558 CYPERACE^. (SEDGE FAMILY.) 



of the perianth stout, downwardly barbed, as long as the striated and pitted-retic- 

 vJated triangular achenium and its tubercle; culms tufted from fibrous roots, 

 about 1° high. 



4. E. tuberculdsa, R. Br. Culms flattish, striate; spike 3" -6" long, 

 many-flowered ; tubercle flattish-cap-shapcd, as large as the body of the achenium. 

 — Wet sandy soil, Mass. along the coast to Virginia and southward. 



5. E. simplex, Torr. Culrns sharply triangular, capillary, twisting when 

 dry; spike 2" -3" long, few-flowered; conical-beaked tubercle much smaller than 

 the achenium. (E. tdrtilis, Schultes.) —Eastern shore of Maryland {W.M.I 

 Canby), and southward. 



§ 3. Spike terete, much thicker than the culm, many-flowered ; the scales imbricated 

 in many or more than three ranks, thin-membranaceous or scarious in texture, with 

 a thicker midrib, usually brownish or purplish, sometimes deciduous at maturity. 

 (Eleogenus, Nees.) 



* Achenium smooth and lenticular, and style 2-cleJl, or in No. 6 more commonly 

 3-cleft : culms slender or thread-form, terete or compressed. 



6. E. Obtusa, Schultes. Culms nearly terete, tufted (8'- 14' high) from 

 fibrous roots ; spike globose-ovoid and with age oblong, obtuse, rarely becoming acute 

 (dull brown); the scales very obtuse and numerous (80-130), densely crowded in 

 many ranks; style 3- (rarely 2-) cleft; achenium obovate, shining, tumid-mar- 

 gined, about half the length of the 6-8 bristles, crowned with a short and very 

 broad flattened tubercle. — Muddy places : most common. 



7. E. Olivacea, Torr. Culms flattish, grooved, diffusely tufted on slender 

 matted rootstocks (2' -4' high) ; spike ovate, acutish, 20 - 30 -flowered ; scales ovate, 

 obtuse, rather loosely imbricated (purple with a green midrib and slightly scari- 

 ous margins) ; achenium obovate, dull, abruptly beaked with a narrow tubercle, 

 shorter than the 6-8 bristles. — Wet sandy soil, Mass. to New Jersey near the 

 coast, and southward : also shore of Lake Ontario, J. A. Paine. 



8. E. paltistris, R. Br. Culms nearly terete, striate (l°-2° high), from 

 running rootstocks ; spike oblong-lanceolate, pointed, many-flowered ; scales ovate- 

 oblong, loosely imbricated in several ranks, reddish-brown with a broad and 

 translucent whitish margin and a greenish keel, the upper acutish, the lowest 

 rounded and often enlarged ; achenium obovate, somewhat shining, crowned 

 with a short ovate or ovate-triangular flattened tubercle, shorter than the us-iaUy 

 4 bristles. — Var. glaucescens (S. glaucescens, Willd.l) : culms slender or fili- 

 form ; tubercle narrower and acute, beak-like, sometimes half the length of the 

 achenium. — Var. calva (E. calva, Torr.) : bristles wanting; tubercle short, 

 nearly as in the true E. palustris, but rather narrower (Watertown, New York, 

 Dr. Crawe). — Very common, either in water, when it is pretty stout and tall; 

 or in wet grassy grounds, when it is slender and lower. (Eu.) 



9. E. COmpressa, Sullivant. Culms flat, striate, erect (l°-2° high); 

 spike ovate-oblong, or at length lanceolate, 20 - 30-flowered (4" -7" long); scales 

 lanceolate-ovate, acute, dark purple Avith broad Avhite pellucid margins and sum- 

 mit ; achenium obovate-pear- shaped, compressed, crowned with a small conical and 

 pointed tubercle; bristles 1 -4, very slender, fragile, shorter than or equalling the 

 achenium, sometimes none or a single rudiment.) — Wet places, N. New York 



