Part 1, 1909] POACEAE 81 
2-3 mm. in diameter; staminate spikelets 3-4 mm. long, the outer scales oblong, rounded 
at the apex. : 
TYPE LOCALITY : Cubilquitz, Department Alta Verapaz, Guatemala. 
DISTRIBUTION: Guatemala and Honduras. 
4, Tripsacum pilosum Scrib. & Merr. Bull. U. S. Dep. Agr. 
Agrost. 24:6. 1900. 
Stems stout, 1-2 m. tall, glabrous, or pubescent just below the inflorescence; leaf- 
sheaths densely papillose-hispid ; blades 4-6 dm. long, 2~4 cm. wide, long-acuminate, nar- 
rowed toward the base, hirsute, at least on the upper surface; spikes up to 2.5 dm. long, 
pistillate for about one quarter of their length or less, rather slender; pistillate spikelets 
about 5 mm. long, the outer scale ovate, acute; staminate spikelets 5-7 mm. long, the outer 
scale oblong, acute or obtuse. 
TYPE LOCALITY: Between Colottan and Bolanos, Jalisco, Mexico. 
DISTRIBUTION: Mexico. 
ILLUSTRATION: Bull. U. S. Dep. Agr. Agrost. 24: /. Z. 
5. Tripsacum laxum Nash. 
Tripsacum Jasciculatum Trin.; Aschers. Bot. Zeit. 35: 525. 1877. Not 7. fasciculatum Rasp. 1825. 
Stems 1-2 m. tall, glabrous; leaf-sheaths glabrous; blades up to 8 dm. long and 7 cm. 
wide, glabrous, long-acuminate ; spikes usually numerous, sometimes few, flexuous, slender, 
up to 2 dm. long; pistillate spikelets about 5 mm. long, the outer scale ovate; staminate 
spikelets 4-6 mm. long, one sessile or rarely on a short pedicel, the other on a slender pedicel 
3-4 mm. long. 
TYPE LOCALITY: Hacienda de la Laguna, Mexico. 
DISTRIBUTION : Southern Mexico. 
6. Tripsacum acutiflorum Fourn. Bull. Soc. Bot. Belg. 15: 466. 1876. 
Tripsacum lanceolatum Rupr.; Fourn. Mex. Pl. Gram. 68. 1881. 
Stems up to 1 m. tall, glabrous; leaf-sheaths glabrous or sometimes ciliate on the 
margin ; blades up to 5 dm. long, 1-2 cm. wide, long-acuminate, narrowed toward the base, 
pubescent on the upper surface; spikes up to 2 dm. long, slender, the pistillate portion 
occupying about one half the length and 3-4 mm. in diameter ; pistillate spikelets 4-5 mm. 
long, the outer scale ovate, acute; staminate spikelets 6-7 mm. long, one sessile, the other 
with a pedicel about 1 mm. long, the outer scales oblong-lanceolate, obtuse, glabrous. 
TYPE LOCALITY : Mexico. 
DISTRIBUTION : Lower California and Sonora to Durango and Oaxaca. 
7. Tripsacum Lemmoni Vasey, Contr. U. S. Nat. Herb. 3: 6. 1892. 
Tripsacum dactyloides Lemmont Beal, Grasses N. Am. 2:19. 1896. 
Stems 1-2 m. tall, glabrous; leaf-sheaths glabrous, or the lowermost sometimes pubes- 
cent; blades up to 4.5 dm. long and 5-10 mm. wide, glabrous; spikes up to 1 dm. long, 
slender, the pistillate portion about one half the length and 4 mm. in diameter; pistillate 
spikelets 5-6 mm. long, the outer scale ovate; staminate spikelets 6 mm. long, the outer 
scales oblong-lanceolate, hispidulous. 
TYPE LOCALITY: Huachuca Mountains, Arizona. 
DISTRIBUTION: Arizona and Mexico. 
4. COIX L. Sp. Pl. 972. 1753. 
Tall branching monoecious grasses, with flat leaf-blades, andsimple or fasciculate 
spikes. Spikelets unisexual. Pistillate spikelets borne in short spikes, consisting of 1 
fertile spikelet and 1 or 2 sterile ones, which are included in a globose or oblong finally 
stony involucre; scales 4, thin, hyaline, the 2 outer empty, the 2 inner bearing flowers or 
the fourth one empty ; styles free almost to the base, very long, filiform. Staminate spikelets 
1- or 2-flowered, in 2’s or 3’s at the nodes of the rachis of spikes which are exserted from 
