IN ue iy ee aN wi Melts AA i ean dats Ce Mh # MUP hey if non 1 one "i vig) cen pis } Me Stake vey hte Alt ie i ANG iat Wb iH, a sete AY Mi Hehe * NOH Denny) eptyuet a Oy Gi Hi 1M why i , iM ie Lata } ) K ata i AMT Ethts a i Aa i ah THSOn, (ORSON JUL 13 1959 LIBRARY # [7 es ei Vou. XIX, PP. 183-192 DECEMBER 8, 1906 are PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON } NOTES ON GENERA OF PANICEAE. I. BY AGNES CHASE. LAA One of the chief distinguishing characters of this tribe of grasses is the single fruit, composed of the more or less indurated lemma and palea, the latter firmly clasped by the margins of the lemma (rarely loose, as in Leptocoryphium and Hymenachne), enclosing the free grain. This simple arrangement is variously modified in the different genera. After several years’ study of the fruits of this tribe the writer proposes to. offer this and sub- sequent papers on the genera with special reference to the fruits, figuring and describing the fruit of the type species of each genus. It may be well to state why the character of the fruit is held to have superior generic value. Itis because: 1. ‘The character of the fruit is constant in the same species. The first glume may be present or obsolete in Paspalum. distichum L., P. Drum- mondii Vasey, P. bifidum (Bertol.) Nash, and ina few others, not only in the same species but in the same specimen, but within are always the same plano-convex, chartaceous-indurated fruits, the lemma with inrolled margins, the palea included at the apex as well as on the margins; Reimaria oligostachya Munro may lack but one instead of both glumes but the fruit remains constant; Echinochloa crus-galli Cu.) Beauv. may have very long awns or be mucronate only, but the fruit will have the charac- teristic abruptly acuminate apex, the palea free at the summit. 2. The fruit with but slight modifications is constant for greater or smaller groups of similar species; that is, taking the fruit as a generic character it assembles species which show other resem- blaneces, and does not arbitrarily assemble those which show no close affinity, as does the character of the presence of the first eum, an Paspalum, which places in Dimoi phostachys, founded on lim monostachyum H. B. K., such diverse species as P. Drummondii Vasey and P. Schaffneri Fourn., when both have 384—Proc. BIoL. Soc. WaAsH., VoL. XIX, 1906. (183) 184 Chase—Ne otes on Genera of Paniceae. I. nearer relatives left in the genus Paspalum. The foregoing does not mean that the fruit is held to be the only generic character but merely that it is a strong one which has not received the attention it deserves; while it is held that any generic character must be constant ina species and assemble species having other affinities. Such a character is the reversed position of the spikelets in Axonopus Beauv. (Anastrophus Schlecht.). The fruits alone would not separate this genus from Paspalum, but not one of the many specimens of the several species examined shows a spikelet placed otherwise than with the back of the fruit turned from the rachis. These studies are based on the material in the National Herba- rium where all the genera of this tribe are represented, most of them by a large series of specimens. The figures* and deserip- tions are drawn from mature or nearly mature fruits; since the spikelets fall at maturity it is difficult to find perfectly ripe fruit in herbarium specimens. The present paper is confined to that group of Paniceae in which the fruits are cartilaginous-indurated (not rigid) papillose, and usually dark colored; lemmas and paleas alike in texture, the lemmas with more or less prominent, white, hyaline margins not inrolled. Kry. Lemma boat-shaped, margin narrow ......... . Anthaenantia Lemma convex only. Palea not inclosed above, lemma hyaline at the summit. Leptocoryphium Palea inclosed, lemma with broad hyaline margin nearly to the base. Fruit lanceolate-acuminate, second glume and sterile lemma clothed with long hairs exceeding the spikelet, grain unequally biconvex .. . : Valota Fruit elliptic ; second glume and sterile lemma aigtied with short hairs or nearly glabrous, grain plano- convex in section. Spikelets disposed in 1-sided racemes which are digitate or racemose .. . 3} Be tees Syntherisma. Spikelets in panicles divergent ae nian Se ae Leptoloma Genus ANTHAENANTIA Beauv. 1812. Agros. 48. t. 10. f. 7 Axis paniculatus: Panicula subsimplex—Glume subaequales, concave, herbaceae.—F osc. INFER. neut.: Paleee membranaceae, oppositx, Paleis * The figures are all magnified 2Q diameters. %, Chase—Notes on Genera of Paniceae. I. 185 hermaphroditis contrarié disposite.—Frosc. supER. hermaph.: Palese sub- cartilagineae.-—Srec. Phalaris villosa Micr. Phatlaris? villosa Michx. 