Port Moresby). 13. Schefflera waterhousei Harms, Notizbl. Bot. Gart. Berlin 15: 678. 1942. PraTe V-B. DiIstrisuTIoN. Bismarck Archipelago: Mussau (St. Matthias) I., New Ireland, New Britain; Solomon Islands: Bougainville to Guadalcanal and Rennell. Schefflera waterhousei is fairly closely related to S. actinophylla, but the smaller leaflets and few-flowered heads are distinctive. The species is rather variable, although most collections fall into one of two distinct groups, of which the ranges are almost mutually exclusive. The typical form occurs in the northern Solomon Islands and the Bismarck Archipelago, while the other form is limited to the southern Solomon Islands. The differences may be sufficient to warrant separation at the species level, but further study is required. 440 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 A RECONSIDERATION OF THE STATUS OF ENOCHORIA Enochoria Baker f., a rather enigmatic araliaceous genus with one species, E. sylvicola Baker f. (1921), was originally described from one collection (Compton 1336) gathered from near Canala on the north coast of New Caledonia in 1914 and preserved in the British Museum of Natural History. This holotype collection consists of single fragments respectively of a leaf and an inflorescence. No isotypes have come to light, and to the best of my knowledge no further collections have been made. The genus was accepted without comment by Guillaumin (1948) for his Flore analy- tigue et synoptique, as well as by Hutchinson (1967). Because of the presence of digitately compound leaves and capituliferous inflorescences, the genus was placed near Schefflera in Hutchinson’s system of the family Araliaceae. In connection with the studies of the group of genera associated with Schefflera, I have re-examined the type specimen of E. sylvicola. The only conclusion that can be drawn is that the specimen is an artifact. The leaf fragment is from a species of Schefflera, probably S. affinis Baillon, while the inflorescence fragment, with flowers all carpellate, repre- sents Meryta macrocarpa Baillon. Although both parts of the specimen carry tags with the same number, it is possible that it was not actually collected by Compton himself, but brought into camp by field workers or local residents. If the identifications of the two elements are correct, they both belong to taxa described well before 1921 and for which generic segregation is not warranted. It is therefore not possible to retain either name for any part of the specimen. The genus Enochoria, and its sole E. sylvicola, should therefore be rejected under Article 70 of the International Code (Stafleu et al., 1972). SUMMARY The long accepted division of the araliaceous genus Schefflera J. R. & G. Forst. sensu lato (including Brassaia Endl.) into two pantropical sections, able. The species of the Cephaloschefflera complex represent an evolu- tionary grade (probably resulting from parallel retardation of pedicel growth) derived from various groups of umbelluliferous species through- out the geographical range of the complex. Special attention has been given to the status of Brassaia sensu stricto, since it has continued to be segregated from Schefflera by a number of authors, and the conclusion is reached that only sectional rank within the latter genus is warranted. Finally, an argument has been made for the reduction to Schefflera of a number of other segregate and allied genera on the grounds that the differences between most of the “attribute states” which have been used to distinguish these taxa are essentially as trivial as those used in the past to separate Brassaia. One of the segregates, Enochoria, has been shown 1975] FRODIN, STUDIES IN SCHEFFLERA 441 to have been based on an artifact. The question of the use of the name Cephaloschefflera for some infrageneric taxon of more restricted extent within Schefflera has also been discussed, with the conclusion that it could not be applied to the Brassaia group as presently lectotypified and is likely to become united with Blume’s Aralia sect. PARATROPIA, An enu- meration of species properly referable to sect. Brassata (Endl.) Tseng & Hoo is given in the second part of this paper. REFERENCES Backer, C. A., & R. C. BAKHUIZEN VAN DEN = 1965. Araliaceae. Flora of Java 2: 161-171. Noordhoff, —— BAKER, ve G. 1921. Araliaceae. Jn: A. B. REN te, E. G. Baker, & S. LE M. Moorrg, A systematic account of the plant collected in New Caledonia and ie Isle of Pines by Prof. R. H. Compton, M.A., in 1914. I. Flower- ing plants (Angiospermae). Jour. Linn. ae Bot. 45: 245-417. pls. 13- Bamps, P. 1974a. Araliaceae. Jn: Flore d’Afrique centrale (Zaire-Rwanda- Burundi). Speers 30 pp. Jardin Botanique National de Bel- ay, Meis 1974b. oe a Vétude des Araliacées africaines. Bull. Jard. Bot. Nat. Belg. 44: 101-139. BauMANN, M. G. 1946. Myodocarpus und die ee der Umbelliferen- Frucht, Ber. Schweiz. Bot. Ges. 56: 13-122. pls. BAUMANN-BopENHEIM, M. G. 1955. Ableitung und cs bicelles: monosper- mer und pao Araliaceen und Umbelliferen-Friichte. /bid. 65: 481-510. BENTHAM, G. 1867. Araliaceae. Jn: G. BENTHAM & J. D. Hooker, Genera Plantarum. Vol. 1. Pp. 931-941. Londini. BeRNarpi, L. 1969. Araliacearum Madagascariae et Comores exordium. I. Revisio et ae nova Schefferarum. Candollea 24: 89-122. Burpipce, N. 1963. Dictionary of Australian plant genera. xviii + 345 pp. Angus 2 Robertson, Sydney. Currorp, H. T., & G. Luptow. 1972. Keys to the families and = of Queensland flowering plants. Univ. of Queensland Press, Brisbane. Eype, R. H., & C. C. Tsenc. 1969. Flower of T ai nana Sacorea: us ancestry. Science 166: 506-5 hyposyay Min — is ene STE sera floral ce of Araliaceae? Jour. Acanid Arb. 52: 205-239. Fropin, D. G. 1970. The complex of Cephalosche flera in Schefflera (Aralia- ceae). Unpubl. Ph.D. dissertation, Univ. of Cambridge. Gituiarp, E. T. 1969. Birds of paradise and bower birds. xxii + 485 pp. Wiedenfeld & Nicholson, London, GrusHvitzky, I. V., & N. T. SKvortsova. 1969. Les espéces du genre Scheflera Forst. & Forst. f, en République Democratique du Viét-Nam. Adans ae 2) 9: 369-387. pisensenerisece gusset 0. O novom tipe slozhnogo lista. Pychkovatoslozhnyi list d leaf type. vidov r. te oat & Forst. f. [On a new compoun bundle compound leaf in the species of Scheffera Forst. & Forst. f. (Araliaceae).] Bot. Zhur. 55: 525-536. 442 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 —_, V. GutntnaA, & R. I. VisozKaya. 1971. Anatomicheskie Setieeis dlja eka hens blizkorodstvennykh vidov roda Schefflera Forst. et Forst. f. (Araliaceae). [The usage of anatomical criteria for distinction and identification of closely related species of the genus Schefflera Forst. et Forst. f. (Araliaceae).] Bot. Zhur. 56: 1511-1516. GuILLauMIN, A. 1948. Flore analytique et synoptique de la Nouvelle-Calé- donie (Phanerogames). 369 pp. Office de la Recherche Scientifique Co- Harms, H. 1894-97, Araliaceae. In: A. ENGLER & K. PRANTL, eds., Die na- tiirlichen Pflanzenfamilien. III. 8: 1-62. Engelmann, Leipzig 1920-21. Die Araliaceae Papuasiens. Bot. ede ag area . 1938. Neue Araliaceae aus Papuasien. /bid. 69: HEMSLEy, W. B. 1906. Geopanax procumbens. Hook. Ic. gis a 7 2821. Huapik, A. 1970. Contribution a l’étude biologique d’une Araliaceae d’Am- erique grcneed Didymopanax morototoni. Adansonia (sér. 2) 10: 383- 407. 5 Hoo, Gin, & ne -JIANG TsENG. 1965. Contributions to the Araliaceae of ‘Ching. Acta Phytotax. Sinica, Addit. 1: 175. HUTCHINSON, J. 1967. Avalinceae. The genera = flowering plants. Vol. 2. Pp. 52-81 & 622-624. Clarendon Press, Oxfor HUuxtey, J. 1958. Evolutionary processes and taxonomy with special refer- e to grades. Uppsala Univ. Arsskr. 1958: JACQUES-FELIx, H. 1970. Contribution a l'étude a "Uebel lidar du Ca- meroun. Adansonia (sér. 2) 10: 35-94. JARDINE, N., & R. Stpson. 1971. Mathematical taxonomy. Wiley, London. Li, Hur-t1n. 1942. The Araliaceae of China. Sargentia 2: 1-134. MacsribeE, J. F. 1959. Araliaceae. Jn: J. F. MAcsripe et al., Flora of Peru 5(1): 8-44. Publ. Field Mus. Natl. Hist. Bot. Ser. 13. Chics cago. MERRILL, E. D. 1923. Araliaceae. Raswneentins of Philippine flowering plants. Vol. 3. Pp. 222-237. Bureau of Printing, Manila. NEAL, M. C. 1965. In gardens of Hawaii. Bishop Museum Press, Honolulu. PARHAM, J. W. 1964. Plants of the Fiji Islands. Government Printer, Suva. Puitipson, W. R. 1951. Contributions to our knowledge of Old World Araliaceae. Bull. Brit. Mus. Nat. Hist. Bot. 1: 1-20. - 1970. Constant and variable features of the Araliaceae. Pp. 87-100 & 1 pl. in N. K. B. Rogpson, D. F. Cutter, & M. Grecory, eds., New research in plant anatomy. [Suppl. 1 to Jour. Linn Soc. Bot. 63. 1970.] Academic Press, London Ropricuez, R. L. 1957. Systematic anatomic studies on Myrrhidendron and other woody Umbellales. Univ. Calif. Publ. Bot. 29: 145-318. pls. 36-47. Rumpuivs, G. E. 1741. Herbarium amboinense. I. Amstelodami. Stupson, G. G. 1961. Principles of animal taxonomy. xiii + 247 pp. Colum- bia Univ. Press, New York. SmitH, A. C. 1944. Araliaceae. In: N. L. Britton ef al., eds., North Ameri- can Flora 28B: 3-41. The New York Botanical Garden, New York. B. C. Stone. 