SEDGE FAMILY. 



89 



of leafy or scale-like bracts, either wholly pistillate and wholly 

 staminate or with both pistillate and staminate flowers which are 

 occasionally dioecious. Flowers in the axils of scale-like bractlets. 

 Staminate flower of 3 stamens. Pistillate flower consisting of a single 

 pistil; ovary enclosed in an inflated bract or sac (perigynium) con- 

 tracted at the top through which project the 2 or 3 stigmas. Achene 

 triangular, lenticular or plano-convex, completely enclosed in the 

 perigynium. (Latin name used by Yirgil for the sedge. The key 

 to our species of this critical and difficult genus has been adapted 

 from Prof. L. H. Bailey's " Preliminary Synopsis of North American 

 Carices." For the briefly described vegetative characters we have 

 drawn largely from Boott's account of the California!) species, in the 

 absence of sufficient material; it is a matter for regret that so few 

 specimens of this interesting genus are brought in by local collectors.) 



Spikelets unisexual or rarely androgynous; staminate flowers forming 1 or more 

 terminal linear or club-shaped spikelets, which are occasionally sparingly 

 androgynous; pistillate flowers usually in distinct and simple mostly pedi- 

 cellate spikelets; cross-section of the perigynium circular, obtusely angled 

 or prominently trigonous in outline; style mostly 3-parted; achene mostly 

 trigonous or triquetrous.— Sub-genus Eu-CAKEX Coss. 

 Perigynium large, tapering into a beak as long as or longer than the body, 

 papery in texture, more or less inflated, smooth, nerved, straw-colored or 

 occasionally purple at maturity; spikeleis few to many, distinct, com- 

 pactly flowered; stigmas 3. 

 Perigynium much inflated, usually prominently few-nerved, beaked, con- 

 spicuously short-toothed; staminate spikelets commonly 2 or more; 

 pistillate usually long and densely cylindrical; plants mostly large and 



stout 1. C. vesicaria. 



Perigynium less inflated, more conspicuously nerved or even costate; teeth 

 more or less setaceous or aristate; bractlet usually aristate; spikelets 



mostly nodding, comose in appearance 2. C. Pseudo-cypems 



var. comosa. 



Perigynium small, nearly or entirely beakless and mostly entire mouthed , 

 thinner in texture; mostly paludose species with colored spikelets; often 

 growing in dense tufis or tussocks. 

 Spikelets short and erect, very closely flowered, the terminal strietly 

 staminate; bracts with purple or black auricles at base; stigmas 2 or 3; 

 mostly stiff and rigid species. 



Stiamas 3 3. C. bifida. 



Stigmas 2 4. C. nudata. 



Spikelets long and large, green or light-colored; stigmas 2; species larger, 

 distinguished mainly bv habit; mostly paludose. 

 Stems clotiied with dead sheaths below; spikelets mostly long pedicellate. 



5. C. obnupta. 



Stems spongy at base; spikelets mostly sessile .... 6. ('. aquatilis. 

 Spikelets large, cernuous or drooping, mostly dark-coloied; stigmas 2; 

 bractlets very long and conspicuous; plants large. 7. C. Sitehensis. 

 Perigynium mostly short and rounded; beak straight and usually 2-fid, firm 

 or hard in texture, not inflated, hairy or scabrous; staminate spikelet 1: 

 pistillate spikelets 1 in. or less long, usually globular or short-oblong, more 

 or less sessile and approximate, or the longer ones radical: bracts sheath - 

 less, short or obsolete; stigmas rarely 2; low species of dry ground, with 

 leaves all radical. 



Spikelets 2 to several, the lowest occasionally long-pedicellate and radical; 

 perigynium abruptly rounded above, contracted above and below, 

 bearing a more or less prominent rib on each side 8. C. plobosa. 

 Spikelets androgynous (rarely dioecious or some of the spikelets unisexual); 

 staminate flowers usually borne at the base or apex of the pistillate spike- 

 lets, rarely the staminate and pist illate flowers irregularly situated: pistillate 

 flowers mostly in short and sessile spikelets (in some cases the spikelets 



