250 



CYPERACEAE (SEDGE FAMILY) 



528. C. riparia. 



smooth, thick in texture, becoming polished with age, the nerves impressed, 

 scales sharp, mostly a little shorter than the perigynia. la. to 

 Kan., and northwestw. FIG. 526. 



Var. aristata (R. Br.) Bailey. Mostly stouter ; leaves 

 4-10 mm. wide, more or less hairy on the under surface 

 and sheaths ; perigynia lance-ovoid, smooth, the teeth 

 longer and more spreading ; scales long and sharp. (C. 

 aristata R. Br.) Ont. to Sask. and B. C., s. to X. Y., 

 526 C trich Mich., Wise., Neb., etc. FIG. 527. Var. IMBERBIS Gray, 

 v Dewevi ' Sheaths glabrous. Ont. to N. Dak. and Mo. 



159. C. riparia W. Curtis. Very large and stout, 

 0.6-1.3 m. high, stoloniferous ; leaves Q.b-1.5 cm. broad, flat, rough, 

 glaucous, much longer than the sharply angled 

 culm ; spikes 2-4, scattered and all more or less 

 peduncled, the lowest of ten very long-stalked, vary- 

 ing from almost globular to slender-cylindric, 2-10 cm. long, 

 erect or the lower somewhat drooping, loosely 

 flowered below ; perigynia lance-ovoid, cori- 

 aceous, rather lightly many-nerved, the beak 

 short and thick; scales varying from blunt to 

 awned, shorter or longer than the perigynia. 

 Swamps and wet shores, N. B. to Man., 

 and southw. May-July. (Eu.) FIG. 528. 



160. C. ACUTIFORMIS Ehrh. Stout, 0.4- 

 1.2 m. high ; culm thick and sharp, mostly 

 smooth ; leaves broad, flat and glaucous, much 

 prolonged ; spikes 2-5, all but the uppermost peduncled, spread- 

 ing or drooping, narrowly cylindric, 2-5.5 cm. 

 long, loosely flowered below ; perigynia ovoid, 

 very strongly many-nerved, the short beak 

 slightly toothed ; scales rongh-awned and longer 

 than the perigynia. Boggy meadow, New 

 Bedford, and formerly at Dorchester, Mass. 529 - c - cutiformis. 

 June, July. (Nat. from Eu.) FIG. 529. 



161. C. squarr&sa L. Caespitose, 3-9 dm. high ; culm sharply 

 angled, more or less rough above ; leaves 

 2.5-6 mm. broad, weak, roughish, exceeding 

 the culm ; bracts slender, elongate ; spikes 

 530 C sauarrosa ^~^' tn ^ c ^> the terminal always two thirds 

 pistillate or more, the remainder more or less 

 stalked, erect or slightly nodding, globular or short-cylindric, 

 1.5-3 cm. long, 1.5-2 cm. thick, brown, 

 exceedingly densely flowered ; perigynia 

 squarrose, the beak rough ; scale short 

 and usually hidden. Swamps and wet 

 woods, w. N. E. to Neb., and southw., 

 local. June-Sept. FIG. 530. 



162. C. typhinoides Schwein. Coarser, 

 the glaucous or pale leaves 0.5-1 cm. broad ; 

 spikes 1.5-5 cm. long, 1-2.2 cm. thick, pale 

 brown ; perigynia less squarrose, the bniks 

 ascending. Meadows and alluvial woods, 

 w. Que. and w. N. E. to la. and southw. 

 June-Oct. FIG. 531. 



163. C. Frankii Kunth. Stout and very 

 leafy, 5-8 dm. high ; culm obtusely amjlcil. 



581. O. typhinoides. very smooth ; leaves 4-9 mm. broad, rough 

 on the nerves, the upper and the bracts 

 very much longer than the culm ; terminal spike often pis- 

 tillate at top ; other spikes 3-7, the uppermost sessile OH the M-2. c. 