1968. Studies of Pacific Island plants. XIX. The Araliaceae of the New Hebrides, Fiji, Samoa, and Tonga. Jour. Arnold . 49: 431-493. 8 pls. STAFLEU, F. A., e¢ al., eds. 1972. International code of botanical nomencla- ture. 426 pp. International Association for Plant Sree Utrecht. StonE, B. C, 1970. Flora of Guam. (Micronesica, 6.) Agan. 1975] FRODIN, STUDIES IN SCHEFFLERA 443 TENNANT, J. R. 1968. Araliaceae. Jn: W. B. Turrity et - eds., Flora of Tropical East Africa. Pp. 1-23. Crown Agents, Tsenc, C. C. 1973. cede ean palynology of Tohdecta: and Plerandra (Aralincess). Grana 13: 51-56. ViIcuIER, R. 1909. Nouvelles pelle sur les Araliacées. Ann. Sci. Nat. Bot. (sér. IX) 9: 305-405. ase - C. 1973. A dictionary of the flowering Sei and ferns. 8th ed., y H. K. Atry SHaw. Cambridge Univ. Press DEPARTMENT OF BIOLOGY UNIVERSITY OF PAapuaA NEw GUINEA P. O. Box 4820 UNIVERSITY, PApuA NEw GUINEA EXPLANATION OF PLATES * PLATE I A (left). Diagram of inflorescence, Schefflera hoi (Dunn) — rises southwestern China). B fioiamie Dia gram of inflorescence, S. capuro (Bernardi) Bernardi (Madagascar PLATE II A (left). iene; of inflorescence, Schefflera bate? Spam Harms sol pope Africa). B (right). Diagram of inflorescen . japurensis (Mart. & Zucc. ex E. March.) Teak (northern South Auterie ye PLATE III Infl ence of Schefflera P near Kaibola, Kiriwina I., Tro- as pb N S ce si + 40 m, 72). 6 (below). Inflorescence of S. versteegii Harms, along upper se we east of Sogeri Plateau, New Guinea, 200-300 m. (1971). PLATE IV Gardens, Schefllera actinophylla (Endl.) Harms, Royal Botanic Set on a 10 m (1967 67). B (right). Cy idee ae Harms, near Zenag, along Lae-Bulolo Road, New Guinea, + 1300 m. (1972). PLATE V 500— f thaumasiantha Harms, Sogeri Plateau, New Guinea, 600 - o a Pr nes anh Mr. J. Dodd). B Saat m ~ waterhousei Harms, 19 (197 crack | to Lelet Plateau, New Ireland, 500-600 m *In the inflorescence diagrams, the cross- — axes near the base represent leaf bases together with their stipules (in bla FRODIN, STUDIES IN SCHEFFLERA ‘ge : Nee » al a : al aati 9¢ “IOA ‘aay aIoNay ‘unof I a1vIg ane muss Oo > FRODIN, STUDIES IN SCHEFFLERA 9§ “IOA ‘aay aAIONuy ‘unof II a1vIg PuaTE III Jour. ARNOLD ArB. VOL. 56 FRODIN, STUDIES IN SCHEFFLERA FRODIN, STUDIES IN SCHEFFLERA ™» . ry a e. tn ies :e, Sa) ’ * v War aia 9¢ “IOA “aay GIONNY ‘anof AI Siv1g FRODIN, STUDIES IN SCHEFFLERA 9¢ “IOA ‘aay aGTONUy ‘anof A avid 1975] HOWARD, LINDERNIA BRUCEI 449 LINDERNIA BRUCEI, A NEW WEST INDIAN SPECIES OF THE ASIAN SECTION TITTMANNIA RicHarp A. Howarp In 1950 I cortectep an unusual herbaceous plant while making gen- eral collections on a fragment of an old volcano above the Soufriére on the island of St. Vincent in the Lesser Antilles. The specimen appeared to be a member of the Gesneriaceae and was sent to the late C. V. Mor- ton, who stated that it was a new genus but that the material was in- adequate for description. Subsequently, botanists visiting St. Vincent were asked to seek that plant, but no one was able to locate the popula- tion. In March of 1971 I returned to St. Vincent again and made sev- eral attempts to find the plant, but without success. Although the ascent of the Soufriére volcano to the edge of the crater at 3300 feet is relatively easy, the Soma to the north of the present crater lake and the dry crater of the 1912 eruption must be climbed by the only directly ascending ridge, which I had used previously. With the frequent cloud cover, this ap- proach to the Soma is not always visible. : In November of 1971 the crater lake of the Soufriére was observed in an agitated condition. The lake level had begun to rise, gases were be- ing emitted, and the temperature was considerably elevated. It was ap- parent that the volcano was in a stage preliminary to an eruption. Eventually a cinder cone was formed from the bottom of the crater, exceeding the elevated water level by nearly 600 feet (W. P. Aspinall, H. Sigurdsson, & J. B. Shepherd, Science 181: 117-124. 1973). When word of this potential eruption was received, a trip was planned to photograph the vegetation around the crater in the event that an eruption occurred or lava or cinders overflowed the rim and destroyed the vegetation, as had happened in the past. (See bibliography im R. - Howard, Volcanism and vegetation in the Lesser Antilles, Jour. ~ Arb. 43: 279-311. 1962). It also seemed that this might be a last chance to locate and collect additional material of the undescribed hee genus.” On this trip in February, 1972, the summit was again a. covered, a condition possibly accentuated by the heat of the vo = ejecta and the 80° C water of the crater lake. The field work was pe ing at the time and remains so in retrospect. Although the cence al the Soma was obscured by clouds and visibility was Loree - "8 trip occasional strong winds lifted the clouds and wes none a progress over the cinder slopes and crevasses. By early afternoon : t that we would not see the approached the Soma cliff. It was apparen © directly in upper levels of any of the ridges, for although they ae esigusrdeler front of us, they ended in clouds. After we had climbed a 450 [voL. 56 JOURNAL OF THE ARNOLD ARBORETUM URE 1. Above: Soufriére crater in February, 1971. give dlgante ae is badekars pedunculata and Freziera undulata. Pho aken Om lens. Below: i th a tures mark comparable positions; in the lower photograph, points of arrows mark the upper limit of hot water damage to the vegetation. 1975] HOWARD, LINDERNIA BRUCEI 451 of the ridges, however, fortune favored us and the plant we sought was finally relocated. Field observations were made and a sizeable set of specimens was obtained. Living plants were returned to the Botanic Garden in Kingstown but did not survive at the lower elevation. Specimens returned to the green- houses of the Arnold Arboretum also progressively declined until, after six months, all were dead. Various methods of maintenance had failed. The plant appeared to be strongly rhizomatous and cuttings of these horizontal stems rooted readily, yet the shoots produced small leaves and failed to elongate. The thick, fleshy, pubescent leaves, reminding one of the leaves of Saintpaulia in texture, also proved capable of developing good masses of roots in a propagation bed; however, as they did not develop shoots, eventually these rooted leaves also failed. In retrospect, we can only surmise that the plant may be an annual. After the death of Dr. Morton, specimens of the new collection were sent to Mr. Hans Weihler, a current student of the Gesneriaceae, who reported that the plant was different from anything known in the family from tropical America. He suggested that this material might be asso- ciated with the poorly known genus Anetanthus reported from Central America. This suggestion led to the study of the species of Anetanthus and the eventual rejection of an association with them. Advice was also sought from Dr. Harold Moore, Dr. B. L. Burtt, and Dr. John Thieret for means of distinguishing between the Gesneriaceae and Scrophularia- ceae. Dr. Burtt, in a thoughtful and very helpful consideration of the problem, concluded that the plant was most likely a member of the Scrophulariaceae, and both he and Dr. Thieret suggested an association near Lindernia of this family. ; The specimen from St. Vincent fits section TITTMANNIA according to the recent monograph of the Malaysian species of Lindernia by David Philcox (Kew Bull. 22: 1-72. 1968), who included a key to the sections of the genus in that area. The stamens in our material are four, are as- sociated in pairs, and all bear fertile anthers. The nonparallel ae sacs are divergent and open by slits. In bud both the posterior pair - stamens and the anterior pair are adherent by their anthers. The fi a- ments of the anterior pair are geniculate at the base. The eds ie deeply divided into equal segments to the base. The aaa aed superior, is ellipsoidal and shorter than the calyx. The stigma 1s pea Although Philcox did not supply a complete list of the Ss tat section TITTMANNIA or geographic ranges, he subsequently “te ai all species occur in South East Asia and that all entries in Index ewe sis under the name Tittmannia are from tropical Asia. The re of a West Indian specimen, clearly not an introduced plant, to this sec- tion requires serious consideration. : The vans Tittmannia Reichenbach (Scrophulariaceae), ry apap considered synonymous with Vandellia L., has been Scag = a. Tittmannia Brongniart (Bruniaceae #3285, ICBN). — : ee Sacal sidered a synonym of Lindernia Allioni by Philcox, who folio 452 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 in this treatment. Thieret did likewise in the treatment of the Scrophula- riaceae for the Flora of Peru (Field Mus. Bot. 13: 685. 1971), although Standley and Williams, in a later treatment of the family for the Flora of Guatemala (Fieldiana Bot. 24: 374. 1973) stated, “We have followed Thieret in placing Vandellia L. as a synonym of Lindernia, but with misgivings.’”’ Yamazaki (Jour. Jap. Bot. 29: 299-305. 