THE CYPERACEAE OF COSTA RICA. 



V 



]iy r. B. Claukk. 



SYNOPTICAL KEY TO THE GENERA. 



Sulifamily L Scirposchoeneae. Fertile flovvc^rs uU wiUi^perfi'Ct stamens. 

 Kmpty gltiinos at the base of the wpikcleLy, 2 or none; feitile glmnes, 2-ranke(l; hypog- 

 ynuus bristles none; inflorescence siibnnil>ellate or cai>itate, never paniculate. 



(Cypkueae.) 

 Style 2-branclicd; nut compressed laterally. 



Raoliilla above the two empty glum(^s deciduous, . 1. Kyllinga (p. 444) 

 Raehilla above the two empty glumes persiyleiit. . 2. Pymus (p. 445) 



Style 3-b ranched. 



Eachilla persistent - 3. Cy perns (p. 447) 



Raehilla deciduous 4, Mariscus (p. 451) 



Raehilla breaking into as Tuany joints as there are 



,^^^3 5. Tor\ilinium (p. 454) 



Empty glumes at base 2 or ncme; fertile glumes in :? to 

 several ranks; inflorescence not panicled (except in 

 Fuirena). (Scirpbak.) 



Style base bulbous, separable from Uu- apex of the 

 nut. Bristles usually obvious; culm leafless; spike- 

 let terminal 6. Ekocharis (p. 454) 



Bri!!;tles none; plants commonly leafy. 



Style persistent, or els<" deciduous along with 



the style base 7. Finibristylis (p. 457) 



Style deciduous, its di.^colored base renuiin- 



ing on the nut »• Bulbostylis (p. 459) 



Style base not bulbous, passing gra<lually from the 



nut into the style proper. 



Plants glabrous; inflorescence capitate 9. Scirpus (p. 400) 



Plants pilose; inflfirescence paniculate,-.. 10. Fuirena (p. 400) 



iMupty glumes at bas(^ of spikelets ;i lo several; styles l)ifid. 



(RYXCnOHrOREAE.) 



Spikelet cylindric; raehilla l)riniking into as many 



joints as there are nuts H • TUdivlivm 1 1>. IfiO) 



Raehilla short, persistent. 



Bristles none; style branches 2, h»ng; hc^ad of 



spikelets, oueonly.- 12. IHrhroweva (p. -101) 



Style branches 2, very short in those speci(^s liav- 

 ing monocei)halous inflorescence, lung in those 



with infloreseeJice not monocephalous 13. Ryncliosporn i p. 1(i2) 



Subfamily II. Sclericariceae. Flowers all imisexual, 



the fertih^ ones axillary. 



443 



