CYPERACEiE. (SKDGK FAMII.Y.) 575 



H- •*- Perennials, with running rootstocks. 



9. E. Oliv&cea, Torr. (PI. 2, fig. 1 - 5.) Culms flattish, grooved, dif- 

 fusely tufted on slender matted rootstocks (2-4' high) ; spikelet ovate, acutish, 

 2Q -SO- flowered ; scales ovate, obtuse, rather loosely imbricated (])urple with a 

 green midrib and slightly scarious margins) ; achene obovate, dull, abruptly 

 beaked with a narrow tubercle, shorter than the 6-8 bristles. — Wet, sandy 

 soil, Mass. to N. C, and western N. Y. 



10. E. palustris, H. Br. Culms nearly terete, striate, 1 - 5° high ; sjiikekt 

 obhwfj-lanreolate, pointed, in(nii/-Jloivered ; scales ovate-oblonrj, loosely imbricated, 

 reddish-brown with a broad and translucent whitish margin and a greenisli 

 keel, the upper acutish, tlie lowest rounded and often enlarged ; achene rather 

 narrowly obovate, somew^hat siiining, crowned with a short ovate or ovate-tri- 

 angular flattened tul)ercle, shorter than the usualli/ 4 bristles. — Very common, 

 either in water, when it is pretty stout and tall, or in wet grassy grounds, 

 when it is slender and lower. (Eu., Asia.) — Var. glaucescens. Gray. Culms 

 slender or filiform ; tubercle narrower, acute, beak-like, sometimes half as long 

 as the achene. With the type. — Var. cAlva, Gray. Bristles none ; tubercle 

 short, but narrower than in the type. — Var. vioENS, L. H. Bailey. Culms 

 very stout, rigid ; achene more broadly obovoid. Lake Champlaiu and along 

 the Great Lakes to Minn. 



* * Achene triangular or turgid ; style 3<left 

 t- Bristles at least equalling the smoo'h achene, doivnwardly barbed, persistent. 



11. E. rostellata, Torr. Cidmsjlattened and striate-grooved, why, erect 

 (1 -2|° high), the sterile ones reclining, rooting and proliferous from the apex 

 (1 - 2° high), the sheath transversely truncate ; spikelet spindle-shaped, 12-20- 

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

 rowed into the confluent pyramidal tubercle, which is overtopped In- tlie 4-6 

 bristles. — Marshes, N. Kng. to S. C, west to Mich, and Ky. 



12. E. intermedia, Schultes. Culms capillary, wiry, striate-grooved, 

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

 spikelet oblong-ovate, acutish, loosely \0-20-Jiowered (2 -3" long) ; scales oblong, 

 obtu.se, green-keeled, the sides purplish-hrowni : achene obovoid with a nar- 

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

 nearly equals the 6 bristles. — Wet slopes, Penn. to Iowa, north to Canada. 



13. E. Torreyana, Boeckl. Like the preceding, but more capillary and 

 heads smaller ( 1 A - 2" long), sometimes proliferous, the one or more short new 

 culms from tlie axil of its lowest scale, which persists as an herliaceous bract; 

 achene very much smaller, with sharper angles and a short conical tubercle, 

 which is hardly equalled by the 3-6 slender bristles. ( E. microcarjia, var. fili- 

 culmis, Torr.) — Wet jiine-barrens, N. J. to Fla. 



■-■-■*- Bristles 2-4, shorter than the achene, slender and fragile, or none. 



14. E. tenuis, .Schultes. Cuhns almost capillary, erect from running root- 

 stocks, 4-(nigular and flattish (1° high), the sides concave ; spikelet elliptical, acut- 

 ish, 20-30-fiou-ered (3" long) ; scales ovate, ohfujp, chestnut-purple with a broad 

 scarious margin and green keel ; achene obovate, roughish-u-rinklcd, crowned 

 with a small depressed tubercle, jiersistent after the fall of the scales; bristles 

 i as long as the achene or uoue. — N. Scotia to N. C, Minn., and Mo. June. 



