618 FLORA OF TEXAS. 



glume lanceolate, transversely rugose; sterile flow er neu- 

 tral. Pine-barren swamps and ponds. September. Culms 

 2°-4° high ; spikes green, 1 J-'-2' long, 1" in diameter. 



MANISURIS, L. 



Annual grasses, with branching culms, flat leaves, and 

 spiked inflorescence ; spikes lateral and terminal, clustered, 

 jointed, the short peduncles inclosed in spathe-like sheaths; 

 spikelets 1 -flowered, placed one at each end of the joints 

 of the spike, the upper neutral, compressed, of two nearly 

 equal hispid membranaceous glumes, the lower perfect, 

 globose; glumes coriaceous, concave, the lower reticulated, 

 the upper smooth; palece 2, hyaline; stamens 3 ; grain 

 included. 



M. GRANULARis, Swartz. Leaves linear-lanceolate, and, 

 like the sheaths, hairy; spikes 6"-10" long; spikelets 

 minute, turning black. Fields and pastures. August and 

 September. Culms l°-2° high. 



TRIPSACUM, L. Gama Grass. 



A tall perennial grass, with solid culms, broad and flat 

 leaves, and spiked inflorescence ; spikelets awnless, monoe- 

 cious, in jointed spikes, the upper ones staminate, the 

 lower fertile, 2-flowered; staminate flowers by pairs on 

 each short triangular joint of the slender rachis, 3-an- 

 drous ; glumes 2, coriaceous ; palece hyaline ; pistillate 

 spikelets single, imbedded in a deep excavation of the 

 thick and polished joints ; the outer giwvciQ cartilaginous, 

 concave, the inner membranaceous, boat-shaped ; loioer 

 flower neutral, the upper pistillate, both with liyaline 

 paleae ; anthers opening by terminal pores ; stigmas elon- 

 gated ; grain free. 



T. dactyloides, L. Rich soil. August and September. 

 Culms erect, from tufted creeping rootstocks, 3°-5° high; 



