C04 oramine.t:. (grass family.) 



pie, spreading; floret four times as loug as tlie oval obtuse or acute glumes, 

 and Jiearly ct|nalliiig the rough awn. (M. cajsjtitosa, C/ut/nn.) — Dry pine 

 barrens, Florida, and westward. 



39. BRACHYELYTRUM, Ikauv. 



A perennial erect grass, with a simple .><lendcr culm, flat lanceolate leaves, 

 and a lou.'^e lanceolate simple ])anicle of large (J' long) 1-flowered spikelets. 

 Lower glume obsolete, tlie upper minute, persistent and awnless. Flowering 

 glume rigid, rough with short bristly hairs, concave, 5-ribbed, tapering into a 

 long straight awn, and enclosing the siiorter 2-pointed palet. An awn-like 

 pedicel of a second flower is apj)lied to the back of the palet. Stamens and 

 long stigmas 2. Grain linear. 



1. B. aristatum, Beauv. — Dry rocky places. July. — Culms solitary, 

 2° -3° higii. 



40. AIRA, L. 



Small tufted annual gras.ses (sparingly introduced), with linear or setaceous 

 leaves, and diffuse panicles of small 2-flowered spikelets. Lower glumes mem- 

 branaceous, acute, etpial, longer than the florets; the flowering glume 2-cleft 

 at the ajiex, faiutly 3-5-nervcd, dorsally awiied in tiie middle. .Stamens 3. 

 Grain free. 



1. A. caryophyllea, L. Culms 5'- 8' iiigli; leaves narrow-linear; 

 spikelets H" long, short pedicelled ; florets both awned. — Near Goldsborough, 

 North Carolina ( ('imhij). 



2. A. capillaris, Host. Culms 8'- 12' iiigh ; leaves setaceous; spike- 

 lets f" long, long-pedicelled ; one floret uuawneJ. — Gravelly hills. Home, 

 Georgia. 



41. DESCHAMPSIA, Beauv. 



Tall perennial grasses. Spikelets 2-flowered, and with a hairy rudiment of 

 a third flower. Glumes shorter than the florets, scarious, acute ; flowering 

 glume truncate and denticulate at the apex, dor.sally awned near the base. 

 Stamens 3. Grain free. 



1. D. flexuosa, Trin. Culms l°-3°high; leaves chiefly radical, seta- 

 ceous; panicle diffuse; flowering glume much shorter than the bent and 

 twisted awn. — Mountains of Georgia and Carolina. July. 



2. D. CSespitosa, Beauv. Culms tufted, 2° -4° high ; leaves linear, flat ; 

 panicle oldoug, with short erect branches; flowering glume as long as the 

 straight appressed awn. — Georgia (Leconte in Herb. Darand). 



42. TRISETUM, Pers. 



Spikelets 2 - several-flowered. Flowering glume compressed-keeled, usually 

 bearing a bent awn below the 2-cleft or 2-pointed apex. Otherwise as in 

 Aira. Spikelets in open or spiked panicles. 



1. T. palustre, Torr. Smooth; culms weak (1°-H° long) ; leaves flat, 

 linear; panicle long and narrow, loose; spikelets 2-3-flowered; the lower 

 flower awnless, the upper with a spreading awn and an awn-like rudiment at 



