@ © Flowers unisexual, usually borne in separate spikes or if in 
| the same spike, the sexes separate; pistillate flower 
4 enclosed in a sac-like perigynium, the styles protruding 
\ through the orifice |, Carex 
O Flowers mostly perfect; pistillate flower not enclosed, usually 
4; subtended by several bristles, 
Ayrg tia 
? Spikelets flattened, the seates in ‘are opposite ranks 
e \A 
ue 
4 Spikeléts in a terminal cae | subtended by 2=3 
; 
4 
j 
i 
4 
> / leaflike bracts 2-3 times as long as the spikelets; 
oO ie ’ 
\ bri stles none 2. Cyperus 
4 Spikelets in the upper axils, the subtending leaves 
g not markedly longer; perianth of barbed bristles 3. Dulichium 
Lyra rk - 
Z Spikelets cylindrical, the semtes spirally imbricated 
6 around the axis, 
4 Flowers subtended by soft hairlike bristles very much 
( longer than the ovary, the inflorescence appearing 
OQ 
‘a 
\a5 a soft cottony tuft 4. Eriophorum 
4 Flowers subtended by barbed bristles about as long 
g as the ovary 
& Base of style swollen, leaving a pronounced conical 
tubercle upon the ovary at maturity; spikelets 
° eee: terminal PA Eleocharis 
(9 Base of style not swollen, completely deciduous or 
sometimes leaving an acute beak on the ovary, not 
jo( however, constricted at the base; spikelets either 
\sol itary or clustered 
ry & Spikelets solitary G Scirpus 
= Spikelets numerous 
)O Spikelets very slender, acute at both ends, 
/4 scarcely more than 1 mm. wide J. Rynchospora 
‘0 Spikelets plump, 2-5 mm. in diameter ri Qa Seirpusy es: 
