ORDER 155. CYPERACEJE. 733 



/?. MINIMUS. Invol. of 1 or 2 Ivs. Spikes 1 or 2, 10 to 12-flowcred; glumes 

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



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

 to 8 distinct, very unequal rays ; spikes alternate, rather remote, linear-lanceolate, 

 10 to 12-flowered, 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; 

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

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

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

 the culms. Spikes 5 to 9" long, 1" wide, iu crowded fascicles of 3 to 6 on each 

 short rachis. Aug. 



5 C. Cavicomus MX. Culm 1 to 3f high, 3-angled ; invol. 3 to 5-leaved, very 

 long; umbd somewhat compound, of many (4 to 7) 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-scarious margin ; 

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

 to Fla. Spikelets 7 to 10" long. Glumes somewhat truncate and emarginate. 

 May Sept. 



6 C. articulatus L. JOIXTED SEDGE. Culm 2 to Gf high, with internal joints, 

 and several leafless sheaths towards the base ; Ivs. 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. erythrorhizos Muhl. Culm 2 3f high, obtusely triquetrous, longer than the 

 leaves; umbel compound; rays 5 9, 3 4 long, each with 3 1 sessile clusters; 

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

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

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

 inner 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. Hydra MX. NUT GRASS. Culm 6 to 12' to 2f high, 3-angled; Ivs. 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 tho tips, of a fine purple brown; stam. 3; sty. 

 3-cleft, much exserted ; ach. 3-angled. Sandy lields, Ya. to Fla, and La. Very 

 troublesome in cotton fields, lihizomes creeping and branching extensively, 

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



9 C. phymatodes Muhl. Culm 1 2f high, 3-angled, striate; Ivs. subradical, 

 as long as the stem; umbel 4 6-rayed; rays often branched, bearing 12 20 

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

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

 glumes veiny, yellowish. 11 Moist fields, N. Y. to Wis. and S. States. Rhizomes 

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



10 C. dissitifloms Torr. Culms slender, tumid at the base, 1 to 2f high ; Ivs. 

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

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

 5 to 7 -flowered, 6" to 1' long ; glumes lance-oblong, acute; ach. brown, 3-angled. 

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

 Spikes divaricate and reflexed. Aug. 



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

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

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

 adnate scales. (J) 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, 7 9-flowered. 



12 C. tetrggoniiB Ell. Culm 2 to Df high; Ivs. shorter, channeled, serrulate on 

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



