CYPERACEiE. (SEDGE FAMILY.) 591 



•:= 5. Muhlenberg Mnce. Spikes green or nearly so when mature, aggregated oi scattered, 



never in compound heads ; perigynium mostly short-ovate, staminate flowers always at 



the top of the spike. — Sp. 109 - 114. 

 ^ 6. Dioicce. Spike commonly one, small , slants small and slender, often dicjecious. — Sp 



115-117. 

 ♦ 12. Hyparrhense. Staminate flowers borne at the base of the spikes (or in n. 124 and 



125 variously situated). 

 -«- 1. Elongatce, Spikes silvery green or sometimes tawny when mature, distinct, mostly 



small ; perigynium not wing-margined nor conspicuously broadened, mostly nearly flat 



on the inner surface. — Sp. 118 - 124. 

 "^ 2. Ovales. Spikes tawny or dark, rather large, sometimes crowded ; perigynium with a 



more or less thin or winged margin, which is mostly incurved at maturity, rendering 



the perigynium concave inside. — Sp. 125 - 132. 

 «- 3. Ci/peroidece. Spikes green, obloug, densely crowded into a short head subtended by 



two or three leafy bracts which are erect and prolonged from six inches to a foot; peri- 

 gynium linear-lanceolate, scarcely margined. — Sp. 133. 



Artificial Key. 



Spike 1, staminate at top ; scales of pistillate flowers leaf-like . . Sp. 93-95 



Spike 1, scales not leaf-like. 



Usually dioecious ; stigma 2 115-117 



Stigmas 3. — Perigynium densely hairy 84 



Spike staminate at base ; perigynia squarrose .... 21 



Spike staminate at top. — Globose ; leaves broad .... 97 



Perigynium nearly linear, beakless . 96 



Perigynium long, spindle-shaped . . 1 



Spikes several or numerous, sessile, spicate or capitate ; stigmas 2. 



All in a globose or ovoid uninterrupted head. 



All staminate above. — Usually green at maturity . . . . 112, 114 



Usually yellow or tawny or brown . . .98, 99, 104, 105 



All staminate below. — Leafy-bracteate . . . , 133 



Not leafy-bracteate. — Green US -120 



Usually tawny or brown . . 125- 132 

 Some or all of the spikes distinct or the head interrupted. 

 Staminate and pistillate flowers variously disposed, some of the spikes often unisexual. 



Head large and long 108, C. arenaria. 



Head short or linear 124, 125 



Spikes staminate above 100-114 



Spikes staminate below 118-133 



Spikes usually more or less pedicelled, the wholly or partially staminate spikes uppermost. 

 Terminal spike (rarely the 2 or 3 uppermost) staminate only at base. 



Stigmas 2 34-38,79 



Stigmas 3 ; spikes erect. 



Short and squarrose 20, 21 



Not squarrose .... .... 22, 30, 32, 46, 47. 54. 79 



Stigmas 3 ; spikes more or less drooping 31,51-53,55-57 



Terminal spike or spikes staminate. 

 Stigmas 2. — Spikes spreading or pendulous ...... 84, 37, 40, 41 



Spikes erect or nearly so 9-16,34-41,85-91,79 



Stigmas 3 : spikes spreading or drooping. 



Perigynium prominently 3-angled . . , . . , . .68-74 



PerigjTiium large, thin, much inflated . . , ... 9-16 



Perigynium firmer, not inflated. 



Beakless 42-45 



Beaked or prominently pointed. — Teeth long, stiff and sharp . . . 17-19 



Teeth short and thin, or none 30, 31, 39, 48 -.53 