1803. F]. Bor. Am. 1:43. ‘Has. in sylvis sab- ulosis Carolinze.” Just what is meant by the paleae of the neuter floret placed contrariwise to those of the perfect floret it is difficult to decide. The figure shows such an empty floret consisting of a small lemma and palea placed laterally against the palea of the fruit. Kunth (Rev. Gram. 1: 217) reducing the genus to Panicum with the specific name of ignoratum, temarks that “ Beauvois who never soaked the spikelets before examining them nor used a needle to open them” mistook the torn margins of the sterile lemma for a 2-valved floret. dAulaxanthus Ell. 1816. Bot. 8. C. & Ga. 1 : 102. “Flores paniculati. Culyx 2-valvis, 1-floris; valvis sequalibus, sulcatis Yorolla 2-valvis, subaequalis.”’ Two species, A. ciliatus and rufus are described, and “Phalaris villosa? Michx.” is given under the first. Though the generic description says the spikelets are 1-flowered, under ciliatus is stated : ‘at the back of the interior valve occurs a neutral floret, l-valved, ovate, 2-cleft, green.” Aulaxia Nutt. 1818. Gen. 1: 47. Description is nearly identical with that of Elliott, “1-flowered, with the rudi- ment of a second” added; Aulaxanthus is given as synonym; no reason is assigned for changing the name. These three generic names are founded on the same species. Description.—Spikelets in narrow panicles, obovoid, first glume obsolete, second glume and sterile lemma subequal,very broad, with 5 strong nerves, the very thin internerves deeply folded and densely clothed with long hairs, the sterile lemma enclosing a small palea and sometimes a staminate flower; fruit as long as the glume, plano-convex, subacute, chestnut brown, the lemma _ boat-shaped, the 3 nerves visible; the white or pale margins very narrow; palea en- folded its entire length, the2 nerves visible ; grain in section plano-convex. eo Genus LEPTOCORYPHIUM Negs. 1829. Acros. Bras. 83. Calyx uniglumis, biflorus, gluma inferiore, deficiente. Flosculus inferior - neuter, uniglumis * * * Flosculus superior hermaphoditus, calycis longitudine, in fructu persistens chartaceus (nec induratus), valvulis atten- uatis apice membranaceo-hyalinis lacero-ciliatis. [Whence the name from “ Nerrés tenuis et Kopyph apex.” | The first species under this genusis LD. lanatum (H.B. K.) Nees, based on Paspalum lanatum H.B.K. 1815. Gen. Pl. et Sp. 1:94. t. 29. ‘‘ Crescit in regno Mexicano prope Venta del Cameron et Alto del Peregrino.” Roemer & Schultes (1817. Syst. Veg. 2 : 322) transfer this species to Milium, in which disposition of it they are followed by Kunth (1829. Rey. 186 Chase—WNotes on Genera of Paniceae. I. Gram. 497), and Trinius (1834. Mem. Acad. St. Petersb. VI. 3? : 121). Bentham (1881. Journ. Linn. Soc. Bot. 19 : 39) transfers it to Anthaenantia stating: “ From these [N. Am. Anthaenantia] I can not separate generically the South American Leptocoryphiun. Nees, which be- sides some slight specific characters only differs from the North American species in the second glume being constantly, instead of occasionally only, empty.” Hems- ley (1885. Biol. Cent. Am. Bot. 3 :483) follows Bentham ; Fournier (1881. Mex. Pl. 2:13) upholds Leptocoryphium, Description.—Spikelets in narrow panicles, lanceolate; first glume obsolete; second glume and sterile lemma 3 and 5 nerved, the internerves, which are not broad and infolded (or plaited) as in Anthaenantia, each with a row of long coarse hairs arising from tubercles (the tubercles sometimes obscure), the second glume shorter than the sterile lemma which equals the fruit and which is empty; fertile lemma slightly cartilaginous- indurated, minutely papillose (the papillae finer than in any of the other genera), chestnut with a white, delicately hyaline, summit, lacerate and often sparingly ciliate, a narrow hyaline margin extending down the sides to about the middle; on the back near the base isa small impressed area thin and white; palea with summit and margins like those of the lemma, not enclosed above, the 2 nerves obscurely visible ; grain oblong-elliptic, in section plano-convex. As shown by the fruit this seems to be,as Nees considered it, most nearly allied to Vulota (Trichachne Nees) from which he separated it chiefly on the absence of the first glume. The inflorescence is like that of Anthae- nantia, which it resembles also in lacking the first glume, but differs from in lacking the neuter palea or staminate flower and in the convex, not boat-shaped, lemma with a broad hyaline summit. It differs from both Valota and Anthaenantia in the fruit open at maturity. (A large number of specimens were examined and none in or past bloom were found closed.) Since this species fits so poorly in any other genus it seems wisest to main- tain the one Nees established for it. Nees’ single other species of Lepto- coryphium we have not seen. 2 Tprehachrne Vee Fs (Gexvs VALOTA Anpans. 