604 GRAMIXEJE. (GRASS FAMILY.) 



pie, spreading ; floret four times as long as the oval obtuse or acute glumes, 

 and nearly equalling the rough a\vu. (M. casspitosa, Chaprn.) Dry pine 

 barrens, Florida, and westward. 



39. BRACHYELYTRUM, Beauv. 



A perennial erect grass, with a simple slender culm, flat lanceolate leaves, 

 and a loose lanceolate simple panicle of large (% long) 1-flowered spikelets. 

 Lower glume obsolete, the upper minute, persistent and awuless. Flowering 

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

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

 pedicel of a second flower is applied 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 high. 



40. AIRA, L. 



Small tufted annual grasses (sparingly introduced), with linear or setaceous 

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

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

 at the apex, faintly 3 - 5-uerved, dorsally awued in the middle. Stamens 3. 

 Grain free. 



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

 spikelets 1A" long, short pedicelled ; florets both awned. Near Goldsborough, 

 North Carolina ( Canby}. 



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

 lets f " long, long-pedicelled ; one floret unawued. Gravelly hills, Koine, 

 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, dorsally awned near the base. 

 Stamens 3. Grain free. 



1. D. flexuosa, Triu. Culms l-3high; 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. CSBSpitOsa, Beauv. Culms tufted, 2 - 4 high ; leaves linear, flat ; 

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

 straight appressed awn. Georgia (Leconte in Herb. Durand). 



42. TRISETUM, Pers. 



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

 bearing a bent awn below the 2-cleft or 2-poiuted 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 awuless, the upper with a spreading awn and an awn-like rudiment at 



