Order 155.— CYPERACE^E. "737 



5 E. tricostata Torr. Culm filiform, flattened, striate-, 1 to 2f high; spike cylin- 

 dric-oblong, dense-flowered, 6 to 9" long; glumes ovate, obtuse, rusty brown, with 

 a broad, searious margin and a green midvein; bristles 0; acli. obovate, with 3 

 prominent, thick angles, roughiab, brown, crowned with a whitish, minuto tuber- 

 cle ; style 3-cleft. — Wet places, N. J. to Fla. 



6 E. Robbinsii Oakes. Culms clustered, 9 — 25' high, rigid, sharply triangular, 

 pale green, several of them fruitless; slieath truncate- ; spike 3 — 12" long, scarcely 

 thicker than the stem, placed 2 — 5'' below its apex ; glumes 3 — 9, linear-lanceo- 

 late, acute, finally brownish ; bristles G, twice longer than the achenium ; ach. 1" 

 long, pale brown; tubercle closely sessile. — Ponds and ditches, N. II. and Mass. 

 (Ricard). Very distinct. In water a part of tho stems arc floating and as fine 

 as hairs. Jl. 



7 E. capitata Brown. Culm filiform, furrowed, angular, 4' to C, in tufts; spiks 

 globular-ovoid, 2" long, greenish white; glumes 12 to 15, oblong, obtuse; 

 bristles 6, some of them a little exceeding tho ach., which is broadly obovate, 

 lens-shaped, black, shining, crowned with a minuto, depressed tubercle ; style 2- 

 cleft. — Wet places, Ga., Fla. to La. 



8 E. albida Torr. Culm filiform, terete, striate, sulcato on one side, 8 to 12'; 

 spike ovoid, acute, 2 to 3'' long; glumes 20 to 30, whitish, ovate, rather acute; 

 bristles G, brown, longer than tho chestnut-colored, smooth, broad-ovate ach. ; 

 tubercle small, acute ; style 3-cleft. — Wet, sandy place3, Ga., Ma. to La. Known 

 at sight by its whitish heads. Sheaths very short. 



9 E. olivacea Torr. Culms cce-pitous, 2 — 4' high, slender, subcompressed, suL 

 cate, soft: spike ovate, acutish, 2 — 3" long, 20 — 30-flowered ; glumes ovate, ob- 

 tuse, reddish-brown, with searious edges and a green midvein, tho lowest largest; 

 bristles G; sty. 2-clcft; ach. broadly obovate, smooth, of a dull, blackish-olivo 

 color when ripe. — Sands, generally partly submersed, Providence, R. I. (Olney) 

 Mass. to Ga. 



10 E. tenuis Scliultes. Culm almost filiform, quadrangular, the sides silicate, 

 8 — 15', with a long, purple sheath at base ; spike 2 to 3" long, elliptic-oval, acuto 

 at each end; glumes dark purple, ovate, obuse, tho lower ones larger and empty; 

 ova. roundish, tapering below, invested with 2 or 3 or setse. — Common in wet 

 places, Can. and U. S. Jn., Jl. 



11 E.- obtusa Scliultes. Culm sulcate, subterete, 6 — 15' high; spike ovoil, very 

 obtuse, often iiearly globous ; glumes GO to 100, round, dark brown, with whitish 

 margins ; ach. obovate, compressed, smooth, brown, invested with 6 setaa as long 

 as the glumes, and crowned with a broad, flat tubercle. — Shallow waters, Can. 

 an I U. S., common. Jl. 



12 E. tuberculosa R. Br. Culm columnar, striate, 12' high, leafless, sheathed 

 at base; spike ovate-lanceolate, acutish, glumes very obtuse, loose; ach. somewhat 

 triquetrous, not larger than the sagittate tubercle with winch it is crowned; bristles 

 6, as long as tho tubercle. — Sandy swamps, N. Eng. to Flor. and La. Remark- 

 able for its large tubercle. Jl. 



13 E. simplex Torr. Culm acutely 3-angled (terete Torr.), filiform, striate, 1 2 to 

 18'; spike ovoid, acutish; scales ovate, obtuse, whitish with a brown center; 

 bristles 6, rigid, longer than the ach., which is broad-obovate, furrowed length- 

 wise, olive-green, crowned with a large, distinct, conic-beaked tubercle ; btylo 3- 

 cleft. — Wet places, N. Car. to Fla and La. 



14 E. rostellata Torr. Culm 15 — 20', clustered, angular and sulcate, slender, 

 almost filiform, rigid ; sheaths obliquely truncate, the lowest blackish at summit ; 

 spike lance-ovate, acute, 3 — i ' long ; glumes 12 — 20, lance-ovate, smooth, light 

 brown, edge searious ; bristles 4 to G, longer than tho smooth ach., which is bi- 

 convex, olive-brown, with a confluent, acuminate tubercle, shorter than tho 6 

 bristles.— R. I. (Olney), N. Y. (Sartwell), to Mich. 



15 E. melanocarpa Torr. Culm compressed, furrowed, slender, almost filiform, 

 wiry, 12 — 18' high; sheaths truncate; spike lance-oblong rather acute, 4 — 6" in 

 length, 20 — 40-flowered; glumes ovate, obtuse, brownish, with searious margins 

 and a prominent, yellowish midvein; bristles 3, purple; ach. obovate-turbinate, 

 blackish ; tubercle broad, flat, pointed in the center. — Providence, It. I. (Olney). 



16 E. compressa Sullivant. Culm 12 — 13' high, csespitou3, much compressed, 



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