CTPERACK.i:. (sedge FAMILY.) 509 



ou the back, thrico the length of the lincar-ohloiij dull nut ; ihizonia creeping, 

 bearing tuber-liko buds; culms stout. (30-5° high), tumid at the sheathed base. 



— Marshes near the coast, Florida to South Carolina. Aug. - Sept. y, — 

 Flowers mostly abortive. 



* * Culms 3-angled, knotless: involucre leafy : nut. olovate. 



17. C. Haspan, L. Umbel many-rayed, decompound, spreading, the fili- 

 form rays mostly longer than the 2-leaved involucre; spikelets small (4" -5" 

 long), 3-5 in a cluster, linear, acute, 20 - 40-flowered ; scales liglit reddisii- 

 brotvn, very small, oblong, mucrouate, 3-ncrvcd, free at the apex ; nut white, 

 round-obovate, granular-roughened ; culms tender, sharply angled ; leaves lin- 

 ear, smooth, shorter than the culms (1° - 1^°), often reduced to membranaceous 

 sheaths. (C. gracilis, J/((/(/. C. leptos, SchulUs.) — Pouds and ditches, Flor- 

 ida to North Carolina, aud westward. July - Sept. 



18. C. dentatus, Torr. Umbel compound, erect, 4- 7-rayed, shorter than 

 the 3-4-Ieaved involucre; spikelets 3-5 in a cluster (3" - 7" long), ovate-ob- 

 long, obtuse, flat, 12-30-flowercd ; scales ovate, acute, compressed, 7-nerved on 

 the green keel, membranaceous on the reddish brown sides, spreading at tho 

 apex ; nut minute, roimd-obovatc, whitish ; rliizomii creeping, bearing tubers ; 

 culms slender (1° high), obtuse-angled, longer than tlie rigid keeled leaves. — 

 Sandy swamps and banks. South Carolina, Torrcy, and northward. Sept. y. 



— Rays 1 ' - 2' long. 



19. C. Lecontii, Torr. Umbel compound, erect, 6-12-rayed, shorter 

 than the 3-leaved involucre ; spikelets commonly three in a cluster, oblong or 

 linear-oblong, obtuse, flat, 30- 7()-flowcrcd (J'- I'long); scales closely imbri- 

 cated, ovate, obtuse, compressed, ycllowi.>h, faintly 7-nei'ved, appressed at tho 

 apex; nut minute, round-obovate, blackish ; culms rigid, obtuse-angled, as long 

 as the rigid leaves. — Low sandy places along the coast. East and West Florida. 

 July- Sept. U — Rhizoma creepmg Culms 6'- 12' high. Rays 2' -6' long. 

 Rachis with very short joints. Whole plant pale straw-color. 



4. GlOMERAti. Umbel sunple or roiu/iouutl : s}>'kilets many-flowered, compressed, 

 numerous in a cluster , forming more or less dense heads at the suinmil of the coni- 

 mon and partial rays: rachis wingless: stamen solitary. 



* Umbel compound : spikelets ovate or oblong, flat : scales S-nerved, concave on the 

 buck, acute . nut minute, lanceolate or oblong.- 



20 C. virens, Michx. Umbel spreading, compound, many-rayed ; invo- 

 lucre 4 - 6-leaved, many times longer than the umbel ; spikelets (4'' - 6" long, 

 and about 20 in a cluster) oblong, 30 - 40-flowered, pale green ; scales oblong- 

 lanceolate, straight; nut lanceolate, acute at each end; culms stout (2° -4° 

 high), rough-angled above ; leaves broad, elongated, reticulated, rough on tho 

 margins. Miry places, Florida to North Carolina. July- Sept. U — Plant 

 pale green. Rays 3' -4' long. Spikelets turning yellowish. 



21 C. vegetUS, Witld. Umbel often decompound, many-rayed, widely 

 spreadinff ; involucre 4-leaved, many times longer than the umbel ; spikelets 

 short (li"-2" long), ovate, 1 - 1 5-flowered, very numerous in the heads ; scales 



43* 



