CYPERACE.E. (SEDGE FAMILY.) 371 



Very broad, covering the perigynium. 



Leaves short, stiff, involute j5 



Leaves ordinary j 4 



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 unintermpted 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 ; perigynixun 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 r 50, 51 



Spikes tawny or whitish. 

 Perigynium lanceolate. 

 Thin and scale-like . .......... , . .81,82,83 



