076 CYPERACIwK. (sedge FAMIL'*.-) 



differs in its flaccid culm, transversely wrinkled slieaths, orbicular aGhcnium, 

 &c.) — Oliio to Illinois and Kentucky. 



19. C. alopeeoidea, Tuckcmian. Head of 8-12 aggregated spikes, 

 oblong, dense ; jierii/ijuia com/inssf-d, uerrcli'ss or nry dmcunJi) mrvetl, ovate, from 

 a broad truncate or somewliat heartshajied base, a little longer than the scale ; 

 achfiiiiiim pi/ri/orm ; base of the. style not tumid. (C. cephalophora, var. maxinui, 

 Drtu.) — Woods, W. New York to Penn., Michigan, &c. — Kcscmbles the last, 

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

 murlji nerveless per'iijynla, and the difl^"crcnt achenium and style. 



20. C. muricata, L. Spikes 4-6, ovoid, approximate but distinct, the 

 lowermost sometimes a little remote; pcrirji/nia ovate-lancwkUe, somawhat com- 

 pressed, iitrveltss, or very obscurely nerved lotvurds the base, rather longer than the 

 scale; achenium ovate; base of the style not tumid. — Fields, Massachusetts 

 (introduced ?), Ohio, and Kentucky : rare. — Spikes mostly looser than in the 

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



* * ^ * Purij/yiiia sessile, plano-convex, compressed, more or less margined, mem- 

 branaceous, with a rather short and rough (or wholly smooth in No. 26) 

 2-toothcd beak, spreading and yreen at maturity: scales of the fertile spikes 

 tawny or white : bracts bristle-shaped, commonly shorter than the culm. — 

 MuiilenbergiXn-e. 



21. C. SparganioldeS, Muhl. Spikes &-l2, ovoid; the upper ones a fjcjre- 

 gated, the lower distinct and more or less distant; perigynia broadly-ovate, nerveless, 

 rough on the narrow margin, about twice the length of the ovate-pointed scale; 

 achenium roundish-ovate ; style short, merely tumid at the base. — Var. JIINOR, 

 Boott, is merely a reduced form. (C. cephalophora, var. Torr. C. muricata, 

 var. ccphaloidca, Deiv. C. cejjhaloidea, Dew. in part. ) — Low rich grounds. — 

 A robust species, with rather wide pale-grceu leaves; sometimes with 1-2 short 

 branches of a few spikes each at the base of the compound spike (probably C. 

 divulsa, Pursh, not of Goodenougli). 



22. C. cephaloidea, Dew. (in part), Boott. Spikes 5 or 6, contiguous; 

 the broadly ovate pirigynia icing-margined, spongy at the base, shorter beaked, 

 equalling or shorter than the cuspidate-tipped scale; style bulbous at the base. — 

 New York? Illinois ( Vasey), — Much resembles and has been confounded with 

 the small form of the foregoing. 



23. C. cephalophora, Muhl. Spikes .5-6, small, and densely aggregated 

 in a short ovoid head ; perigynia broadly ovate, with 3-4 indistinct nerves on the outer 

 side, scarcely longer than the ovate roughly-pointed scale ; achenium and style 

 as in the last. (C. cephaloidea. Dew. (in part.) — Var. angustifAlia, Boott, 

 is a narrow-leaved, smaller form. (C. Leavcnworthii, /)(-«?.) — Woods and 

 fields : common. 



24. C. Muhlenbdrgii, Schk. Spikes 3-9, closely approximate, forming 

 an oblong head ; jieriijijiitti orbit ular-ovate, with a very short beak, prominently many- 

 yiervedon both sides, about the length of the ovate roughly-pointed scale; ache- 

 uium orbicular, with a very short buUmts style. — Fields: rather common, especially 

 southward. — Culms 12' -18' high, and with the leaves pale and rigid: com- 

 monly with a bract to each spike. 



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