130 CYPERACEAE 



2-keeled but otherwise nerveless, tapering at the base, very minutely beaked, 

 the orifice truncate. Achenes triangular, with nearly flat sides, closely enveloped 

 by the perigynia, tipped by the minute persistent base of the stjde, constricted 

 at base. Stigmas 3, elongated. 



73. C. Geyeri Boott. Rootstock woody, elongated; culms up to 3.5 dm. 

 high, very rough; leaf -blades thick, 2-3.5 mm. wide, those of the culm develop- 

 ing after flowering; perigynia 1-3, 6 mm. long. Dry mountain sides and open 

 woods: Alta. — Colo. — Utah — -Ore. — Wash. Suhmont. — Subalp. Aly-Au. 



24. FiLiKOLiAE Tuckerm. Densely cespitose. Leaf-blades filiform or nar- 

 row. Spike solitary, linear or linear-oblong, androgynous, denseh- flowered, 

 bractless. Perigynia more or less triangular, nerveless except for the two lateral 

 ribs, not stipitate, jmberulent or pubescent, the hyahne-tipped beak obliquely 

 cut. Achenes triangular. Stigmas 3. 



74. C. elynoides Holm. Culms 8-12 cm. high; spike 8-15 mm. long, with 

 4-8 ascending perigynia; pistillate scales with dingy white hyaline margins; 

 perigynia 2.5-3 mm. long, slightly puberulent above, slenderly beaked. C. fili- 

 /oZia var. ??n'sfra Bailey. Mountain summits: Mont. — Colo. — Nev. Alp. Je-Au. 



75. C. filifolia Xutt. Culms 8-30 cm. high; spike 1-2 cm. long, with 5-10 

 perigynia; pistillate scales with broad bright white h3-aline margins; perigynia 

 3 mm. long, puberulent, abruptly and minutely stout-beaked. Plains and ridges: 

 Sask.— Tex.— N.M.— Wash.— Yukon. Plains—Mont. Ap-Jl. 



76. C. oreocharis Holm. Culms 1-2 dm. high; spike 1-2 cm. long, with 

 3-7 perigynia; i)istillate scales ovate, acuminate; perigynia 4 mm. long, broadly 

 obovoid, minutely pubescent, abruptly short-beaked. C. filifolia var. valida 

 Bailey. Dry slopes: Colo. Submont. Je. 



25. SciRPiNAE Tuckerm. Rootstocks creeping. Culms leafy below. Leaf- 

 blades narrow. Spike usually 1, linear, staminate or pistillate, many-flowered, 

 occasionally with an additional spike and normally w^ith an empty scarcely 

 sheatliing squamiform bract a short distance below the spike. Perigynia tri- 

 angular or flattened-triangular, membranous, 2-keeled, pubescent or puberulent, 

 tapering at the base, contracted at apex into the short cylindric entire or bi- 

 denticulate beak. Achenes triangular, with flat sides, sessile. Style slender, 

 slightly enlarged at the base, not jointed. Stigmas 3, short. 



77. C. pseudoscirpoidea Rydb. Rootstocks stout; culms 1-3 cm. high; 

 leaf-blades 2-3 mm. wide; spike 12-36 mm. long, 2-5 mm. wide; scales brownish 

 black; perigynia obovoid, strongly pubescent, triangular, 2.5 mm. long, with 

 bidenticulate beak. Mountain sides: Mont.^ — Colo. — Utah. Mont. — Subalp. 

 Jl-Au. 



78. C. stenochlaena (Holm) Mackenzie. Rootstocks stout, densely matted ; 

 culms 2.5-4 dm. high; leaf-blades 2-2.5 mm. wide; pistillate spikes 1.5-3 cm. 

 long, 4-7 mm. wide; scales oblong-ovate, blackish, with narrow hyaline margins, 

 ciliate; perigynia blackish at the apex. Mountains: Alaska — Alta.— Ida.— 

 Wash. Suhmont.— Mont. Jl-S. 



79. C. scirpoidea Michx. Rootstocks stoutish; culms 2-3.5 dm. high; 

 leaf-blades 1-2 mm. wide; pistillate spikes 1.5-3 cm. long, 2.5-5 mm. wide; scales 

 ovate, chocolate-brown, ciliate and puberulent; perigynia 3 mm. long, not black- 

 ish. Arctic-alpine, along streams: Greenl. — N.H. — N.Y. — Mich. — Mont.— 

 B.C. — Alaska; Eurasia, where rare. Alp. — Subalp. Je-Au. 



80. C. scirpiformis Mackenzie. Rootstocks stoutish; culms 2.5-4.5 dm. 

 high; leaf-blades 2-3 mm. wide; pistillate spikes 2-4 cm. long, 4-5 mm. wide; 

 scales ovate, brownish, strongly pubescent and ciliate at the apex; perigynia 

 2.5 mm. long, not blackish. Mountains: Alta. — N.D. Mont. Jl. 



26. MoNTANAE Fries. Cidms slender, leafy at the base. Leaf-blades nar- 

 row, rough above. Terminal spike linear, normally staminate. Lateral spikes 

 1-5, small, pistillate, or sometimes androgynous, subglobose to oblong, closely 

 few-many-flowered, approximate and sessile or short-peduncled, or in some 



