582 FLORA OF TEXAS. 



** Spikes 2-many, apparently lateral ; Vu 1-leavtd involucre erect and continuous with 



the culm. 

 t Spikes in sessile clusters. 



S. PUNGENS, Vahl. Culms stout, acutely 3-angled, two 

 of the sides concave, leafy at the base; leaves channeled, 

 sharply keeled ; involucre slender (3'-4:' long) ; spikes 3-G, 

 light brown, oblong ; scales membranaceous, oval, 2-cleft, 

 mucronate-awned, slightly ciliate; anthers slender-pointed; 

 sti/le 2-cleft; nut ronnd-obovate, plano-convex or lenticular, 

 as long as the 3-5 hispid bristles. (S. American us, Pers.) 

 Sandy marshes along the coast. June-September. Culm 

 2°-3° high ; leaves 2-3, mostly shorter than the culm ; 

 spikes 4:"-6" long. 



S. Olxeyi, Gray. Culms stout, with three-winged angles, 

 and three deeply channeled sides, leafless, or the sheaths 

 ending in short pointed leaves ; involucre short (IJ'-l' long) 

 rigid : spikes 7-13, short, ovate, dark brown ; scales smooth, 

 orbicular, 2-cleft, mucronate ; anthers obtuse; style 2-cleft; 

 met round-obovate, plano-convex, as long as the 6 hispid 

 bristles. Brackish marshes. June-September. Culms 

 2°-4° high; leaves 2-4' long; spikes 2" long. 



% Culms jointed, leafy throughout; mnbel terminal; invducre 2several-leaved, 



spreading. 

 * Bristles hispid downward. 



S. POLYPHYLLUS, Vahl. Ctihn obtuse-angled, smooth; 

 leaves long, rough on the margins; umhel decompound, 

 spreading ; spikes small, 3-8 in a cluster, ovate, yellowish- 

 brown ; scccles ovate, mucronate, keeled ; bristles 6, slender, 

 hispid near the summit, mostly tortuous, 2-3 times as long 

 as the pale compressed-3-angled pointed nut. (S. exaltatus, 

 Pursh.) Shady swamps. July. Culm 2°-5° high; spikes 

 1' long. 



ERIOPHORUM, L. Cotton Grass. 



Spikes many-flowered ; scales imbricated in many rows ; 

 perianth composed of numerous (rarely 6) smooth and flat 



