Carex. CYPERACE.E. 225 



inflated sac enclosing the ovary, with rarely an hypogynous bristle (racheola) between 

 them. Style 1 : stigmas 2 or 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 largest genus of the order, including nearly 700 species, abundant in the temperate and 

 cooler regions of both hemispheres and occurring more sparingly in mountainous districts within 

 the tropics. About 180 species are found in the Atlantic States (many of them also of the Old 

 World), and the flora 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 difficult or even impossible in the case of imperfect or imma- 

 ture specimens. In collecting, care should be taken to secure mature fruit if possible, as well as 

 rootstocks' and foliage. 



* Spike solitary and simple, terminal, androgynous, male at top : stigmas 3. 

 Bracts scale-like, colored. 



Perigynium spindle-shaped, reflexed : stigmas rarely 2. 1. C. PYRENAICA. 



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

 form. 2. C. FIUFOLIA. 

 Perigynium a large much inflated sac. 3. C. BKEWEUI. 

 Bracts foliaceous, green. 

 Spike linear : perigynium triangular-ellipsoidal, closely applied to 



the rhachis, 1-nerved on two of its sides. 4. C. GEYERI. 



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

 lets : stigmas 2. 

 Spikes dioecious, or the spikelets androgynous with the male and 



female flowers irregularly situated. 



Perigynium narrowly lanceolate, spongy at base. 5. C. BROMOIDES. 



Wide creeping : perigynium ovate-lanceolate, abruptly long-beaked. t>. C. SICCATA. 

 Extensively creeping : spikelets numerous : perigynium ovate, less 



tapering, the margins not united to the top. 7. C. DISTICUA. 



Some of the spikes occasionally wholly female : perigynium ovate, 



stipitate, concealed by the scale, at length nearly black. 8. C. MARC1DA. 

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



ovate with short minute beak, gibbous on the outer sides. 9. C. GAY ANA. 

 Dioecious : spikelets crowded, large : bracts and scales large. 10. C. DOUGLASII. 



Spikelets androgynous, aggregated at the top of the stem. 

 Spikelets male at top. 



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



bidentate. 11. C. HOODII. 



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

 lets : perigynium ovate or elliptical, bidentate, stipitate. 12. C. FCSTIDA. 

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



than the awned bracts. 13. C. MUKICATA. 



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

 lets, shorter than the setaceous bracts. 14. C. GLOMERATA. 

 Spikelets ferruginous, oblong, crowded, sessile : perigynium ovate 



or deltoid, coriaceous, spongy at base. 15. C. PANICULATA. 



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. 16. C. LAGOPINA. 



Leaves and often the filiform bracts far exceeding the stem : 



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



gradually beaked, sharply margined, serrate, nerveless. 17. C. PHYLLOMANICA. 

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



margins not winged, smooth or rarely scabrous. 18. C. BONPLANDII. 



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. 19. C. FESTIVA. 

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

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

 strongly nerved, serrate on the narrow wings, spreading. 20. C. SUBFUSCA. 