1763. Fam. Pt. 2°: 498. Gramen. Avenae. Sloan. t. 14. f. 2. Couronne de la gaine des feuilles ; Membrane médiocre. Fleurs: Panicule étagée. Calice: Ovoide, sans arétes, 4 3 bales velues. Corolle: Sans arétes. The reference to Sloane serves to identify the genus, which the very in- sufficient description would not do, and fixes its identity with Andropogon insulare L. Andropogon insulare L. 1759. Pugill. Jam. 30; and Sp. Pl. Ed. 2. 1763. 2:1480. In the Pugillus no citation is given; in the Species Plantarum aaa LEG TS Chase—Notes on Genera of Paniceae. I. 187 the previous publication by Linnaeus is cited, and also Brown Jam. 365, and Sloane, 1: 43. t. 14. f. 2. ‘Hab. in Jamaica.” Brown (l.c.) after his polynomial cites Sloane t. 14. Sloane’s figure (1. ¢.) is an excellent representation of the upper portion of the plant, a leaf and overmature panicle. Panicum lanatum Rottb. 1776. Descr. Pl. 3. Based on Andropogon insu- lare L.; the same reference to Sloane is also given. Here follows the first adequate description of the species, even the fruit being described : “ Corol- le valve 2 lanceolate, concave, acutissimee, membranacee.” Milium villosum Sw. 1788. Prod. 24. Based on Andropogon insulare L. Beauvois 1812. Agros. 150, in the index refers Andropogon insularis to Monachne, but this species is not mentioned under that genus on p. 49. Panicum leucophoeum H. B. K. 1815. Nov. Gen. et Sp. 1:97. Based on Andropogon insulare L. This species and P. adscendens H. B. K., which is Syntherisma sanguinalis or a close ally, are placed together under “3) Spicis verticillatis, fasciculatis aut paniculatis (Digitarize plurimee).” Panicum insulare Meyer. 1818. Prim. Fl. Esseq. 60. Based on Andropogon insulare L. The “valves of the corolla” are given as coriaceous with mem- branaceous margins. Acicarpa Raddi. 1823. Agros. Bras. 31. with one species A. sacchariflora Raddi |. c. t. 1. f.4. This is given on the authority of Nees. We have not seen the original publication. Trichachne Nees. 1829. Agros. Bras. 85. (a Opté capillus et dxvn gluma.) Calyx bivalvis, subbiflorus, gluma inferiore minuta. Flosculus inferior univalvis vel bivalvis hirsutus, neuter; superior hermaphroditus, valvulis membranaceis mucronatis Caryopsis flosculi valvulis membranaceis vestita * * * Tnflorescentia : racemi elongati, simplices, unilaterales, verticil- -latim paniculati. Spiculae geminae ternaeve, altera brevius pedicellata. *« * * Flosculus hermaphroditus * * * bivalvis, glaber, mem- branaceus, valvulis lanceolatis in mucronum subulatum attenuatis ad fructum persistentibus membranaceo-chartaceis caryopsin tegentibus neque cum eadem induratis. * * * Differt a Panico praesertim gluma flosculi hermaphroditi, * * * at minime crustaceo seu cartilagineo indurato sed semper flexili. . Acicarpa Raddi 1823. Agros. Bras. 31. t. 1. f. 4. is cited as synonym and a note of explanation added that the name is expunged because of its similarity to Acicarpha Juss. [1803]. Nees’ first species is Trichachne insu- laris (L.) Nees, based on Andropogon insulare L. Five other species are included, T. sacchariflora (Raddi) Nees, and four new species from Brazil, T. recalva, tenwis, velutina, and ferruginea, the last two of which Nees says he saw in the Royal herbarium at Berlin.. Grisebach (1864. Fl. Br. W. 1.557) places Panicum insulare and P. sac- charatum Buckl. in Tricholaena; Stapf (1898, in Fl. Cap. 7 : 382) transfers ** Panicum leucophaea Sw.” to Digitaria, remarking, “the structure of the spikelets is * * * as in Digitaria.’ Stapf probably means P. leuco- phoeum H.B. K., which is atyponym of A. insulare L. Swartz did not pub- lish the name given by Stapf. Millspaugh and Chase (1903, Fl. Yucatan, Tomiiessnn. drchronnin git Sod, 188 Chase—WNotes on Genera of Paniceae. I. Field Col. Mus. Bot. 3 : 23) transfer T. insularis to Syntherisma, remarking : “ That this species belongs in the genus Syntherisma rather than in Panicum is shown chiefly by the fruiting glumes which are of the form characteristic of the former, having a floral glume with hyaline margins not inrolled.” Description.—Spikelets in pairs, short-pediceled in 2 rows along one side of a narrow rachis, the slender racemes erect or nearly so, solitary or fascicled along a common axis forming a narrow panicle; spikelets lanceolate, first glume minute, glabrous, the second and sterile lemma us- ually as long as the fruit or longer, 3-5 nerved, copiously . clothed with long silky hairs (in one species, only, the silky hairs are not longand dense) ; fruit lanceolate, usual- ly brown, the flat, white, hyaline margins broad; grain ellipsoid, in section unequally biconyex. This genus is very closely allied to Syntherisma Walt. One species, Panicum Pittieri Hack., has the inflorescence of Valota, but the hairs on the second glume and sterile lemma are not long and copious, and the second glume is shorter than the fertile lemma as in some Syntherismas. But considering the diverse aspect of the two genera as a whole it seems wisest to regard them as distinct. The following species are transferred fo this genus: : Valota insularis (L.) = ey OOS Pe oS We Andropogon insulare L. 1859. Pugill. Jam,330. , Valota saccharatuss- (Buckl.) Ake ‘pect arta leee Nark =] calf Panicum lachnanthum Torr. 1856. Pac. Rail. Rep. 7? : 21, not Hehe 1855. ij Panicum saccharatum Buckl. 