512 CYPF.T7ACE.ffi. (SEDGE FAMHY.) 



16. C VlilpiilOsdca, Michx. Spike oblong and dense, or more or lest 

 interrupted, of 8-10 crowded dusters (U'-^V long); pcrigynia cvate from a 

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

 flora, Muld. C. braeteosa aud C. polymorpha, ,Si /<//:. C. microsperma, Wahl.) 



Varies witli the perigynium narrower, and the beak tapering and more strongly 

 serrulate. (C. setaeea, AT.) Low meadows; very common. Varies ex- 

 ceedingly in the size and shape of the perigynium and beak. 



# * * Perigynia on short, stalks, plano-convex, without a mart/in, membranaccous, 

 u-ith a thick and spongy base and a long tapering 2-toothed rough beak, distinct- 

 ly nerved (only obscurely so in Xo. '20 and 21), widely spreading and yellow at 

 maturity : spikes dense, more or less aggregated, sometimes decompound : 

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

 shorter than the thick and triangular culms. VULPIN^E. 

 11. C. crus-c6rvi, Slmttleworth. Spike very large, decompound, the 

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

 ^.-toothed at the base; perigynia attenuated from an orate dilated and truncate base into 

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

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

 southward. A conspicuous, very large species, with spikes 4' -9' long, often 

 somewhat paniculate, and glaucous It-ares \' wide. 



18. C. Stipiita, Muhl. Spikes 10-15, aggregated, or the lower ones dis- 

 tinct and sometimes compound ; periyynia lanceolate, with a long beak tapering 

 from a truncate base, much exceeding the scale; st.yle not tumid at the base. (C. vul- 

 pmoidea, Torr., Cyp., not of Michx.) Swamps and low grounds; common. 



19. C. viilpma, L. Spikes numerous, aggregated into a cylindrical and 

 dense (or at times elongated and somewhat interrupted) compound spike; peri- 

 gynia compressed, tapering from a broadly-ovate base into a beak not much longer than 

 the scale; achenium oval; style tumid at the base. Ohio, Illinois, and Kentucky. 



A tall, robust species, 3 -4 high, with wide leaves and a remarkably thick 

 rough culm. It is very like the last, from which it chiefly differs in the more 

 compressed and wider base and shorter beaks of the perigynia. The forms 

 with interrupted spikes have also a general resemblance to No. 22 ; which, how- 

 ever, is distinguished by the margined and nerveless perigynia. (Eu.) 



20. C. alopccoidca, Tuckerman. Head of 8-10 aggregated spikes 

 oblong, dense ; perigynia compressed, very obscurely nerved, ocate from a broad trun- 

 cate or somewhat heart-shaped base, a little longer than the scale ; achenium pyri- 

 form; base of the style not tumid. (C. cephalophora, var. maxima, Dew.) 

 Woods, W. New York to Penn., Michigan, &e. Much resembling the last, 

 but smaller, with shorter and more compact spikes ; easily distinguished by the 

 nearly nerveless perigynia, and ihe ditl'erent achenium and style. 



21. C. mail irtJa, L. Spikes 4-G, ovoid, approximate but distinct, tho 

 lowermost sometimes a little remote; -p< rii/ytiia. or.ale-lnnccolatc, somewhat com- 

 pressed, nt-rrcU-Ks, or rcry oLsrurc/y n<rc< </ Imrards lite, base, rather longer than the 

 scale; acheniunt orate, base of the style not tumid. Fields, Massachusetts (in- 

 troduced?), Ohio, and Kentucky; rare. Spikes mostly looser than in the last, 

 the perigynia narrower, with a longer and more tapering beak. ^Eu.) 



