572 FLORA 01' TEXAS. 



Tribe IV. Rhynchosporeae. Flowers perfect or 

 polygamous. Spikdds commonly 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 EhyncJiospora). 

 Style 2-cieft, dilated and persistent at the base. Nut lenticular or globose. 



RHYNCHOSPOnA. 



Style entire or minutely 2-cleft, the lower persistent at the base. Nut flat. 



CERAT0SCH(ENIIS. 



** Peiianth none. 

 Spikes few-floweredy only the uppermost flower perfect. Nut globose Cladium. 



Tribe V. Sclerieae. Fhicers monoecious. Sterile 

 spike many-flowered. Scales one to each flower, imbricated 

 in furrows. Fertile spike 1-flowered, with two or more 

 scales. Perianth none. 



style Z-cleft, deciduous. Nut bony, globose or Z-angled Scleeia. 



Tribe VI. Cariceae. Floicers 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 inclosed in a sac. Perianth none. 



Bristles within the sac none. Spikes axillary and terminal Cakex. 



CYPERUS, L. 



Spikelets 2-many-flowered, commonly flat or compress- 

 ed ; scales imbricated in two opposite rows, often decurrent 

 on the jointed rachis, deciduous ; peria7ith none ; stamens 

 1-3; style 2-3-cleft, deciduous; nut lenticular or o-an- 

 gled; culms 3-angled (rarely, terete), jointless, leaf}' 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; rays 

 sheathed. 



