CYPERACEiE. (SEDGE FAMILY.) 575 



••- -t- Perennials, with running rootstocks. 



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

 fusely tufted on sleuder matted rootstocks (2-4' high) ; spikelel ovate, actitish, 

 20 - ^O-Jiowered ; scales orate, obtuse, rather loosely imbricated (purple 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 

 soO, Mass. to X. C, and western N. Y. 



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

 oblong-lanceolate, pointed, man /-Jioiccred ; scales ovate-ohlong, loosely imbricated, 

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

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

 narrowly obovate, somewliat shining, crowned witli a short ovate or ovate-tri- 

 angular flattened tubercle, shorter than the usual I ij 4 bristles. — Very common, 

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

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

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

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

 short, but narrower than in the type. — ^"ar, vigens, L. H. Bailey. Culms 

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

 the Great Lakes to Minn. 



* * Achene triangular or turgid ; style 3-cleft 



■^Bristles at least equalling the smooth achene, downwardly barbed, persistent. 



11. E. rostellata, Torr. Cuhnsjiattened and striate-grooved, \v'iry, 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, Avhich is overtopped by the 4-6 

 bristles. — ]\Iarshes, N. Eng. to S. C, west to Mich, and Ky. 



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

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

 spikelet oblong-ovate, acutish, loosely 10 - 20-Jlowered (2 - 3'' long) ; scales oblong, 

 obtuse, green-keeled, the sides purplish-brown : 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^-2" long), sometimes proliferous, the one or more short new 

 culms from the axil of its lowest scale, which persists as an herbaceous bract : 

 achene very much smaller, M'ith sharper angles and a short conical tubercle, 

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

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



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



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

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

 ish, 20-30-fou-ered (3" long) ; scales ovate, ohfu3e, chestnut-purple with a broad 

 scarious margin and green keel ; achene obovate, ruughish-wrinkled, crowned 

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

 ^ as long as the achene or none. — N. Scotia to N. C. Minn., and Mo. June. 



