854 



CXLVI. CYPERACE^. 



Stigmas 3 ; fruit a trigonous or triquetrous nut. 

 Khacliilla of spikelets persistent. 



Inflorescence usually umbellate, rarely capitate. 



Spikelets digitate or clustered, not spicate or racemose. 

 Annuals (except C. Haspan). 

 Glumes niucronate. 

 Nut ^5 in. long. 



Nut oblong, pale brown or yellow ; style 

 shorter than the nut; stamens 1-2; margins 



of glumes hyaline .. 13. C. castaneiiS. 



Nut oboToid, dark-brown ; style longer than 

 the nut ; stamens 3 ; margins of glumes 



hyaline 14. C. Teneriffa. 



Nut ^-^ in. long, obovoid, dark-brown ; style 

 shorter than the nut; stamens 1-2; margins 



of glumes hyaline 15. C. unciiiatus. 



Glumes not mucronate. 



Nut white when ripe, ^V in. long, globosely 

 obovoid ; stamen 1 (rarely 2) ; whole plant 



yellowish 16. C.flavidus. 



Nut brown. 



Nut nearly as long as the obovate-oblong 



glume; stamen 1 (rarely 2) 17. C. dijfonnis. 



Nut I the length of the glume ; glumes with 



crisped incurved tips; stamens 1-2 18. C. pulcherrinms. 



Nut ^ the length of the glume ; stamens 2- 

 3 ; flowering in the first season but often 



biennial or perennial 19. C. Haspan. 



Pei'ennials with a woody rootstock ; stamens 

 usually 3. 



Inflorescence of 1 head (sometimes umbellate 

 in C. conglomemtus and C. Afkinsoni). 

 Rhizome very short ; rootlets wiry. 



Stems slender, close-set, nodose at the 

 base. 



Stems closely 1-seriate ; spikelets 

 3-12 in a lax head ; stamens 3 ; 



glumes J in. long 20. C. niveus. 



Stems ceespitose with 1 dense head ; 



stamen 1 ; glumes -r'^ in- long 21. C. leiicocephalus. 



Khizome creeping ; rootlets thick. 

 Rootlets not woolly. 



Stem solitary, distant ou a much- 

 divided, elongate, creeping rhizome. 22. C. arenarius. 

 Stems caispitose, on a short rhizome 



(inflorescence sometimes umbellate) 23. C. Atkinsoni. 

 Rootlets woolly (inflorescence sometimes 



umbellate) 24. C. conglomeratns. 



Spikelets spicately, rarely subracemosely disjjosed ; 

 stamens usually 3. 



Rhachilla of spikelets not or scarcely winged. 

 Annuals with tufted stems. 



Stems 4-l() in. long ; spikelets ^H in. long ; 



nut about ^ as long as the glume 25, C. coynpretaus. 



Stems 3-0 in. long; spikelets i-^ in. long; 



nut less than ^ the length of the glume ... 26. C. aristatus. 

 Stems 14-20 in. long ; nut nearly as long as 



theglume 27. C. Iria. 



Perennials with woody rhizome and often long 

 stolons. 



Spikelets compressed ; rootstock with 



elongate stolons ; bracts divaricate 28. C. procerus. 



