CYFERACE^. (SEIXiE FAMILY.) 591 



t- .1. Muhlmbergianre. Spikes gi-een or nearly so when mature, aggregated or scattered, 



never in compound heads ; perigj-nium mostly short-ovate, staminatc flowers always at 



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

 ■•- 6. Dioicrr. Spike commonly one. small . ulants small and slender, often dioecious. —8p. 



115- 117. 

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



125 variously situated). 

 -•- 1. Elongatcv. 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 witl> a 



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



the perigynium concave inside. — Sj). 125-1J2. 

 ■*- 3. Cj/peroldecP: Spikes green, oblong, 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. 



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

 Spike I, scales not leaf-like. 



Usually dioecious : stigma 2 115-117 



Stigmas 3.— Perigynium densely hairy 84 



Spike staminate at base ; pcrigynia squarrose 21 



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



Perigynium nearly linear, beakless . . 96 

 Perigynium long, spindle-ohaped . . 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, ICS 



All staminate below. — Leafy-bracteate 133 



Not lea fy-bracteate.— Green 118-120 



Usually tawny or brown . . 125-182 

 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 lOS, 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 84-38,79 



Stigmas 3 ; spikes erect. 



Short and squaiTose 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 34,37,40,41 



Sjiikes erect or nearly so 9-10,34-41,85-91,79 



Stigmas 3 : sjiikes siireading or ilrooping. 



Perigynium prominently 3-angied 68-74 



Perigynium large, thin, much inflated 9-16 



Perigynium firmer, not inflated. 



Beakless 42 -4."^ 



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

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



