488 



CVI. CYPERACE^. 



Okd. CVI. CYPERACEiE Juss. 



Floioers perfect or imperfect, furnished each with a solitary 

 partial bractea called a glume, imbricated on a common axis 

 or racMs, the whole constituting a spikelet. Perianth ? (Iiere 

 called perigynium) only in the fertile imperfect flowers rarely 

 membranaceous, 2— 3-valved, the valves distinct or usually 

 united (in Carex), generally entirely wanting. Stamens hypo- 

 gynous, definke^(l— 12), usually 3, with sometimes an addi- 



^xy „i,„..x:-.„ filaments (called seta>, or hwoirvnmit 



Stigmas 2 



Iristles). Anthers erect, 2-celled. Ovanj superior,"! -celled" 

 with one erect ovule at its base. Style single, 2— 3-cleft! 



3. Fruit an achene, crustaceous, ol- with a corky 

 or fleshy, sometimes bony skin. Embryo lenticular, enclosed 

 in the base of copious albumen. — Stems often angular, fre- 



Leaves with entire sheaths. Lower 

 often destitute of stamens or pistil. 



quently without joints. 



if' 



5. 



If 



) Hi' 



i 



1. 



. 2. 



* Flowers perfect. Spikelets 2-ranked. Perigijnium 0. 



Cyperus. Spikelets many-flowered ; glumes of one valve, keeled 

 mostly all fertile, equal. Bristles none. Style deciduous ' 



bCHCENus. Spikelets 1—4-flowered; lower glumes smaller, empty 

 Style deciduous. ^^ 



** Flowers perfect. Spikelets with the glumes imbricating on all sides. 



Perigynium 0. 



t Several of the lower glumes empty or smaller than the fertile ones. 



O 



4, 



Cladium. Spikelets with 1—2 perfect flowers. Achene with a fleshy 

 or somewhat corky coat, pointed with the slender base of the style. 



Ehynchospora. Spikelets few-flowered. Achene compressed, 

 crowned with the persistent dilated base of the style. Bristles 



ft Loivest (1—2) glumes empty or larger than the others, sometimes all 



fertile. 



X Bristles scarcely so long as the glumes, or wanting. 



5. Blysmus. Spikelets brac^teated, alternate, forming a distichous or 



compressed spike. Acbenes crowned with the persistent filiform 



6. Eleocharis Spikelets solitary. Achene crowned with the dilated 



persistent base of the style. Bristles 4— 12 



r,';rrow bff ''?^!^' Solitary or fascicled. Achene pointed with the 



Bo[n?W / ?' o ^^' ^^^"^ remainder of which is deciduous), or 

 pomtless. Bristles 0. '^ 



^" ^Tpr«tl J^^'''^'^' f ^^^^7 u f=^«"cled. Achene pointed with the 

 hZI? . ™'':i^^'' of the style (the remainder of which is de- 

 ciduous), or pomtless. Bristles about 6. 



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