Order 155.— CYPERACEiB. 733 



/?. minimcs. Invo). of 1 or 2 lvs. Spikes 1 or 2, 10 to 1 2 -flowered ; glumes 

 loosely imbricated, acute ; stain. 1. — Culm and lvs. setaceous. N.J. (Torn) 



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

 to 3 distinct, very unequal rays ; spikes alternate, rather remote, linear-lanceolate, 

 10 to 12-llowered, the lowest compound; scales acute, loose, pale straw-yellow ; 

 stam. 2; 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; umbel of 2 to 4 short rays; 

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

 ovate, l-veined; stam. 3; sty. deeply 2-cloft; ach. suborbicular, dark brown, shin- 

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

 the culms. Spikes 5 to 9" long, li" wide, iu crowded fascicles of 3 to C on each 

 short rachis. Aug. 



5 C. flavicomus Mx. Culm 1 to 3f high, 3-angled ; invol. 3 to 5-lcavcd, 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-veitied ou tho keel, with a broad, white-scar ious margin; 

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

 to Fla. Spikelets 7 to 10" long. Glumes somewhat truueate and c-marginate. 

 May — Sept. 



6 C. articulatus L. Joixted Sedge. Culm 2 to Cf high, with internal joints, 

 and several leafless 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 dot3 ; stam. 3 ; sty. 3-cleft ; aeh. acutely 

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



7 C. eruthrorhisos Muhl. Culm 2 — 3f high, obtusely triquetrous, longer than tho 

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

 sheaths entire; spikelets very numerous, G" long, crowded and spreading in tho 

 oblong subsessilo (heads) clusters, a littlo flattened, about 13-flowered ; outer 

 glumes mucronate, closely imbricated, chestnut-brown, veinless and shining, the 

 inner ones entirely free from tho rachis; sta. 3; aeh. smooth and shining, much 

 shorter than the glume. — Wet grounds Pcnn. and Southern States. 



8 C. Hydra Mx. Nutt Grass. Culm G to 12' to 2f high, 3-angled; lvs. shorter 

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

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

 ovate, veinless, acute, separato at tho tips, of a fine jmrple brown; stam. 3; sty. 

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

 troublesome in cotton fields. Rhizomes creeping and branching extensively, 

 bearing tubers. Spikes G to 12" long. Apr. — Jl. 



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

 a3 long as tho stem; umbel 4 — G-rayed; rajs often branched, bearing 12 — 20 

 linear, obtuse spikelets somewhat in 2 rows; sheath3 obliquely truncate, involu- 

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

 g'umes veiny, yellowish. — 2£ Moist fields, N. Y. to Wis. and S. States. Rhizomes 

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



10 C. dissitiflorus Torr. Culms slender, tumid at tho 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, tubdistychous on tho slender rays, teretish, slender, 

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

 — E. Tenn. ? to La. Plant slender, erect Rays of tho umbel 1 to 3' iong. 

 Spikes divaricate and reflexed. Aug. 



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

 short rays ; spikelets G — d-fiowercd, the lower ones compound ; rachis very broad, 

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

 adnate scales. — (J) Brackish swamps, generally near the sea, Middlo and Southern 

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

 lets 9" long, 7 — 9-flowered. 



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

 the margins and keel; umbel many-rayed, invclucels none; clusters oblong-cyiin- 



