CYPERACE^. (SEDGE FAMILY.) 393 



head (1 to 3 inches long and 3 to 9 lines wide) which is sometimes sub- 

 tended by a bract of its own length: perigynium tawny, ovate, promi- 

 nently nerved, scarcely wing-margined, rough above, shortly beaked (the orifice 

 nearly entire), bearing a conspicuous fissure on the outer side, commonly 

 longer than the acute brown scale. — Dry places, Utah, Colorado, and north- 

 ward. (Eu.) 



70. C. Gay ana, Desv. Creeping: culms slender (1 to 2 feet high), longer 

 than the leaves : spikes 4 to 15, globose or loosely ovoid, dark brown, simple, 

 nearly dicecious (rarely staminate at the top), rather loosely aggregated into a 

 small ovoid head (8 lines to one inch long) : perigynium triangular -obovoid, about 

 as wide as long (sometimes wider), gibbous below, rough on the top, squarely 

 contracted into a very short nearly entire beak, obscurely nerved below, brown and 

 shining at maturity, shorter than the acute chaffy scale. — Colorado and south- 

 ward. 



h- *- Spikes mostly nearly linear or narrowly oblong, chaffy: the scales long, 

 attenuated or awned: heads pale. 



71. O. Douglasii, Boott. Creeping: culm 6 to 12 inches high, obtusely 

 angled and mostly smooth, longer or shorter than the long-pointed leaves : 

 spikes usually many, simple or compound, pale and chaffy, dicecious or nearly 

 so, densely aggregated into a conspicuous and heavy head an inch or two 

 long and often an inch wide, which is sometimes subtended by a setaceous 

 bract of nearly its own length : perigynium ovate-lanceolate, nerved, pro- 

 duced into a slender toothed beak, much shorter and entirely concealed by 

 the long, acute, scarious scale : stamens and stigmas long and conspicuous. — 

 C. Fendleriana, Bckler. Var. minor, Olney, includes small forms 2 to 6 

 inches high, with smaller spikes not closely aggregated. Common, especially 

 in Wyoming, Colorado, Utah, and southward. Mature perigynia of this 

 species are rarely seen. 



Var. brunnea, Olney. Usually taller than the species and more slender 

 (12 to 20 inches high) : leaves equalling or exceeding the culm: spikes fewer 

 (3 to 8), the lower distinct, borne in an oblong fuscous head : lower bract 

 short-awned. — Nevada and westward; probably in our region. 



§ 15. Spikes staminate at the base. (No. 77 is sometimes dicecious, No. 72 

 has the central spikes staminate or is rarely dicecious, and No. 78 some- 

 times has spikes staminate at the top.) — Hypaerhenj;, Anderss. 



* Spikes silvery green or tawny when mature, distinct, mostly small : perigynium 

 not wing-margined nor conspicuously broadened, mostly nearly flat on the inner 

 surface. — Elongate, Tuckm. 



-i- Perigynium nearly linear or ovate-lanceolate, in loose spikes. 



72. C. foromoidss, Schk. Cespitose : culms usually very slender, 1 to 2 

 feet high, longer than the narrow and grass-like leaves : spikes 4 to 8, becoming 

 tawny with age, erect, loosely aggregated into a narrow and lax head about an inch 

 long, the middle ones usually staminate, or some rarely staminate at top or bottom 

 (or dicecious), mostly much longer than the inconspicuous scarious bracts : 

 perigynium Hnear-lanceolate , contracted below, strongly nerved, erect, attenuated 

 into a long rough beak which has a fissure on its outer side, the whole longer thar 



