Oeder 155.— CTPESACEiE. 751 



fields, not very common, readUy distinguished from the three preceding and fol- 

 lowing. 



13 C. Btenoph^Ua Wahl. Spilces 3 to 5, aggregated mto a roundish head;' perig. 

 ovate, raundisJirveniricom, subplano-eonvex, Tsined, scabrous or serrulate on the 

 margin, bidentate, about equaling the ovate, acute ■glume; culm 3 to 6' high, smooth, 

 with long, narrow leaves. — 111. to Nebraska and Brit. Am. 



14 C. cbordorrhiza L. SpiJceleis 3 — 5, aggregated into a head, ovate, sessile ; 

 perig. ovate, acuminate, subrostrate, convex above, equaling the broad, ovate and 

 acute glume ; st. branching towards the base and sending out roots at the joints ; 

 spikes rarely bearing only stamens. — Marshes, N. T., common (Sartwell), Mich. 

 (Cooley.) 



15 C. Leavemworthii Dew. SpiJcelets 4 to 6, small, ovate, sessile, braoteate, 

 aggregated into an ollong head, the lower sometimes separated a little ; perig. 

 ovate, broad, short, convex above, abruptly short-beaked, slightly bifid, glabrous, 

 scabrous on the edge, scarcely twice longer than the short, ovate, acute glume; 

 culm rarely If high, slender, leafy towards the base; Ivs. narrow, flat; whole 

 plant pale green. — Ky. (Short) to Ala. (Wood), Fla. (Chapman) and La. (Leaven- 

 worth.) 



16 C. cephaloidea Dew. Spikelets 4 — 6, ovate, aggregated closely, sessile and 

 bracteate; perig. ovate, obtusish; bifid, scabrous on the margin, plano-convex, 

 very diverging in maturity, about twice as long as the short, ovate, obtusish ghime. 

 — Dry fields, not abundant, but common over New England and New York. In 

 hedges it is often four feet long, and subrostrate, leafy towards the base. (C. 

 sparganoides, /3. Carey.) 



17 Cf. irrario&ta L. Spikelets about 5, ovate, sessile, approximate, bracteate, lower 

 ones sometimes remotish ; perig. ovate-lanceolate, plano-convex, 2-toothed, hori- 

 zontal, scabrous on the margin, sometimes longer than the ovaie-lcmceolate glume, — 

 Fields near Boston (Green, Curtis), and common in Arc. Am. 



18 C. sparganioides Muhl. Spikelets 1 — 10, ovate, rather distant, bracteate, 

 sessile ; perig. ovate, acute, compressed, diverging, acuminate, 2-toothed, scabrous 

 on the margin, nearly twice the length of the ovate, acute, or mucronate glume ; si. 

 about 2f high, with long, striate leaves. 



/3. EAIIBA Dew, has one branch or more at the base, with several spikelets in 

 the place of the lower spikelet, and is the C. divulsa of Pursh.-r- About culti- 

 vated and moist fields, common. 



19 C. rosea Schk. Spikelets 3 — 5, subremoto, sessile, alternate, stellate, even 

 before maturity, lowest long-braoteate ; perig, oblong-lanceolate, 5 — 12, convex 

 above, scabrous on the margin, 2-toothed, very diverging, or even reflexed, twice 

 as long as the ovate-obtuse glume; si. 8 — 16' liigh. 



/?. RADIATA Dew. Spikelets distant, about 3-flowered, with setaceous bracts ; 

 perig. oblong, acute ; st. 4 — 8' high, flaccid or lax, setaceous, with very nar- 

 row leaves. — Common in pastures and moist woods ; the variety is about 

 woods, or open places in woods. 



20 C. retrofl^xa Muhl. Spikelets about 4, ovate, alternate, subapproximate, 

 sessile, braoteate and stellate in maturity ; perig. ovate, acutish, 2-toothed, sub- 

 scabrous or smooth on the margin, reflexed and spreading, about equal to the ovate 

 and acute glume; ct. about a foot high. — EeadUy distinguished from the preced- 

 ing. Woods and pastures, not abundant. (0. rosea, j3. Toum.) 



21 C. disperma Dew. Spikelets 3 or 4, erect, subapproximate, lowest bracte- 

 ate ; perig. 1 or 2, rarely 3, ovate, obtuse, nerved, plano-convex, short-beaked, 

 glabrous, twice longer than the ovate, acute, submucronate glume ; st. slender, 5 

 to 12' high, flexile, in tufts of several, with narrow and linear leaves. — ^Wet 

 woods, N. Eng. to Wis. (C. tenella, Carey, Boott., not of Ehrh.). — ^The species is 

 common in N. Eur., but had never been recognized in this country, when de- 

 scribed, 1824. 



22 C. vulpinoidea Mx. Spikelets ovate-oblong, obtuse ; spike decompound, 

 bracteate, conglomerate ; perig. ovate, acuminate, densely imbricate, bifid, tripli- 

 nerved, diverging, a little shorter than the ovate-cuspidate glume; st. obtusely 

 triangular, round and leafy towards the bass. — Common in fields. (C. multiflora 

 Muhl.) 



