212 CYPERACEAE (SEDGE FAMILY) 



k. Kemnants of the old leaves persisting as stiff tufted 

 shreds ; scales acuminate, sharp-pointed, nearly 

 or quite equaling the perigynia. 

 Perigynia 1.7-2.4 mm. thick. 

 Beak nearly or quite as long as the body of the 

 perigynium. 



Perigynia puberulent 93. O. umbellata. 



Perigynia glabrous (93) C. umbellata, v. toma 



Beak one third as long as the body . (93) C. umbellata, v. bremrostris. 



Perigynia 1.8-1.6 mm. thick 94. G. nigro-marginata. 



fc. Remnants of old leaves soft, slightly if at all shredded ; 

 scales blunt or acute, much shorter than the 



perigynia 95. C. deflexa. 



j. Culms elongate, none of them hidden at the base of the 



plant I. 

 I. Perigynia much exceeding the scales ; spikes closely 



approximate 96. C. albicans. 



I. Perigynia nearly or quite equaled by the scales m. 

 m. Mature leaves 3-5 mm. wide (if exceptionally nar- 

 rower, the spikes remote) 97. C. communis. 



m. Mature leaves 1-2.5 mm. wide (if exceptionally 



broader, the spikes approximate). 

 Staminate and pistillate spikes all sessile. 

 Scales of pistillate spikes whitish or greenish . 98. C. varia. 



Scales purplish (98) C. varia, v. colorata. 



Staminate and the lowermost pistillate spikes 



short-peduncled 99. C. novae-angliae. 



g. Culms leafy, the leaves elongate n. 

 n. Pistillate spikes sessile or subsessile ; basal sheaths fibrillose. 



Staminate spike overtopping the pistillate .... 154. C. vestita. 

 Staminate spike shorter than the pistillate . . . (154) C. vestiia, v. Kennedyi. 

 n. Pistillate spikes (or at least the lower) distinctly peduncled ; 



sheaths not fibrillose. 



Leaves soft, ribbon-like, dark green, the lower bract ex- 

 ceeding the culm ; perigynia long-beaked . . . 150. C. scabrata. 

 Leaves firm, short, glaucous ; the bracts short ; perigynia 



barely beaked 103. C. glauca. 



#. Perigynia glabrous o. 

 o. Leaves setaceous, basal ; culms setaceous, naked ; bracts reduced 



to pale tubular sheaths 117. O. eburnea. 



o. Leaves flat or plicate p. 



p. Leaves lanceolate, 1.5-3 cm. broad, firm and evergreen ; culms 

 slender, bearing numerous tubular colored sheaths and 



remote slender spikes 121. 0. plantaginea. 



p. Leaves linear or linear-lanceolate, less than 1.5 cm. broad q. 

 q. Perigynia beakless or with minute entire beaks n 



r. Pistillate spikes mostly on capillary peduncles, wide-spread- 

 ing or drooping s. 



a. Scales brownish or purplish, nearly equaling or exceed- 

 ing the compressed short- tipped perigynia t. 

 t. Spikes globose to oblong-cylindric, rarely 2 cm. long; 



scales exceeding the perigynia u. 



u. Scales long-attenuate with subulate tips, much ex- 

 ceeding the perigynia. 

 Scales dark brown or purplish throughout. 



Pistillate spikes 4-8 mm. long .... 111. C. paupercula. 

 Pistillate spikes 1-1.6 cm. long . . (Ill) C. paupercula, v. irrigua. 

 Scales green with pale-brown or yellowish margins 



(111) C. paupercula, v. pall 'ens 



u. Scales obtuse or acute, barely exceeding the perigynia. 

 Leaves involute, 0.5-1 mm. wide, glaucous ; scales 



brown. . . . . , . . . 112. C. limosa. 

 Leaves flat, 1-3 mm. wide, dark green ; scales 



purple-black 113. C. rariftora. 



t. Spikes linear-cylindric, 2-5 cm. long; scales barely 



equaling the perigynia 114. G. litloralis. 



s. Scales whitish, much shorter than the sharply trigonous 



attenuate perigynia 115. G. prasina. 



r. Pistillate spikes sessile or short-peduncled, erect v. 

 v. Plant glaucous, loosely stoloniferous ; Staminate spikes 



long-stalked, their scales mostly purple-brown. 

 Leaves 2.5-5 mm. wide, revolute in drying, harsh; 



culms harsh ; perigynia brown 103. C. glauca. 



Leaves 1-3 mm. wide, becoming plicate or involute, 

 smooth ; culms smooth ; perigynia pale green or 



whitish 104. O. limda. 



v. Plant green, densely tufted ; Staminate spikes sessile or 

 ttort-stalked, their scales pale brown or straw 

 Aolor. 



