128 CYPERACEAE 



simple. Bracts inconspicuous. Perigj-nia plano-convex, white-puncticulate, 

 lanceolate, ovate, oval, or obovoid, appressed 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 bv the lenticular achene. Style- 

 base not enlarged. Stigmas 2. 



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

 with slender rootstocks; leaf-blades 1-L5 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. ienella Schk, Bogs: Newf.— N.J.- 

 Ind.— N.M,— Calif.— B.C.— Alaska; Eurasia. SuhmonL—Subalp. Je-Au. 



60. C, trisperma Dew-ey. 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 

 mmute btak smooth or nearl> so. Sw^amps and wet woods; Lab. — Md. — 

 (?Neb.)— Sask. Boreal J^-S. • 



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

 tose and stoloniferous; leaf-blades 0.5-2 ram. wide; perigynia oblong-obovoid, 

 3.5-3.5 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. Grcenl.— 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, famtly few-nerved. Swamps and bogs: Lab.— Va.— Calif.— Alaska; 

 Eurasia; S. Am.; Australia. SubmonL—Subalp. My-Au. 



A ^^^n ^' ^runuescens (Pers.) Poir. Cuhns slender, 2-5 dm. high; spikes 4r-8, 

 4-10-tiowered, subglobose, 4-13 mm. in diameter; perigynia mostly smaller th^" 

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

 Colo.— Wash.— Alaska; Eurasia. SubmonL—Subalp. Je-Au. 



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

 mni. 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. 

 caMesce/i^var. oregana Bailey. Swamps and wet w^oods: N.B.— N.Y.— Mont.— 

 Cahf.— B.C. SubmonL Je-Au. 



^•1 l^j Phyllostachyae Tuckerm. Culms densely cespitose, weak, compressed, 

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

 androg^mous, the rachis zigzag, dilated; one spike terminal, the others basal on 



elongated 



e-s 



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



m 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. widp: lowpr T^UfHInfo cool^a oa ;« th^^ npvt.r 



5-6 



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



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



.5—3 dm. lone". .^— fi mm -UT-irlA* Ir^TT'tiT' r^io^-i'llo*-^ c«r,1^^ l„«f i;i-« rtrtrti^ofo" 



pengynia 



