130 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



DESCRIPTION. 



Plants perennial; culms widely creeping and branching, the flowering culms usually 

 erect from an ascending base, as much as 70 cm. tall but usually about 30 cm. , glabrous 

 or somewhat pubescent; sheaths glabrous or densely papillose-hispid; ligule mem- 

 branous, about 0.5 mm. long, short-ciliate; blades lanceo- 

 late or oblong-lanceolate, mostly 5 to 10 cm. long, 1 to 

 2 cm.^wide, rather abruptly narrowed above into an 

 acuminate apex, glabrous or pubescent, papillose-cilia te 

 at base; panicle long-exserted, 5 to 10 cm. long, the main 

 axis pubescent, or the lower part nearly glabrous, the 

 lowest internode commonly about 2 cm. long; racemes 

 mostly 3 to 7, ascending or spreading, rather distant, 

 compact or sometimes rather loose, the lowermost 1 to 2 

 cm. long, the rachis pubescent and also papillose-hispid; 

 spikelets in pairs, the pairs alternating on two sides of 

 the triangular rachis, appressed-villous or hispid or 

 nearly glabrous, green or, especially the awns, purple; 

 glumes^nearly equal, a little more than half as long as 

 the sterile lemma, more or less notched at apex or taper- 

 ing into the rather stout smooth awn, the first 5-nerved, 

 with an awn 5 to 10 mm. long, the second 7-nerved, 

 the'awn once or twice as long as the glume, sometimes 

 shorter; the sterile lemma 2.5 to 3 mm. long, 7-nerved, 

 usually notched at apex, the awn mostly 1 to 2 mm. 

 long, sometimes wanting; fruit 2 to 2.5 mm. long. 



There are two forms of this species, one with glabrous 



sheaths[and one with hispid sheaths, which appear, when 



growing,|rather distinct. The forms differ in no other 



way, however, and are found growing together under the 



same conditions, but all the shoots originating from a given plant are of one form. 



A form of Oplismenus with variegated foliage, found in the West Indies, appears 



to belong to 0. compositus (L.) Beauv., an allied Asiatic species (Guadeloupe, Duss 



3155; Dominica, Jones 37; Martinique, Duss 1325; Grenada, Hitchcock 17674). 



Fig. 23. — Oplismenus hirtellus. 

 From Amer. Gr. Nat. Herb. 602, 

 Trinidad. 



DISTRIBUTION. 



Moist woods and shady banks, southern Mexico and throughout the West Indies to 

 South America. 



Michoacan: Morelia, Arsene in 1909. 



Veracruz: Minatitlan, Smith 575. Sanborn, Orcutt 3067. Jalapa, Hitchcock 6636, 

 6637, 6681. Orizaba, Botteri 724; Purpus in 1903; Smith 578. Colipa, Liebmann 

 363, 364. Mirador, Nelson 109. Cordoba, Amer. Gr. Nat. Herb. 422; Karwinsky 

 965. San Sebastian, Liebmann-^11. Jicaltepec, Liebmann 366. 



Morelos: Cuernavaca, Pringle 6203' Amer. Gr. Nat. Herb. 423; Bourgeau 1302. 



Tabasco: San Juan Bautista, Rovirosa 67, 83. 



Mexico (Republic of): Without locality, Liebmann 366, 367. 



Guatemala: Laguna de Ayarza, Heyde & LuxS922. Secanquim, Maxon & Hay 3154. 

 Guatemala City, Hitchcock 9054. Sepacuite, Cook & Griggs 225. Trece Aguas, 

 Goll96. Coban, Tilrckheim 438. Cubilquitz, Tiirckheim 8802. 



Salvador: Volcan San Salvador, Hitchcock 8930. San Salvador, Renson 63. 



•Honduras: San Pedro Sula, Thieme 323, 5581 in part. Ruatan Island, Gaamer 136. 

 Puerto Sierra, Wilson 208. 



