573 CLX. CYPERACE.E. ERIOPHORUM 



11. S. BRUNNEUS. Muhl. 



St. obtusely triangular, leafy, 2 3f high; cyme decompound, 'its principal 

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

 heads of 3 6 ; glumes 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. TRICOPHORUM. Bristles 6, muck longer than the achenium, tortuous 

 smoothish. Stem leafy. Umbel decompound. 



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



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

 bel terminal, decompound, large and loose ; spikes mostly pedicellate ; bristles 6, 

 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. Pm.) 



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

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

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

 long as the glumes. Swamps, in most of the States. Aug. 



8. ERIOPHORUM. 



Gr. epiov, wool, (f>pa), 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 clothed with the long^ silky hairs. 

 * Spikelet, solitary. 



1. E. ALPlNUM. 



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 caespitose, 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 numerous. 



3. E. CONFERTISSIMUM. 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; invol. 2- 

 icaved, 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, 

 H" long, flat on one side, carinate on the other ; bristles 100 200, white, f 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 ; candine 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 ; seta 30 40 to 

 each flower, reddish-white, 6 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 



