362 OKDEB 154. CYPERACE^E. 



7 S. Smithii Gr. Culm slender, 312' ; sheath often with a short blade ; ppk. 1- 3. 



ovoid, greenish, 23", sessile about halfway up ; setae 01 ; ach. smooth, lenticu- 

 lar; culm-leaf always erect Shores, Penn. (Porter) Sodas Bay (Hankenson.) 



8 S. validus Vahl. Culm cylindric, smooth, 5-8f, its sheath with or without a short 



blade ; panicle cymous, overtopping the short pungent culm-leaf; spk. ovoid, brown. 

 2", numerous ; gls. mucronate, ciliate ; setae 3 or 6. Our stoutest Bullrush. Shores. 



9 S. pnugens Vahl. Culm 1 4f, 3-angled, 1-3-leaved ; Ivs. 3 12', also 3-angled ; 



epk. 1 6, crowded, sessile, ovate, obtuse, 3 / below the summit ; gls. notched and 

 mucronate ; anth. ciliolate at apex ; style 2-cleft ; setae 2 6. Ponds and marshes. 



10 S. Torreyi Olney. Culm 2 3f, 3-angled ; Ivs. 1 3 at base, 1 l*f, 3-angled; ?pk 

 ] 4, oblong, sessile, 2 4' below the summit; gls. ovate ; sty. 3-clcft; ach. triq 

 obovate, pointed, shorter than the setae. Borders of ponds, N, E. to N. J., and W. 



US. Olneyl Gr. Culms triquetrous-winged, 2 7f, leafless, or with 1 very short leal 

 at base ; spk. 6 12, in a sessile head an inch or so below the summit ; gls. round- 

 ovate, mucronate ; setae 6; style 2-cleft. Salt marshes, E. and S. 



12 S. leptolepis Chapm. Culms 3-angled, 2 5f ; leaves 13, slender, channelled, 

 sheathing at base ; spikes loosely umbelled, single, oblong, 4 6", OC-flowered; 

 invol. of several small bracts besides the long culm-leaf; gls. lance-ovate, acute; 

 style 3-cleft; setae 6, equalling the 3-sided ach. Md. (Porter), and S. (S. Canbyi Gi.) 



13 S. maritimus L. Culm acutely 3-angled, leafy, 1 3f; Ivs. broad-linear, chan 

 nelled, 1 3f ; spk. 312". oblong, 6 10 in each cluster ; clusters 1 9, sessile and oo 

 short rays ; invol. of 2 or 3 very long leaves ; setae 14, deciduous, ohort ; achenium 

 plano-convex. Salt marshes. 



14 S. fluvlatills Gr. Culm triquetrous-winged, leafy, 2^4f; Ivs. as in No. 13 ; spk 

 610", oblong, 15 in a cluster; clusters sessile and on rays ; setae 6; ach. 3-angled 

 Shores, Eastern, Middle, and Western States. 



15 S. atrovireiis Muhl. Culm obtusely 3-an^led, leafy, 2f; invol. of 3 long leaves , 

 ppk. ovate, li", 1020 in the round dense heads ; hds. 4" in a compocnd cyme ; dark 

 olive-green ; setae 4, as long as the smooth white ach. Com. in swales. N., M., & W. 



16 S. sylvaticus L. Culm 3f, leafy; invol. of 3 leaves, hardly equalling the thrico 

 compounded cyme ; ppk. 1", olive-gren, 139 in the small heads ; hds. on slendei 

 pedicels ; gls. acnte ; setae 6, straight, as long as the pale 3-an<rled ach. Mts. N. H., & N 



17 S. polyphyllus Vahl. Culm 2 3f, leafy ; invol. of 3 leaves ; cyme decompound 

 spk. yellow-ferruginous, 1", 36 in the clusters : gls. obtuse ; ach. yellowish-white 

 8-augled, twice shorter than the 4 5 tortuous setae. Margins of waters. Rare. North 



18 S. divarieatus Ell. Culm 3 4f, very leafy; cyme large, loose, decompound , 

 spk. all separate, 23", oblong, pendulous, ferruginous; setae tortuous. Wet barrens. S. 



19 S. Kriopliorum MX. Culm teretish. 3 5f, Ivs. 2f ; invol. 4-5-1 vd., longer than 

 the large loose decompound cyme; spk. very numerous, J 3", pedicellate; setae 6. 

 hair-like, curled, conspicuous, 5 or 6 times longer than the white ach. Swamps. Com. 



20 S. Ilnearis MX. Culm 3-angled, 2 3f, very leafy; cymes term, and axillary, de 

 compound, at length nodding; invol. 1-3-bracted, much shorter than the cyme; set 

 as long as the glumes, hardly at maturity exserted. Swamps. Common. S. 



7. ERIOPHORUM, L. COTTON GRASS. Glumes imbricated all 

 around into a spike. Ach. invested with many (rarely but 6) very long, 

 woolly or cottony hairs. It Culms with or without leaves. Spikes showy 

 after the long setae have grown. June August. 



S Setae 6, crisped, woolly. Spike single. Culms scape-like, naked No. 1 



Setae numerous, straight, cottony. Culm jointed. 1-3-leaved (a) 



a Spike single. Culm bearing 2 sheaths instead of leaves No 2 



a Spikes several, collected into a subsessile, capitate cluster No. 3 



o Spikes several, separate, in umbel-like cymes Ncm. 4, f 



