128 CYPERACEAE 



simple. Bracts inconspicuous. Perigynia plano-convex, white-puncticulate, 

 lanceolate, ovate, oval, or obovoid, ap pressed to spreading, beakless to promi- 

 nently beaked, more or less nerved on both sides, not winged or margined, but 

 acute-edged above, nearly or entirely filled by the lenticular achene. Style- 

 base not enlarged. Stigmas 2. 



59. C. disperma Dewey. Culms weak, 1.5-6 dm. high, in large clamps, but 

 with slender rootstocks; leaf-blades 1-1.5 mm. wide; spikes distant or the upper 

 aggregate, 1-5-flowered; perigynia ovoid-elliptic, 2 mm. long, 1.5 mm. wide, 

 finely nerved, the minute beak smooth. C. tenella Schk. Bogs: Newf. N.J. 

 Ind. N.M. Calif. B.C. Alaska; Eurasia. Subrnont. Subalp. Je-Au. 



60. C. trisperma Dewey. Culms filiform, weak, 1.5-8 dm. long, in large 

 clumps, but with slender rootstocks; leaf-blades 1-2 mm. wide; perigynia oblong, 

 2.5-4 mm long, nearly 2 mm. wide, finely nerved, narrowed at the apex, the 

 minute btak smooth or nearly so. Swamps and wet woods: Lab. Md. 

 (?Neb.) Sask. Boreal. Je-S.~ 



61. C. tenuiflora Wahl. Culms slender, weak, 2-6 dm. long, loosely cespi- 

 tose and stoloniferous; leaf-blades 0.5-2 mm. wide; perigynia oblong-obovpid, 

 2.5-3.5 mm. long, 1.5 mm. wide, obscurely nerved. Bogs: N.B. Me. Minn. 

 Alta.; Eurasia. Boreal. Je-Au. 



62. C. Lachenalii Schkuhr. Culms stiff, erect, 0.7-4 dm. high; leaf-blades 

 1-3 mm. wide; spikes 2-6, many-flowered; perigynia 2-3.5 mm. long, several- 

 nerved, abruptly short-beaked. C. lagopina Wahl. Greenl. Canadian Rock- 

 ies Alaska; Eurasia. Arctic. Jl-Au. 



63. C. Heleonastes Ehrh. Culms stiff, erect, 1-4.5 dm. high; leaf-blades 

 1-2 mm. wide; spikes 2-5, with 5-10 perigynia; the latter 3 mm. long, 1.25 mm. 

 wide, several-nerved, tapering into the short beak. Bogs: Ont. Alta. B.C. 

 Mack.; Eurasia. Subalp. Boreal. Jl-Au. 



64. C. canescens L. In large clumps, the culms slender, 2.5-8 dm. high; 

 spikes 4-9, 3-12 mm. long, 3-5 mm. wide; perigynia 1.8-2.8 mm. long, 1-1.8 

 mm. wide, faintly few-nerved. Swamps and bogs: Lab. -Va. Calif. -Alaska; 

 Eurasia; S. Am.; Australia. Submont. Subalp. My-Au. 



65. C. brunnescens (Pers.) Poir. Culms slender, 2-5 dm. high; spikes 4-8, 

 4-10-flowered, subglobose, 4-13 mm. in diameter; perigynia mostly smaller than 

 in the preceding species. In wet places, banks and open woods: Lab. N.C. 

 Colo. Wash. Alaska; Eurasia. Submont. Subalp. Je-Au. 



66. C. arcta Boott. Culms slender, erect, 1.5-8 dm. high; leaf-blades 2-4 

 mm. wide; spikes 5-15, many-flowered, aggregate into a head 1.5-3 cm. long; 

 perigynia ascending or somewhat spreading, 2-3 mm. long, many-nerved. C. 

 canescens var. oregana Bailey. Swamps and wet woods: N.B. -N.Y. Mont. 

 Calif. B.C. Submont. Je-Au. 



18. PHYLLOSTACHYAE Tuckerm. Culms densely cespitose, weak, compressed, 

 dilated below the spikes, mostly much exceeded by the leaves. Spikes 2-4, 

 androgynous, the rachis zigzag, dilated; one spike terminal, the others basal on 

 often much elongated peduncles; staminate portion with small tight scales; 

 pistillate portion loosely one-several-flowered, the scales elongated and con- 

 spicuous. Perigynia glabrous, 2-keeled, but otherwise nerveless, nearly round 

 in cross-section, more or less beaked, the beak flattened-triangular, the orifice 

 hyaline. Achenes triangular, stipitate, the sides convex, filling the perigynia, 

 the apex rounded. Stigmas 3, short. Style jointed at the base with achene, 

 soon withering. 



67. C. durifolia Bailey. Culms up to 2.5 dm. long; leaf-blades green, not 

 glaucous, 1.5-3 dm. long, 2.5-6 mm. wide; lower pistillate scales as in the next; 

 perigynia 5-6 mm. long, the body oval, the beak smooth, about as long as the 

 body. C. Backii Boott. Woods: Que. Mass. N.Y. Alta. e B.C. 



68. C. saximontana Mackenzie. Culms up to 1.5 dm. long; leaf -blades 

 glaucous, 1.5-3 dm. long, 3-5 mm. wide; lower pistillate scales leaf-like, saccate; 

 perigynia 4 mm. long, the body oblong-globose, the beak barely 1 mm. long, 



