CTPEEACEiE. (sedge familt,) 559 



to Ohio and Illinois. — Culms tufted on running rootstocks, Strikinglj flat,, 

 often spirally twisted in drying. 



» » Achenium triangular or turgid: style 3-clefi. 

 *- Bristles- equalling or surpassing the smooth achenium, downwardly barbed, persistent. 



10. E. rostellkta, Torr. Culms flattened and striate-grooved, wiry, erect 

 (l°-2^° high), the sterile ones reclining, rooting and proliferous from the apex 

 (l°-2° high), the sheath transversely truncate; spike spindle-shaped, 12-20- 

 flowered; scales ovate, obtuse (light-brown); achenium obovate-triangular, 

 narrowed into the confluent pyramidal tubercle, which is overtopped by the 

 4-6 bristles. — Marshes, Rhode Island (Olney), E. Massachusetts ( W. Boott), 

 and Vermont [Tuckerman) to New Jersey (Dr. Allen), Alexandria, Virginia (A. 

 H. Curtiss), Michigan and southward. 



11. E. intermddia, Schultes. Culms capillary, wiry, striate-grooved, 

 densely tufted from fibrous roots, diffusely spreading or reclining (6'- 12' long) ; 

 spike oblong-ovate, acutish, loosely lO-20-flowered (2"-3" long); scales oblong, 

 obtuse, green-keeled, the sides purplish-brown ; achenium obovoid with a nar- 

 rowed base, beaked with a slender conical-awl-shaped distinct tubercle, which 

 nearly equals the 6 bristles. (E. reclinata, Kunth. !) — Wet slopes : common 

 from New York and Penn. to Illinois and northward. 



12. E. mieroearpa, Torr., var. filicx'tlmis, Torr. Like the preceding, 

 but more capillary and beads smaller (l^"-2" long), sometimes proliferous, the 

 one or more short new culms from the axil of its lowest scale, which persists - 

 as an herbaceous bract ; achenium very much smaller, with sharper angles and a 

 short conical tubercle, which is hardly equalled by the 3-6 slender bristles. — 

 Wet pine barrens. New Jersey and southward. 



■1- -1- Bristles 2-4, shorter than the achenium, slender and fragile, or none. 



13. E. tenuis, Schultes. Culms almost capillary, erect from running root- 

 stocks, i-angular and flattish (1° high), the sides concave; spike elliptical, acut- 

 ish, 20-30flowered (3" long); scales ovate, obtuse, chestnut-purple with a broad 

 scarious margin and green keel ; achenium obovate, roughish-urrinkled, crowned with 

 a small depressed tubercle, persistent after tlie fall of the scales; bristles half the 

 length of the achenium, or wanting. (E. elDptica, Kunth.!) — Wet meadows 

 and bogs : common, early.flowering ; June. 



14. E. melanoc^rpa, Torr. Culms flattened, grooved, wiry, erect (9'- 

 18' high) ; spike cylindrical-ovoid or oblong, thick, obtuse, densely many-flowered 

 (3" -6" long) ; scales closely many-ranked, roundish-ovate, very obtuse, brown- 

 ish with broad scarious margins ; achenium smooth, obovate-top-shaped, obtusely 

 triangular, the broad summit entirely covered like a lid by the flat depressed tubercle, 

 which is raised in the centre into a short abrupt triangular point ; bristles shorter 

 than the (soon blackish) achenium, often obsolete. — Wet sand, Plymouth, 

 Massachusetts, to Virginia, and southward along the coast. 



15. E. tricost&,ta, Torr. Ciilms flattish (l°-2° high); spike soon cylin- 

 drical, densely many-flowered (6" -9" long, thickish ; scales ovate, very obtuse, 

 rusty brown, with broad scarious margins ; achenium obovate, with 3 prominent 

 thickened' angles, minutely rough-wrinkled, crowned with a short-conical acute tubercle; 

 bristles none. — Quaker Bridge, New Jersey {Knieskern), and southward. 



