MONOCOTYLEDOXOUS OR EXDOGENOUS PLANTS. 599 

 * Glumes unequal, the upper one shorter. 



A. PURPURASCENS, Poir. Culms (l^°-2° high) slender, 

 sparingly branched ; sheaths smooth ; glumes sometimes 

 nearly equal, purple; lo2cer palea (3" long) \-\ as long as 

 the nearly equal awns. Dry soil. August. Panicle slen- 

 der, 1° long, with the branches appressed. 



** Glumes equal, or the upper one longer . 



A. GRACILIS, Ell. Cuhiis much branched at the base, 

 very slender; leaves flat; panicle very narrow, with distant 

 appressed branches; middle atvn rather longer than the 

 rough and spotted lower palea, the lateral ones much 

 shorter ; glumes nearly equal. Dry gravelly soil. August. 

 Culms (with the panicle) 6-12' high; spikelets purple. 



A. SPiciFORMis, Ell. Culms simple, rigid, erect (1°-1J° 

 high); leaves rigid, erect, convolute, smooth; panicle 

 spiked; glumes much shorter than the long (1') very slen- 

 der paleae, the upper one twice as long as the lower ; aiuns 

 nearly equal, widely spreading, the middle one as long as 

 the paleae. Low pine-barrens. August and September. 

 Panicles 2-4' long, at length twisted. 



A. TUBERCULOSA, Nutt. C^ihus rigid, branching (l°-li° 

 high); leaves flat; glumes nearly equal, longer than the 

 paleas, bristle-awned; awns (2' long) equal, jointed with 

 the paleae, twisted below, then widely spreading, several 

 times longer than the paleae. Dry ridges. September. 

 Panicle simple. 



GYMNOPOGON, Beauv. • 



Loio perennial grasses, with short and crowded distichous 

 spreading leaves; spikelets appressed, scattered on the 

 straight and at length reflexed branches of the simple 

 panicle, consisting of one perfect flower, and the awn-like 

 pedicel of a second flower above; glumes 2, subulate, hispid- 

 serrulate; ^jalece 2, shorter than the glumes, the lower one 

 awned under the apex ; stamens 3. 