1954) rec- ognized both Lindernia and Vandellia in his treatment of the plants of eastern Asia, with the latter genus including Tittmannia. The species of Vandellia listed in Index Kewensis are all from Asia except V. diffusa L. of the New World and V. racemosa Sprengel, said to be from Brazil. Vandellia diffusa L., currently called Lindernia diffusa (L.) Wettst., is clearly distinct from the St. Vincent material. Vandellia racemosa Sprengel (Neue Entdeck. 1: 262. 1820) is described as having alternate leaves, and I can find no modern use of this binomial or any description in the many recent floras of Brazil. A glabrous, fleshy, and quite conspicuous glandular process at the base of the ovary of the St. Vincent material, associated with the fleshy op- posite leaves and the adherent anthers, directed my original search for the identity of this material with the Gesneriaceae. Neither Pennell in his many papers nor Philcox in his treatment of the Malaysian species of Lindernia nor any other modern floristic treatment has described this basal gland, although Philcox illustrated it indistinctly in his figures 2-3, 3-3, and 4-3 (Kew Bull. 22: 14, 16, 22. 1968). However, the gland was described and illustrated by Yamazaki (Jour. Jap. Bot. 29: 303. 1954), who in figure 4 showed the variations in this basal glandular process for Lindernia pyxidaria, Vandellia angustifolia, V. crustacea, and Torrenia violacea. The St. Vincent material has a gland similar to that illustrated by Yamazaki for Vandellia angustifolia, a species Philcox calls Lindernia anagallis (Burm. f.) Pennell. I have examined material which Philcox cited and assigned to sect. TITTMANNIA and have found a comparable gland. Other species of other sections examined at random do show variation in the shape of the gland, so that it is possible that a character of taxonomic value may exist in the basal gland. The St. Vincent material appears to conform to the limits of the genus Lindernia and does not represent a new genus. The copious pubescence of simple unicellular hairs present on all parts of this Lindernia from St. Vincent is distinct from the multicellular uni- seriate hairs of Anetanthus and other genera of the Gesneriaceae. Com- parable hairs are found on specimens of Lindernia viscosa, L. montana, and L. stemodioides cited by Philcox. The following description of the pollen grains and the photograph (FicuRE 2) were supplied by Dr. Umesh Banerjee: pollen grains prolate, tricolpate, colpi long tapering, membrane in the colpus region consisting of warty structure, no well defined pores present, exine reticulate, thick- ness 1.0 wm. Superficially, the pollen grains resemble those of Anetanthus and Goyazia of the Gesneriaceae and are unlike those of Stemodia pe- duncularis Benth. of the Scrophulariaceae (Howard, Jour. Arnold Arb. 1975] HOWARD, LINDERNIA BRUCEI 453 i 1 tern of the epidermis, X 150. Below: “D om the north of the ‘Soufriére crater lake. Foreground vegetation 1s raed ga spp. and Pitcairnia spp. Slopes of the Soma are visible in the background. 56: 364-368. 1975). I have been unable to find other published SEM photographs of the Scrophulariaceae or Gesneriaceae for further com- parison. Dr. Philcox has examined material of this St. Vincent plant and agrees that the new Lindernia should be assigned to sect. TITTMANNIA, for whi 454 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 3. Lindernia brucei Howard: a, habit: ; b, flower in bud; er; d, longitudinal section showi c, open flow- ng basal ovarian disc and geniculate filament; air g ate stamens with fused anthers; f, flower after corolla has fallen stigmatic lobes flat; g, open fruit; h, reticulate seed. it comprises a major range extension. He has suggested L. latifolia (B1.) Koord. as the closest related species. I am grateful to the several people cited for their help in this problem. Lindernia brucei Howard, sp. nov._ Herba, rhizomatibus vel caulibus serpentibus copiose radicantibus, ramis floriferis erectis usque 30 cm. altis. Lamina elliptica vel oblonga, 1975] HOWARD, LINDERNIA BRUCEI 455 4X 2.5 ad 5.5 & 3 cm., apice rotundata vel obtusa, basi rotundata vel cuneata, margine obtuse crenata, nerviis primariis 4-5, utrinque copiose pubescentia, pilis simplicis unicellularibus. Petioli 5- 15 mm. longi. In- florescentia ad medium bibracteata, bracteis ambitu deltoideis, basi trun- catis, apice acutis, 1.3 1.1 ad 3.5 & 2.5 cm., bracteis flovalibus multo deminutis, ovato- deltoideis, 5 & 3.4 mm. Pedicelli ca. 1.5 cm, longi pu- bescentes. Sepala 5 libera, aequalia, lanceolata 5 & 2.5 mm. longa lataque, extus copiose pubescentia. Corolla purpureo-rosea, tubo 1 cm. longo, in alabastro labio inferiore superiorem includente; labio superiore bifido, lobis rotundatis, 3.0-3.5 mm. labio inferiore majore tripartito, lobis cen- tralis 5.5 & 6.5 mm., lobis lateralis 4.0 < 4.8 mm. Stamina didynama, glabra; filamentis duobus superioribus basi geniculatis, 3 mm. longis, in- ferioribus rectis 2 mm. longis. Pistillum glabrum, glandula carnosa glabra 0.8 mm. alta dimidio basi ovarii cingente; stylo 1 cm. longo, supra com- planato; stigmatibus 2 planis, marginibus erosis; ovario 2 mm. longo, ellipsoideo leviter complanato. Fructus ellipsoideus 2.5 mm. longus, calyce fructifero brevior; seminibus globosis 0.4-0.45 mm. diametro, brunneis, testa reticulata. DistrIBUTION. St. Vincent, Lesser Antilles, West Indies. Ridges at the base of the Soma, north of the crater lake on the Soufriére mountain at an altitude of 3600 ft. Flowering in February with flowers and fruit in April. SPECIMENS EXAMINED. R. A. Howard 11912 (cH, us); R. A. & B. R. Howard 18060 (holotype, A), Feb. 26, 1972. I take pleasure in naming this species for my son, Bruce Howard, a companion on the trip on which I re-collected the material and my as- sistant in earlier field work on Pico del Oeste in Puerto Rico. I am grateful to Ms. Karen Velmure and Dr. L. M. Perry for as- sistance in the preparation of this paper. ARNOLD ARBORETUM HARVARD UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 456 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 THE PODOSTEMACEAE IN THE SOUTHEASTERN UNITED STATES #4 S. A. GRAHAM AND C. E. Woop, JR. PODOSTEMACEAE L. C. Richard ex C. A. Agardh, Aphor. Bot. 125. 1822, “Podostemeae,” nom. cons. (RIVERWEED FAMILY) Moss- or alga-like, submerged aquatics, generally restricted to sunny, clear, swiftly flowing streams and waterfalls of the tropics and subtropics. Plant body often reduced to a “thallus” and anchored to the rock sub- strate by cement-secreting root hairs and haptera (specialized rootlike or- gans that act as holdfasts). Stems present [or lacking]. Leaves alternate, simple to much divided. Inflorescences diverse, the flowers solitary [or fasciculate or in a 2-sided spiciform monochasium], [enveloped by a few leaves or] entirely inclosed within a membranaceous spathella (or bo ° = WwW rp [or 5 to many] tepals (staminodes?), [petaloid to] reduced and scalelike. Stamens [1 or] 2 [to many]; anthers 4-loculate; pollen com- monly in dyads [monads or polyads]. Gynoecium [1-], 2- [or 3-] car- pellate, syncarpous; ovary superior, [1-], 2- [or 3-] loculate; ovules [2 to] many, on an axile placenta. Fruit a septifragal [or septicidal] cap- sule; seeds many, without endosperm; embryo straight. TyPE GENUS: Podostemum Michx. *Prepared for the Generic Flora of the Southeastern Asay bear a joint en- deavor of the Arnold Arboretum and the Gray Herbariu rvard Caivemity a South Carolina, Georgia, Florida, Tennessee, Alabama, Mississippi, Arkansas, and Louisiana. The descriptions are based primarily on an plants of this area, with ad- ditional material in brackets [ ]. References that we have not seen are marked by an asterisk, The ~~ for this account was originally prepared when the first author was a ee § f the Generic Flora project in Cambridge in 1963-64 (NSF Grant GB-171, C. E. Wood, Jr., principal investigator). Since only a single species was iavahed. and the New World members of the family had been recently revised, pub- came to us through the kindness of S. A. Spongberg and R. E. Weaver, respectively. 