OEDER 155. CYPERACE^E. 739 



5 S. lacustris L. LAKE BULLRUSH. Culm smooth, leafless, filled with a- porous 

 pith, 5 to 8f high, cylindric, tapering above the panicle, and abruptly ending in a 

 short cusp ; panicle cymous near the top ; ped. rough, twice compound ; spikelets 

 ovoid, closely imbricate ; scales ovate, mucronate, pubescent ; bracts shorter than 

 the panicle. The largest species of bullrush, frequenting tho muddy margins of 

 rivers and ponds, U. S. to Arc. Am. July. (8. acutus MuhL) 



6 S. pungens VahL Culm nearly naked, 3-angled, corners acute and two of 

 the sides concave, about 3f high and ending in a sharp point ; Ivs. few and short, 

 from the top of the sheath; spikes lateral, 1 5, ovate, crowded and sessile, at, 

 various distances below the point ; glumes round-ovate, mucronate ; bristles G ; 

 style 2-cleft. Ponds and marshes, fresh and salt, throughout N. America. (S. 

 triqueter MX.) 



7 S. Olneyi Gray. Culm triquetrous-winged, leafless, 2 7f high ; sheath radical, 

 tipped with a short (1 2') leaf; spikes 6 12, sessile, aggregated. 2 3" long, 

 placed 9 12'' below the triangular apex of the stem; glumes roundish-ovate, 

 mucronato; bristles 6 12: ach. obovate, plano-convex, gibbous at apex. Salt 

 marshes, Sekonk river, R. I. (Olney), Tom river, N. Y., Kneiskern. Remarkably 

 distinguished by its 3-winged stem. July. 



B S. Torreyi Olney. Culm 2f high, 3-angled, with concave sides, rather slender, 

 kafy at the base; Ivs. 2 or 3, If or more long, slender; spikes 2 4 (rarely 1), ses- 

 sile, distinct, acute, ovate-oblong ; scales ovate, mucronate, smooth ; sty. 3-clefi ; 

 ach. obovate, acuminate, unequally 3-sided, shorter than the bristles. Borders of 

 ponds, N. Eng. to Mich. The stem here as hi the last, is prolonged above the 

 spikes, in the form of an involucral leaf. Jl., Aug. (S, mucronatus Ph. ? Torr.) 



9 S. maritimus L. SEA EULLRUSII. Culm acutely 3-angled, leafy, 2 3f high ; 

 Ivs. broad-linear, rough-edged, cariuate, taller than "the stem; spikes conglome- 

 rate, 6 10, nearly an inch long, corymbous; invol. of about 3 very long leaves; 

 glumes ovate, 3-clcft, the middle segment subulate and reflexed ; style 3-cleft ; 

 bristles 34, much shorter than the broad-obovate, lenticular, dark brown, polished 

 achenium. Salt marshes, N. Eng. to Flor. Aug. 



10 S. Cuviatilis Gray. Culm triangular-winged, leafy, stout, 3 or 4f high ; Ivs. 

 broadly linear, very long ; invol. Ivs. 5 to 7, far exceeding the umbel ; umbel 

 somewhat compound, spikes separate or conglomerate, large (9 to 12" long), ful- 

 vous ; glumes 3-cleft, bristles G. whitish, longer than the sharply 3-angled, oblong, 

 Hack achenium, which is tipped with a whitish beak. Borders of lakes and rivers, 

 W. X. Y. and \\'. States. Jl., Aug. (S. maritimus, ,3. iluv. Torr.) 



11 S. atrovirens Muhl. Culm obtusely triangular, leafy, 2f high ; cyme com- 

 pound, proliferous ; invcL of 3 leaf-like bracts longer than the cyme; spikes ovate, 

 acute, crowded, 10 to 20 in a globcushcad; hds. numerous, 4" diam., dark olive 

 green; glumes ovate, mucronato; bristles 4, straight, hispid downward, as long as 

 the smooth, white achenium. Common in meadows, Mid. and W. States. Jn., Jl. 

 Very different from S. sylvaticus L. of Europe. 



12 S. polyphyllus Vahl. Culm obtusely triangular, leafy, 3f high ; cymo 

 decompound, its principal branches about 5, unequal, with truncate sheaths at 

 base ; spiktleis clustered in heads of 3 6 ; glumes obtuse, reddish-brown ; ach. 

 smooth, yellowish-white, twice shorter than the 4 or 5 smooth to r nuou-s bristles. 

 Much resembles tho last species. Margins of waters, N. Eng., 111. and S. States. 

 (S. brunneus MuhL) 



13. S. divaricatus Ell. Culm obtusely triangular, very leafy, 3 to 4f high ; 

 Ivs. ilar. broadly linear or lance-linear, 3 to 6" wide, snorter than the culm; umbel 

 loose, large, decompound, rays filiform, divaricate, recurved ; spikes all separate, 

 pendulous, oblong-ovoid, 2 to 3" long, rust colored, pendulous; glumes many, 

 acute ; bristles tcrtuous, rather longer than the achenium which is tawny, elliptic- 

 3-angled, acute at each end. TVet barrens, S. Car. to La. (Hale). 



14 S. Eriophomm MX. Culm obtusely triangular, leafy, 3 to 5f high, Ivs. 2f 

 long, rough-edged; invol. 4 cr 5-kai'cd, longer than the umbel; umbel terminal, 

 decompound, large ar.d loo;: ; spikes n:cstly pedicillate, 2 to 3'' long, ovoid, in 

 smaller clusters ; bristles G, capillary, curled, very conspicuous, being 5 or 6 times 

 as long as the white achenium. A common, stiff, rank, meadow sedge, which 



