740 ORDER 155. CYPERACE^E. 



cattle do not eat, TL S. and Can. Aug. (Tricophorum cyperinum 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 lanceolate, ferruginous ; 

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

 Aug. (Tricophorum, Pers.) 



7. ERIOPH'ORUM, L. COTTON GRASS. (Gr. epiov, wool, <tpw, to 

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

 bricated all around into a spike ; acheniutn 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. 



S Bristles of tho perigynium 6. Spike sinple No. 1 



Bristles of tho perigynium numerous. Spike single .'. . .No. 2 



Spikes several. (*) 



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



* Spikes separate, pedunculate, in umbellate clusters Nos. 4, 5 



1 E. alpinuni 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, N. H. to N. 

 Y. and Penn. Jl. 



2 E. vaginattim L. SHEATHED COTTON GRASS. Sts. densely csespitous, obtusely 

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

 spikelet ovate, oblong, 6 8" long, of a blackish color, with scarioua glumes ; 

 hairs 30 iO 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. 1ST. Eng. to Mich., N. to Arc. Am. Jn., JL 



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

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

 cence; spikes many, owid, 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 the back, pointed, invested with 70 to 200 

 pale cinnamon colored seta3 which are 4 to 7" long. Bogs, Can. and U. S. Jl., 

 Aug. In flower the heads are tawny red. 



3. CONFERTISSIMUM. Heads very large (20" diam.) and dense with white seta3. 

 In Northern N. H. (E. confertissimumxEd. 2d.) 



4 E. polystachyon L. Culm somewhat triangular, smooth, 1 2f high ; cauline 

 Ivs. 2 3, broad-linear, flattened below, triquetrous at the end; invol. 2-kaved; 

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

 branched; setae 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; 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. lance-obovate, obtuse. 

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



8. HEMICARTHA, Nees. (Gr. r\\u,av$, half, icap^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 fruit ; 

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

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

 ceous culms and leaves. 



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

 high; Ivs. setaceous, shorter than the scape; spikes 23, terminal (appa' 

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



