8 
1. T. polymorphus Hack. (Vasey, Grasses of the Southwest, Pl. 17.) Perennial; 
culms 2 to 4 feet high; leaves flat, 3 to 6 inches long ; spikes 3 to 6 inches long, rather 
loosely flowered, sometimes one-sided; spikelets 3 lines long, pubescent; outer glume 
lance-oblong, obtuse, 7-nerved ; awn 14 to 2 inches long.—Texas to Arizona and New 
Mexico. 
HETEROPOGON Pers. 
Spike densely flowered, appearing one-sided. Thesessile spikelets 
awned fertile, cylindrical; the pediceled spikelets male, imbricated 
and obliquely bent to one side of the spike, awnless. Glumes in the per- 
fect flower 4, the outer one hard and convolute, the second softer, 
keeled, the third thin and hyaline, the fourth, hyaline at the base, above 
terminating in a hard, twisted, and bent awn. 
1. H. contortus R. & 8. (Andropogon contortus Linn.) (Vasey, Grasses of the South- 
west, Pl. 16.) Perennial, strongly rooted ; culm tufted, smooth, branching above, erect, 
about 3 feet high; leaves 6 to 12 inches long, smooth, sheaths flattened ; spike cyl- 
indrical, about 2 inches long without the awns; rachis with a tuft of brown hairs at 
the base of the spikelets ; sessile spikelet about 3 lines long, the male one 5 inches, 
flattish, oblique.—Texas, New Mexico Arizona and in tropical countries. 
2. H. acuminatus Trin. (Andropogon melanocarpus Ell.) (Chapm. FI. 8. States, 
p. 582.) Culms 4 to8 feet high ; leaves elongated; spikes numerous, approximate, 
1-sided, 1 to 2 inches long, shorter than the sheathing bract; spikelets large, the 
sterile one 6 to 8 lines long, of 3 flattish, nerved, twisted, glumes, the fertile spikelet 
2 lines long, rusty bearded; the glumes coriaceous, obtuse; awn 4 inches long.— 
Florida and westward to Texas and Mexico. 
IMPERATA Cyrill. 
Inflorescence in a narrow, or spike-like panicle; spikelets in pairs, one 
sessile, the other pediceled, both perfect, awnless; the 2 outer glumes 
densely clothed with long silky hairs, Stamens 1 to 2. Stigmas 2. 
1. I. Brasiliensis Trin. Mem. Acad., Petersb. Ser. 6, 11. p. 331. Culms 2 to 3 feet 
high, simple, rather slender, from long creeping rootstocks; radical leaves broadly 
linear, 2 feet long, cauline ones few, the lower 6 inches long, blade much reduced or 
wanting; panicle linear-oblong, 4 to 6 inches long, spikelets 2 lines long.—Florida. 
2. I. Hookeri Rupr. in Anderson. (/. brevifolia Vasey in Bull. Torr. Club x11. p. 
26.) Culms 3 to 4 feet high, from creeping rootstocks, rather stout, simple, smooth; 
radical leaves 6 to 12 inches long, cauline ones shorter, gradually decreasing up- 
ward, ligule short, ciliate; panicle nearly cylindrical, erect, 6 to 12 inches long, 
sometimes interrupted below, lower branches | to 2 inches long, appressed ; spike- 
lets little more than 1 line long.—Texas, New Mexico to Southern California and 
Mexico. 
ERIANTHUS Michx. 
Inflorescence an ample or narrow panicle; spikelets in pairs, one 
sessile and one pediceled, both alike fertile and awned. ‘Tall and stout 
reed-like perennials. 
1,B. saccharoides Michx. (E. alopecuroides Ell.; Andropogon alopecuroides Linn. ) 
(Gray’s Manual, 6th ed., p. 687.) Culms 4 to6 feet high, woolly-bearded at the nodes; 
panicle dense, contracted, 4 to 10 inches long; general rachis woolly; partial rachis 
woolly-tufted below the spikelets, the hairs longer than the spikelets; awn % to 1 
inch long, straight; spikelet 2 lines long ; outer glumes sparsely hairy ; stamens 2.— 
New Jersey south to Florida and Texas. 
