207' CYPERACEAE 



A. Spike one, androgynous, tiractless; perigynia glabrous, beaked, the beak with closed 



suture at apex dorsally. 

 Achenes triangular; stigmas tliree, rarely two. 



Pistillate scales persistent ; perigynia inflated, sessUe, not becoming reflexed— .1. Inflatae. 

 Pistillate scales deciduous; perigj-nia not inflated, stipitate, at least the lower reflexed at 



maturity 2. Athrochlaenae. 



Achenes lenticular ; stigmas two 3. Capitatae. 



B. Spikes one to many; if one, not as in A. 



1. Achenes lenticular and stigmas two; lateral splices sessile; terminal spiJce partly pistillate, 



or if staminate the l^iteral spikes short or heads dioeoUms. 

 PerigjTjia not white-punctieulate. 



Eootstocks long-creeping, the culms arising singly or few together; perigynia with beak 

 obliquely cut, at most bidcntulate. 

 Spikes densely aggregated into a globose or ovoid head, appearing like one spike 



4. FOETIDAE. 



Spikes, at least the lower, distinct 5. Divisae. 



Cespitose or rootstoeks short-creeping; perigj'nia obliquely cut to deeply bidentate. 

 Spikes androgynous (i.e., staminate flowers uppermost). 

 Perigynia abruptly contracted into the beak. 



Spikes few (usually ten or less) ; perig}-nia green or tinged with reddish-bro^Tn. 



6. Muhlenberqianae. 

 Spikes numerous; perigynia yellowish or bro"\™ish at flowering. 



Perigynia yellowish; opaque part of leaf -sheath usually transversely rugidose. 



7. Mui.tiflorae. 

 Perigynia brownish ; opaque part of leaf -sheath not transversely rugulose. 



8. Paniculatae. 

 Perigynia tapering into the beak 9. Stenorhynchae. 



Spikes gynaecandrous (i.e., pistillate flowers uppermost). 

 Perigynia at most thin-edged. 



Perigynia spreading or ascending at maturity 10. Stellulat^ve. 



Perigynia appressed 11. Dewetanae. 



Perigvnia narrowly to broadly wing-margined 12. Ovales. 



Perigynia wliite-puncticulate 13. Canescentes. 



2. Achenes triangular and stigmas three, or leiiticular and stigmas two; if lenti<nilar, lower 



lateral spikes conspicuously peduncled, or terminal spike staminate 

 and lateral spikes elongated. 



Staminate and pistillate spikes on different culms; stigmas 3, short 17. Scirpinae. 



Staminate and pistillate spikes on the same culms. 

 Spike solitary. 



Perigynia many-nerved, rounded and beakless at apex; stigmas 3, short 



14. POLYTRICHOIDEAE. 



Perigynia 2keeled, not rounded at apex, beakless or beaked. 



Perigynia glabrous; stigmas 3, elongated 15. Firmiculmes. 



Perigynia pubescent or puberulent; stigmas 3 16. FilieolIjVE. 



Spikes more than one. 



Perigynia closely enveloping the achene, strongly tapering at base, pubescent or puberu- 

 lent; bracts sheathless or nearly so; stigmas normally 3, long 18. Montan.\e. 



Perigynia not as above ; or if so, at least the lowest bract strongly sheathing. 



Bracts (at least lowesf) long-sheathing, more or less purplish-tinged, the blades 



absent or rudimentary; stigmas 3, early deciduous 19. Digitatae. 



Lowest bract sheathless or long-sheathing; if long-slieathing its blade well-developed. 

 Lowest bract .strongly sheathing; perigynia never strongly bidentate with stiff 

 teeth. 



Achenes lenticular; stigmas 2 20. BiCOLORES. 



Achenes triangular; stigmas 3. 



Scales greenish or light reddish-brown or purplish tinged. 



Rootstoeks long-creeping; scales purplish tinged 21. Paniceae. 



Rootstoeks not long-creeping; scales greenish to reddish-brown tinged. 

 Perigynia glabrous or hispidulous; leaves not pubescent. 



Pistillate spikes erect on stiff peduncles 22. L.IXIFLORAE. 



Pistillate spikes slender on slender peduncles, the lower droop- 

 ing 2-t. Debiles. 



Perigynia or leaves or both strongly pubescent 23. Triquetrae. 



Scales dark reddish-brown to blackish tinged _...2.5. FRiGn).\E. 



Lowest bract sheathless or sheathing; if sheathing, perigynia strongly bidentate 

 with stiff teeth. 