1975] GRAHAM & WOOD, PODOSTEMACEAE 457 A remarkable pantropical family of highly modified submerged aquatics, including about 45 genera and 200 species, many of these narrow endemics, a few widely distributed. Almost all are restricted to rocky substrates in clear, sunlit, swift-running streams and rivers, where they occur especially in waterfalls and rapids. About 140 species are known from the Americas, 40 from Africa, and 20 from Asia (northward to southern Kyushu, Japan) and Australia (Queensland). Podostemum ceratophyllum Michx., one of the few representatives of the family in temperate regions, occurs in the southeastern United States. The unique habitat of these plants is shared by hardly any others, ex- cept Hydrostachyaceae. The family is notable for a high degree of specia- tion and endemism, with several species and some genera known only from a single rapids or cataract, and with some closely related species occupy- ing adjacent tributaries of the same river or nearby rivers (Van Royen, 1951, p. 13). A few exceptional species, including Podostemum cerato- phyllum, are widely distributed. Tristicha trifaria (Bory ex Willd.) Sprengel is noteworthy, extending as it does from Cuba to Mexico, south- ward to Uruguay and Argentina, and over a large part of Africa to Mada- gascar. The plants flower as the water level recedes (usually with the onset of a dry season) and as they become exposed to the air. Pollination is usu- ally by insects or wind and is followed by very rapid fruit development, in some cases the fruit maturing in as little as 24 hours (e.g., in A pinagia; see Went, 1926, 1929). The seed coat is mucilaginous when moistened and adheres to the substrate, where the seed germinates if it is not washed away as the water level rises (cf. Podostemum). Polypleurum submersum J. B. Hall is a rare exception in the family in that it grows in still rock pools in the River Asuboni, Ghana, prospering “even in pools that are stagnant and separated from the flowing water. Spathellae open under the surface and flowers are pollinated by the current.” The fruits dry and dehisce, however, only when exposed to the air. — : Podostemaceae are so variable morphologically that it has proved dif- ficult to devise a satisfactory subfamilial classification, although several have been proposed. Most recently, Van Royen (1951) has recognized two subfamilies: Tristichoideae Engler emend. Royen, with sien veloped by a few leaves and with a 3- or S-lobed perianth, gated si stemoideae. with flowers inclosed in a “spathella” and with the tepals r duced to scales. The four tribes (Tristicheae, Weddelineae; oe a Podostemeae), two in each subfamily, are based mainly on characters sulaceae, Nepenthaceae, and Scroph strong evidence of its relationships to ceae, a small family once united with * characteristic features of the embryology of the 458 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 tetranucleate megagametophyte (embryo sac) that lacks antipodal cells or has only a single one; the absence of endosperm; the growth of the top of the megasporangium (nucellus) beyond the inner integument into the endostomium; the restriction of the megagametophyte (embryo sac) o the upper part of the megasporangium (nucellus), while the lower part. elongates to form a pseudo-embryo sac; and the appearance of the outer integument to form the micropyle before development of the inner integ- ument. Maheshwari, drawing support from the earlier embryological studies and conclusions of Mauritzon, has suggested that the Podostema- ceae (and Hydrostachyaceae) are derived by reduction from the Crassu- laceae, a theory based mainly on the highly developed suspensor haustoria found in both families and the similarities in embryogeny between some aquatic Crassulaceae (e.g., Tillaea aquatica) and the Podostemaceae. In floral morphology the evolutionary trend appears to have been from actinomorphic to zygomorphic flowers, accompanied by a change from entomophily to anemophily or autogamy. A high degree of ovule abortion, of unknown cause, has been reported. The only chromosome numbers reported are those of Terniola ceylanica (Gardner) Tulasne (as Lawia zeylanica), 2n = 20; Podostemum subula- tum Gardner, 2n = 40?; and Weddelina squamulosa Tulasne, 2” = Van Royen notes that plants of this family throw off part of the outer tissues after the water level subsides, producing great changes in appear- ance and making it difficult to judge herbarium material, in which these same changes can occur during the process of pressing and drying. The best way of preserving specimens is in 60—70 per cent alcohol, in 4 per cent formalin, or in a mixture of the two. The Podostemaceae are of great biological interest but of no economic importance. b oO REFERENCES : Accors!i, W. R. Biology and a ire of the Podostemonaceae of the Piracicaba Fall. Proc. Seventh Int ere eae 1950. 681, 682. 1953. [Apinagia, Mniopsis, ear Moure ARBER, A. Water plants. 436 pp. Canbsiee 1920. [Podostemaceae, 112- 122, 327-332.] BaILton, H. Podostémacées. Hist. Pl. 9: 256-273. 1888. BatTTaGLiA, E. The embryo sac of Podostemaceae — an interpretation. Caryolo- gia 24: 403-420. 1971. [Regards megagametophyte as reduced bisporic type rather than reduced Allium type. BENTHAM, G., & J. D. Hooker. Podostemaceae. Gen. Pl. 3: 105-115. 1880. Cuao, H. C. Discovery of Podostemonaceae in China. Contr. Inst. Bot. Pei- ping 6(1): 1-16. pls. 1-3. 1948. [3 spp. in 2 genera (1 new) from western Fukien. | ENGLER, oa Podostemonaceae africanae. IV. Bot. Jahrb. 60: 451-467. 1926. ee ostemonaceae. Nat. Pflanzenfam. ed. 2. 18a: 3-68. 1930. [Includes an pass bibliography. | . Die Pflanzenwelt Afrikas 3(1). Characterpflanzen Afrikas. vi + 869 pp. 1915. Jn: A. ENGLER & O. Drupe, Die Vegetation der Erde. Vol. 9. [Podostemaceae, 268-277. ErDTMAN, G. Pollen morphology and plant taxonomy. V. On the occurrence 1975] GRAHAM & WOOD, PODOSTEMACEAE 459 of tetrads and dyads. Sv. Bot. Tidskr. 39: 286-297. 1945. [Podostemaceae, 93. GAFFIER, L. Etude morphologique et anatomique des Podostémacées de Mada- gascar. These, Fac. Sci. Univ. Marseille. 140 pp. GARDNER, G. Observations on the structure and affinities of the plants belong- ing to the natural order Podostemaceae, together with a monograph of the Indian species. Calcutta Jour. Nat. Hist. 7: 165-189. 1847. [Includes some details of life history; suggests affinity with Nepenthaceae. } GOEBEL, K. Pflanzenbiologische Schilderungen. Teil II. iv + 386 pp. 31 ls. Marburg. 1891, 1892. [Podostemaceae, 311-354. pls. 26-30.] Hai, J. B. New Podostemaceae from Ghana with notes on related species. Kew Bull. 26: 125-136. 1971. [Includes discussion of Jnversodicraea, Poly- pleurum (Taylor ex Tulasne) Warming (Dicraeia Thouars, nom. illegit.), Saxicolella. Hess, H. Ueber die Familie der Podostemonaceae und Hydrostachyaceae in Angola. Bull. Soc. Bot. Suisse 63: 360-383. 1953. JAcer-Ztizn, I. Embryologische Untersuchungen an vier Podostemaceen. Osterr. Bot. Zeit. 114: 20-45. 1967. [Tristicha trifaria, Inversodicraea bemarivensis, I. minutiflora, Anastrophea abyssinica. Macnus, W., & E. WERNER. Die atypische Embryonalentwicklung der Podo- stemaceen. Flora 105: 275-336. pls. 11-14. 1913. [6 spp. from Ceylon, including Podostemum subulatum, 285-292.] Mauesuwakrt, P. The place of angiosperm embryology in research and teach- ing. Jour. Indian Bot. Soc. 24: 25-41. 1945. [Relationships of Podostema- ceae to families in Rosales based on embryological studies, 31.] Martin, A. C. The comparative internal morphology of seeds. Am. Midl. Nat. 36: 513-660. 1946. [Podostemaceae, 592. ] Matruigsen, F. Beitrage zur Kenntnis der Podostemaceen. Bibl. Bot. 15(Heft 68): 1-55. pls. 1-9. 1908. [Includes general account of the morphology and anatomy of the group. ] Mauritzon, J. Contributions to the embryology of the orders Rosales and Myrtales. Lunds Univ. Arsskr. II. Sect. 2. 35(2): 1-121. 1939. [Podoste- maceae & Crassulaceae, 37, 38; see also his earlier paper, Bot. Not. 1933: 172-180. 1933.] MELcuIor, H. Podostemales. 12. 2: 244-246. 1964. Metcatre, C. R., & L. CHALK. Anatomy of the dicotyledons. 2 vols. 1500 pp. Oxford. 1950. [Podostemaceae, 2: 1101-1104. ] Muxxapa, A. J. Some observations on the embryology of Dicraea stylosa Wight. Pp. 139-145 im Plant embryology, a symposium. vi + 2 4 pp. Council of Scientific & Industrial Research. New Delhi. 1962. [Polypleurum stylosum (Wight) J. B. Hall.] Narr, P. K. K. Pollen grains of Indian Po 34: 381, 382. 1965.* Nasu, G. V. Podostemonaceae. N. Am. Fi, 22: 3 rections. /bid. 535. 1918. Razt, B. A. Embryological studies of two me Gaz. 111: 211-218. 1949.* Some aspects of the embry Engl., and Lawia zeylanica Tul. Lawia zeylanica = Terniola cey Romano, G. R., & J. D. Dwyer. A A. Engler’s Syllabus der Pflanzenfamilien. ed. dostemaceae. Curr. Sci. Bangalore 6, 1905. Additions and cor- mbers of the Podostemaceae. Bot. ology of Zeylanidium olivaceum (Tul.) Bull. Bot. Soc. Bengal 9: 36-41. 1955. lanica (Gardner) Tulasne. | demonstration of phloem in the Podo- 460 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 stemaceae. Bull. Torrey Bot. Club 98: 46-53. 1971. [In Marathrum & Tristicha. | Rompacu, S. Die Entwicklung der Samenknospe bei den Crassulaceen. Rec. Trav. Bot. Néerl. 8: 182-200. 1911. [Relationship to Podostemaceae. ] Royven, P. vAN. The Podostemaceae of the New World. I. Meded. Bot. Mus. Utrecht 107: 1-151. pls. 1-16. 1951. [Nearly complete bibliography of the family; summary of its history, classification, distribution, and biology; taxonomy of Apinagia, Marathrum, Rhyncho tacis: Wettsteiniola, He oe gyne, Monostylis, Jenmaniella, Macdieiia. II. Acta. Bot. Neerl. 2: 1-21. 1953. [Taxonomy of Trisiicha, Weddelina, Mourera, Tulasneantha eae Lonchostephus.| UI. Ibid. 3: 215-263. 1954. [Taxono omy of Oserya, Devil- lea, Ceratolacis, Mniopsis, Podostemum, Castelnavia, and five dubious genera. . Nomenclatural notes on the genera Dalzellia, Lawia, Mnianthus, and Terniola (Podostemaceae). Acta Bot. Neerl. 8: 473-476. 