1866. Prel. Rep. Geol. & Agr. Sury. Tex. App. 2. “ Middle Texas.” Trichachne saccharatum (Buckl.) Nash. 1903 in Small Fl. So. U.S. 83. Valota Pittieri (Hack.)< Trchachae fattisa(hed Panicum Pittieri Hack. 1901. Oest. Bot. Zeitst. 51 : 367. ~ “ Costariea: in ripa rivi Rio Tirili prope San José leg. Tonduz: Pittier distribuitsub nro. 6945.” _ The species represented in American herbaria by Nealley’s Texas collec- tions and passing under the name Panicum tenerrimum Kunth, (based on Trichachne tenuis Nees) does not well agree with Nees’ description. Since Yor authentic specimens of this and Nees’ other Brazilian species have not yet \. : been seen, his species and the Texas form are left for future study ; and to avoid the possibility of making unnecessary combinations by taking up possible synonyms these species and an Australian one with stramineous fruits are not here transferred to this genus. = ye) Grexus SYNTHERISMA Waur. 1788. Fu. Carot. 76. He Digitaria Haller 1768. Stirp. Helv. 2: 244 not Adans. 1763, nor Heist. 1759, though Haller gives Heister and Adanson as authors of his Digitaria; but his description, though he evidently makes an effort to harmonize it. Chase—Notes on Genera of Paniceae. TI. 189 with those of Heister and Adanson by emphasizing the “ excavations ” of the rachis, applies not to Tripsacum but to the grasses so long known as Digitaria, and his pre-Linnaean references lead to P. sanguinale L. Antiquum nomen, «& characteristicum, reddo plantis nostris, quee adeo -vehementer a Linnamnis Panicis abludunt, ut nullo modo eo referri possint. Receptaculum Tritici, alternis scrobibus excavatum. Ad eas scrobes appli- eantur flosculi petiolati. Calyx biglumis, lineatus, altera gluma parva, ‘mucronata, altera majori faciei floris respondente, lineata: ita mucronata, compressa, ovato lanceolata uniflora, locusta oritur. Flos durus, nitens, siccus, convexus inde, hine complanatus, & linea quasi divisus, non tamen penetrante. Nonquam satis potui distinguere divisionem in duas glumas. In cavea certe undique clausa semen sedet, compressum, planum. Under his first species, to which Haller, who evidently opposed such an innovation as a binomial system, applies a polynomial, “ Linn. p. 84” is cited, with Linnaeus’ description of P. sanguinale used as a polynomial, the name sanguinale being omitted. The reference is to the 1762 edition of Species Plantarum. For discussion of Digitaria Heister see Hitchcock, Bot. ‘Gaz. 38 : 298, and Nash, Bul. Torr. Bot. Club 25 : 289. Panicum sanguinale L. 1753. Sp. Pl. 57. “ Spicis aggregatis, basi interiore nodosis, flosculis geminis muticis, vaginis folioram punctatis. * * * Habitat in America, Europe australi.” The specimen under this name in the Linnaean herbarium is the tradi- tional P. sanguinale fide’ Prof. A. S. Hitchcock who has seen it. The first reference after the description is to Royen FI. Leyden 55, where, after the polynomial quoted by Linnaeus, Sloan. Hist. 1 : 113, t. 70, f. 3 iscited. The second reference is to Gron. Virg. 154 [error for 134]. Gronovius refers to Clayton n. 457. Linnaeus’ reference (Sp. Pl. 57) to Sloane 1: 113 t. 70 f.2 is evidently an error. The polynomial and figure cited in Royen applies to P. sanguinale. Syntherisma Walt. 1788. Fl]. Carol. 76. Cal. 1-florus, 2-valvis: valvulis planis, acutis interiore minore recta, exteriore lateribus corollam subamplexante. Cor. 2-valvis: valvulis mag- “nitudine et figura valvulae majori calycis simillimis. * * * Semen unicum, calyce corollaque persistentibus vestitum. The first species is S. precox Walt. “No specimen in [ Walter’s] her- barium. There is not much doubt but this refers to Panicum sanguinale L, (Digilaria sanguinalis), as stated by Elliott and Michaux.” Hitchcock, Six- teenth Ann. Rept. Mo. Bot. Gard. 44. _ Michaux (1803. Fl. Bor. Am. 1: 45) includes Syntherisma praecox Walt. as synonym under Digitaria sanguinalis Scop. - This group has been held to be a genus or reduced to a section of Pani- cum according, seemingly, to the weight given its form of inflorescence. Nees, while noting the less indurated and “always pliable” lemma of _ Trichachne, does not seem to have noted that the same is true of the group he placed as section Digitariae of Panicum, nor that the differences from Panicum which he points out for Trichachne do not separate that genus from his section Digitariae. The form of inflorescence does not clearly distinguish ‘this genus from Panicum, since the species known as Punicum Perrotteti ’ 190 Chase—WNotes on Genera of Paniceae. I. Kunth (Paspalum Perrotteti Hook f.) and its close allies have sparingly branched racemes more or less naked at the base forming a panicle not greatly unlike that of Panicum proliferum and