Order 155.— CYPERACEiE. 751 



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

 lowing. 



13 C. stenoph^-lla Wahl. Spikes 3 to 5, aggregated into a roundish head; perig. 

 ovate* roundish-ventricous, subplauo-convex, veined, scabrous or serrulate on tho 

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

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



14 C. chordorrhiza L. Spikdets 3 — 5, aggregated into a head, ovate, sessile ; 

 perig. ovate, acuminate, subrostrato, convex above, equaling the broad, ovato and 

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

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

 (Cooley.) 



15 C. Leavenw6rthii Dew. Spikelets 4 to G, small, ovate, sessile, bracteate, 

 aggregated into an oblong head, tho lower sometimes separated a little ; perig. 

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

 scabrous on tho edge, scarcely twice longer than tho short, ovato, acute glume; 

 culm rarely If high, slender, leafy towards the base; lvs. narrow, flat; wholo 

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

 worth.) 



16 C. cephaloidea Dew. Spikelets 4 — G, ovate, aggregated closely, sessilo and 

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

 very diverging in maturity, about twico as long as tho short, ovate, obtusish glume. 

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

 hedges it is often four feet long, and subrostrato, leafy towards tho base. (C. 

 sparganoides, /?. Carey.) 



17 C. muricata L. Spiheleis about 5, ovate, sessile, approximate, bracteate, lower 

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

 zontal, scabrous on tho margin, sometimes longer than the ovate-lanceolate glume. — 

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



18 C sparganioidea MuhL Spikelets 1 — 10, ovato, rather distant, bracteate, 

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

 on tho margin, nearly twia the length of the ovate, acute, or mucronate glume; st. 

 about 2f high, with long, striate leaves. 



/?» ramea Dew, has ono branch or more at the base, with several spikelets in 

 the placo of the lower spikelet, and is tho C. divulsa of Pursh. — About culti- 

 vated and moist fields, common. 



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

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

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

 as long as the ovate-obtuse glume ; si. 8 — 1G' high. 



/?. 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 ; tho variety is about 

 woods, or open places in woods. 



20 C. retroflesa Muhl. Spilcelels about 4, ovate, alternate, subapproximate, 

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

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

 and acute glume; ct. about a foot high. — E.eadily distinguished from tho preced- 

 ing. "Woods and pastures, not abundant. (C. rosea, /?. Tourn.) 



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 tho ovate, acute, submucronate glumo ; 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. vrdpinoidea 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 ; sL obtusely 

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

 Muhl.) 