1959. [Lawia Tulasne, 1849, a later homonym of Lawia R. Wight, 1846; substitute names Dalzellia R. Wight, Terniola Tulasne, and Mnianthus Walpers, all pub- lished in 1852, with priority uncertain; Terniola first adopted in preference to Dalzellia and Mnianthus. Indotristicha Royen established as a new genus. | SCHNELL, R. Etudes sur sapere et la morphologie des Podostémacées. Can- dollea 22: 157-225. 1967. SCULTHORPE, C. D. The biology of aquatic vascular plants. xviii + 610 pp. London. 1967, [Includes numerous references to the fam SUBRAMANYAM, K. Embryology in relation to systematic sae with particular reference to the Crassulaceae. Pp. 94-112 in Plant embryology, a sym- posium. vi + 274 pp. Council of Scientific & Industrial Research. New Delhi. 1962. [Many comparisons with Podostemaceae. ] . Aquatic angiosperms, a systematic account of common Indian angio- perms. Council Sci. Indus. Res, Bot. Monogr. 3. viii + 190 pp. New Delhi. 1962. [Podostemaceae, 43-51; includes Podostemum. ] & . SREEMADHAVAN. A conspectus of the families Podostemaceae and Tristichaceae. Bull. Bot. Survey India 11: 161-169. 1971 [1969].* Taytor, G. Notes on Podostemaceae for the revision of the Flora of West Tropical Africa. Bull. Brit. Mus. Nat. Hist. Bot. 1: 53-79. 1953 TuLasnE, L. R. Monographia Podostemacearum. (In Latin.) Arch. Mus. Hist. Nat. Paris 6: 1-208. pls. 1-13. 1852. [Basic monograph. ] WarmMinG, E. Familien Podostemaceae. Afhandling I. (In Danish; French summary.) Danske Vidensk. Selsk. Skr. Nat. Math. Afd. VI. 2: 1-34. pls. 1-6. 1881; Il. Ibid. 77-130. pls. 7-15. 1882; III. Ibid. 4: 443-514. pls. 16-27. 1888. IV. Ibid. 7: 133-179. 1891; V. Ibid, 9: 105-154. 1899; VI. Ibid. 11: 1-67. co [Podostemum ceratophyllum, 2: 1-34 (in part), pls. 1-3, 4 (in part), 7.] : Pie Nat. Pflanzenfam. ITI. 2a: 1-22. 1890. WEDDELL, H. A. Podostemaceae. DC. Prodr. 17: 39-89. 1873. [Podostemum, 2-76. | Went, F. A. F. C. The development of the ovule, embryo-sac and egg in Podo- stemaceae. Rec. Trav. Bot. Néerl. 5: 1-16. pl. 1. 1908. [ In Oenone & Mourera. | . Untersuchungen iiber Podostemaceen. I. Verh. Akad. Wet. Amsterdam 16: 1-88. pls. 1-15. 1910; II. Ibid. 17: 1-19. 2 pls. 1912;* III. Ibid. 1975] GRAHAM & WOOD, PODOSTEMACEAE 461 25: 1-59. pls. 1-11. 1926. [Observations on Oenone, Apinagia, Lophogyne, Mourera, Tristicha. ur la transformation du collenchyme en sclérenchyme chez les Podo- stémonacées. Rec. Trav. Bot. Néerl. 21: 513-520. 1924. [In Oenone.] . Morphological and histological peculiarities of the Podostemonaceae. Proc. Int. Congr. Plant Sci. Ithaca, 1926. 1: 351-358. 1929. [Observations on Oenone, Mourera, Apinagia. | Wiis, J. C. On the dorsiventrality of the Podostemaceae with reference to current views on evolution. Ann. Bot. 16: 593, 594. 1902a. . A revision of the Podostemaceae of India and Ceylon. Ann. Roy. Bot. Gard. Peradeniya 1: 181-250. 1902b. [Tristicha, Lawia (= Terniola), Di- craea (= Polypleurum), Podostemum (228-231), Grifithella, Willisia, Hy- ] drobryum, Farmeria. . Studies in the morphology and ecology of the Podostemaceae of Ceylon and India. /bid. 267-465. pls. 4-38 (lacking 23 & 27). 1902c. [Includ- ing observations on the structure and biology of Podostemum, 327-340. ]| . On the lack of adaptation in the Tristichaceae and Podostemaceae. Proc. Roy. Soc. London B. 87: 532-550. 1914. . A new natural family of flowering plants — Tristichaceae. Jour. Linn. Soc. Bot. 43: 49-54. 1915. . The origin of the Tristichaceae and Podostemaceae. Ann. Bot. 29: 299-306. 1915. [Ancestor believed to be a terrestrial plant that, by a single large mutation, produced Podostemaceae. | . The relative age of endemic species and other controversial points. / bid. 31: 189-208. 1917. [Podostemum regarded as an old genus with wide dis- tribution, 201, 202. ; _ The evolution of the Tristichaceae and Podostemaceae. I. /bid. 40 349-367. pl. 13. 1926. [“It is probable, therefore, that in at least a large proportion of the species of these families the changes were large enough to create new species, or even larger groups, at once.” Subfam. PODOSTEMOIDEAE Tribe PoDOSTEMEAE 1. Podostemum Michaux, Fl. Bor. Am. 2: 164. pl. 44. 1803. Gregarious, dark green to reddish herbaceous perennials of shallow, tushing streams or rapids, firmly attached to rocks or gravel by means of cement-secreting root hairs and fleshy disclike haptera arising from the lower surface of + dorsiventral, photosynthetic, horizontal _(plagio- tropic), creeping, branched roots. Stems present [or lacking], a. in pairs along the sides of the roots, without a growing point, the mii alternating in two ranks, each leaf arising from the base of the next older leaf in its rank: lateral shoots arising at the base of the leaf on its outer (abaxial) side, not in the axil of the leaf. Leaves distichous, onnsiand forked [or entire], spathulate to mainly filiform, with the exception 0 the lower leaves with an intrapetiolar stipule. Flowers axillary, solitary on short pedicels, the spathella rupturing at the distal end, the a and stamens restricted to the adaxial side of the flower. Tepals (the “staminodes” of some authors) 2 or 3, filiform, acute, one on each side 462 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 3; c¢, detail of branch, showing bases of leaves with intrapetiolar pteron stipules, each flower solitary ates spa oe in axil of leaf, * 3; d eme 8 Tging from spathella e, e flower from behind (removed from spathella), a tepal to each side s pais and a third inserted on androphore 1975] GRAHAM & WOOD, PODOSTEMACEAE 463 of the androecium (partially fused filaments, androphore, andropodium), the third (the ‘“‘scale” of some authors), when present, in the fork between the filaments of the two stamens. Androecium of (1), 2 (or 3) stamens, borne by an andropodium or androphore (or this interpreted as the staminal filaments fused for about one-half their length); anthers introrse, 4-locular, longitudinally dehiscent; pollen grains in dyads. Gynoecium 2-carpellate, syncarpous; styles 2, simple, equal, free, the stigmata indis- tinct; ovary superior, 2-loculate, the abaxial locule larger; ovules many, anatropous on a thick, fleshy, axile placenta. Fruit a [6- or] 8-ribbed, septifragal, 2-valved capsule, the smaller, adaxial valve caducous, the larger, abaxial valve persistent, the enlarged placenta and seeds becoming detached; seeds numerous, minute, with an outer mucilaginous layer (when moistened). Type species: P. ceratophyllum Michx. (Name from Greek, pous, podos, foot, and stemon, stamen, in reference to the stamens apparently supported by a pedicel: ‘“stemonia pedicello sufful- ta.”) — RIVERWEED. A primarily tropical genus of 17 or more species of North and South America, and perhaps India and Ceylon: Podostemum ceratophyllum in eastern North America, Hispaniola, and Honduras; P. riccitforme (Liebm.) Royen in Mexico and Costa Rica; and 15 species distributed from cen- tral Brazil to Uruguay, Paraguay, and northern Argentina. Species at- tributed to this genus have been described from Africa, Madagascar, In- dia, and Ceylon, but all except two, P. subulatum Gardner (Ceylon and southern India) and P. Barberi Willis (southern India), have been ex- cluded (cf. Engler, 1915; Willis 1902b, c; Hall). The taxonomic disposi- tion of these two species appears to be unresolved, but it may be worth noting that their leaves are spirally, rather than distichously, arranged and lack stipules. aks Podostemum ceratophyllum, the only species of the family in eastern North America, has an unusually broad distribution, extending north- ward to New Brunswick, Quebec, and Ontario, and sout ward to Georgia, Alabama, Mississippi, Louisiana, southeastern Oklahoma, and western Arkansas, and with disjunct localities in the Dominican Republic and ( as var. circumvallatum Royen) in Honduras. It is of local occurrence and is extremely variable in habit, especially in size and dissection of the seh One extreme with lax, elongate leaves has been named i abrotanot 4 (Nutt.) Fassett, and the opposite extreme with coarse, rigid leaves . : chondroides Fassett, the author of the combinations acknowledging t . the two are not geographically distinct and are connected by a serles 0 anthesis, X 6; g, flower : i to unequal locules and axile eo ee 2 abet en whe nearly mature fruit to upper left (spathella mostly broken away), imm , fruit after dehiscence, larger valve of aie persistent on pedicel, X 12; 1, placenta removed from fruit, X 12; m, seed, moistened to show mucilaginous seed coat, between filaments, X 6; f, flower immediately before i s 464 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 intermediates. Whether this variation is genetic or ecological is largely unstudied. Hammond found, however, that at Difficult Run, Virginia, three forms grew side by side, forming colonies of various sizes, the plants of a colony being usually uniform in size and structure. When plants of the two extremes were transplanted to two localities in Maryland, they grew well and retained their original characteristics during an observation period of several weeks. The extraordinary life history of Podostemum ceratophyllum was stud- ied by Hammond, who observed the entire cycle in Maryland and Virginia, with the exception of seed