Carex. 



CYPERACE.-E. 



225 



inflated sac enclosing the ovary, with rarely an liypogynous bristle {racheola) between 



them. Style 1 : stigmas 2 



3. Nutlet lenticular, plano-convex, or triangular. 



Perennial herbs, with triangular stems, more or less scabrous on the angles, 



rarely smooth. Spikelets terminal and solitary or with additional ones borne in the 

 axils of leafy or scale-like often sheathing bracts. Leaves grass-like, commonly rough 

 on the margins and keel. 



The lar<^est genus of the order, iiielu.ling nearly 700 species, aLundant in the temperate and 

 cooler regfons of both hemispheres and occurring more sparingly in mountaiiious districts within 

 the tropins. About 180 species are found in the Atlantic States (many ol them also ot the O d 

 World) and the Hora of the interior region adds some others. The following key embraces only 

 such as have been detected within the limits of California. The genus is a very intricate one and 

 the determination of species often diffi.;ult or even impossible in the case ot impeitect or imina- 

 In collecting, care should be taken to secure mature truit if possible, as well a3 



1. C. Pyrexaica. 



FILfFOLIA. 



Bkeweui. 



4. C. Geyeri. 



cooler regmns of both hemispheres and occurring more sparingly in mountaiiious districts with iii 



the trop 



World), 



sue 



the 



ture specimens 



rootstocks and foliage. 



* Spike solitary and simple, terminal, androgynous, male at top 



Bracts scale-like, colored. 



Perigynium spindle-shaped, reflexed : stigmas rarely 2. 

 Perigynium obovoid, hairy at top : scales very broad : leaves fali- 



form. 

 Perigynium a large much inflated sac. 

 Bracts foliaceous, green. r i <- 



Spike linear : perigynium triangular-ellipsoidal, closely applied to 

 the rhachis, 1-iierved on two of its sides. 

 * * Spike composed of sessile androgynous or rarely dicecious spike- 

 lets : stigmas 2. 

 Spikes dioecious, or the spikelets androgynous with the male and 

 female flowers irregularly situated. 

 Perigynium narrowly lanceolate, spongy at base. 

 Wide creeping : perigynium ovate-lanceolate, abruptly long-beaked. 

 Extensively creeping : spikelets numerous : perigynium ovate, less 



tapering, the margins not united to the top. 

 Some of the spikes occasionally wholly female : perigynium ovate, 



stipitate, concealed by the scale, at length nearly black. 

 Nearly dioecious : perigynium coriaceous, chestnut-colored, shining, 

 ovate with short minute beak, gibbous on the outer sides. 

 Dioecious : spikelets crowded, large : bracts and scales large. 

 Spikelets androgynous, aggregated at the top of the stem. 

 Spikelets male at top. 



Spikelets ovate, 8 to 10, light chestnut : perigynium ovate, sharply 



bidentate. 

 Spike capitate, roundish, of many crowded dark chestnut spike- 

 lets : perigynium ovate or elliptical, bidentate, stipitate. 

 Spike oblong or cylindrical, of 4 to 10 spherical spikelets, shorter 



than the awned bracts. 

 Spike elongated, of very many small spikelets or clusters of spike- 

 lets, shorter than the setaceous bracts. 

 Spikelets ferruginous, oblong, crowded, sessile : perigynium ovate 

 or deltoid, coriaceous, spongy at base. 

 Spikelets male at bottom. 



Spikelets usually 3 : perigynium oval and gradually or obovate 

 and abruptly short-beaked, nerved, coriaceous; margins 

 obtuse or slightly serrate above. 

 Leaves and often the filiform bracts far exceeding the stem : 

 spikelets 3 to 6, lance-ovate: perigynium membranous, 

 gradually beaked, sharply margined, serrate, nerveless. 

 Spikelets 3 to 6, dark brown : perigynium attermate-lanceolate ; 



margins not winged, smooth or rarely scabrous. 

 Spikelets 6 to 12 or more, crowded in a round or oblong ferru- 

 ginous head : perigynium ovate or elliptical, beaked, ser- 

 rate on the winged margins, divergent. 

 Spike oblong, tawny, of 4 to 6 small contiguous spikelets : peri- 

 gynium ovate, abruptly short-beaked, very convex outside, 

 strongly nerved, seiuate on the narrow wings, spreading. 



