750 Oeder ,155.— OYPERAOB^. 



suboval or oblong, tapering at base, veined, convex-terete, aitmuate above into a 

 terete, shortish, straight or svbrecwrved, bidentate beak, nearly horizontal in maturity, 

 longer than the ovate and acute glume ; cuhn slender, 4 to 6' high, with long slan- 

 der leaves sl\eathing at base. Wayne Co., N. Y. (Sartwell), N". to Greenland. 

 (C. Davalliana, 2d edit.) 



3 C. ^xilis Dew. (Boott, lUust, No. 45.) S Spike terminal, ovate or oblongi 

 close-flowered, st&minate below, sometimes a single 3 spike or a single S -spike ; 

 perig. ovate-lanceolate, convex above and slightly below, sernUate on the margin, 

 minutely veined above, 2-toothed, diverging, some longer than the ovate-lanceolato 

 glume; cvlm 12 to 20' high, stiffly erect, and Ivs. setaceous. — Swamps, E. Masa 

 (Oakes), Sandford Lake, N. T. (Sartwell). 



/?. ANDKOGYNA. One Or more short S spikes below the terminal. — Manches- 

 ter, N. T. (Kneiskern). 



4 C. st6rilis Willd. (Boott, lUus., No. 135.) Spike compound, i below, often 

 dicecious ; spikelets 4 — 6, ovate, subapproximate ; perig. ovate, acuminate or sub- 

 rostrate, bifid, compressed, triquetrous, scabrous on the margin, equaling the ovate, 

 acutish glume ; st. 2f high, erect and stiff. AVet places, common. (C. stellulata 

 (3. STEEiLis Torr., Carey.) 



5 C. bromoidea Schk. Spikelets numerous, alternate, S below, sometimes all 

 ! ; perig. lanceolate, erect, acuminate, scabrous, nerved, bifid, twice longer than 



iJie ovaie-lanceolaie glimie. — Common in small bogs, in wet places. 



6 C Bicoata Dew. (Boott, Illust., No. 50.) Spikelets numexom, $ above, often 

 whoUy $ , ovate, 'dose or approximate ; perig. ovate, lanceolate, acuminate, com- 

 pressed, nerved, bifid, scabrous on the margin, equaling tlie ovate, lanceolate glume. 

 — Sandy plains, Westfield, Mass. (Davis) ; Ipswich, Mass. (Oakes) ; widely spread 

 over the country, but not abundant, W. to 111. 



7 C. Sarfwellii Dew. Spikelets 12 — 20, ovate, sessile, compact, bracteate, lower 

 ones especially fructiferous ; upper often $ at apex, sometunes wholly S ; perig. 

 ovate, lanceolate, convexo-concave, subulate, shghtly 2-toothed, margined and 

 scabrous on the edge, a little longer than the ovate and acute glume ; Ivs. flat, 

 linear, shorter than the stem. — Junius, Seneca Co., N. Y. (Sartwell). 



8. C. distycha Huds. Spikelets mamy, 2-rowed or compressed into a flattened, 

 compound, loose spilce ; spikelets oblong-ovate, close, alternate, often branched be- 

 low and the lowest sometimes remote, upper and lower often S , and the inter- 

 mediate wholly S , or from the middle wholly S upwards ; perig. ovate, narrow- 

 rostrate, margin serrulate, narrow, equaling tho ovate, acute glume ; culm erect, 

 leafy below. — Wis. (Lapham), 111. (Tasey), Mich. (Cooley), N. to Arc. Am. (0. 

 intermedia Good.) 



9. C decomp6sita Muhl. (Boott, Illust., 53.) Spike decompound or paniculate; 

 spikelets very many, ovate, alternate ; perig. ovate, convex on botli sides, triangu- 

 lar, acutish or short rostrate, short, brownish, glabrous, lairger than the ovate, acu- 

 minate, whitish glume; St. 18 — 30' high. — Found in swamgs, Michigan, and in 

 Yates Co., N. York (SartweU). 



10 C. prairea Dew. Spike below branched ; spikelets ovate, sessile, 5 to T on a 

 branch ; perig. ovate-lanceolate, convex both sides, scabrous on the margin, slightly 

 bifid, smaMer than the ovate-lanceolate glume ; St. 2 — 3f high, leafy towards the 

 base. — Abundant in the prairies of Michigan, and sparingly found in N. England 

 and N. Y. Resembles C. paniculata L., which has a much broader ovate glume 

 shorter than the perigynium and is far more paniculate, and for which this has 

 been taken. Prom No. 24 it is far separated by its panicle, and the color and 

 shape of its fruit 



11 C. oephalophora Willd. Spikelets ovate, densely aggregated into an ovaie 

 head (1 J' hng), bracteate, about 5 ; perig. ovatft acuminate, compressed, bifid, 

 scabrous on the margin, with a short, ovate, and scairo-daspidate glume, which 

 equals it; st. 8 — 16' high. — Borders of fields and woods, common, but not 

 abundant. 



12 C. Mulilenbergii Schk. Spikelets alternate, obtuse, approximate into an 

 ovate-oblong head, i' long, with a long bract at the lower one ; perig. ovate con- 

 vex above, very smooth, nerved, bifid, scabrous on the margin, some diverging, 

 it little shorter than the ovate and mucronaie glume; st. 12 — 18' hio-h. ^In 



