KEPOET OF THE STATE BOTANIST. 23 



Spikelets contiguous above, separate below, or all contiguous, 

 sometimes the lower ones compound ; perigynia lanceolate, 

 without a distinct margin, divergent. G-7. 



Spikelets approximate above, separate below, or all contiguous, 

 (capitate in 10) ; perigynia with a distinct margin, widely diver- 

 gent or refiexed at maturity. 8-13. 



t Spikelets staminate at the base, pistillate above. 



Spikelets 3-8, 3-5 flowered, the upper ones approximate or 

 subdistinct, the lowest distinct or remote (capitate in 15), or 

 12-30 flowered and disposed in an interrupted spike l^-'-2|' 

 long, silvery green and shining; perigynia spreading but not 

 reflexed. 14-17. 



Spikelets 3-8, the upper 2 or 3 approximate, separate below, 

 or all contiguous (spikelet single in 18); perigynia slightly con- 

 cave, widely divergent or reflexed at maturity ; plants bright green 

 becoming yellowish. 18-21. 



Spikelets 3-15 or more, aggregated or approximate, or the upper 

 contiguous and the lower separate (clustered in 31) ; perigynia 

 concave, thin, mostly wide winged-margined, the tips erect or 

 spreading, not reflexed. 22-31. 



t Staminate and pistillate flowers variously situated ; spikelets 

 often wholly sterile or wholly fertile. 32-3i. 



* Stigmas 3 ; achenium triangular. 



Flowers borne in a short spike or head, staminate at the apex, 

 pistillate below ; pistillate scales small, caducoiis, the staminate 

 mostly conspicuous. 35-36. 



Pistillate scales green and leaf -like, 2^ersistent, the lowest as 

 long as the spike ; perigynia globular, with a long slender beak 

 37-39. 



B. Staminate and pistillate flowers disposed in separate spikes 

 on the same culm or plant (monoecious), or on separate plants 

 (dioecious), the former frequently androgynous.— Caeex proper. 



* Stigmas 2 (rarely 3) ; achenium lenticular. 



Plant dioecious. Sterile spike linear, 5" long or less ; fertile 

 spike 3"-5'' long, densely flowered ; perigynia oblong, reflexed at 

 maturity. 40. 



Sterile spikes 1-4, stalked or sessile ; fertile spikes 2-5, erect or 

 recurved, sessile or short stalked, densely or subdensely flowered; 

 perigynia with a short point or pointless ; scales Uachish-purple 

 or reddish-hrown, not aioned. 41-46. 



