740 Order 155. — CYPERACE^. 



cattlo do not cat, U. S. and Can. Aug. (Tricophorum cypcrinurn Pere.) 

 Variable. 

 15 S. lineatus Mx. Culm triangular, very leafy, 2 to 3f high ; umbels terminal 

 and axillary, decompound, at length nodding ; invol. 1 or 2 bracts, shorter than 

 the tivtbels ; spikes ovoid, pedunculate, solitary ; glumes lanceolate, ferruginous ; 

 bristles G, as long as the glumes, hardly exserted. — Swamps in most of tho States. 

 Aug. (Tricophorum, Pers.) 



7. ERIOPH'ORUM, L. Cotton Grass. (Gr. cpiov, wool, 0i'pw, to 

 bear ; alluding to the copious bristles of the perigynium.) Glumes im- 

 bricated all around into a spike; acbenium invested with many, rarely 

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

 Spikelets mostly in umbels, finally clothed -with tbc long, silk hairs. 



S Bristles of tho perigynium C. Spike single No. 1 



5 Bristles of the perigynium numerous. — Spike single No. 2 



— Spikes several. (*) 



* Spikes collected into a suhsessilc, capitate cluster No. 3 



* Spikes separate, pedunculate, in umbellate clusters Nos. 4, ft 



1 E. alpinum L. Culm very slender, acutely 3-angled, naked, somewhat sca- 

 brous, 8 — 1G' high, with 3 — 4 radical sheaths; radical lvs. very short, subulate; 

 spike oblong, terminal, about 2" in length ; hairs G to each flower, woolhy, white, 



. crisped, 4 time3 as long as tho spike. — Bog meadows, often alpine, N. II. to N. 

 Y. and Pcnn. Jl. 



2 B. vaginatum L. Sheathed Cotton Grass. Sts. densely csespitous, obtusely 

 triangular, slender, smooth and rigid, 1 — 2f high ; uppermost sheaths inflated ; 

 spikelct ovate, oblong, G — 8" long, cf a blackish color, with scarious glumos; 

 hairs 30 — 40 to each flower, straight, white and glossy, twice as long a3 tho 

 spikelet, conspicuous, as well as in other species, even at a distance among the 

 meadow grass. — N. Eng. to Mich., N. to Arc. Am. Jn., Jl. 



3 E. Virginicum L. Culm strict, firm, slender, tereteish, 2 to 3f high ; lvs. 

 smooth, narrowly linear, shorter ; invol. 2 to 4-leaved, longer than tho iuflores- 

 cenco; spikes many, ovoid, acute, 3" long, glomerate, with very short peduncles, 

 forming a capitate cluster; stam. 1, tawny, exserted with 3 tawny styles; ache- 

 nium flattened, obovate, keeled on tho back, pointed, invested with 70 to 200 

 palo cinnamon colored seta; which aro 4 to 1" long. — Bogs, Can. and U. S. Jl., 

 Aug. In flower the heads aro tawny red. 



U. confeutissijiuji. Heads very largo (20" diam.) and donso with white seta;. 

 — In Northern N. H. (E. confertissimum Ed. 2d.) 



4 E. polystachyon L. Culm somewhat triangular, smooth, 1 — 2f high ; cauLi-m 

 lvs. 2 — 3, broad-linear, flattened below, triquetrous at the end; invol. 2-leaved; 

 spikes about 10, on rough peduncles which aro long and droopiugand sometimes 

 branched; setaa 30 — 40 to each flower, white, G — 8" long, ach. obovate, obtuse. 

 — Very conspicuous in meadows and swamps, U. S. and Brit. Am. 



5 E. gracile Koch. Culm obtusely 3-angled, 18' to 2f high, roughish above; lvs. 

 triquetrous, channeled on tho upper side, scarce 1' wido ; invol. one-leaved, very 

 short; pod. roughish or subpubescent, nodding ; spike3 3 to 8, ovoid, some sub- 

 sessile, others on peduncles 1 to 4" long ; glumes striate, brownish ; bristles 50 

 or more in each flower, 8 to 10" long, white; ach. lance-obovato, obtuse. — 

 Bogs, N. States and Can. Common in N. J. (Jackson) (E. angustifolium Ton - .). 



8. HEMICAR'PHA, Nees. (Gr. ?//ucrrc, half, ndp<pa, straw or chaff, 

 there being but one scale to the flower.) Spike many-flowered ; glumes 

 imbricated all around ; interior scale 1, embracing the flower and fruit ; 

 bristles ; stamens 1 ; style 2-cleft, not bulbous at base, deciduous ; 

 acbenium compressed, oblong, subterctc. — If. Low, tufted, with seta- 

 ceous culms and leaves. 



H. Bubsquarrosa Nees. Culm setaceous, compressed, sulcate, recurved, 2 — ^ 

 high; lvs. setaceous, shorter than tho scape; spikes 2 — 3, terminal (appa' 

 rently lateral), subsessile, ovoid, nearly 2" long; invol. of 2 bracts, one appear- 