germination. Growth of roots and shoots begins in the spring from the bases of plants of the previous season; by June flower buds are formed in the axils of leaves, where they remain inclosed in the spathella as long as the plants are submerged. If the water level subsides, exposing the plants, the pedicel promptly elongates and the spathella ruptures, revealing the flower. Self- or perhaps wind-pollina- tion occurs, and within a few days the seeds are mature and shed from the open capsule, where they adhere to the surrounding dry rocks by means of mucilaginous seed coats. In our area, where wet and dry sea- sons are indistinct, the plants may remain submerged through an entire summer, never flowering, but growing vegetatively and propagating by regeneration from pieces of roots, stems, or leaves that have broken from the parent plant. Seed germination apparently has not been observed in Podostemum ce- ratophyllum but is probably like that of P. subulatum (cf. Willis, 1902c, p. 329) and many other genera of the family. With the rise in water level the hypocotyl emerges from the seed, bends downward, attaches itself to the substrate by root-hair-like rhizoids and expands to form a larger area of attachment. The seedling becomes erect, cotyledons and primary leaves appear in two ranks, and the primary axis then stops growing. No de- veloped primary root has been reported for any member of the family, and the secondary root is adventitious from the base of the hypocotyl. The root is dorsiventral, and in P. ceratophyllum there are only two rows of lateral roots, all of which retain this symmetry. Branches are pro- duced in pairs a short distance behind the root growing point. The roots attach themselves by root hairs and by disclike or fingerlike haptera that arise exogenously from the underside of the root, usually under the base of each shoot. The haptera are entirely parenchymatous, have a terminal growing point, and lack vascular tissue. They are believed by some to be derived phylogenetically from the root, by others to be similar to ten- drils in origin. The shoots grow out transversely to the root and more or less erectly from the substrate. There is no stem growing point, each of the two-ranked leaves arising from the base of the next older leaf in its rank. Each leaf has an intra- petiolar stipule. Lateral branches of the shoot are not axillary within these stipules but arise at the base of the abaxial side of the leaf (i.e., on the side opposite the stipules) and are covered by a stipulelike struc- ture formed on this same side of the leaf. Stomata are completely absent, 1975] GRAHAM & WOOD, PODOSTEMACEAE 465 and the epidermal cells of the root, as well as of the leaves, contain chlorophyll. The only chromosome number reported for the genus is 2n = 40? in the Ceylonese and southern Indian Podostemum subulatum. REFERENCES: Under family references see especially MAGnus & WERNER (pp. 285-292), Van Royen (1951; 1954, pp. 228-244), TuLASNE (pp. 129-132), WARMING (1881, pp. 1-34), and Writs (1902b; 1902c, pp. — see also GARDNER, Martin, NASH, SPRAGUE, SUBRAMANYAM, and WEDD: Fassett, N. C. Notes from the herbarium of the University of Wisconsin. XVIII. Podostemum in North America. Rhodora 41: 525-529. 1939. FREEMAN, O. M. An extraordinary plant in ses County, North Carolina. Cas- tanea 19: 38. 1954. [See also ibid. 20: 4 Hammonp, B. L. Regeneration of a ite ceratophyllum. Bot. Gaz. 97: 834-845. 1936. . Development of Podostemon ceratophyllum. Bull. Torrey Bot. Club 64: 17-36. 1937. Louis-Marig, Pére. Hydrocharis et Podostemon. Revue Oka 34: 168, 169. 1960.* S. A. G. C EW: DEPARTMENT OF ARNOLD ARBORETUM BIOLOGICAL SCIENCES HARVARD UNIVERSITY KENT STATE UNIVERSITY CAMBRIDGE, MASSACHUSETTS 02138 Kent, OnTO 44242 ADDENDA The following family references contain material of general biological interest. Grupert, M. Podostemaceen-Studien. Teil I. Zur Okologie einiger venezo- lanischer Podostemaceen. Beitr. Biol. Pflanzen 50: evecne 1974 (15 July 1975). [Many important observations, especially in the Rio Caroni, on Apinagia multibranchiata, Mourera Auviatilis, Rhyncholacis penicillata, and Weddellina squamulosa. Includes morphology, habitat, conditions favoring flowering, structure, and behavior of inflorescences, fruit development (these species requiring at least three weeks), and seed dispersal (by wind SCHNELL, R. Contribution a l’étu I. 9: 249-271. 1969. [List of specie taxonomic characters and variability an _ Cusset. Remarques sur la structure des plant nacées. Ibid. 3: 358-369. 1963. de des Podostémacées de Guyane. Adansonia s collected in Guyana, remarks on d on ecology and biogeography. | ules des Podostémo- 466 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 INDEX Acacia, 186, 290, 322, 333, 334 Aperula, — caven, Aphioia, ic 77, 78, 86, 89, 90, 96 PE 199, 200 — myrtifiora, Acalypha, —theiformis, 26, 77, 78 Acetosella, ae Apinagia, 457 Achimene 164, tee a 169 = endlchei 68, 169 — hillii, Decteaie 165 — por ? simplicifolia, 16 ubs eo-scotica, 169 — — subsp. pe is, 169 —-—subsp. simplicifolia, 168 Adaptations in Prosopis (Leguminosae, Mimosoideae), Reproductive, 185 Additional Notes on the Genus Flindersia Alnus, 277, 310, 311, 333 —incana subsp. a ee — jorullensis, 333 — — exigua, 277 Amentiferae, 94 Ananas, 376-378, 395-397 Anatomy of the Xylem and Comments on the ae of ‘aontee. Systematic, 20 Ancistrothyres, 26, 74, 75, 88 — tess: ; a0 siroitiedts ‘ahastorosans. 241 Anetanthus, 364-368, 451, 452 — pusillus, 364, 365, 367 — villosus, 7 Anetanthus (Geeneriacent). The Genus, 364 Pe fot Antidesm: Antirhea A 245 , 96 Araliaceae, a ee 433, 440 Araliaceae, Development of the Digitately Decompound Leaf in Cussonia spicata, 256 Araliaceae, The Cephaloschefflera Com- plex, Studies in Schefflera, 427 Aralia sect. Paratropia, 435, 441 —rigida, 435 —— uva-ursi, 135 360 Section Tittmannia, indern brucei, A New West Tadin ee a the Asteriastigma, 555355 Asteropeia, 78, 85, ts 96 — micras Averrhoaceae, 224 Azara, 26, 40, 41, 62, 86, 87 —integrifolia, 26, 62 — microphylla, 26, 62 — serrata, 26, 62 — uruguayensis, 26 Baccharis, 310, 333 413 Balsaminaceae, 224, 413-4 Balsaminaceae in the Southeastern United Banara, 26, 41, 43, 53, 85, 87 — axillifiora, 26, 33 — guianensis, 26, 53 1975] Bartholomaea, 27, 41, 53, 84 — sessiliflora u Bartonia, 211, 220 a haibtetats, 211, 220 11 Taxonomic Bawa, eee S., and Orro T. Sot- me Variation : Sesh of Prosopi is ; Bee tedendenn. 27, 40, Pe +6 61, 86, 87 —leprosipes, 27 — grandifolium, 15 —obtusilobum, 12 — praecox, 14 peeenaops, 27, 40, 41, 43, 44, 83, 89- —97 ae nh a: Betula ae subsp. humilis, 135 226 — crave 436 — pullei, a, 376 ictanese: 375-397 INDEX 467 Bromeliaceae subfam. Bromelioideae, 377, ’ ? — subfam. Pitcairnioideae, 376-378 — subfam. Tillandsioideae, 377, 378, 383 Bromeliaceae in the Southeastern United alt The Genera of, 375 Bromeli 7 Lao fianl ly, 375 Brossaea a 241 — coccin Buchnerodndron, 21,40, “41, 43, 92,780 — specios 27 Bursera, 18 334 —bipinnata, 319, 334 — tomentosa, 319, 334 Calamagrostis murrag rare 135 Calantica, 27, 41, 54, 55, 85, 87 — cerasifolia, 27 Californian laurel, 8 ae ae 21t, 212 — frigidus, 212, 216 Caloncoba, y 41, 43, 49, 50, 84, 93 mip D., and . SoL- BRIG. ” Reproductive Adaptations in Prosopis (Leguminosae, Mimosoideae), Capparaceae, 95 Capparales, 95, 97 Caraguata, 383, 391 —rostrata, 135 Carpteoche 28, 40, 41, 43, 47, 83, 84 — brasiliensis, 28, 4 pig ony 28, 47 sigdiriaes 28, 40, 41, 43, 86 c — racemosus, 171 468 a Aissicgg area What and Was Miller 71 Cephaloschefflera Complex, Studies in Schefflera (Araliaceae) : The e, Cercidium, 186 Chamaedaphne calyculata, 135 Chelonanthus, 212, 213, 216, 220 Chironia, 213 cig on 267, an 272, 274-277, aA, OSes; — archeri, ar 269, 270, 273, 277-281, 327, 343. pa Sele ey 271; 303,306, 333, — coyucae, 269, fg 282-285, 333, 273, 281, 334 —cupulata, 274, 285, 286, 301, 322, 333, 334 — dimorpha, 267, 269, 274, 286-288, 317, 334 3, —glauca, 267, 269, 322, 333, 334 Bi stage 266, 267, aay eee z07; 270, 271, Ont 286, 292- 296, 311, 313,324, 333, —harlingii, 267, 269, nly ee 274, 279, 296-298, 322, 333, 334 —hintonii, 271, 274, 298, 333, 334 3 —inorna, ee 269, 271, 273, 288, 303- 300, 200, eRe 267, 271, 272, 274, 298. 306-311, 316, 329, 333, 334 JOURNAL OF THE ARNOLD ARBORETUM 282, 271, 275, 288-290, 271, 274, 290-292, [voL. 56 Cladocolea mcvaughii, 267, 271, 274, 294, 301, 311-313, 334 —microphylla, 267, 271, 272, 274, 298, Binge an yore 273, 274, 288, 317- ~ pedicel 269, 271, 275, 290, 319- Eee 267, 271, 274, 286, 294, 301, $10, 313, 322-329, 304 ele 269) 273, 279,326, 327, 334 —stricta, 274, 327-329, 334 — tehuacanensis, 267, 271, 274, 290, 329- 331, 334 Cladocolea (Loranthaceae), The Genus, 265 Cochlospermaceae, 20, 23, 92 Colubrina, 292, 333 Comastoma, 215 Combinations in Raeuschel’s Nomenclator, Gaultheria swartzii, nom. nov. and the, 0 Commelinaceae, 248, 376 Compositae, 129, 298, 310, 333, 334 Coutoubea, 213 Crepinella, 428 Croton niveus, 303, 333 Cussonia, 256, 260, 263 —arenicola, 25 —ga amtoosensis, 256 — nicholson = ee 256 263 (Arali aceae), Develop- e Digitately Decompound Cyperaceae, 129 Cyrtandra, 164 Cytotaxonomic Notes on Some Gentian- aceae, 211 Dapania, hig Daphnidium, 10 Dasylepis, sd 43, 45, 46 — brevipedicellata, 28 rpon minbiciin, 133 Desmaria , 26 Development of the Digitately Decom- 1975] pound Leaf in Cussonia spicata (Arali- ©),.256 Duar, Usa, and M. R. VIJAYARAGHAVAN. Kadsura heteroclita — Microsporangium and Pollen Diaphoranthema, 383, 385 n ’ hus, 432 Digitately Decompound Leaf in Cussonia = cata (Araliaceae), Development of Dilleniaceae 79197 oe 42 Dovyalis, 28, 62, 86, 87 — caffra, 28, 62 Diroseracens, 91 Elaeocarpaceae, - ie ee 95 Eleutherandra, 2 9, — pes-cervi, 29, mpetrum olarans 135 Enochoria, we 435, 440, 441 — sylvicola, Epigaea pace 240, 241 Equisetum 135 eae, 12 Eriocaulaceae, 248, 376 ospermum, 29, . 