ORDER 15G. GRAMIXEJ2. 807 



cave, coriaceous, inner thin or hyaline, like the (smaller) pales ; sta- 

 mens 3. Grass erect, tall. 



1 R. campestris Nutt? Glabrous; culm simple, slender (2 to 4f), with black- 

 ish, somewhat geniculate joints ; Ivs. very narrow, involute-setaceous ; spike soli- 

 tary, 'terminal, little thicker than the culm, 2 or 3' long ; ped. spikekt obsolete ; $ 

 gl. ovate, acute, faintly impressed-dotted. La. (Hale.) 



2 R. rugdsa. Glabrous ; culms rather stout, 3 to 5f, erect, Iranched ; Ivs. flat, 

 linear; spikes solitary, several, terminal and axillary, 2 to 3', less thick than the 

 base of the culm ; ped. fl. of 2 empty glumes ; 5 outer gl ovate, acute strongly 

 reticulately rugous. Prairies, La. (Hale.) (Apogonia, Nutt.) 



66. STENOTAPHRUM, Trin. Spike compressed ; spikelets 2-flow- 

 crcd, in pairs at each joint, imbedded, 1 sessile and 1 pedicellate (or in 

 4s to Cs) ; glumes membranous, the outer minute, inner large ; flowers 

 each of 2 coriaceous pales, similar, but the lower $ ; styles 2, slender; 

 stamens 3 ; grain free. 2 Culms decumbent, branched joints of spikes 

 not separable. 



S. dimidiaturn. Glabrous, very leafy ; culm 2 to 4f ; Ivs. flat, broadly linear, on 

 broad, open sheaths ; spikes lateral and terminal, solitary, much compressed, 3', 

 by 2 to 3", the rachis flat on the back, spikelets in 2 lateral rows in front, the ses- 

 sile embraced by the pedicel of the other. Low grounds, coastward, S. States. 

 Jn. Sept. (Rottboellia, Thumb. S. Americanum Schrank.) 



67. ERIAFTTHUS, Rich. PLUME GRASS. BEARD GRASS. (Gr. 

 epiov, wool, avOog.) Spikelets 2-flowered, all fertile, in pairs at each 

 joint of the slender rachis, one sessile, the other pedicellate ; glumes 

 membranous, subequal, longer than the flowers ; pales hyaline, the 

 lower flower of 1 neutral, the upper of 2, perfect, with the lower pale 

 awned ; spikelets involucrate at base, with a tuft of bristly hairs. 2 

 Stout, erect grasses, remarkable for their large woolly or silky, tawny 

 panicles. 



* Hairs of the involucre much longer than the spikelct Nos. 1,2 



* Hairs of the involucre shorter than the spikelet, or nearly none Nos. 8, 4 



1 E. alopecuroides Ell. Culm 5 to 8 or lOf, erect, stout, silky bearded, espe- 

 cially at the joints; Ivs. broadly linear; flat, silky pubescent, 2 to 3f by 1 to 2' ; 



' pan. dense, cyliudric-oblong, very large (12' to 20' long); hairs of the invol. twico 

 longer than the short (2 to 2|") spikelets, a third as long as the straightish awn 

 which is terminal on its pale. Swampy pools in pine barrens, Va. to Fla. and La. 

 The plume-like panicles are magnificent ! 



2 E. contortus Ell. Culm 4 to Gf, erect, glabrous; Ivs. broadly linear, flat, 

 smooth, except a tuft of silky hairs at base ; pan. contracted, oblong, 6 to 10' ; 

 hairs of the iuvol. long, silky, thrice longer than the spikelet (which is 3"), the 

 length of the spirally contorted awn which issues from near the base of its deeply 

 bifid pale. Wet grounds, about Charleston, S. C. to N. Orleans. Pan. of a lighter 

 hue than the last. 



3 E. brevibarbis MX. Culm stout, 3 to ff, erect, glabrous ; Ivs. broad-linear, 

 smooth, except at the base; pan. large (1 to 2f), contracted, lance-oblong, the 

 rac. more distinct from the fewer hairs ; hairs of the invol. hardly as long as the 

 larger (4'') spikelet, % the length of the awn which is some twisted arid its pale 

 bifid. Low grounds, S. States. Sept., Oct. 



4 E. strictus Baldw. Culm 4 to 7f, strictly erect and glabrous ; Ivs. very long f 

 / narrower (3 to 5") than in the other species, rough-edged ; pan. very strict, 1 to 



2f long, branches erect, appressed; invol. of hairs minute; awn straight, terminal 

 on its deciduous pale. Ga. to La. The whole panicle is reddish brown. Aug., 

 Sept. 



68. SACCHARUM, L. SUGAR CANE. (Gr. odtcxap, Arabic, souJcar. 

 Eng. sugar.) Spikelets all fertile, in pairs, one sessile, the other pedi- 



