528 
CYPERACEJE. (SEDGE FAMILY.) 
leafy (2?-(P high) ; leaves broadly linear, flat, rough-margined ; um¬ 
bel cymose-decompound, irregular, the numerous spikes clustered 15- 
20 together in dense heads , ovoid , dark lead-colored or olive-green turn¬ 
ing brownish; bristles 6, scarcely exceeding the obovoid compressed 
triangular achenium. — Low grassy grounds, very common northward. 
July. — Involucre of 3 principal leaves, like those of the culm (dark 
green), but shorter. Heads 2" - 3" long : scales mucronate. 
12. S. polypliyllllS, Vahl. Culm rigid, sharply triangular 
above, very leafy (2°-6° high); umbel cymose-decompound, the 
spikes clustered in heads of 3-8, ovoid , cylindrical with age , yellowish- 
brown; bristles 6, pubescent downwards, somewhat crisped , nearly 
twice the length of the achenium. (S. exaltetus, Pursh. S. brunneus, 
Muhl.) — Swamps and shady borders of ponds, W. New England to 
Ohio and southward, rare. July.— Resembles the last: leaves, &c., 
similar, but pale : involucre about 5-leaved. 
§2. Trichophorum, Richard. — Bristles capillary , tortuous and en¬ 
tangled , not barbed , much longer than the ( triangular ) achenium , 
when old projecting beyond the rusty-colored scales ( leaves , involucre , 
fyc-, as in the preceding species). 
13. S. li neat US, Michx. Culm triangular, leafy (l°-3P high); 
leaves linear, flat, rather broad, rough on the margins; umbels Jer- 
minal and axillary, loosely cymose-panicled, drooping, the terminal 
with a 1 - 3-leaved involucre much shorter than the long and slender 
rays; spikes oblong, becoming cylindrical, on thread-like pedicels; 
bristles at maturity scarcely exceeding the ovate green-keeled and 
pointed scales; achenium sharp-pointed. — Low grounds, W. New 
England to Michigan, chiefly southward. July. 
14. S. Eriopliorum, Michx. (Wool-grass.) Culm nearly 
terete, very leafy (2P-5° high); leaves narrowly linear, long, rigid* 
those of the involucre 3-5, longer than the decompound cymose-pani¬ 
cled umbel; spikes ovate, clustered, or the lateral pedicelled, woolly 
at maturity ; the rusty-colored bristles much longer than the pointless 
scales; achenium short-pointed. (Eriophorum cyperlnum, L.) —* 
Wet meadows, &c., common. July, Aug. — There are severa 
marked varieties, some with a very large and loose umbel, others 
with the spikes clustered in small heads, at least when young; no 
northward are slender, less leafy forms, with much smaller umbe s, 
and greenish-brown scattered small heads. — Longer involucral leaves 
often 1° long. 
8. ERIOPHORUM, L. Cotton-grass. 
Spikes many-flowered. Scales imbricated all round in several 
ranks. Perianth woolly, of numerous (rarely 6) flat hairs, much 
longer than the scales, persistent and forming a silky or cotton 