yet are true Syntherismas as shown by the spikelets and especially by the cartilaginous-papillose lemma with flat, hyaline margins. Hooker f. (1896 Fl. Br. Ind. 7:10) places these and other species of Section Digitaria in Paspalum, saying ‘‘ As above defined, Paspalum includes the Digitaria section of Panicum, which appears to me to be artificially placed in the latter genus, because of the occasional presence of a very minute scale-like glume at the base of what is the 3rd gl.of Panicum (that opposite the flg.). This minute glume which is present or absent even in the same species, is nerveless and never embraces that above it, as the lowest glume always does* in Panicum proper.” The first glume is not only present or absent in the same species in Syntherisma, but sometimes in the same specimens, asin those of P. Perrottetiin the National Herbarium. Nash (Bul. Torr. Bot. Club 25 : 289) while contending that ; Syntherisma is as worthy of generic rank as are Paspalum, Anthaenantia, Eviochloa, Isachne, Ichnanthus, and Tricho- laena fails to point out why it is so, and adds: ‘Our own view is that Syntherisma is more nearly related to Paspalum than to Punicum, and if its union with either genus were desirable it would certainly be with the former and not with the latter.” If the cartilaginous-papillose lemma with flat hyaline margins be taken for the chief generic char- acter, Syntherisma is at once clearly distinguished from both Panicum and Paspalum, with no intermediate species. Description.—Spikelets solitary or in 2’s or 3’s, subsessile or short-pediceled, alternate in 2 rows on one side of a 3-angled winged or wingless rachis, the slender racemes usually more or less spreading, usually digitate or in ap- Kuh proximate fascicles at the summit of the culm, rarely dis- tributed along the axis; spikelets lanceolate or elliptic ; first glume minute or wanting, the second glume equalling the sterile lemma or shorter, fruit lanceolate or elliptic, the flat, hyaline margins white or pale; grain sub- elliptic, in section plano-convex or slightly concavo-convex. The affinities of Syntherisma are with Valola on the one hand and An- thaenantia on the other. ‘To the former it is allied through V. Pittieri and the species mentioned above as “ Panicum tenerrimum” from Texas. Syn- therisma approaches Anthaenantia through Panicum (% Digitaria) adustum Nees and Anthaenantia Hackeli Avech. allied species, and Panicum badium Scribn. & Merr., which are placed in Syntherisma rather than in Anthae- nantia on the following characters: Spikelets in pairs in 2 rows along one side of a triangular rachis ; a minute first glume present (though this has little weight) ; second glume not equalling the sterile lemma (which is empty or contains only a nerveless rudiment of a palea), neither of them broad with deeply folded internerves as in Anthaenantia; lemma not boat-shaped, the hyaline margins broad. In addition to the species con- * Hooker was probably not acquainted with the Dichotomous Panicums in which he first glume is often nerveless and seldom embraces the second, | Chase— Notes on Genera of Paniceae. I. Sih Finlered by Nash (1. ¢.) in his treatment of the genus the tollowing are here transferred : @ Syntherisma adusta Acoso ras , Panicum adustum Nees. 1829. Agros. Bras. 101. “ Habitat in Brasilia meridionali. (Sellow.)” Syntherisma badia (Scribn. & Merr.) 4B Fowl Panicum (Syntherisma) badium Scribn. & Merr. 1901. U.S. Dept. Agr. Div- Aeros. Bul. 24:12. “Sierra de San Felipe, State of Oaxaca” 915 s) ie @. by Smith: w& /, trig (Troan Pe he fore aaa (ireh Syntherisma Hackeli (Arech.) Hen. Ie Anthaenantia Hackeli Arech. 1894. Anal. Mus. Nac. Montevideo 2 : 96, t. Wy | 6. Figueira, Uruguay. . ves ZL f . Syntherisma velutina (DC.) Biakutivra ( ) H 5 Milium velutinum DC. 1813. Cat. Hort. Monsp. 126. “ Hab. in Mexico.” Paspalum ? velutinum Kth. 1829. Rev. Gram. 1:27. see Wig fo Wieth Cami Represented by Pringle 6623 and 9565. \S bags e SX Syntherisma Perrotteti (IKth.) & brypptet yy ay Panicum Perrotteti Kth. 1829. Rev. Gram 5.t. 8. “Crescit in Sene- galia, prope Walo.” Syntherisma stenotaphro\des (Nees) &. gtaelaphrvde (hee) tt] Panicum (% Digitaria) stenotaphroides Nees 1854 in Steud. Syn. Pl. Glum. 1:41. “Ins. Choin legit Cuming.” This and an allied species are peculiar in having a thickened rachis, the solitary spikelets sunken in the alternate notches. ' Species as yet imperfectly understood are not here transferred. Genus LEPTOLOMA Gen. Nov. _Inflorescentia paniculata, panicula pauciflora, maturitate diffusa; spiculae 1-florae, fusiformae, solitariae, aut raro per paria, in pedicellis tenuibus triangularibus ; gluma prima minuta aut deficiens, secunda 3-nervis ; lem- ma neutrum 5-7 nerve; fructus ellipticus, acutus ; lemma hermaphroditum eartilagineo-induratum, papillosum, marginibus delicatus hyalinas, planis; palea similis; caryopsis oblongo-elliptica lemmate paleaque