573 CLX. CYPERACE^. Eriophorum. 



11. S. BRUNNEUS. Muhl. 



St. obtusely triangular, leafy, 3— 3f high ; cyvie decompound, its principal 

 branches about 5, unequal, with truncate sheaths at base ; spikelets clustered in 

 heads of 3—6 ; glii7n.es obtuse, reddish-brown ; ach. smooth, yellowish-white, 

 shorter than the 4 or 5 tortuous bristles.— Much resembles the last species. 

 Margins of waters, N. Eng. to Penn, W. to Ohio, rare. 

 § 2. Tricophorubi. Bristles 6, imich longer thayi the achenium, tortuous, 

 smoothish. Stem leafy. Umbel decompound. 



12. S. Eriophorum. Michx. (Tricophorum cyperinum. Pers.) 



St. obtusely triangular, leafy, 3— 5f high ; Ivs. 2t long, rough-edged ; um- 

 bel terminal, decompound, large and loose ; spikes mostly pedicellate ; bristles &, 

 capillary, curled, very conspicuous, being 5 or 6 times as long as the white 

 achenium. — A common, stiff, rank meadow sedge, which cattle do not eat, U. S. 

 and Can. Spikes numerous, 2—3" long, ovoid, obtuse, in small clusters, in a 

 large, showy panicle. Involucre 4-leaved. Aug. 



13. S. LiNEATUs. Michx. (Tricophorum. Pers.) 



St. triangular, very leafy, 2 — 3f high ; U77ibels terminal and axillary, de- 

 compound, at length nodding ; inrol. of 1—2 bracts, longer than the leaves ; 

 spikes ovoid, pedunculate, solitary ; glumes lanceolate, ferruginous ; bristles 6, as 

 long as the gliunes. — Swamps, in most of the States. Aug. 



8. ERIOPHORUM. 



Gr. cpiov, wool, (pepio, to bear; alluding to the copious bristles of the perigynum. 



Glumes imbricated all around into a spike ; achenium invested in 

 very long, dense, woolly or cottony hairs. — Stem generally leafy. 

 Spikelets mostly in umbels, finally cloUied with the long, silky hairs. 

 * Spikelet solitanj. 



1. E. ALPiNO.M. 



St. very slender, acutely 3-angled, naked, somewhat scabrous, 8 — 16' high, 

 with 3 — 4 radical sheaths; radical Ivs. very short, subulate ; spike oblong, ter- 

 minal, about 2" in length ; hairs 6 to each flower, woolly, white, crisped, 4 times 

 as long as the spike. — Bog meadows, often alpine, N. H. ! to N. Y. and Penn. Jl, 



2. E. VAGiNATUM. Sheathed Cotton Grass. 



Sts. densely cffispitose, obtusely triangular, slender, smooth and rigid, 1 — 

 2f high; uppermost sheaths inflated; spikelet ovate, oblong, 6 — 8" long, of a 

 blackish color, with scarious glumes ; hairs 30 — 40 to each flower, straight, 

 white and glossy, twice as long as the spikelet, conspicuous, as well as in other 

 .species, even at a distance among the meadow grass. — N. Eng. to Mich., N. 

 to Arc. Am. June, July. 



* * Spikelets ninnerous. 



3. E. coNFERTissiMfM. Wood. Dense-headed Eriophorum: 



St. strictly erect, firm but slender, 2 — 3f high; Ivs. narrowly linear, chan- 

 neled, rigid, triangular-subulate above, 8 — 12' long; sheaths close; i7ivot. 2- 

 kaved, one leaf twice, the other 4 — 5 times longer than the spikelets; spikelets 

 5 — 8, crowded, erect, on very short (2 — 4"), slightly scabrous peduncles, 20 — 30- 

 flowered ; glumes obovate, carinate, very obtuse ; ach. compressed, oblanceolate, 

 1 J" long, flat on one side, carinate on the other ; bristles 100 — 200, white, J' long, 

 straight and silky. — Bogs, Meriden, N. H. ! Distinguished for its very large 

 and dense heads. 



4. E. POLYSTACHYUM. Many-Spiked Cotton Grass. 



. St. somewhat triangular, smooth, 1 — 2f high ; caitline Ivs. 2 — 3, broad- 

 linear, flattened below, triquetrous at the end ; spikelets about 10, on rough pe- 

 duncles which are long and drooping and sometimes branched ; sctce 30—40 to 

 each flower, reddish-white, G — 8" long. — Very conspicuous in meadows and 

 swamps, U. S. and Brit. Am. 



5. E. ANGUSTiFOLiuM. Rich. Narrow-leaved Cotton Grass. 



St. slender, leafy, smooth, 10 — 15' high; cauline Ivs. narrow, 3-cornered, 

 with concave sides, 1 — 3' long ; invol. of one bract, with a loosely sheathing 



