3 2 4 



CYPERACEAE. 



Vol. I. 



4. Eriophorum callithrix Cham. Sheathed Cotton-grass. Fig. 794. 



E. vaginatum Torr. Fl. 65. 1824. Not L. 

 E. callithrix Cham. ; C. A. Meyer, Mem. Sav. Etrang. 

 1 : 203. 1831. 



Plants not stolonif erous ; culms tufted, stiff, ob- 

 tusely triangular, forming tussocks, slender, 8'-2o' tall, 

 leafless, except at the base, rough at the top, bearing 

 2 or 3 distant inflated sheaths, the upper one usually 

 above the middle. Leaves stiff, filiform, triangular, 

 channeled, slightly rough, shorter than or sometimes 

 overtopping the culm; involucral leaf wanting; 

 spikelet solitary, erect; scales ovate-lanceolate or the 

 lowest lanceolate, acuminate, purple-brown to nearly 

 black, thin ; bristles white or red-brown, straight, 

 glossy, 4-5 times as long as the scale ; anthers linear ; 

 achene obovoid, obtuse, brown, minutely apiculate. 



In bogs, Newfoundland to Alaska, south to Massachu- 

 setts, Pennsylvania, Wisconsin and Manitoba. Also in 

 Asia. Hare's-tail. Cotton-grass or -rush. Canna-down. 

 Catlocks. Moss-crops. June-Aug. 



5. Eriophorum opacum (Bjornst.) Fernald. 

 Close-sheathed Cotton-grass. Fig. 795. 



E. vaginatum opacum Bjornst. Grunddr. af. Pit. Lappm. 

 Vaxt. 35. 1856. 



E. opacum Fernald, Rhodora 7 : 85. 1905. 



Loosely tufted, not stoloniferous. Culms slender, 

 terete or nearly so, i°-2° high, smooth; basal leaves 

 elongated, filiform-channeled ; stem-leaves reduced to 

 2 or 3 close sheaths, the lower one sometimes with 

 a short blade; spikelet solitary, erect; scales thin, 

 ovate-lanceolate or the inner ones linear-lanceolate, 

 acuminate; bristles white or brownish; achene obo- 

 vate-oblong, apiculate. 



Bogs, Maine and Massachusetts to Ontario, Alberta, 

 the Yukon Territory and British Columbia. Also in 

 Europe and Asia. Summer. 



6. Eriophorum gracile Koch. Slender Cot- 

 ton-grass. Fig. 796. 



E. gracile Koch ; Roth, Catal. Bot. 2 : 259. 1800. 

 E. triquetrum Hoppe, Taschenb. 1800: 106. 1800. 



Culms slender, smooth, nearly terete, spreading 

 or reclining, 2° long or less. Leaves triangular- 

 channeled, the basal ones mostly wanting at flower- 

 ing time, those of the culm 2 or 3, the upper one 

 with a blade shorter than its sheath, ii' long or 

 less; involucral leaf about i' long; spikelets 2-4, 

 rarely 6, the slender peduncles pubescent, mostly 

 less than 1' long; scales ovate, grey to nearly black, 

 acutish, the midvein prominent; achenes obovate- 

 oblong, about 1" long; bristles bright white, i'-l' 

 long. 



In bogs, Quebec to British Columbia, New Y° rk > 

 Pennsylvania, Iowa, Nebraska, Colorado and Cali- 

 fornia. Also in Europe and Asia. June-Aug. 



