74-0 Oedee 155.— OTPBBACEiE. 



cattle do not eat, U. S. and Can. Aug. (Trioophorum oyperinum Pers.) 

 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 umbels ; spikes ovoid, pedunculate, solitary ; glumes lanoe(Jlate, ferruginous ; 

 bristles 6, as long as the glwmes, hardly escserled. — Swamps in most of the States. 

 Aug. (Trioophorum, Pers.) 



7. ERIOPH'ORUM, L. Cotton Grass. (Gr. epiov, -wool, <pepa, to 

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

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

 only 6, very long, dense, woolly or cottony hairs. — Stem generally leafy. 

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



§ Bristles of the perigynium 6. Spilce single No. 1 



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



— Spikes several. (*) 



* Spikes collected into a subsessile, capitate cluster No. 8 



* Spikes separate, pedunculate, in umbellate clusters Nos. A, 5 



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

 brous, 8 — 16' high, with 3 — 4 radical sheaths; radical Ivs. very short, subulate; 

 spike oblong, terminal, about 2" in length ; hairs 6 to each flower, woolly, white, 

 crisped, 4 times as long as the spike. — Bog meadows, often alpine, KT. H. to N. 

 Y. and Peun. Jl. 



2 E. vaginatum L. Sheathed Cotton Grass. Sts. densely oasspitoua, 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. lilng. to Mich., If. to Arc. Am. Jn., Jl. 



3 E. Virginioum L. Culm strict, firm, slender, tereteish, 2 to 3f high ; Ivs. 

 smooth, narrowly Hnear, shorter ; invol. 2 to 4-leaved, longer than the inflores- 

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

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

 nium flattened, obovate, keeled on the back, pointed, invested with TO to 200 

 pale cinnamon colored setae which are 4 to 1" long. — Bogs, Can. and IT. S. Jl., 

 Aug. In flower the heads are tawny red. 



8. CONFERTISSIMDM. Hoads Very large (20" diam.) and dense with white sette. 

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



4 B. polystaohyon L. Culm somewhat triangular, smooth, 1 — 2f high ; cauline 

 Ivs. 3 — 3,' Iroad-linear, flattened below, triquetrous at the end; invol. 2-leaved; 

 spikes about 10, on rough peduncles which are long and drooping and sometimes 

 branched; setae 30 — 40 to each flower, white, 6 — 8" long, ach. obovate, obtuse. 

 -^Tery conspicuous in meadows and swamps, TJ. S. and Brit. Am. 



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

 triquetrous, channeled on the upper side, scarce 1' wide ; invol, one-leaved, very 

 short; ped. roughish or subpubescent, nodding; spikes 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. lanoe-obovate, obtuse. — 

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



8. HEMICAR'PHA, Nees. (Gr. rjjj,iavg, half, Kdp(j>a, 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 fi'uit ; 

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

 achenium compressed, oblong, subterete. — 2J! Low, tufted, with seta- 

 ceous culms and leaves. 



H. BubsquarroBa Nees. Culm setaceous, compressed, sulcate, recurved, 2 — 3' 

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

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



