66 



CYPERACEAE. 



Spikelets with scales spirally arranged and over- 

 lapping all around. 

 Spikelets 1-4-flowered, some of the flowers 



imperfect. 

 Spikelets with several-many perfect flowers. 

 Style swollen at the base, persistent on 



the akene. 

 Style not swollen at the base, deciduous. 

 Spikelets 1-many; bristles 1-6, short, 



rarely none. 

 Spikelets 1 or a few; bristles 6-many, 

 soft, smooth, very long, slender, 

 much exserted. 



97. Rynchosposa, 82. 



98. Eleocharis, 82. 



99. Scirpus, 83. 



100. Eriophorum, 84. 



94. CAREX. Sedge. 



Grass-like plants, perennial by rootstocks; stems mostly 

 triangular; leaves 3-ranked, the upper (bracts) elongated or very 

 short and subtending the spikes of flowers, or wanting; flowers 

 solitary in the axils of bracts (scales), monoecious or dioecious; 

 spikes either wholly staminate, or pistillate, or sometimes 

 androgynous; perianth none; staminate flowers of 3 stamens; 

 pistillate flower of a single pistil with a style and 2-3 stigmas 

 borne in the axil of a second bract (the perigynium) which com- 

 pletely encloses the akene; akene 3-angled, lenticular or plano- 

 convex. 



Key To Sections. 



Spikes solitary, terminal. 

 Spikes several. 



Spikes all alike. 



Spikes of two sorts. 



I. Primocarex. 



II. VlGNEA. 

 III. EUCAREX. 



Section I. Primocarex. 



Spike solitary, terminal. 



Perigynia pubescent; plant dioecious. C. stenochlaena. 



Perigynia glabrous; plant not dioecious. 



Spike ovoid, brown; perigynia thin and inflated. 



Perigynia 6-7 mm. long, much exceeding the scales; 



stems longer than the leaves. C. breweri. 



Perigynia 5 mm. long, slightly exceeding the scales; 



stems shorter than the leaves. C. paddoensis. 



Spike not ovoid nor brown; perigynia not bladder-like. 

 Perigynia refiexed when fully mature, fusiform, 

 beaked, stipitate at base. 

 Perigynia few, 3-5; scales pale. C. pauciflora. 



Perigynia more numerous; scales colored. 



Scales dark purple; spikes 8-10 mm. thick; 



leaves flat, 3-4 mm. wide. C. nigricans. 



Scales brownish; spikes 3-4 mm. thick; 



leaves involute, 2 mm. wide. C. pyrenaica. 



Perigynia not becoming refiexed; not stipitate (ex- 

 cept C. circinata). 



