SEDGE FAMILY. 107 



obovoid, faintly reticulate; tubercle thick, deltoid. Perhaps not distinct from 

 E. montana H.B.K. Sandy shores: S.C. -Fla. Tex. Calif. Colo. Son 

 Submont. 



10. E. rostellata Torr. Stems slender, flattened, the sterile ones often re- 

 clining and rooting at the summit, grooved; spikelets oblong, 6-12 mm. long, 

 2 mm. thick; glumes ovate, obtuse, or the upper acute, green with a darker mid- 

 vein; bristles 4-8, longer than the achenes; achenes obovoid, finely reticulate. 

 Marshes and wet meadows: N.H. -Fla. -Tex. -Calif. 'B.C.; Mex. Plain 

 Submont. Au-S. 



5. STENOPHYLLUS Raf. 



Scapose annuals, with narrowly linear or filiform leaves. Spikelets umbellate, 

 or capitate, rarely solitary; glumes spirally arranged, imbricate, deciduous. 

 Flowers perfect; perianth wanting. Stamens 2 or 3. Base of the style swollen, 

 persistent, forming a tubercle; stigmas 2 or 3. Achenes 3-angled or lenticular. 



1. S. capillaris (L.) Britton. Annual; stems tufted, filiform, smooth, 5-25 

 cm. high; leaves filiform, roughish; bracts 1-3, setaceous; spikelets narrowly 

 oblong, 5-8 mm. long, less than 2 mm. thick, in terminal, simple or compound 

 umbels; glumes oblong, obtuse or emarginate, dark-brown with green keel; achenes 

 yellowish, transversely wrinkled. River valleys: Me. -Fla. Calif. Ore. (but 

 no specimens seen from the Rockies). Jl-S. 



6. FIMBRISTYLIS Vahl. 



Annual or perennial sub-scapose herbs, with grass-like leaves. Spikelets 

 capitate or in ours umbellate, terete, several- or many-flowered; glumes spirally 

 arranged, imbricate. Flowers perfect; perianth none. Stamens 1-3. Style 

 usually enlarged at the base, but wholly deciduous at maturity; stigmas 2-3. 

 Achenes lenticular or 3-angled. 



1. F. interior Britton. Perennial, with short stolons; stem thickened at 

 the base, striate, smooth, 3-6 dm. high; leaves rough-margined, involute; spike- 

 lets in somewhat compound umbels, ovoid or ovoid-oblong, acutish, 1 cm. long 

 or less; glumes yellowish-brown, ovate, striate, mucronate, dull; achenes broadly 

 obovate, blunt, cancellate, chestnut brown. F. castanea and F. thermalis of Fl. 

 Colo. Meadows: Colo. -Neb. Tex. Plain. Jl-Au. 



7. ERIOPHORUM L. COTTON-GRASS. 



Perennial bog plants, with rootstocks. Stems triangular or terete. Leaves 

 with linear blades or some of them reduced to bladeless sheaths. Spikelets 

 terminal, solitary, or a few in heads or umbels. Glumes spirally arranged, all 

 usually subtending perfect flowers. Perianth of 6 members, but each 4-6-cleft 

 to the base into long soft, usually white bristles, exserted much beyond the glumes 

 at maturity. Stamens 1-3. Styles deciduous; stigmas 3. Achenes 3-angled, 

 oblong, ellipsoid or obovoid. 



Spikelets solitary; involucre wanting. 

 Plant stoloniferous. 



Glumes purplish-brown with narrow, pale margins. 1. E. Scheuchzeri. 



Glumes purplish-brown with white, broad margins. 2. E. Chamissonis. 



Plant tufted, not stoloniferous. 



Upper sheaths inflated; stem rough above. 3. E. callitrix. 



Upper sheaths not inflated; stem smooth. 4. E. opacum. 



Spikelets several, subtended by foliaceous bracts. 



Leaf-blades triangular-channeled throughout. 5. E. gracile. 



Leaf-blades flat, at least below the middle. 



Midrib of the glumes not prominent at the tip of the glume. 



6. E. angustifolium. 

 Midrib of the glumes prominent to the very tip. 7. E. viridicarinatum. 



1. E. Scheuchzeri Hoppe. Stem slender, 2.5-4 dm. high; sheaths all 

 blade-bearing or the uppermost one bladeless; blades filiform, channeled. E. 

 capitatum Host. Bogs: Lab. Newf. Wyo. -B.C. Alaska. Mont. Alp. 

 Jl-O. 



