ORDER 155. CYPERACE^E. 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-ventr icons, subplano-convex, veined, scabrous or serrulate on the 

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

 with long, narrow leaves. III. to Nebraska and Brit. Am. 



14 C. ckordorrhiza L. Spikelets 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 tho joints ; 

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

 (Cooley.) 



15 C. Leavenworthii Dew. SpiJcelets 4 to G, small, ovate, sessile, bracteate, 

 aggregated into an oblong 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. (Leavea- 

 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 glume. 

 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 C. nvuricata 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 ovate-lanceolate glume. 

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



18 C. sparganioidea Muhl. Spikelets 7 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 ; st. 

 about 2f high, with long, striate leaves. 



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

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

 vated and moist fields, common. 



19 C. rcsea Schk. Spikelets 3 5, subremote, sessile, alternate, stellate, even 

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

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

 as long as the ovate-obtuse glume; st. 8 16' 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 ; the variety is about 

 woods, or open places in woods. 



20 C. retroflexa Muhl. Spikelets about 4, cvate, alternate, subapproximate, 

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

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

 and acute glume; ct. about a foot high. Readily 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 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 basn. Common in fields. (C. multiflora 

 Muhl.) 



