5 
aves 5-6 mm. wide, 
e 
between the veins 14. C. vegetus 
not transversely nerved 
between the veins 15. C. surinamensis 
b. Rachis distinctly winged. 
la Sere perennial by root- 
re leaves grass-like ; 
ste and culti- 
vated ground 16. C.rotundus 
Basal leaves reduced 
sheaths ; tall marsh sedges 
with pseudo-septate culms 
Culm terete 17. C. articulatus 
Culm trigonous at the apex 18. C. nodosus 
Annuals, flowering the first 
season 
Basal leaves reduced to 
pp involucral leaves 
very numerous, longer than 
the umbels 19. C. giganteus 
Basal leaves normal, half 
as aoe as the culm or 
lon 20. C. radiatus 
2. Rachis of the spikelet falling away 
above the two lower empty scales 
Achene miltrdied linear-oblong, 
2.5 to 4 times as long as thic 
Spikelets spicate, several- 
flowered 21. C. platystachys 
Spikelets capitate or capitate- 
Spicate, only 1-4—flowered. 
globose 22. C. globulosus 
Heads cylindric 23. C. cyperoides 
more than twice as long as thick 
Spikelets 1-5—flowered 
Umbel simple, or culm mono- 
cephalous 
Scales of the spikelets im- 
bricated 
share tis aeeet spicate, 
tetrago 
Spikelets Beneely spicate 
or capitate : 
Spikelets 2-5 mm. long 25. C. cayennensts 
readin I.5 mm. long 
or les 
Saas several, rarely 
solitary; leaves 2-3 
24. C. tetragonus 
: e 26. C. Swartaii 
Spike solitary, rarely 
2; culms and leaves . 
almost filiform 27. C. granularis 
