272 CYPERACEAE. 



2. Eriophorum vaginatum L. Sheathed Cotton-grass. (Fig. 638.) 



Eriophorum vaginatum L. Sp. PI. 52. 1753. 



Culms tufted, stiff, obtusely triangular, smooth, 

 slender, S / -i6 / tall, leafless, except at the base, 

 bearing two 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, ovoid, erect; scales 

 ovate-lanceolate or the lowest lanceolate, acumi- 

 nate, purple-brown, thin; bristles numerous, white, 

 straight, glossy, 4-5 times as long as the scale; an- 

 thers linear; achene obovoid, obtuse, brown, dull, 

 minutely apiculate. 



In bogs, Newfoundland to Alaska, south to Mas- 

 sachusetts, Pennsylvania and Minnesota. Also in 

 northern Europe and Asia. June-Aug. 



3. Eriophorum Scheuchzeri Hoppe. Scheuchzer's Cotton-grass. (Fig. 639. ) 



Eriophorum Scheuchzeri Hoppe, Taschenb. 1800: 104. 

 1800. 



Eriophorum capitatum Host, Gram. Aust. i: 30. pi. 38. 

 1801. 



Similar to the preceding species but the sheaths all 

 blade-bearing or only the upper one bladeless, culms 

 slender, smooth, nearly terete, io / -2o / tall. Leaves 

 filiform, channeled, usually much shorter than the 

 culm; spikelet solitary, terminal, erect; involucre 

 none; scales ovate-lanceolate, long-acuminate, pur- 

 ple-brown, membranous; bristles numerous, white 

 or slightly yellowish, weak, nearly straight, 4-5, 

 times as long as the scale; "anthers cordate-ovate;" 

 achene narrowly oblong, acute, brown, dull, subu- 

 late-beaked. 



In bogs, Newfoundland and Labrador to Manitoba, 

 Alaska rind Oregon. Also in Europe. Summer. 



4. Eriophorum russeolum Fries. Russet Cotton-grass. (Fig. 640.) 



Eriophorum russeolum Fries, Novit. Mant. 3: 67. 1842. 



Culms solitary or little tufted, triangular, erect, 

 smooth, S'-iS' tall, much longer than the leaves. 

 Upper sheath inflated, bladeless, mucronate, rarely 

 with a short subulate blade, usually borne below the 

 middle of the culm; leaves filiform, triangular-chan- 

 neled, mucronate, i / -4 / long; spikelet solitary, erect; 

 involucre none; scales ovate-lanceolate, acuminate, 

 thin, purplish-brown with nearly white margins; 

 bristles numerous, bright reddish-brown, 3-5 times 

 as long as the scale; achene oblong, narrowed at each 

 end, apiculate. 



Scarcely differs from the preceding species except in 

 the color of the bristles and the shorter-pointed achene. 

 In bogs, Newfoundland to Quebec. June-Aug. 



