CYPERACE^E. (SEDGE FAMILY.) 379 



21. C. tetanica, Schk. Creeping: culms strict, slender, 6 to 20 inches 

 high, sharply angled, longer than the pale or bluish leaves : staminate spike long- 

 pedunded: pistillate spikes 1 to 4, usually all pedunded, slender, cylindrical, 

 varying from compactly to loosely flowered, attenuated at the base : perigynium 

 tapering at each end, more or less 3-angled, scarcely inflated, with a very short 

 bent point, longer than the nearly obtuse or shortly cuspidate scale. Indian Ter- 

 ritory and northward ; also in British America. Distinguished from its east- 

 ern allies, C. panicea and C. Meadii (the latter of which may occur within our 

 limits), by its more slender spikes, which are loosely flowered at the base, and 

 its less inflated perigynium. 



* * * * Terminal spike stalked, pistillate at the top: pistillate spikes oblong or 



cylindrical, densely flowered, erect : bracts sheathless or nearly so, leaf-like : 

 perigynium ovate orobovate, straight, nearly or quite beakless. VIRESCENTES, 

 Kunth. 



22. C. Shortiana, Dew. Culms leafy, 1 to 2 feet high : leaves long, 

 flat, rather wide, smooth or very nearly so: pistillate spikes 3 to 6, evenly cylindri- 

 cal, to 2 inches long, the lower long pedunded, all sparingly staminate at the 

 base: perigynium broadly and shortly obovate, nerveless, minutely pointed, squar- 

 rose, somewhat longer than the rather obtuse 'scale. Indian Territory ( Geo. D. 

 Butler) ; Nebraska (Hayden). 



23. C. triceps, Michx. Cespitose: culms slender, 8 to 18 inches high, 

 shorter or longer than the soft, narrow, flat and hairy (rarely nearly smooth 

 eastward) leaves: spikes 1 to 3, approximate and nearly sessile, globular, ovoid, 

 or short cylindrical, thick ( inch or less long) : perigynium sparsely hairy 

 when young, smooth when mature, ovate or broadly obovoid, turgid and conspicu- 

 ously many-nerved when ripe, pointless and nearly entire or tipped with a very 

 short and slightly 2-toothed beak, about the length of the acute or awn-pointed scale. 

 C. hirsuta, Willd. C. Smithii, T. C. Porter. Indian Territory (Geo. D. 

 Butler) and southward. 



24. C. virescens, Muhl. Cespitose : culms many, very slender, 8 inches to 

 3 feet high, often much attenuated, about the length of the narrow and fat 

 long-pointed, hairy leaves : spikes green, oblong or narrowly cylindrical, J to 2 

 inches long, rarely nearly globose in attenuated specimens, short-stalked and 

 ascending : perigynium ovate or oval, thickly hairy at maturity, strongly few-nerved, 

 beakless, mostly longer than the acute whitish scale. Indian Territory ( Geo. D. 

 Butler). 



7. Staminate spike mostly solitary and pedunded (sometimes sessile in No. 26), 

 the upper part usually pistillate in the Gracillimo?. : pistillate spikes several or 

 many, more or less loosely flowered, all or the lower on filiform weak or nodding 

 peduncles: bracts foliaceous and sheathing : perigynium thin and membrana- 

 ceous, usually slender or oblong, tapering gradually into a distinct or long 

 minutely toothed straight beak, smooth and shining (in No. 23 usually hairy on 

 the angles and not lucid), mostly light-colored, somewhat inflated. Scales 

 thin, white, tawny, or brown. HYMENOCHL^EN^;, Drejer. Mostly slender 

 and open-flowered lax-growing species. 



* Terminal spike usually pistillate above : pistillate spikes narrow, long-cylindri- 



cal, rather compactly flowered, the lower on long-exserted or nodding peduncles : 