41, 44, 89, 93 etary eet agro 9, 44 — candi a epee pret ie 175 71 cotinifolia, 1734175 175 — (Syzygium) Beles at 245 ons 164 Eupatorium mairetianum, 310, 333 Eup ie Zi, ae 94, 97, 224 qocha rbiales, 93, Euroschin ws fleas, 245 Evodiella, 1 Farinosae, 376 aeweets 29, 41, 61, 86, 87 — cataphracta, 29 —indica, 29, 61 INDEX 469 Flacourtia rukam, 29, 61 — subintegra, 29, 61 Flacourtiaceae, sake Banareae, 53, 80, 82, 85-87, 96 — trie mA iy 43, 80-83, 87, tbe ecm 21, 23, 40, 66, 80-82, 87, 96 —- ie heen co , 83 — tribe shoal ate 23, . 80, 82, 86, 87, 90, oe a. 23, 54, 80, 82, 85-87, vee oe Idesiinae, 94 —tribe Oncobeae, 20, 23, 47, 80-84, 95, 96 — tribe Pangieae, 23, 55, 80~84, 90, 95 —tribe Scolopieae, 21, 23, 52, 80, 82, 84, 86, 87, 91, 96 Flacourtiaceae, Systematic Anatomy of the Xylem and Comments on the Rela- 0 carpa, 245 — unifoliolata, 243, 2 Flindersia (ace), Additional Notes on the Genus, 243 C. Fropin, D . Studies in Schefflera (Araliaceae) The Cephaloschefflera Complex, 42 Gaultheria, 240 anastomosans, 241 ede, 241 — cordifolia, 240, 241 —domingensis, 24 —sphagnicola, 240-242 — swartzii, 24 Gaultheria swartzii, nom. nov. d the Com era in Paar nnne Nomen- clato: Genera sor ig TEE. in the South- eastern United States, ag 375 — 211, 213-215, 2 ondrophyllae, an 214, 220 — subg. Gentianella, 21 —altaica, 220 — argente a, 220 — aff. briquetiana, 221 — aff. si gry 221 470 Gentiana eg 220 — pulla, — pyren 220 —sedifolia, 213, 214, 217 — zollingeri, 220 Gentianaceae, 10 , 211-222 —tribe Genti e, 104, 213 —subtribe Chironiinae, 213 —subtribe Tachiinae, 104 Gentianaceae, Cytotaxonomic Notes on me, 211 gee oscame The Neotropical Genus Gentianela, 2u, 214, ee 220 t —sect. Gentianella, 214, 220 — acuta, 22 —amarella, 220 — subsp. ape 220 — i aaloataat ~ aurea, pal 215, 220 —austriaca, 220 ~aampet subsp. = 220 p. islandica, 221 — moorcroftiana, es 215, 221 — nevadensis, 215, 217 Gentianopsis, 215 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 — 428 ales, 415 Gesneriaceae, 364, 365, 367, 368, 449, 451- 453 Gesneriaceae, The Genus Anetanthus, 364 Glochidion, 93 Goethalsia, 83, 90, 96 Gossypitepcrasum. 29, 67 9 yn The eesckas in ‘the steal oor a rel, Grevillea conten 245 Guttiferae, 23 uzmania, 391, 393-395 Beans 30, 43, 56, 58, 84 —o mnie miihlenbergii, 133 Habitats, cour yobs sae: in Shore, 126 — cuatrecasasii, 217 — decumben -— deflexa, 222 — phyllophora, 217 —rhyacophila, 215, 217 — shannonii, 222 Halfordia kendack, 245 Hamamelidales, 94 Harpin, Feaeak W. Hybridization and In- trogression in Quercus alba, 336 — in Temperate North America, Lau- EY, Tuomas G. A New Species of Costhekyeax (Rutaceae) from N Guinea, 369 Hartiey, T. G., and B. P. M. Hytanp. Additional N se on the Genus Flinder- sia (Rutaceae), 243 Hasseltia, 30, a 43, 72, 73,85, 86 — floribunda, 73 —cf. pital 30575 1975] Hasseltia lateriflora, 30, 73 — laxiflora, 30, 73 Hasseltiopsis, 85 Hecatostemon, 30, 41, 68 — guazumaefolius, 30 Hechtia, 395 pols Howarp, RicuHarp A. Gaultheria Pcie: n and the Combinations in ee a Nomenclator, 2 40 Howarp, Ricuarp A. Lindernia brucei, A New West Indian Shack of the Asian Section Tittmannia, 449 peng Ricuarp A. The Genus Anetan- hus {Gestierinceasy, 364 a eatinn and Introgression in Quer- cus alba, 336 eddiaous 31, 40, 41, 43, 55, 56, 83, 8 6 Hydroc Hydonichyaces 457, 458 HYLA and T. G. HartTLey. isp Pe: on the Genus Flinder- e), 243 ceae, 23 Hypseocharis, 224, 225 Hypseocharitaceae, 224 Idesia, 31, 32, 40, spe 66, 86, 87, 94, 97 66 — sect. Longicornes, 419 INDEX —sect. Microcentron, 419 416 Introgresion i in Quercus im Hybridiza- tion and aie 2 29, 232 Isozyme Variation - Saget of Prosopis (Leguminosae), Itoa, 32, “ 65, a = 87, 94, 97 — stapfii, 32, 66 Txocactus, oe 273, 303 —hutchisonii, 271 Juncaceae, 129 Juncus hadvietis var, littoralis, 135 Kadsu 176 — heterocita 176-182 — roxburghiana, 181 Kadsura heteroclita — Microsporangium and Pollen, 176 Kiggelaria, 32, 40, 43, 60, 93 africana, 32 Mave: velutina, 32 Kuzyt, Jou: ~The Lenses 26 Genus Cladocolea Lacistema, 84, 88, 93, 96 — suaveolens, 32, 68 — te rstroemioides 32, 68 —tham ee 215,216 — parviflorus, 216 —princeps, 215~217 Larrea, 186 — cuneifolia, 208 Lauraceae, 1-19 Lauraceae — in Temperate North Ameri se Laurel, sent ane aurus, 6, 7, 9 Ee — benzoin, . — canariensis, — caroliniensis i: pubescens, 18 — nobilis, 9, 10 ——— angustifolia, 10 472 Laurus nobilis f. crispa, 10 1 ’ Cussonia spicata (Araliaceae), Development of the Digitately De- n 135 Leguminosae, 185, 205, 333, 334, 398 — subfam. Mimosoideae, 185, 202 Leguminosae, Isozyme Variation: in Species of Prosopis, 3 Leguminosae, Mim cata Reproductive Adaptations in Prosopis, 185 e, 224 Lethedon, - 78, ‘79, 91, 96 — le-ratii, — setosa “ Licuala ate 245 Ligustrum, 310, 333 Linaceae, Lindackeria, 33, 41, 43, 50, 84 550 — oe daria, 4 _ stemoatoids, 452 — visco JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Lindernia brucei, A New West Indian = Ry s of the Asian Section Tittmannia, a 265, 266, 269, 270, 303, 327 Loranthaceae, a ee Cladocolea, 265 Loranthus, 272 — clandestinus, at, 282, 334 — grahami, 292, 294, 334 — inconspicuus, st, 304, 334 —inornus, 304, 3 334 — microphyllus, ne 317, 334 — oerstedii, 33 — tehuacanensis, 329, 331, 334 Loxania, 266, 267, 271, 272, 308, 334 a siligg ees 334 pet ny sae 105, 216, 222 — dens 217 — shire ie —thamnoides, ; 16, 222 valerii °F ee ad hl 33, 41, 43, 74, 85, 86 —macroterantha, 33, 74 Macropana See ina Rocess. What and Whence Was Miller’s Caryophyllus cotinifolius, 171 ee aa 179 Macurre, Bassett, and Ruicuarp E. We, ae The penecopion! Genus & pilanacene),:1 a, 248— Mayacaceae, 248-255 Mayacaceae in the Southeastern United State 248 i 248 Mayna, 34, 40, 41, 43, * 49, 83, 84 — Pacifica, 34, 47, 49 — zuliana, 34, 47, 49 1975] Medusandra, 89 Medusandraceae, 76, 89, 96 Melastomataceae, 281, 333 6 i 440 aetits seq wes Metrosidere pie sy Microsem spitibsarcnkon vate fect heteroclita, 176 Kadsura . Systematic Anatomy m and Comm pag Rela a of Flacourtia Miller’s Caryophyllus pea roucrate coe and Whence Was, 171 Mimosa palmeri, 303, 333 Myrcia, — citrifolia, LiLo iss Myzodendron, 267 Neocussonia, 428 zh pn a 34, 40, 41, 71, 72, 81, 4, 87, : , 93, 96 apodan 34 Mie meri Gubke Tachia (Gentianaceae), The, Nepenthaceae, 91, 457 02 7 89, Neumanniaceae, 77, 89, 90, 96 New Guinea, A New Species of Zan- thoxylum (Rutaceae) from, 369 New West Indian Species of the Asian reat Tittmannia, Lindernia brucei, uniaeies Spepoectte swartzii, nom. nov. and the Combinations in Raeu- schel’s, 240 North America, Lauraceae Hardy in emperate, 1 Notes on Some Gentianaceae, Cytotax- onomic Notes on ‘hee Genus Flindersia (Rutaceae), Additional, 243 Nuphar Geet: 135, 155 Octotheca, 4 Olmediella, re 40, 41, 60, 86 — betschleriana, 34 Oncoba, — 43, 49, 84 — spino Ophiobotys 34, 70 INDEX 473 Oregon myrtle, Oreodaphne aye Umbellularia, 8 — californica, 4 —tehuacanensis, 329, 334 Osmelia, 34, 40, 43, 69, 70 —grandistipulata, 34, 70 —philippina, 35, 70 Statés, nee 223 Oxalis, valet 229-239 — sect. peengripial 230 —sect. Articulat 4 —sect. Co saieulanee, se en 234, 235 — sect. Ionoxalis, 225, oasi family, 2 Pangium, 35, 40, 41, 58, 84 —edule, 3 Parabenzoin, 10, 14 fire at macrostachya, 437 Parmelia saxatilis, 133 Paropsia, 21, = 75, 76, 88 Passiflora, 9 Passifloraceae, 21, 74-76, 82, 88, 89, 93, 96 —tribe Paropsieae, 21, 88, 95, 97 — Bi, 93, 97 Peppe Mee! Peridsaceae 23, 76, 89, 93, 96 Peridisc see 76, 77, 89, 93, 96 bescens, 18 474 Persea humilis, 18 — pubescens, a Phellodendron, 1 Phthirusa, 266, oe 273, 281, 334 334 — oligantha, 334 — mexicana, 35, pebcenis neriifolius, 245 Podopterus mexicanus, fer 333 Podostemaceae, 456-465 —subfam. Podostemoideae, 457, 461 hoeveriniir sient 35, 41, 43, 73, 85, 86 73 — tribe Mourereae, 457 —tribe Podostemeae, 457, 461 — subfam. Tristichoideae, 457 i e€ Podostemaceae in the Southeastern United States, The, 456 Podostemeae, 456 Podostemum, 456, 457, 461-465 tric 35, 40, 41, 65, 86,27 — sinensis, Pollen, cider heteroclita — Microspor- ngium and, 176 Polygalaceae, 414 Prockia, pe = - 85-88, 96 cruci he Prosopis no 398-412 — sect. Algar obia, 193, 194, 196, 199, 399 Pp as —alba, 194, 199, 398, 400, it ae 406, , 409 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Prosopis algarobilla, 400, 402, 404-406, 408, 409, 4 —alpataco, 400, 402, 404-406, 408 eatin’ pe 199, 400, 402, pe a8, 