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. JI. 



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

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

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

 closely 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 surface, 

 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 

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

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

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

 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 hyahne margins, conceal- 

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

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

 —N.M. —Calif .—Wash. Suhmont.—Mont. My-S. 



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

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

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

 4-10 perigynia; 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 smiace. 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. — 111.— Colo. — Mont. Plain — Suhmont. 

 — Boreal. My-Au. 



8. CHORDORRHIZ.A.E Fries. Culms elongate, prostrate, branching, the root- 

 stocks and roots Uttle 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 obhquely cut. Achenes lenticular, closely 

 enveloped. Stigmas 2. 



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

 perigynia 4-5 mm. long. Sphagnum bogs: Anticosti — 'Me.— Ind. — Sask. — 

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



