CYPERACEJE. (SEDGE FAMILY.) 505 



8. SCIRPUS. Tubercle none : culms mostly leafy at the base or throughout : spikes com- 



monly few or many : perianth of 3 - 6 bristles. 



9. ERIOPHORUM. Perianth of numerous long and woolly hairs : otherwise like Scirpus. 



* * * Perianth none : style tumid at the base. 

 - Scales imbricated in several rows : spikes terete. 



10. FIMBRISTYLIS. Style deciduous : stigmas 2 : nut lenticular or globose. 



11. TRICIIELOSTYLIS. Style deciduous : stigmas 3 : nut 3-angled. 



12. ISOLEPIS. Style persistent at the base : stigmas 3 : nut 3-angled. 



t- -t- Scales imbricated in 2 rows : spike compressed. 



13. ABILGAARDIA. Style 3-cleft, jointed to the 3-angled nut. 



TRIBE IV. RIIYNCHOSPORE^E. Flowers perfect or polygamous : spikelets com- 

 monly few-flowered : scales one to each flower, imbricated in few -several rows, the lower 

 ones empty, the upper mostly sterile : perianth bristly, or none. 



* Perianth bristly (occasionally wanting in Rhynchospora). 



14. RHYNCHOSPORA. Style 2-cleft, dilated and persistent at the base : nut lenticular or 



globose. 



15. CERATOSCIKENUS.- Style entire or minutely 2-cleft, the lower half persistent : nut flat. 



16. CH^TOSPORA. Style 3-cleft, deciduous : nut 3-angled : spikelets terminal. 



* * Perianth none. 



17. PSILOCARYA. Spikes terete, many-flowered, cymose : flowers perfect. 



18. DICHROMENA. Spike*ompressed, capitate : most of the flowers imperfect. 



19. CLAD1UM. Spikes few-flowered, only the uppermost flower perfect : nut globose. 



TRIBE V. SCLERIE.ZE. Flowers monoecious : sterile spike many-flowered : scales one 

 to each flower, imbricated in furrows : fertile spike 1-flowered, with two or more scales : 

 perianth none. 



20. SCLERIA. Style 3-cleft, deciduous. Nut bony, globose or 3-angled. 



TRIBE VI. C ARICEJE. Flowers monoecious, very rarely dioecious : sterile and fertile 

 flowers on the same spike, or on separate spikes : scales one to each flower, imbricated 

 in few -many rows : nut enclosed in a sac : perianth none. 



21. CAREX. Bristles within the sac none. Spikes axillary and terminal. 



1. CYPERUS, L. 



Spikelets 2 - many-flowered, commonly flat or compressed. Scales imbricated 

 in two opposite rows, often decurrent on the jointed rachis, deciduous. Perianth 

 none. Stamens 1-3. Style 2 -3-cleft, deciduous. Nut lenticular or 3-angled. 

 Culms 3-angled (rarely terete), jointless, leafy or occasionally sheathed at 

 the base. Spikelets numerous (rarely 1-2), disposed in single or umbellate 

 heads or spikes, and surrounded with a leafy involucre. Kays sheathed. 



1. PYCREUS. Style 2-cleft: nut lenticular: spikes more or less umbelled. 

 Annuals: spikelets linear or linear-oblong, fiat, many- '(10- 40-) flowered: 

 rachis narrowly margined: scales compressed-keeled, 5-nerved. 



* Spikelets clustered on the common rachis. 



1. C. flavescens, L. Umbel sessile or of 2-4 rays, shorter than the 



spikelets ; spikelets 3 - several in a cluster, oblong-linear, acute, spreading, 20 - 



30-flowered ; scales yellowish brown, ovate, obtuse, oppressed ; rachis margined ; 



semens 3; nut orbicular, black, smooth and shining; culms clustered, 4' -10' 



43 



