CYPERACEiR. 89-3 



Spikelets solitary on each stem. 



Stems branched, leafy, floating in water or in matted 



tnfts on its edge 6. Floating S. 



Stems simple, erect or ascending. 



Outer bract of the spikelet without any leafy tip. 

 Stems very slender, not 2 inches high. Styles 



3-cleft 1. Needle S. 



Stems rather stiff, 3 or 4 inches to a foot high or 

 more. 



Styles mostly 2- cleft 2. Creeping S. 



Styles mostly 3-cleft. 



Sheaths at the base of the stem obtnse or 

 oblique at the top, without any leafy tip. 

 Spikelets oblong. 

 Flow 7 ers numerous in each spikelet, the 

 thickened base of the style rather bulb- 

 shaped 3. Many-stalked S. 



Flowers 3 to 6 in each spikelet, the thick- 

 ened base of the style gradually tapering 



from the nut 4. Feiv-flowered S. 



Sheaths at the base of the stem with a short 



leafy tip. Spikelet ovoid 5. Tuftel S. 



Outer bract of the spikelet ivith a leafy tip as long 

 as the spikelet or longer. 

 Stems rather firm, 6 inches to a foot high, with 

 numerous sheaths at the base, each with a 



short point 5. Tufted S. 



Stems very slender, 1 to 6 inches high, with 1 or 2 

 subulate leaves. 

 Nut marked with longitudinal ribs and fur- 

 rows 7. Bristle S. 



Nut without ribs or furrows 8. Savi's S. 



Spikelets 2 or more, in a cluster or umbel below the sum- 

 mit of the stem. 

 Stems very slender, 1 to 6 inches high, with 1 or 2 subu- 

 late leaves. 

 Nut marked with longitudinal ribs and furrows . . 7. Bristle S. 



Nut without ribs or furrows 8. SavVs S. 



Stems firm, 1 to 2 feet high or more. 



Stems leafless, or with 1 or 2 short, stiff leaves at the 

 base. 

 Stems acutely triangular from near the base. 

 Spikelets all sessile, in a close cluster. Leaf- 

 blade narrow, 2 or 3 inches long 10. Sharp S. 



Spikelets more or less pedicellate, in a compound 



cluster. Leaf-blade very short . . . .11. Triangular S. 

 Stem3 cylindrical, or scarcely angular at the top. 



