80 NORTH AMERICAN FLORA [VorumE 17 
cate remaining scales; fourth scale enclosing the flower; style slender ; stigmas 2, exserted. 
Grain enclosed in the appressed outer scale and the internode. Staminate spikelets 2- 
flowered, in pairs at the nodes, sessile or pedicellate ; scales 4, the outer 2 empty, coriaceous 
and shining, or membranous, the 2 inner thinner, each enclosing a flower; stamens 3. 
Type species, Tripsacum dactyloides L. 
Staminate spikelets both sessile, or one with a very short pedicel, the outer scales coriaceous; 
spikes single, or sometimes 2-4, usually digitate. 
Leaf-blades less than 3 cm. wide, rarely pubescent on the upper surface; staminate spikelets 5 
mm. long or more. 
Leaf-blades 1.5-2.5 cm. wide, flat ; stems stout, exceeding 1 m.in height. 1. 7. dactyloides. 
Leaf-blades usually under 5 mm, wide, often involute ; ; stems slender, 
under 1 m. tall. 2. T. floridanum. 
Leaf-blades 4-5 cm. wide, pubescent on the upper surface; staminate spike- 
lets 3-4 mm. long. 3. 7, latifolium. 
Staminate spikelets, 1 or sometimes both, on long pedicels, the outer scales 
membranous. 
Leaf-sheaths hispid. T. pilosum., 
Leaf-sheaths glabrous, or nearly so. 
Blades 3 cm. wide or more, glabrous. T. laxum. 
Blades 2 cm. wide or less, pubescent on the upper surface. 
Stems stout ; blades 1-2 cm. wide. 
T. acutifiorum. 
Stems slender ; blades 5-10 mm. wide, sometimes involute. 
T. Lemmoni, 
Soy. oe 
1. Tripsacum dactyloides L. Syst. Nat. ed. 10. 1261. 1759. 
Cotx dactyloides I. Sp. Pl. 972. 1753. * 
Tripsacum monosiachyum Willd, Hort. Berol.1: 1. 1803. 
Tripsacum dactyloides monostachyon Wood, Class Book 453. 1845. 
ene compressum Fourn. Bull, Soc. Bot. Belg. 15: 466. 1876. Not 7. compressum Rasp. 
Tripsacum dactyloides hispidum Hitche. Bot. Gaz. 41: 295. 1906. 
Stems glabrous, or sometimes pubescent below the inflorescence, up to 2.5 m. tall, from 
stout horizontal rootstocks; leaf-sheaths glabrous, or hirsute at the apex; blades up to 6 
dm. long, usually 1-2 cm. wide, rarely broader, long-acuminate, narrowed at the base, 
glabrous, or sometimes hirsute or hispid on the upper surface; spikes usually single on the 
branches, often 2-4 at the summit of the stem, 1-3 dm. long, the lower one quarter to one 
half pistillate ; pistillate spikelets 7-10 mm. long, the first or outer scale broadly ovate, 
acute; staminate spikelets 7-11 mm. long, the outer 2 scales oblong, from rounded to acute 
at the apex, glabrous or pubescent. 
TYPE LOCALITY: America. 
DISTRIBUTION: Rhode Island to Nebraska, south to Florida, Texas, and Mexico; southern 
Bahamas; Haiti; alsoin South America. 
ILLUSTRATIONS : Lam. Tab. Encyc. p/. 750 ; Britt. & Brown, Ill. Fl. 7.210; A. Gray, Man. pi. 14; 
Mart. Fl. Bras. #/, 73; Bull. U. S. Dep. Agr. Agrost. 7: J 20: F-35314: F883; 3: f. 87; Vasey, 
Agr. Grasses U. S. gl. 21; Beal, Grasses N. Am. 2: 7. 3; Bull. Tenn. Exp. Sta. 7: 2. "LS. 1; 
Willd. Hort. Berol. AZ. Z. 
2. Tripsacum floridanum Porter; Vasey, Contr. U. S. Nat. Herb. 
3:6. 1892. 
Tripsacum dactyloides floridanum Beal, Grasses N. Am.2: 19. 1896. 
Smooth and glabrous. Stems upto 1m. tall, slender, from stout horizontal rootstocks ; 
leaf-blades up to 4 dm. long, usually under 5 mm. wide, rarely broader, long-acuminate, 
narrowed toward the base; spikes on the branches and at the summit of the stem single, 
8-20 cm. long, slender, the lower one quarter or less pistillate; pistillate spikelets 6-7 mm. 
long, the outer scale acute to acuminate; staminate spikelets 5-6 mm. long, the outer 2 
scales glabrous or pubescent, oblong, obtuse to acutish. 
TYPE LOCALITY: Miami, Florida. 
DISTRIBUTION : Southern Florida. 
3. Tripsacum latifolium Hitche. Bot. Gaz. 41: 294. 1906. 
Stems stout, up to 2-3 m. tall, from stout horizontal rootstocks; leaf-sheaths glabrous, 
or pubescent at the apex; blades up to 7 dm. long and 4.5 cm. wide, long-acuminate, flat, 
the upper surface pubescent; spikes on the branches usually single, 1-3 at the summit of 
the stem, 1-3 dm. long and more slender than in 7. dactyloides, with the pistillate portion 
