112 CYPERACEAE 



Spikes one to many; if one, plant not as above. 



Aclienes lenticular and stigmas two: lateral spikes sessile; terminal spike partly 

 pistillate, or if staminate, the lateral spikes short, or heads dioecious. 

 Spike one. 



Spike orbicular to short-ovoid. 4. C.\pit.\t.\e. 



Spike linear. 5. Dioic.VE. 



Spikes more than one. 



Perigynia not white-puncticulate. 



Rootstocks long-creeping, the culms arising singly or few together. 

 Perigj-nia not thin or wing-margined, the beak obliquely cut. 

 Culms not branching. 



Spikes densely aggregate into a globular-ovoid head, appearing 



like one spike. 6. Foetid.\e. 



Spikes distinct. 7. DI^^s.VE. 



Culms becoming decumbent and branching. 



8. Chordorrhiz.\e. 

 Perigynia thin or wing-margined, the beak bidentate. 



9. Arex.\.ri.ve. 

 Rootstock not long-creeping, the culms densely cespitose. 



Spikes androg>-nous. 



Perigj-nia abruptly contracted into the beak. 



Spikes few (ten or less) ; perigj-nia green or tinged with reddish 

 brown. 10. Muhlexbergianae. 



Spikes numerous; perigj-nia yellowish or brownish. 



Perigj-nia j-ellowish; opaque part of leaf-sheath transversely 



rugulose. 11. Multiflor.^e. 



Perigj-nia brownish; opaque part of leaf-sheath not trans- 

 verselj- rugulose. 12. Paxicul.\t.\e. 



Perigj-nia tapering into the beak. 13. Stexorhynch.\E. 



Spikes gynaecandrous or pistillate or rarely staminate. 

 Perigj-nia at most thin-edged. 



Perigj-nia spreading at matiu-ity. 14. Stellt:l.\tae 



Perigjnia appressed. 15. De^-et.\xae. 



Perigj-nia narrowly- to broadly wing-margined. 



16. OVALES. 



Peiigj-nia white-puncticulate. 17. C.^x-escextes. 



Achenes triangular or lenticular: if lenticular, lower lateral spikes conspicuously 

 peduncled, or ternimal spike staminate and lateral spikes elongated. 

 Achenes stronglj constricted at base, rounded at apex. IS. Phyllostachyae. 

 Achenes not strongly constricted at base, pointed at ape.x. 



Spike one; perigj-nia rounded and beakless at ape.x. 19. PoLYTR[CHOinE.\E. 

 Spikes one or more; when one, perigjnia not both rounded and beakless at 

 the apex. 

 Perigynia both coriaceous and shining, the beak obliquelj- cut. 

 Spike soUtarj-. 20. OBTrs.\TAE. 



Spikes several. 21. Nitidae. 



Perigj-nia not both coriaceous and shining. 



Spike one: perigynia triangular, glabrous, not reflexed or flattened. 

 Perigj-nia prominently- beaked, finely nianj'-nerved. 



22. RUPESTRES. 



Perigj-nia nearlj^ beakless, 2-keeled but otherwise nerveless. 



23. FrRMICULMES. 



Spikes one to manj-; when one, perigynia differing from above. 



Perigj-nia closely enveloping the achene, stronglj- tapermg at base, 

 pubescent or puberulent; bracts sheathless or nearlj- so. 

 Spike normally one. 



Spikes androgynous: leaf-blades very narrow. 



24. FILIFOLL^^. 



Spikes dioecious. 25. SciRPrx.VE. 



Spikes two or more. 26. Moxtaxae. 



Perigj-nia not as above; or if so, bracts stronglj- sheathing. 

 Lowest bract long-sheathing, its blades rudimentary-. 



Leaf-blades flat; perigynia puberulent or pubescent. 



27. DiGITATAE. 



Leaf-blades filiform; perigynia glabrous. 



28. Alb.ae. 



Lowest bract sheathless or long-sheathing; if long-sheatliing, its 

 blade well-developed. 

 Lowest bract strongly sheatliing; perigj-nia never strongly 

 bidentate with stiff teeth. 

 Achenes lenticular; stigmas two. 29. BiCOLORES. 

 Achenes triangular: stigmas three. 

 Scales not dark-tinged. 



Pistillate spikes short -oblong to linear, erect. 



Perigynia tapering at base, triangular, closely 

 enveloping the achenes. 

 Rootstock long-creeping. 



30. P.\XICEAE. 



Rootstock not long-creeping. 



31. L.AXI FLORAE. 





