SEDGE FAMILY 121 



elliptic-lanceolate, 3.5 mm. long, 1.25 mm. wide, finely conspicuously many- 

 nerved, not inflated, nor membranous, stipitate. Alpine ridges: Alta. Alp. Jl. 



7. DiviSAE Christ. Rootstocks long-creeping, dark-colored, tough, the culms 

 arising singly or in small ckunps at intervals, mostly stiff, dark-tinged at the 

 base, aphyllopodic. Leaf-blades narrow. Spikes few to many, more or less 

 closety aggregated into an oblong or oblong-ovoid head, androgynous or dioeci- 

 ous, ovoid or oblong. Heads in some species dioecious or nearly so. Lowest 

 one or several of the lower bracts developed, short-prolonged, the others bract- 

 like. Perigynia appressed-ascending, plano-convex, smooth, often shining, 

 coriaceous, more or less nerved on outer and nerved or nerveless on inner svu-face, 

 sharp-edged but not wing-margined, rounded and spongy at base, the obliquely 

 cut beak in age bidentulate. Achenes lenticular, closely enveloped. Stigmas 2. 



10. C. Douglasii Boott. Culms 6-30 cm. high; leaf-blades 1-2.5 mm. wide; 

 staminate spikes linear-elliptic, 8-15 mm. long, 2.5-4 mm. wide: pistillate spikes 

 wider; scales ovate to lanceolate, yellowish-brown, with hyaline margins and 

 lighter center, concealing the perigynia; perigynia lanceolate, strongly nerved, 

 4 mm. long, 1.75 mm. wide, light brownish; styles elongate. C. irrasa Bailey. 

 Dry or alkaline soil: Man. — Neb. — N.M.— Calif.— B.C. Plain—Mont. My- 

 Au. 



11. C. stenophylla Wahl. Culms 5-20 cm. high; leaf-blades 1.5 mm. wide 

 at the base, involute above; spikes few, densely aggregated into a head 7-15 

 mm. long; scales broadly ovate, brownish with hyaline margins; perigynia few 

 to a spike, ovate, lightly nerved on both surfaces, 3 mm. long, 1.75 mm. wide, 

 blackish at maturity; styles short. C. Eleocharis Bailey. Dry soil: Man. — 

 Iowa — N.M. — Utah — Yukon; Eurasia. Plains — -Mont. Je-Jl. 



12. C. simulata Mackenzie. Culms 3-5 dm. high; leaf-blades 2-4 mm. 

 wide, flat; head 12-25 mm. long, 6-10 mm. wide, the spikes densely aggregated, 

 pistillate, staminate, or androgynous; scales brown with hyaline margins, conceal- 

 ing the perigynia; perigynia 2.25 mm. long, 1.4 mm. wide, round-truncate at 

 base, abruptly beaked, serrulate above. C. Gayana N. Am. auth. Wet soil: Mont. 

 —N.M.— Calif.— Wash. Suhmonl.—Moni. My-S. 



13. C. praegracilis W. Boott. Culms 2-5 dm. high; leaf-blades 1.5-3 

 mm. wide, flattened or channelled; head linear-oblong to ovate-oblong, 1-5 cm. 

 long, 6-12 mm. wide, the 5-15 spikes densely aggregated, androgynous, with 

 4-10 perig\Tiia; scales ovate-lanceolate, acute to cuspidate, light brownish, with 

 hyaline margins, nearly concealing the perigynia; perigynia 3-4 mm. long, 1.5 

 mm. wide, dark brown at maturity, nerved on the outer, nearly nerveless on 

 the inner surface. C. marcida Boott. C. usta Bailey. C. alterna (Bailey) 

 Clarke. C. camporum Mackenzie. Meadows, widely distributed and variable: 

 Man. — Iowa — -Kans. — -Calif. — B.C.; Mex. Prairie — Plains — Suhmont. My- 

 Au. 



14. C. Sartwellii Dewey. Culms 4-7 dm. high, rough above; leaf-blades 

 2.5-4 mm. wide, flat; head oblong, 3-5 cm. long, about 1 cm. wide, the numerous 

 spikes densely aggregated, the larger with 15-20 perigynia; perigynia lance-ovate, 

 2.5-4 mm. long, 1.5-2 mm. wide, finely nerved, the beak much shorter than the 

 body. Marshes and bogs: Ont. — 'N.Y. — Ill.^Colo. — Mont. Plain — Submont. 

 — Boreal. My-Au. 



8. Chordorrhizae Fries. Culms elongate, prostrate, branching, the root- 

 stocks and roots httle developed. Leaf-blades narrow. Spikes 3-10, androgy- 

 nous, few-flowered, closely aggregated into an ovoid head. Bracts absent or 

 inconspicuous. Perigynia very thick, plano-convex, oblong-ovate, smooth, 

 shining, coriaceous, closely many-nerved, rounded on the margins, rounded and 

 spongy at the base, the short beak obliquely cut. Achenes lenticular, closely 

 enveloped. Stigmas 2. 



15. C. chordorrhiza Ehrh. Culms 1.5-3 dm. high; head 1-1.5 cm. long; 

 perig>Tiia 4-5 mm. long. Sphagnum bogs: Anticosti — Me. — Ind. — Sask. — 

 Mack. — B.C.; Eurasia. Boreal. My-Jl. 



