CYPERACE.E. (SEDGE FAMILY.) 371 



Very broad, covering the perigynium. 



Leaves short, stiff, involute 15 



Leaves ordinary 14 



Narrower, shorter than perigynium . . . .... . . 17 



Scabrous or hairy. 



Perigynia 1 to 4, scabrous above 4 



Perigynia several to many, hairy 5 



Stigmas two 52, 53 



II. Spikes all aggregated into a round or ovoid uninterrupted head, stigmas two. 



Spikes densely packed, the individual ones scarcely discernible. 



Head black 50 var. nigra. 



Head tawny or brown, 



Subtended by 1 or 2 long leafy bracts 80 



Naked or nearly so. 



Perigynium nearly orbicular, dark 70 



Perigynium ovate or lanceolate. 



Spikes staminate at base 78, 79 



Spikes staminate at top. 



Perigynium rough-angled 58, 59 



Perigynium smooth 60, 61, 62 



Head green 58 



Spikes simply aggregated, the individual ones readily recognized. 



Spikes nearly linear, light colored 71 



Spikes oval or ovoid. 

 Perigynium wing-margined, 



Broadly ovate or oval 84,87 



Lanceolate 82, 83, 85 



Perigynium wingless, 



Nerved, beak longer than the body 64 



Nerved, beak short 57 



Nerveless. 



Heads small globular 62 



Heads oblong 76 



III. Some or all the spikes distinct 



Terminal spike staminate above (staminate flowers inconspicuous), spikes often all approxi- 

 mated into an interrupted head or panicle, stigmas always two. 



Spikes conspicuously panicled 65, 64 (sometimes). 



Spikes not panicled. 

 Perigynium strongly nerved. 



Culm flat 63 



Culm broadly 3-angled 64 



Culm nearly terete 57 



Perigynium nerveless or nearly so. 



Spikes 1 to 3-flowered, scattered ; perigynium erect ; plants delicate . . 54 



Spikes 5 to many-flowered ; perigynhim divaricate or reflexed. 



Spikes all distinct 55 



Upper spikes aggregated 66 



Spikes 5 to 12-flowered ; perigynium nearly upright .... .59 



Terminal spike staminate below. 

 Stigmas two. 

 Spikes very dark. 



Scales long and sharp 49 



Scales ordinary 50, 51 



Spikes tawny or whitish. 

 Perigynium lanceolate. 

 Thin and scale-like 81,82,83 



