Oedee 165.— OTPERACB^. 733 



/3. MiKiML-s. Invol. of 1 or 2 Ivs. Spikes 1 or 2, 10 to 12-flow6red; glumes 

 loosely imbricated, acute ; stam. 1. — Culm and Ivs. setaceous. N. J. (Torr.) 



3 C. Gatdsii Torr. Culm 8 to 12' high, slender, obtusely 3-angled, umbel of 6 

 to 8 distiTict, very unequal ra/ys ; spikes alternate, rather remote, linear-lanceolate, 

 10 to 12-flowered, the lowest compound; scales acute, loosa, pale straw-yeUow ; 

 stam. 2 1 sty. deeply 2-cleft ; ach. obovate, obtuse, dull, dark gray. — Near Mobile, 

 Ala. (Gates, in Torr. Cyp.). Plant pale green. Invol. about 3-leaved. 



4 C. flavescens L. Culm 4 to 10' high, leafy below; wnbd of 2 to i sliort rays; 

 spikes linear, obtusish, 15 to 20 or 30-flowered; glumes obtuse, straw-color, broad- 

 ovate, l^eined; stam. 3 ; sty. deeply 2-cleft; ach. suborbioular, dark brown, shin- 

 ing. — Marshy grounds, U. S., common in Penn. (Jackson). Lvs. about as high as 

 the culms. Spikes 5 to 9" long, IJ" wide, in crowded fascicles of 3 to 6 on each 

 short raohis. Aug. 



5 C. flavioonms Mx. Culm 1 to 3f high, 3-angled ; inyoL 3 to 5-leayed, very 

 long ; umbel somewhat compound, of many (4 to 1) spreading rays ; spikes nume- 

 rous, lance-linear, divaricate, loosely 12 to 30-flowered; glumes very obtuse, brown- 

 ish yellow, green and 3-veined on the keel, with a broad, white-scariovs margin ; 

 stam. 3; sty. short, 2-cleft; ach. obovate, blackish. — Bogs, also in dry soils, Va. 

 to Pla. Spikelets 1 to 10" long. Glumes somewhat truncate and emarginate. 

 May — Sept. 



6 C. articulatus L. Jointed Sedge. Cukn 2 to 6f high, with internal joints, 

 and several ifeafless sheaths towards the base ; lvs. none or sheath-like ; umbel 

 compound, loose, with about 5 rays ; invol. 2 or 3-leaved, short , spikes linear- 

 subulate, alternate, 14 to 20-flowered; glumes lanceolate, obtusish, with a green 

 keel, membranous sides, white, with red dots ; stam. 3 ; sty. 3-cleft ; ach. acutely 

 3-angled. — River swamps, S. States. Rt. Jointed, creeping. Jn. — Aug. 



7 C. eruthrorbizos Muhl. Culm 2 — 3f high, obtusely triquetrous, longer than the 

 leaves; umbel compound; rays 5 — 9, 3 — 4' long, each with 3 — i sessUe clusters; 

 sheaths entire; spikelets very numerous, 6" long, crowded and spreading in the 

 oblong subsessile (heads) clusters, a little flattened, about 13-flowered ; outer 

 glumes muoronate, closely imbricated, chestnut-brown, veinless and. shining, the 

 imter ones entirely free from the rachis ; sta. 3 ; ach. smooth and shining, much 

 shorter than the glume. — ^Wet grounds Penn. and Southern States. 



8 C. H:^dra Mx. Kutt Grass. Culm 6 to 12' to 2f high, 3-angled ; lvs. shorter 

 than the culm ; umbel simple, 3 or 4-rayed, rays nearly as long as the involucre ; 

 spikes linear, alternate and 2-rowed on the rachis, 14 to 24-flowered; glumes 

 ovate, veinless, acute, separate at the tips, of a fine purple brown; stam. 3; sty. 

 3-cleft, much exserted ; ach. 3-angled. — Sandy fields, Ta. to Fla. and La. Very 

 troublesome in cotton fields. Rhizomes creeping and branching extensively, 

 bearing tubers. Spikes 6 to 12" long. ' Apr. — Jl. 



9 C. phymatddes Muhl. Culm 1 — 2 f high, 3-anglcd, striate; lvs. subradical, 

 as long as the stem; umbel 4 — 6-rayed; rays often iDranched, bearuig 12 — 20 

 linear, obtuse spikelets somewhat in 2 rows ; sheaths obliquely truncate, involu- 

 cels ; spikelets 12 — 20-flowered, G — 8" long, the lowest generally fasciculate ; 

 glumes veiny, yellowish. — 71 Moist fields, N". Y. to "Wis. and S. States. Rhizomes 

 creeping, bearing small, round tubers at the ends. May — Aug. 



IOC. dissitiflorus Torr. Culms slender, tumid at the base, 1 to 2f high ; lvs. 

 narrow, nearly radical; umbel 3 to 5-rayed, suberect, half as long as the involu- 

 cre ; spikes remotely alternate, suidistychous on the slender rays, teretish, slender, 

 5 to 7-flowered, 6" to V long ; glumes lance-oblong, acuto; ach. brown, 3-angled. 

 — E. Tenn. 7 to La, Plant slender, erect. Rays of the umbel 1 to 3' long. 

 Spikes divaricate and reflexed. Aug. 



11 C Michausianus Schultes. Culm acutely triangular ; umbel compound, with 

 short rays ; spikelets 6 — 9-fiowered, the lower ones compound ; rachis very broad, 

 easily separating at the joints; ova» ovoid-triangular, enfolded by the interior, 

 adnate scales. — Q Brackish swamps, generally near the sea. Middle and Southern 

 States. Stem 12 — 15' high, reddened at the base, longer than the leaves. Spike- 

 lets 9" long, 1 — 9-flowered. 



12 C. tetragonus Ell. Culm 2 to 3f high ; lvs. shorter, channeled, serrulate on 

 the margins and keel ; umbel many-rayed, involuoels none ; clusters oblong-cylin- 