inclusa, libera. Gramina perennia, caespitosa, ramosa, culmis fragilibus, laminis planis, ligulis membranaceis. Maturitate paniculae se dissipant et pervolvunt Panico capillari similes. Nomen ab Xerrés delicatus et Nua margo. nN Inflorescence a few-flowered panicle diffuse at maturity . spikelets 1-flowered, fusiform, solitary or rarely in 2’s on slen- der triangular pedicels; first glume minute or obsolete, the second 3-nerved, nearly as long as the 5-7 nerved sterile lemma, a more or less prominent stripe of appressed silky hairs down the internodes and margins of each ; sterile lemma empty or enclosing a minute nerveless rudimentary palae ; fruit elliptic, acute, brown; fertile lemma cartilaginous-indu- rated papillose, with delicate hyaline flat margins, enclosing a palea of the same texture: styles long and delicate, stigmas plumose, the branches more long and slender than in Panicum, rather less so than in Syntherisma; grain oblong-elliptic, in section plano-convex ; free within the closed lemma and palea. Tufted branching perennials with brittle culms, flat blades, 92 Chase—Notes on Genera of Paniceae. I. és and membranaceous ligules. At maturity the panicles break away and roll like tumble-weeds. Name from derrés delicate and \éua border in refer- ence to the hyaline margins of the fertile lemma. Type.— Panicum cogyatum Schultes. Leptoloma cognata (Schultes.) Panicum divergens Muhl. in Ell. 1816. Sk. Bot. 1: 130. not H. B. K. 1815. Specimen in Elliott herbarium in College of Charleston. Elliott gives “ Muhl. Cat.” without page as authority for this name; in Muhl. Cat. 9 (1813) divergens is a nomen nudum. Panicum divergens Muhl. 1817. Gram. 120. “ Habitat in Carolina.” Specimen in the Muhlenberg herbarium in Philadelphia Academy of Nat- ural Sciences, marked “ Elliott 353.” In the same folio with this is a specimen of Panicum Philadelphicum marked “ M. 112b.” Panicum cognatum Schultes 1824. Mant. 2: 235. Muhlenberg’s descrip- tion is copied and P. divergens Muhl. is cited as synonym, the name changed, doubtless, because of P. divergens H. B. K., though this older use of the name is not mentioned. Thus it is the second publication of P. divergens Muhl. (that in Muhl, Gram.) on which Schultes bases his P. cog- natum. Hence the specimen in Muhlenberg’s herbarium is the type. Panicum autumnale Bose. Spreng. 1825. Syst. 1 : 320. This name as used by American authors is synonymous with above, but we have not seen Bose’s specimen. Sprengel (1. c.) places the description of P. autumnale next to that of P. divergens Muhl. The brief description would apply to any Panicum with an effuse capillary panicle. It was not known to Sprengel where the specimen came from ; “ Patria?” he adds to his description, and indicates he saw the specimen in the Willdenow her- barium. The sheaths and blades of this species, especially the lower ones, are often papillose pubescent, commonly soin Western specimens, though the type is almost glabrous. Pringle 489, Chihuahua, Mexico, represents an extreme form with slightly larger spikelets, having densely silk y-pubescent internerves, which would appear to be a distinct species except for the fact that the inter-grades are more numerous than the extreme form. This is the only species of this genus known in thenorthern hemisphere. Three or four species are found in Australia. Leptoloma divaricatissinia (R. Br.) Panicum divaricatissimum R. Br. 1810. Prod. 192. Port Jackson, New Holland. : Leptoloma macratenium (Benth.) Panicum macratenium Benth. 1878. Fl. Australia 7: 468. ‘“ Queensland, Rockhampton, O’Shanesy.” . Leptoloma coenicola (F. Muell.) Panicum coenicolum F, Muell. 1855 in Trans. Vict. Inst. 45. Cudnaka, S. Australia, #. Mueller. Panicum papposum R. Br, Prod. 192, and P. nematostachyum Bailey 1903 in Bot. Bul. Dept. Agr. Queensl. 16 : 2, of which we have not seen speci- mens, probably belong here. The former is P. autumnale F. Muell. Fragm. 8 : 196, not Bose, fide Bentham FI. Australia 7 : 469. VoL. XXI, pp. 1-10 JANUARY 23, 1908 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON NOTES ON GENERA OF PANICEAE. II.* BY AGNES CHASE. The two genera, Hymenachne and Sacciolepis, discussed in the present paper, while not very closely related, have been con- fused because of the similarity in the form of the inflorescence of most of the species in each, a spike-like panicle. Genus HYMENACHNE Beauv. 1812, Agros. 48. t. 10. f. 8. ‘‘Axis paniculatus: Panicula simplex, spiceformis: Rami conferti.— Glumee inzequales, herbaceze, acutee: infer. multo brevior. FLosc. INFER neut.: Palea infer. acuta: super. brevissima, membranacea, hyalina.— Frosc. super. hermaphroditus: Palex herbacex membranacex acute. * * * Spec. Agrostis myuros Lam. monostachya Porr.’’ The illustration represents the second species mentioned by Beauvois, Agrostis.monostachya Poir., which according to the American Code, t should therefore be taken as the type of the genus, although Beauvois gives the ; name Hymenachne myuros in the explanation of plate 10, showing that he misunderstood Lamarck’s species. Agrostis monostachya Poir. 1810, Eneye. Suppl. 1: 256. ‘‘ Cette plante a été recueillie & Porto-Ricco, par M. Riedle. (V. s. in herb. Desfont.)’’ The type labeled in Poiret’s hand, ‘‘Agrostis mo- nostachya Poir. enc. sup. Reidel Porto-Ricco,’’ was examined by Professor A.S. Hitchcock# in the Des- fontaine herbarium at Florence. The accompany- ing figure is drawn from this specimen. Panicum myuros Lam. (incorrectly given as Agros- Fig. 1. tis myuros Lam.) cited by Beauvois under Hy- Hymenachne amplexi- menachne is not the same species as Agrostis mono- caulis: stachya Poir., as most subsequent authors seemed tothink. The type of this was seen in Lamarck’s herbarium in Paris, *Notes on Paniceae I, with general discussion of the importance of the fruit asa generic character in this tribe appeared in Proc. Biol. Soc. Wash., 19: 183-192. Dec. 1906, + Canon 15, b. 5 t All the type specimens definitely mentioned as found in the different European herbaria were examined by Professor A. S. Hitchcock in the spring of 1907. 1—Proc. BIOL, Soc. WASH., VOL. X XI, 1908, (1) 2 Chase—Notes on Genera of Panicex. II. and was found to be a congener of Sacciolepis striata (L.) Nash., Pan- icum indicum, and allied species. Beauvois emphasizes the simple spike-like panicle, and also the real distinguishing character of the genus, the membranaceous lemma and palea, to which latter character the name refers, ‘‘ De 0#qv’’ Membrana,; ‘< dyn Palea.’’? But, probably because he did not know Lamarck’s species, Beauvois included in Hymenachne P. myuros which does not have a mem- branaceous lemma and palea. Subsequent authors have placed in the genus or section Hymenachne various Panicum allies having a spike-like panicle, but often without other similarity. It is not evident whether Beauvois considered the two species he cites synonymous or not. In the index only Hymenachne myuros is given; A. monostachya is not formally transferred and is not mentioned in the index. Roemer & Schultes (1817, Syst. 2: 25) maintain this and others of Beau- vois’ new genera without comment. Trinius (1820, Fund. Agros. 176) upholds Hymenachne as a genus with one species, myurus, though Digitaria, Monachne and other genera are included in Panicum. Trinius adds the note: ‘‘ Obs. Panicis maxime affinis. An hujus generis (forte tune emendandi) Andropogon insu- laris L.?’’ which seems to indicate that he gave greater weight to the membranaceous fruit than to the spike-like panicle. This is assuming that Trinius supposed H. myurus and A. monostachya to be synonyms. Later (1826. Gram. Pan. 51) Trinius places Hymenachne together with Trichachne, Setaria, Pennisetum and other genera in Panicum under the following synoptical division ‘‘e) Thyrsus (simplex vel compositus), aut Racemi compositi longe plerumque sparsi et jubati. Spiculee oblongee 1. lanceolatze, pl. min. ineequaliter disposite. Gluma inferior manifesta (Jubaria).*)’’ [‘‘*Species quarum radii, quantumyis racemos mentientes, radiolos, distinctos emittunt, ad sectionem sequentem Miliariam referun- tur.’’?] This gives a wholly artificial grouping based solely on the narrow panicle and includes Chetochloas, various true Panicums and _ allies. Jubaria (1. ¢. p. 159-183) is subdivided into four groups, the third of which, ‘‘* * * Thyrsi pl. min. compositi spiculee basi nudee (absque in- volucello)’’ includes Panicum indicum L., P. vilvoides Trin., P. gibbum Ell. (which belong in Sacciolepis), and P. amplexicaule Rudge (true Hy- menachne) under which Hymenachne myuros Beauy. and Panicum myu- ros Kunth ‘‘ (nec Lam.)’’ are given as synonyms. Trinius observes ‘*Lamarckii gramen, cui ‘folia angusta, convoluta’ certe hue non per- tinet.’’ But Panicum myuros Lam. and P. ample:ricaule-continued to be considered synonymous by other authors. Under his fourth division of Jubaria Trinius includes Panicum palustre Trin. (a true Hymenachne having a racemose panicle) between Panicum leucopheum Kunth (which is Valota) and P. plicatum Lam., which belongs in section Ptycophyllum of Panicum. These details are given only to show that the cause of con- fusion was the form of the inflorescence. Nees (1829, Agros. Bras. 273) recognizes Hymenachne as a genus, but like Trinius groups with it the allies of Panicum gibbum Ell., though he places the following observation after them: ‘‘ Hac in specie ac in preece- Chase— Notes on Genera of Panicee. TIT. 3 dente [H. fluviatilis, which is the sameas Panicum vilvoides and H.cam- pestris| flosculus hermaphroditus glumis et neutro flosculo brevior est multo, non vero herbaceus ut in H. mywro, sed subcartilagineus.’’