SEDGE FAMILY. 89 



of leafy or scale-like bracts, either wh.olly 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 Virgil for the sedge. The key 

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

 from Prof. L. H. Baileys "Preliminary Synopsis of North American 

 Cariees." For the briefly described vegetative characters we have 

 drawn largely from Bootts account of the Californian species, in the 

 absence of sufiieient 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 iisually in distinct and simple mostly pedi- 

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

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

 trigonoDs or triquetrous. — Sub-genus Eu-carex Cosa. 

 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 pnrple at maturity; spikeleis few to many, distinct, com- 

 pactly flowered; stigmas 3. 

 Perigynium much inflHted, 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. ve^icnria. 



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

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

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



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 tufts or tussocks. 



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



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



mostly stiff and rigid species. 



Stiamas 3 . . .... 3. C. bijida. 



Stigmas 2 *■ C. nudata. 



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

 distinguished mainly bv habit; mostly paludose. 

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



5. C. obnupta. 

 Stems spongy at base; spikelets mostly sessile .... 6. C. aquaiilis. 

 Spikelets large, cemuous or drooping, mostly dark-colored; stigmas 2; 

 bractlets very long and cnnspieuons; plants large. 7. C. SUchensis. 

 Perigynium mostly short and rounded; beak straight and u&nally 2-fid. firm 

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

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

 or less sessile and approximate, or the longer onis radical; bracts sheatn- 

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

 leaves all radical. . ,, , j- „ . j j- , 



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

 perigynium abruptly rounded al)ove, contracted above and below, 

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

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

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

 lets rarely the staminate and pistillate flowers irregularly situated; pistillate 

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



