CYPERACE^E. (SEDGE FAMILY.) 575 



base ; scale acute, rather shorter than the perigynium ; achenium obovoid-pyriform, 

 obtusely triangular. ( C. paniculata, var. teretiuscula, Wahl. ) — Swamps, especially 

 northward. (En.) 



Var. major, Koch. Spikes more panicled ; perigynia rather narrower. 

 (C. Ehrhartiana, Hoppe. C. prairiea, Dew.) — Bogs and low grounds, New 

 England to Wisconsin, and northward. (Eu.) 



14. C. decomposita, Muhl. Panicle large, with very numerous densely- 

 crowded spikes on the rather short spreading branches ; perigynia obovate, un- 

 equally biconvex, sessile, with a short very abrupt beak, conspicuously nerved on each 

 side, about the length of the ovate pointed scale. (C. paniculata, var. decom 

 posita, Dew.) — Swamps, W. New York (Sartwell) to Pennsylvania, Illinois, 

 and south westward. 



* * Perigynia small, compressed, 2-3-nerved, membranaceous, with a short 



2-toothed rough beak, yellow or brown at maturity : spikes decompound, with 

 numerous small very densely -flowered heads : scales of the fertile spikes tawny, 

 with the green keel prolonged into a rough point : bracts short and resem- 

 bling them at the base, or often becoming green and bristle-shaped, and 

 much exceeding the culm. — Multifl6r^e. 



15. C. VUlpinoidea, Michx. Spike oblong and dense, or more or less 

 interrupted (l^'-2^' long), of 8-10 crowded clusters; perigynia ovate from a 

 broad base, with a more or less abrupt beak, diverging at maturity. (C. multi- 

 flora, Muhl. C. bracteosa and C. polymorpha, Schw. C. microsperma, Wahl.) 

 — Varies with the perigynium narrower, and the beak tapering and more 

 strongly serrulate. (C. setaoea, Dew.) — Low meadows : everywhere common. 



* * * Perigynia on short stalks, plano-convex, without a margin, membranaceous, 



with a thick and spongy base and a long tapering 2-toothed rough beak, dis- 

 tinctly nerved (only obscurely so in No. 19 and 20), widely spreading and 

 yellow at maturity : spikes dense, more or less aggregated, sometimes decom- 

 pound : scales of the fertile spikes tawny, with a sharp point : bracts bristle- 

 shaped, shorter than the thick and triangular culms. — Vulpin^e. 



16. C. crus-eorvi, Shuttleworth. Spike very large, decompound, the 

 lower branches long and distinct, the upper shorter and aggregated ; bracts often 

 2-toothed at the base ; perigynia attenuated from an ovate diluted and truncate base into 

 a very long slightly-winged beak, much exceeding the scale ; style tumid at the base. 

 (C. sicaefbrmis, Boott. C. Halei, Dew.) — Swamps, Ohio to Wisconsin, and 

 southwestward. — A conspicuous, very large species, with spikes 4' -9' long, 

 often somewhat paniculate, and glaucous leaves 6" wide. 



17. C. stipata, Muhl. Spikes 10-15, aggregated, or the lower mostly 

 distinct and sometimes compound ; perigynia lanceolate, with a long beak tapering 

 from a truncate base, many-nerved, much exceeding the scale; style slightly tumid at 

 the base. (C. vulpinoidea, Terr., Cyp., not of Michx.) — Low grounds: com- 

 mon. — Culm flaccid : spikes pale. 



18. C. COnjlincta, Boott. Resembles the preceding; but the spikes 

 (6-12) more simple; perigynia ovate from a subcordate flat (not corky-tumid) 

 base, short-beaked, fewer-nerved, longer and broader than the pointed scale ; 

 style bulbous at the base. (C. vulpina of former editions; — from which it 



