Order 156.— GR AMINES. 807 



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

 mens 3. — Grass erect, tall. 



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

 ish, Boraewhat geniculate joints ; lvs. very narrow, involute-setaceous ; spike soli- 

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

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



2 R. rugosa. Glabrous; culms rather stout, 3 to 5f, erect, branched; lvs. flat, 

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

 base of tho culm ; ped. fl. of 2 empty glumes; g outer gl. ovate, acuto strongiy 

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



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

 ored, in pairs at each joint, imbedded, 1 sessile and 1 pedicellate for in 

 -is to Gs) ; glumes membranous, the outer minute, inner large ; flowers 

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

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

 not separable. 



S. dimidiatum. Glabrous, very leafy ; culm 2 to 4S ; lvs. 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. (Rottbcellia, Thumb. S. Americanum Schrank.) 



67. ERIANTHUS, Rich. Plume Grass. Beard Grass. (Gr. 

 Ipioi', wool, avdoc.) 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. — 71 

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

 panicles. 



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



* Hairs of the involucre porter 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 ; lvs. broadly linear ; flat, silky pubescent, 2 to 3f by 1 to 2' ; 

 pan. dense, cylindriooblong,- 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 siraightish awn 

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

 Tho plume-like panicles are magnificent ! 



2 E. contortus Ell. Culm 4 to 6f, erect, glabrous; lvs. broadly linear, flat, 

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

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

 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 7f, erect, glabrous ; lvs. broad-linear, 

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

 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 somo twisted and its pale 

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



4 E. strictus Baldw. Culm 4 to If, strictly erect and glabrous ; lvs. very long, 

 narrower (3 to 5'') than in the other species, rough-edged ; pan. very Btrict, 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. odicxap, Arabic, soukar, 

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