? Pani- cum paludicola Nees, a Hymenachne, and P. striatum Lam., a Sacciolepis, are given among true Panicums. Desvaux (1831, Opus. 82) transfers Agrostis monostachya Poir. to Pani- cum, changing the name to P. Hymenachne Desy. He observes that this plant had been confounded with Agrostis [Panicum] myuros, which was very different. Kunth (1833, Enum. Pl. 1: 86) under division 5 includes a miscella- neous group of Sacciolepis, Hymenachne, Eriochloa and other allies, as well as several species of Panicum itself. Trinius (1883, Pan. Gen. 165) includes about the same group under his section Virgaria of Panicum. Nees (1841, Fl. Afr. Aust. 50.) makes a section Curviflora of Panicum for two species of Sacciolepis. Steudel (1854, Syn. Pl..Glum. 2: 101) includes in the genus Hymen- achne four names referable to Sacciolepis, and two (which are, however, synonyms) to Hymenachne; a seventh species, which is probably a Saccio- lepis, he includes with the mark of doubt. Grisebach (1864, Fl. W. 1.553) includes in the genus Hymenachne one species which belongs there and two which belong to Sacciolepis. Doell (1877, Mart. Fl. Bras. 2’: 231) in the first part of the section Miliaria of Panicum gives seven species, five of which are referable to Sacciolepis, one to Hymenachne, and one probably to Steinchisma. Pani- cum auriculatum, a Hymenachne with ascending, not oppressed, panicle branches, is placed in the second part of the section in which most of the species are true Panicuwms. It is worthy of note that Doell uses the name Panicum myuros Lam. for the species to which the type really belongs, stating that he saw the specimen in the Paris Museum. Under Panicum amplexicaule Rudge, he straightens out the hitherto confused synonomy of this species. Bentham (1878, Flora Australiensis 7: 465) makes a section Myuroidex of Panicum under which he places three species, two of which belong in Sacciolepis and one in Hymenachne. Fournier (1881, Mex. Pl. 2: 36) includes eight species in the genus Hy- menachne, two of which are referable to Sacciolepis, three to Hymenachne, and two to Panicum. The remaining species, 7. Gowini Fourn., unknown to us, is probably a Hymenachne. Hackel (1887, Engler & Prantl. Pfl. Fam. 2?: 35) recognizes Hymen- achne as a section of Panicum with spike-like panicles and slightly indu- rated glumes. No species are mentioned. Hooker (1896, Fl. Brit. Ind. 39) places seven species under Hymenachne as a section of Panicum, three of which are referable to Hymenachne and four to Sacciolepis. Stapf (1898, Flora Capensis 386) makes a section Vilfoidex for three species referable to Sacciolepis. Description.—Spikelets short-pediceled, crowded in slender racemes 4 Chase—Notes on Genera of -Panicee. IT. which are erect, forming a dense spike-like panicle, or narrowly ascend- ing; spikelets lanceolate, acuminate; first glume 44 to 44 as long as the spikelet, remote, a distinct stipe below the second glume; sterile lemma 5-nerved, acuminate, exceeding the lanceolate stramineous fruit; lemma and palea membranaceous, margins of the lemma thin (not broad and hyaline), not enrolled; palea not inclosed above; grain oblong, at ma- turity readily falling from the open lemma and palea. Perennial aquatic or semi-aquatic grasses, decumbent at base and rooting at the lower nodes, with rather stout simple stems and long lanceolate blades cordate-clasping at base, except in Hymenachne montana. Species seven or eight, con- fined to the tropics and subtropies. *Panicles elongated, spike-like. HYMENACHNE AMPLEXICAULIS (Rudge) Nees 1829, Agrost. Bras. 276, - based on the next. Panicum amplexicaule Rudge 1805, Pl. Guian, 1: 21. t. 27. Type ‘‘ex herb. Rudge’’ in the British Museum. Agrostis monostachya Poir. 1810, Encye. Suppl. 1: 256. (See note above on type. ) Panicum Hymenachne Desy. 1831, Opus. 82. Based on Agrostis mono- stachya Poir. Panicum myuros of authors not Lam. In the tropics and subtropics of western hemisphere. HyYMENACHNE PATULA Fourn. 1881, Mex. Pl. Gram. 37. ‘‘ Bejucal in insula Cuba (Liebm. n. 402. )’’ A specimen of this number from Fournier is in the herbarium of the 3otanical Garden at Copenhagen. The panicle is less dense than in the preceding. Known only from Cuba. HyYMENACHNE PSEUDO-INTERRUPTA C. Muell. 1861, Bot. Zeit. 19 : 333. ‘‘Tndia orientalis, Bengalia et Malacca. Griffith.’’ Specimens in the National Herbarium from India, Malacca and Java answer to Mueller’s description. They differ from H. amplexicaulis in having blades narrowly cordate at base, long-attenuate or involute above; and in the longer spikelets with longer-pointed glumes. Nees’ descrip- tion of P. auritum Presl (ex Nees 1829, Fl. Bras. 2: 176) seems to apply to this species, but we have not seen the type of either. HYMENACHNE MONTANA Griseb. 1879, in Goett. Abh. 24: 307. “© [‘*C = Proy. Cordoba und Santiago del Estero.” 1. ce. 4.] 8. Achala.”’ The type is in Grisebach’s herbarium at Géttingen, labeled ‘‘Achala, Hieronymus 640.”’ An anomalous species, bearing about the same relation to the typical species that Panicum Chapmanii Vas. and related forms bear to Eupani- cum.