SCIRPUS CYPERACEZ 691 
ERIOPHORUM | 
in capitate clusters at the ends of the usually spreading raylets: scales 
brown with a green midrib, obtuse or subacute: bristles 4, somewhat lon- 
_ger than the achene: stamens 2: style 2-cleft: achenes oblong-obovate, 
nearly white, plano-convex or with a low ridge on the back, pointed. In 
swamps and wet woods, Alaska to California and the Atlantic States 
S. atrovirens Muhl. Gram. 43. Stems rather slender, leafy, 2-4 feet 
high, from slender perennial rootstocks: leaves elongated, rough on the 
margins, dark green, 3-6 lines wide one or two of them usually exceeding 
the inflorescence: umbel simple or 1-2-compound: spikelets ovoid-oblong, 
acute, 6-20 in the dense capitate clusters at the ends of the rays or raylets: 
scales greenish-brown,oblong, acute, the midrib excurrent, bristles usually 
6, about as long as the achene: stamens 3: style 3-cleft: achene obovoid- 
oblong, 3-angled, pale dull brown. In swamps, Oregon to Nova Scotia 
and Georgia. 
S. lineatus Michx. Fl. i, 32. Perennial by stout rootstocks: stems 
rather slender, erect, 1-3 feet high, leafy: leaves light green, shorter than 
the stem, 2-4 lines wide, the upper ones and those of the involucre not 
exceeding the inflorescence, flat, rough on the margins: umbels terminal 
and commonly also axillary, decompound, the rays very slender, becoming 
pendulous: spikelets mostly solitary at the ends of slender raylets, oblong, 
obtuse, 3-5 lines long: scales ovate or oblong, reddish-brown with green 
midrib: bristles 6, weak, smooth, much longer than the achene: stamens 
3: style 3-cleft: achenes oblong, pale brown, narrowed at both ends, 
3-angled, short-beaked. In.wet places, Oregon to Texas, Georgia and 
Ontario. 
§ 3 Stems leafv, bearing a sessile head of spikelets subtended 
by a few involucral bracts. Bristles elongated, the barbs directed 
upward. . : 
S. crimiger Gray Proc. Am. Acad. vii, 392. Stems slender, 3 inches 
to 3 feet high, from slender matted rootstocks, triangular and striate, 
rough above: leaves flat, rough on the margins, the radical one elongated 
but shorter than the stem, the cauline only an inch or two long, distant, 
the uppermost usually very near the top: involucral bracts Aisa’ and 
scale-like, acuminate, 2-4 lines long: spikelets 5-9, oblong, 3-4 lines long: 
seales thin and soft, brownish, oblong: bristles 6: filaments slender, much 
exserted: style 3-cleft: achenes oblong, 3-angled, acute and shortly beaked, 
a line long. In marshes, southern Oregon to California, 
4 ERIOPHORUM L. 8p. 52. 
Low herbs with creeping perennial rootstocks, triangular or 
nearly terete stems, grass-like leaves and small perfect flowers in 
terminal solitary or umbellately clustered spikelets subtended by 
a one- to several-leaved involucre or naked. Scales spirally im- 
bricated, usually all fertile. Perianth of few to many filiform 
smooth soft exserted bristles. Stamens 1-3. Style 3-cleft. 
Achenes 3-angled, oblong, ellipsoid or obovoid. 7 
* Involucral leaves none: spikelets solitary. 
E. vaginatum L. Sp. 52. Stems stiff, tufted, obtusely. triangular, 
smooth, slender, 8-16 inches high, leafless except at base, bearing 2 inflat- 
ed sheaths, the upper one usually above the middle: leaves stiff, filiform, 
triangular, channelled, shorter than or sumetimes exceeding the stem: 
spikelet ovoid, erect: scales ovate-lanceolate or the lowest lanceolate, acu- 
minate, purple-brown, thin: bristles numerous, white, straight, glossy, 
4-5 times as long as the scale: anthers linear: achene-obovoid, obtuse 
