362 ORDER 154. CYPERACE^E. 



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



ovoid, greenish, 2 3", sessile about halfway up; setae 1; ach. smooth, lenticu- 

 lar ; culm-leaf always erect Shores, Penn. (Porter) Sodus 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. pnngens Vahl. Calm 1 4f, 3-angled, 1-3-leaved ; Ivs. 312', also 3-angled ;- 



spk. 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; *pl 

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

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



1 1 S. Olneyi Gr. Culms triquetrous-winged, 2 7f, leafless, or with 1 very short leaf 

 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", OO-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 Gr.) 



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

 nelled, 1 3f; spk. 312", oblong, 610 in each cluster; clusters 19, sessile and oa 

 short rays ; invol. of 2 or 3 very long leaves ; setae 1 4, deciduous, ehort ; achenium 

 plano-convex. Salt marshes. 



14 S. fluviatills Gr. Culm triquetrous-winged, leafy, 2-^f; 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-angled, leafy, 2f; invol. of 3 long leaves , 

 spk. ovate, H", 10 2 ) in the round dense heads ; hds. 4" in a compound cyme ; dark 

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



16 S. sylvaticus L. Culm 3f, leafy; invol. of 8 leaves, hardly equalling the thric<! 

 compounded cyme ; ?pk. 1", olive-gren, 1 39 in the small heads ; hds. on slendei 

 pedicels ; gls. acute ; setae 6, straight, as long as the pale 3-angled ach. Mts. N. H., & N 



I 7 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 

 3-angled, Uviee shorter than the 45 tortuous setae. Margins of waters. Raro. North 



1 8 S. divarifatus Ell. CulmS 4f, very leafy; cyme large, loose, decompound 

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



19 S. Eriopliorum MX. Culm teretieh, 3 5f, Ivs. 2f ; invol. 4-5-lvd., longer than 

 the large loose decompound cyme ; spk. very numerous, 33", pedicellate; setae 6. 

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



20 S. lim-aris 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; ettai 

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



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

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

 woolly or cottony hairs. 1$. Culms with or without leaves. Spikes showy 

 aAcr the long setse have grown. June August. 



S Setae 6, crisped, woolly. Spike sii-gle. 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 9 



a Spikes several, collected into a siibsessilp, capitate cluster No. A 



a Spikes everal, separate, in umbel-like cymes . Nos. 4, ft 