408, 409, — chilensis, ad. —189, 192-194, 196, 199, 201, 203-206, hn 398, 400, 402, 405, 406, 408, 409, — ferox, 199, sete asl — flexuosa, 185-187, 189, 192-196, 199, 201, 203-206, 208, 400, 402, 405, 409 ‘glandulosa, cg hese sie 208, 398, 400, 402, 405, 407-4 — juliflora, 401, se an 407-411 —kuntzei, 194 — laevigata, 194, 199, 401, 403-405, 407, — nigra, 194, 199, 398, 401, 403, 405, 407- 409 — pubescens, 199 — pugionata, 194 —reptans, 193, 194 —ruscifolia, 194, te 206, 208, 398, 401, hae 401, 403, 407-410 Se coins 193, 194, 199 — tamarugo, 199, 398, 401, 403-405, 408- 411 — torquata, 193, 194, 199, 202 —velutina, 185-187, 189, 192-194, 196, 199, 203, dct 206, 208, 209, 398, 401, 403-405, 407-409, 411 Prosopis (Leguminosae) , Isozyme Varia- 9 opi Leguminosae, Mimosoideae), Reproductive Adaptations in, 185 ica, — racemosa, 240 Quassia bidwillii, Quercus, 275, 294, 1. SOI, 310; 313: 316, 334 — subg. Ley 336, 342, 358 — alba, an nie ——Xa 346, 351 Sale 339, 346, 347, 351, 352 —— X durandii, 346 —— X lyrata, 347, oe gor —-— X macranthera, 359 ——x marten 348-350 1975] cnerens alba X margaretta, 7 351, 356 355 —— > prinus Fah 351, 354, 355 —— > robur, 355, 356 —— & stellata, 350, 356, 357 —-— & stellata var. margaretta, 350 uber, ee Seay 313, — austrina, 340, cot 346, 351, 357 — beadlei _ —x bebbiana a, — bicolor, 338, i 353, 358 Same coin: abe Hei 353,357 — mexicana, — michauxii, 38 351, 352.998 — minima, 358, — montana, 352 mes — muehlenbergii, 352, 353 — oglethorpensis, 338, 358 — prinoides, 354 — prinus, 338, 351, 352, a 355, 360 —robur, oe 340, 3 — X sau Le a — stellata, es 356, 357, 360 — undulata, 357 — Virginiana, 338, 358 Quercus alba, Siti aciasaal and Intro- gression in, 336 Raeuschel’s Die ode Gaultheria d the Combina- Randia, 292, 304, 333 Ranunculaceae, 129 Rapateaceae, 248 Raup, Hucn M. Species Versatility in pene. Relationsbins of Flacourtiaceae, Syste- INDEX 475 matic Anatomy of the Xylem and Com- ments on the, 20 e Renealmia, 383 Reproductive Adaptations in Prosopis (Le nosae "Mice 185 Re ise 248 and H. P. vAN DER Scu alee Development of the Digitately Decom es Leaf in Cussonia spicata (Araliac i256 Mhisscacton gael inatum, 133 Rhodamnia blairiana, 245 Riverweed, 463 Riverweed family, 456 RoBER x, KENNETH R. The Oxalidaceae in the Suihescey United States, 223 Rosaceae, 129 Rubiaceae, 240 DENBERG, Lity, and Ruicuarp E. EAVER, Jr. Cytotaxonomic Notes on Some Gentianaceae, 21 Rumfordia, 310, 333 aesey a, 364 ata, 364 Ratacen, 164, 243, 369 Rutaceae, Additional Notes on the Genus Flindersia, 2 Rutaceae, from New Species of Zanthoxylum, Rutaceae, The — ie of the Genus Bauerella, 1 Rutales, 224 Ryania, 36, 40, 43, 68, 69 — angustifolia, 36, 69 — pyrifera, 36, 69 —— speciosa var. chocoensis, 36, 69 Ryparosa, 36, 41, 43, 59, 60 j ica, 36 = A New = heated, 36, 59 Sabati 95, 97 Salix, 94, i 130, 310, 329, 334 — bebbiana, 135 — glauca var, acutifolia, 135 Sapindales, 415 arcandra ivingbail 181 422 —albidum, 16, 17 476 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 Sassafras albidum f. moldenkei, 17 Schefflera pullei, 436, 438 idum, —Tigida, 435 ——molle, 16 eee — officinale, 16 —rubiginosa, 432 —— albidum, 16 — schumanniana, 429, 431 —randaiense, 16 —sciadophyllum, 431, 434 — tzuma, —scortechinii, 432 — variifolium, 1 — secunda, 438, 439 Saxifragaceae, 129 — sessilis, Scaphocalyx, 36, 40, 43, 59 — singaporensis, 436 —spathacea, 36 —sphaerocoma, 431 Schefflera, 427-4 — stenopetala, 439 — sect. Brassaia, 429, 434-436, 441 —stolleana, 431 — sect. Cochalieehetticcd 427-435, 440 — stolzii, 431 = ae 428, 429, 432, 440 — ternata, 430 t. Schefflera, 429 — thaumasiantha, god 438, 439 carlton Aainechsti. 434, 435 — tomentosa, 43 Sees ct. Cephaloschefflera, 434 — trianae, oe 427, 431, 433, 435-439 —venulosa, 434 — affinis, 440 versteegii —an nite 432 — volkensii, 431, 43 —apiculata, 432 —wallichiana, 431, 434 — barteri, 431, 432 — waterhousei, 437, 439 — bougainvilleana, 431 — yatesii, — brassaiella, 436, 438 Schefflera (Araliaceae): The Cephalo- —Capitata, 431, 434 schefflera a Studies in, 427 — carrii, Schefflero < cephalotes, 432-435 Seine. 176, 179, 181 — chaetorrhachis, 431 Schisandra chinensi is, 181 — chinensis, 432, 433 — coccinea, 181 — corallinocarpa, 436, 437 — grandiflora, 179-181 — digitata, 428 — henryi, 179 — euryphylla, 432 —neelects, Soh 181 — gigantea, 438 — nigra, — goetzenii, 431 tc 391 — havilandii, 432, 435 Sciadophyllum macrostachyum, 437, 438 — hellwigiana, 431 Scolopia, 37, 41, 43, 52, 84, 85, 87 —herthae, 43 — luzonensis, Sf; 52 — heterotricha, 432 — mundii, — hullettii, 432, 435 + spinosa, 37, — hypoleuca, 433 — satelrggie . — hypoleucoides, 433 zeyheri, 37, — khasiana, 431, 434 Scotti, oh 43, 46 — kraemeri, 433, 437 — klainea = 46 — lasiosphaera, 431, 432 —— mim ate 37 — a, 432, 435 Scrophulariacene, 129, 364, 365, 368, 451- — lucescens, 435 oa, — macrostacya, 437, 439 Shore Habitats, eB Versatility in, 126 —mannii, 431 Simaroubaceae, 41 — megalantha, 437, 438 Sipapoa vestita, ro — merrillii, Siphonodon, —morobeana, 431 SMITH — B., and Carrot E. Woop — ovalis, 43 Th era of Bromeliaceae in the — pachycla da Si asec United States, 375 — pachystyla, — 438 Sodiroa, 391 pe a, Sulerain refractum, 311, 334 — pseudobrassaia, 438 Sorsric, Orro T., sad Kamatyir_ S. 1975] Bawa. Isozyme Variation pr Species of Prosopis — - Sotsric, Otto T., an N- TINO. Repro odu itive aptations in tee 5 Poe mire 185 per ronnie en States, The Balsa- Se teapot ge ited States, The Genera of Bromeliaceae in the — United States, The Mayaca- ceae Southeastern ‘United States, The Oxalida- e i Southeastern Waited Pate The Podo- the, Sparmannia, 83 Species of Prosopis (Leguminosae), Iso- zyme Variation in, Species of the Asien Section Tittmannia, Lindernia brucei, A New West Indian, Species of nan Es (Rutaceae) from ew Guinea, A Species Versatility in acne Habitats, 126 12 lis, 270 SPONGBERG, STepHEN A. Lauraceae Hardy in Temperate No th: merica Status of the Genus Bauerella (Queue, flora, 365 pedancli 365, 452 Stercalases ,9 pope ti tomentosum, 133 Strepsia, Strentothamnus, 37, 40, 41, 43, 83, 89-91, 95-97 324, 334, 3 — alni, 275, Pit; a4 — inconspicuus, 302, i 335 —inornus, ; — johnstonii, — leptosta ; 279 — loniceroides, 306, 335 exicanus, 308, 310, 335 —microphyllus, 313, 335 — oliganthus, 317, 319, 335 — orbicularis, 270, 273, 279, 296 — palmeri, 324 INDEX moorei, 37 Struthanthus, 265, 266, 269-273, 279, 280, 335 477 Struthanthus polystachyus, 270, 273, 277, 279 — venetus, Studies in i fflera Soa Cephaloschefflera Complex, Swamp bay, Sweet bay, 9, 10, 17, — 21252165222 pulcherrimus, 2 —tricolor, 21 Systematic see omy of the Xylem and n the Relationships of Fla- eee nacin Syzygium, 171 The Tachia, 103-125 —sect. Schomburgkiana, 103, 104, 108, 09 —sect. Tachia, 103, 104, — gracilis, 104, 108, 109, pon 123 — grandiflora, 108, 109, 117, 119 — grandifolia, 104, 108-110, 113 —— grandifolia, 113 —— orientalis, 110-113 — guianensis, 104, 108, 109, 113-115, 117 — loretensis, 104, 108, 109, 117 — occidentalis, 104, 108, 109, 115, — parviflora, 103, 104, 108, 109, 123-125 Seay geal, 103, 104, 108, 109, 119 Petre Tachia Satan The Neotropical 103 — villosa, 364, Taraktogenos, = ee 96 Taxodium, Taxonomic Status of the Genus Bauerella henson es, 164 Temperate rth America, Lauraceae ardy in 2 ‘Teteassititik en Tetranthera oitae — S 37, a ss 80, 87, 88, 96 han 71 ar, — macr ie arak Theaceae, 21, 78, 91, 96 Th 96 Tiliaceae, 21, 82, 83, oo 90, 96, 97 —tribe Prockieae, 40, 72, 82, 85-87, 95-97 a 478 Tiliales, 89, 91, 97 Tillandsia, 378, 383-389, 391, 395 —subg. Allardtia, 385 — subg. oapeent ik 387 ouch-me-not fami ly, ironed - 43, ts as 87, 96 — tro Teiphyopbytum, 38, 79, 84, 90, 91 8 u Tytonia, 413, 414 Umbelliferae, 428 Umbbellularia, . 8 — californica, 8, pen als: 9 — —fresnensis, 9 Vandellia, 451, 452 5 Van DER Scuiyjrr, H. P., and NEKE. Development of the Decompound Lea (Araliaceae), 256 Variation in Sane . Pipes (Legu- minosae), Isozyme Vavaea amicorum Vepris simplicifoli, 168, 169 Vernonia, . bei 13 — nigrescens, Versatility in Shor sree mie Pe UsH R Digitately f in Cussonia spicata VIJAYARAGHAV. Kadsura haces a Mileeeua Vitex acuminata, 245 JOURNAL OF THE ARNOLD ARBORETUM [voL. 56 WEaAvER, RicHarp E., Jr., and BASSETT MAGUuIRE. Neotropical Genus Tachia (Gentianaceae), E., Jr., and Liry RU- Notes on West Indian Species of the Asian Section Tittmannia, Lindernia brucei, A New What and Whence Was Miller’s Caryo- phyllus cotinifolius, 171 Whittonia, 89 Wild pine, 385 Winteraceae, 179, 181 Woop, Carrot E., Jr. The Balsamina- ceae in the Southeastern United States, 413 Woop, Carrot E., Jr., and Lyman B SmitH. The Genera of Bromeliaceae in the Southeastern United States, 375 The Woon, C. E., Jr., and S. A. GRAHAM. Podostemaceae in the Southeastern United States, Wood-sorrel, 230 Xanthophyllum . 245 Xanthoxalis, 229, 234, d ae on of Flcourtiacae, Anatomy of the, Xylosma, 38, 41, ee ae 86, 87 — benthamii, 38, 64 e Relation- " gauie — venosum, 39, 64 Xyridaceae, 248 Rig teehee SOS, 333, 369.371 371 Zanthoxylum (Rutaceae) from Guinea, A New Species of, 369 Zosteraceae, 129 Zuelania, 39, 69 — guidonia, 39, 69