GRAMINEAE. 



i. Tripsacum dactyloides L. Gama 

 Grass. (Fig. 210.) 



Coir daclyloides !. Sp. PI. 972. 1753. 

 Trif>sa,-iim dactyloides L. Sp. PI. Ed. 2, 1378. 1763. 

 Trifmaciini dactyloides var. monostafliyinn A. Gray, 



Man. 616. 1848. 



Rootstock #'-!' thick, culms stout, erect, 4-8 

 tall. Leaves smooth and glabrous, i or more 

 loug, y^'-iy*' wide, long-acuminate, truncate or 

 subcordate at the base ; spikes terminal and in the 

 upper axils, solitary or 2-3 together, 4 / -o/ long, 

 the lower spikelets pistillate, the upper staminate 

 and very numerous ; outer scales of the staminate 

 spikelets linear and obtuse, 4" long, about i" 

 wide, faintly many-nerved ; exterior scale of the 

 pistillate spikelets horny, shining, closely appressed 

 in fruit. 



In swamps or along streams, Connecticut to Florida, 

 Texas and Mexico, north to Illinois, Missouri and 

 Kansas. Also in South America. One of our largest 

 grasses, sometimes used for fodder. June-Sept. 



2. ERIANTHUS Michx. Fl. Bor. Am. i: 54. 1803. 



Tall generally robust perennial grasses, with thick creeping rootstocks, long flat leaves, 

 and perfect flowers in terminal panicles. Spikelets generally with a ring of hairs at the 

 -base, 2 at each node of the jointed rachis, one sessile, the other with a pedicel, generally 

 i-flowered. Scales 4, the two outer indurated, the inner hyaline, the fourth bearing a terminal 

 straight or contorted awn ; palet small, hyaline ; stamens 3. Grain oblong, free, enclosed in 

 the scales. [Greek, referring to the woolly spikelets.] 



About 17 species, natives of the temperate and tropical regions of both hemispheres. Besides- 

 the following, two others occur in the Southern States. 



Awn spiral. i. E. alopecuroid.es. 



Awn straight. 



Panicle lax; branches long and spreading; basal hairs longer than the outer scale of the 



spikelet. 

 Panicle compact or strict; branches short and erect or appressed; 



shorter than the outer scale of the spikelet. 

 Outer scale about 2^" long. 

 Outer scale about 4" long. 



2. E. saccharoides. 

 basal hairs equalling or 



3. E. compac/us. 



4. E. brevibarbis. 



i. Erianthus alopecuroides (I v .) Ell. Spiral-awned Beard-grass. (Fig. 211.) 



Andropogon alopecuroides L. Sp. PI. 1045. 1753. 

 Erianthus alopecuroides EH. Bot. S. C. & Ga. i : 38. 

 1816. In part. 



Culms stout, erect, 6-io tall ; nodes naked or 

 barbed, the summit and the axis of the panicle 

 densely pubescent with appressed long rigid silky 

 hairs Sheaths glabrous ; leaves usually glabrous, 

 6 / -2 long, Ifc'-i' wide, acuminate, narrowed and 

 sometimes hairy on the upper surface near the 

 base ; panicle oblong, 7'-i2 / long, 2 / -3 / wide, 

 branches spreading, 3'-$' long, slender, loose, in- 

 ternodes about 2" long ; outer scales of the spike- 

 let about 3" long, exceeding the pedicel and about 

 two-thirds as long as the basal hairs, lanceolate, 

 acuminate ; inner scales shorter, the awn 6" -8" 

 long, scabrous, the portion included in the outer 

 scales tightly spiral, bent at point of exsertion, and 

 thence loosely spiral. 



In ilamji sc.il. North Carolina to Kentucky and Missouri, south to Georgia and Alabama. Com- 

 parison with the original sni-dim-ns of Linnaeus proves that the name alopecuroides belongs to 

 this sj,< Hrs. Sept. 



