40 



CONTRIBUTIONS FROM THE NATIONAL. HERBARIUM. 



margin ; ligule a ring of hairs about 1 mm. long ; blades rather thick, 5 to 15 

 cm. long (rarely longer), 5 to 10 mm. wide, flat, rounded at the base, papillose- 

 ciliate on the margins toward the base, sparsely pilose or nearly glabrous on 

 both surfaces ; primary panicles long-exserted, those of the branches short- 

 exserted or included at the base, the common axis rather stout, angled, pilose; 

 racemes mostly 5 to 10, usually approximate, 1.5 to 4.5 cm. long, the lower 

 usually naked at the base; spikelets crowded, glabrous, 3 mm. long, about 1.8 

 mm. wide, ovate, abruptly acute, turgid, the minute pedicels long-pilose ; first 



glume one-third to scarcely half the length 

 of the spikelet, broad, acute or subacute, 

 3-nerved ; second glume and sterile lemma 

 equal, 5-nerved ; fruit 2.5 to 2.6 mm. long 

 (excluding the awn), about 1.5 mm. wide, 

 papillose-roughened, the lemma tipped with 

 an awn about 0.5 mm. long. 



DISTRIBUTION. 



Low moist open ground on the uplands 

 of Mexico. 



Chihuahua : Chihuahua, Pringle 375. 

 Coahuila : Saltillo, Hitchcock 5593. 

 Durango : Durango, Hitchcock 7619 ; Pal- 



'mer 533 in 1896. 

 San Luis Potosi : San Luis Potosi, Hitch- 

 cock 5668. Cardenas, Hitchcock 5770. 

 Queretaro : Queretaro, Hitchcock 5S02 ; 

 Agniel 10262. 

 Zacatecas : Zacatecas, Hitchcock 7516. 

 Aguascalientes : Aguascalientes, Hitchcock 7492. 



Jalisco : San Nicolas, Hitchcock 7225. Rio Blanco, Palmer 254 in 18S6. 

 Pueblo : Atlixco, Nelson in 1893 ; Puebla, Arsene 315, 493. 

 Federal District: Hitchcock 5891; Pringle 9592; Bourgeau 222, 439; Orcutt 



3692. 

 Guanajuato: Ac&nibaro, Hitchcock 6928. Irapuato, Hitchcock 7416. 

 Oaxaca : Oaxaca, Conzatti & Gonzalez 348. ^ f 



5. Brachiaria rolatyphylla _ (Griseb. ) Nash. 



Paspalum platyphyllum Griseb. Cat. PI. Cub. 230. 1866. " Cuba occ. 

 (Wr[ight] 3441), in humidis pr. Zarabanda (Wr. a. 1865)." The type speci- 

 men in the Grisebach Herbarium consists of two plants, each with two racemes. 



Panicum platyphyllum Munro; Wright, Anal.- Acad. Cienc. Habana 8: 206. 

 1871. Based on Paspalum platyphyllum Griseb. 



Brachiara platyphylla Nash in Small, Fl. Southeast. U. S. SI, 1327. 1903. 

 Based on " Panicum platyphyllum Munro." 



DESCRIPTION. 



Fig. 4. — Brachiaria meziana. 

 the type specimen. 



From 



Plants annual, rather coarse; culms compressed, glabrous, decumbent at the 

 base, rooting and commonly branching at the lower nodes, the flowering 

 branches ascending, sparingly branching from the lower nodes; sheaths rather 

 loose, sparsely pilose, at least along the margins and toward the summit ; ligule 

 a ring of hairs scarcely 1 mm. long; blades rather thick, 4 to 12 cm. long 

 (rarely longer), 6 to 12 mm. (usually about 10 mm.) wide, flat, glabrous ex- 



