GRAMIXE^. (grass FAMILY.) 595 



androus, flat, twisted, membrauous, 6" -8" long, the fertile smaller, indurated, 

 closely pubescent, dark brown ; awu twisted and pubescent below, 4' - 6' long. 

 — Margins of fields, Georgia, Florida, and westward. 



23. IMPERATA, Cyrill. 



Spikelets in pairs on tlie slender brandies of the spike-like panicle, both 

 perfect and awnless ; lower glumes clothed with long silky hairs, the upper 

 hyaline. Stamens 1-2. 



1. I. Brasiliensis, Trin. Culm simple, erect from long creeping root- 

 stocks, 2° -3° higli ; radical leaves broadly linear, 2° long, those of the culm 

 few and short ; panicles lanceolate, 4' - 5' long ; spikelets 2" long. — South 

 Florida. 



24. ERIANTHUS, Michx. 



Tall reed-like grasses, with long flat leaves, and panicled inflorescence. 

 Spikelets by pairs on the slender branches, alike, one pedicelled, the other 

 sessile, both with a tuft of hairs at the base. Glumes 4, the 2 lower nearly 

 equal, membranous, the 2 upper hyaline, the 4th awned. Stamens 2-3. 



1. E. alopecuroides, Ell. Culms 4°- 10° high; sheaths of the broad 

 (6"- 12") very rough or pubescent leaves woolly above, rough below; panicle 

 (l°-2° long) woolly, expanding, pyramidal; hairs of the involucre copious, 

 twice as long as the sparsely hairy (2" long) glumes; awn straight. — Yar. 

 coxTORTUS. (E. contortus, Ell.) Smaller (2° -4° high) ; leaves and sheaths 

 smooth ; panicle (6'- 12' long) oblong ;" awns short and twisted. — Var. brevi- 

 BARBis. (E. brevibarbis, .y/c/(r.) Smooth or nearly so ; rachis of the oblong 

 panicle rough (not woolly) ; spikelets 3" long; hairs of the involucre shorter 

 than the glumes. — Dry or wet soil. — Sept. - Oct. 



2. E. Strictus, Baldw. Culms, leaves, and sheaths smootli or slightly 

 roughened; panicle (10'- 15' long) spiked; involucre very short or none; 

 glumes rough ; awns straight. — River banks, Florida and the lower districts 

 of Georgia, and westward. Sept. — Culms 4° -8^ higli- Leaves 3" — 6" 

 wide. Spikelets twice the size of the preceding. 



25. SORGHUM, Pers. 



Spikelets 2-3 together on the slender branches of the loose panicle; the 

 lateral ones sterile or a mere pedicel; the middle or terminal one fertile. 

 Lower glumes coriaceous or indurated, mostly bearded, sometimes awnless. 

 Otherwise like Andropogon. 



§ 1. Blumexbachia. — Branches of Ihe panicle angular, scabrous: spikelets 

 ovate or ovate-lanceolate : two loiver c/l.Hmes at length strongli/ indurated. — 

 This section embraces the following introduced species, which are more 

 or less common in cultivation, viz. : S. vulgare, Durra Corn; S. .sacchara- 

 tnm, Broom Corn ; S. ceruuum, Guinea Corn ; and S. Halapense, Johnson 

 Grass. 



§ 2. Chrtsopogox. — Branches of the panicle terete, smooth : spikelets lanceo- 

 late: glumes less indurated. — Culms mostly simple. Pedicels bearded under 

 the spikelets. Sterile spikelets none. 



