CYPERACE^. 411 RHYKCHOSPORA. 



somewhat squarrose at the tip. A minute, caespitose rush, with setaceous 

 leaves and stems, on sandy banks Aug. 



21. S. Baldwin'ia'nus. SchuU. Fimbristylis ferruo-inia. Vnhl. 



Stern compressed, deeply striate, leafy at base ; umbel mostly siniple, 

 3 — 4-rayed, central spikelets sessile ; involucre subulate, 2-leaved, as long as 

 the Umbel ; spitietcts ovoid, acute ; gliinus ovale, brown ; style bifid, ciliate; 

 achenium white, longitudinally furrowed. Swamps. July. 



6 . E R I O' P H O R U M . 

 Glumes imbricated all around into a ?[)ike; achenium in- 

 vested in very long, dense, woollj or cottony Iiairs. 



* Spikelet solitary. 



1. E. alpi'num. 



Stem acutely 3-angled, naked, somewhat scabrous, S — 10 inches high, with 

 3 — 4 radical sheaths ; radical leaves very short, subulate; spikelit oblong, 

 about 2 lines in length ; seta 6 to each flower, woolly, white, crisped, 3 times 

 as long as the spike. Bog meadows. July. 



2. E. vagina'tum. E. CEPspitosum. Host. 

 Steins densely csespitose, obtusely triangular, very slender, smouth and 



rigid, about a foot high ; uppermost slienths inflated ; spiket/t ovate, oblong, 

 6 — 8 lines long, of a blackish color, with scarious glumes ; setce 15 — 20 to each 

 flower, straight, white, and glossy, twice as long as the spikelet, conspicuous, 

 as well as in other species, even at a distance amonjr the meadow grass. Jn. Jl. 

 * * Spikelets numerous. 



3. E. polysta'chton. 



6i^w somewhat triangular, smooth, 1 — 2 feet high; cnuline leaves 2 — 3, 

 broad-linear, flattened below, triquetrous at the end; s/iiki lets about 10, on 

 rough peduncles which are long and drooping and sometimes branched ; 

 setcB 30 — 40 to each flower, reddish white, G — 8 lines long. Very conspicu- 

 ous in meadows and swamps. July. 



4. E. ANGusriFo'LiuM. Rich. JVarroic-lr.aved Cotton grass. 



Stem slender, leafy, smooth, 10 — 15 inches high; cauline leaves rmriow, 

 3-cornered, with concave sides, 1 — 3 inches long ; involucre of one bract, with 

 a loosely sheathing base ; spike'ets2 — 4, on short peduncles, noddino- ; 5Cte 

 40 — 50 to a flower, long, white and cottony. Swamps. July. 



5. E. Virgi'nicum. Virginian Cotton grass. 



Stem nearly round, leaiy, smooth, 2 — 3 feet high; leaves flat, few, Ion?, 

 with scabrous margins ; involucre 2 — 4-leaved, outer leaves much longer ; 

 spikcUts in a sort cf umbel, erect, nearly sessile; glumes ovate, brown at the 

 sides ; keel green ; hairs 50 — CO, reddish white, long and cottony. Wet 

 grounds. July. 



7. RHYNCHOSPO'RA. 

 Spikelets few-flowered ; glumes imbricated all around, 

 lower ones empty; achenium invested with hypogynous seiae, 

 and crowned with the persistent, enlarged, conical base of 

 the style. 



1. R. ALBA. Vahl. White Bng-rush. Schoenus albus. L. 



Stem triangular above, very slender, leafy, smooth, 10 — 16 inches high; 

 leaves setaceous, channeled ; corymbose fascicles pedunculate, both terminal 

 and from the axils of the sheaths, with setaceous bracts; spikd'ts lanceolate, 

 acute at each end, with crowded, lanceolate, white glumes. In wet, shady 

 grounds; common. July — Sept. 



