CYPERACE^E. (SEDGE FAMILY.) 565 



§ 2. TRICH6PII0RL t M, Richard. Bristles capillary, naked, not barbed, elon- 

 gating, Incoming tortuous and entangled, much longer than the triangular achenium, 

 when old mostly projecting beyond the rusty<olored scales : culm, leaves, <j-c. as in 

 the preceding subdivision ; umbel-like cymose panicle decompound. 



20. S. line&tUS, Michx. Culm triangular, leafy (l°-3° high); lcave3 

 linear, flat, rather broad, rough on the margins ; umbels terminal and some- 

 times axillary, loose, drooping, the terminal with a 1 -3-leaved involucre much 

 shorter than the long and slender rays ; spikes oblong, becoming cylindrical 

 (2"- 4" long), on thread-like drooping pedicels ; bristles at maturity scarcely 

 exceeding the ovate green-keeled and pointed scales ; achenium sharp-pointed. 



— Low grounds, W. New England to Wisconsin, and common southward. 



21. S. Eriophorum, Michx. (Wool-Grass.) Culm nearly terete, very 

 leafy (2° -5° high) ; leaves narrowly linear, long, rigid, those of the involucre 

 3-5, longer than the decompound cymose-panicled umbel, the rays at length droop- 

 ing ; spikes exceedingly numerous, ovate, clustered, or the lateral ones pedi- 

 celled, woolly at maturity (l£"-3" long) ; the rusty -colored bristles much longer 

 than the pointless scales ; achenium short-pointed. (Eriiiphorum cyperinum, L.) 



— Var. cyi'erinus (S. cyperinus, Kunth) is the form with nearly all the spikes 

 conglomerate in small heads. — Var. laxus (S. Eriophorum, Kunth) has the 

 heads scattered, the lateral ones long-pedicelled. Various intermediate forms 

 occur ; and the umbel varies greatly in size. — Wet meadows and swamps : 

 common northward and southward. 



9. ERIOPHORUM, L. Cotton-Grass. (PI. 3.) 



Spikes, scales, achenium, &c. as in Scirpus. Bristles of the perianth of 

 numerous (in one species few) flat and delicate capillary bristles, which lengthen 

 greatly after flowering, much exceeding the scales, and forming of the capitate 

 spike a (white or reddish) conspicuous cotton-like tuft in fruit. Stamens 1 -3. 

 Style 3-cleft. Perennials. (Name composed of cpiov, wool or cotton, and (popa, 

 bearing.) 



* Bristles of the flower only 6, crisped, white ; spike single : small, involucre none. 



1. E. alpinum, L. Culms slender, many in a row from a running root- 

 stock 6' -10' high), scabrous, naked; sheaths at the base awl-tipped. — Cold 

 bogs, New England to Penn., Wisconsin, and northward. June. (Eu.) 



* * Bristles very numerous, not crisped, forming dense cottony heads in fruit. 

 •*- Culm bearing a single spike : involucre none. 



2. E. vaginatum, L. Culms in close tufts (1° high), leafy only at the 

 base, above with 2 inflated leafless sheaths ; root-leaves long and thread-form, 

 triangular-channelled ; scales of the ovate spike long-pointed, lead-color at 

 maturity. — Cold and high peat-bogs, New England to mountains of Penn. 

 (Prof. T. Green), Wisconsin, and northward; rare. May, June. (Eu.) 



(E. russeolum, Fries, with copper-colored wool, found in New Brunswick 

 by Rev. J. Fowler, may be expected in N. E. Maine.) 



-t- -»- Culm leaf j, bearing several umbellate-clustered heads, involucrate. 



3. E. Virginicum, L. Culm rigid (2° -4° high) ; leaves very narrowly 

 linear, elongated, flat; spikes nearly sessile, crowded in a dense cluster or head; 



