62 CYPERACEAE. 



1. Perigynia compressed; scales very dark. 



Spikes all gynaecandrous or the lateral pistillate ; stigmata 3 (except some- 

 times in C. misandra). 



Spikes all gynaecandrous. 12. MELANANTHAE. 



Lateral spikes pistillate. 



Spikes sessile or nearly so. 12. MELANANTHAE. 



Spikes long-peduncled. 18. STENOCARPAE. 



Terminal spike staminate, the lateral pistillate or the uppermost of these 



staminate or androgynous. 



Stigmata 3 ; spikes oblong. 35. C. Raynoldsii. 



Stigmata 2; spikes cylindrical. 13. MICRORHYNCHAE. 



2. Perigynia turgid. 



Spikes 2-4, all gynaecandrous, dark brown ; perigynia gibbous, papillose. 



14. AEOEASTACHYAE. 

 Spikes several ; the terminal and sometimes the uppermost of the lateral 



ones staminate ; the rest pistillate or in C. Backii all androgynous. 

 Perigynia glabrous ; spikes peduncled. 



Beak short or none ; spikes erect, loosely flowered ; perigynia nerved. 



15. CENCHROCARPAE. 

 Beak prominent, bifid or bidentate. 



Spikes not very densely flowered, drooping ; perigynia faintly nerved, 

 erect or slightly spreading. 23. HYMENOCHLAENAE. 



Spikes densely flowered, erect ; perigynia nerved, squarose at ma- 

 turity. 24. SPIROSTACHYAE. 

 Perigynia pubescent. 



Pistillate spikes few-flowered, roundish ; perigynia obovate to globose, 

 obscurely nerved ; bracts foliaceous but sheathless. 



21. SPHAERIDIOPHORAE. 



Pistillate spikes cylindric, dense-flowered ; perigynia ovate or ovate- 

 lanceolate, nerved ; bracts sheathing. 22. TRICHOCARPAE. 

 II. Perigynia inflated and tapering into a long beak. 



Perigynia abruptly contracted into a very long, slender beak. 



66. C. longirostris. 

 Perigynia gradually tapering into the beak. 



Perigynia, at least the lower, reflexed at maturity, sessile ; bracts sheathing. 



25. ECHINOSTACHYAE. 



Perigynia not reflexed. 



Bracts sheathless ; perigynia sessile. 26. PHYSOCARPAE. 



Bracts sheathing; perigynia stipitate. 27. RHYNCHOPHORAE. 



I. VIGNEAE. Stigmata 2. Spikes all or nearly all bisexual or dioecious, 



sessile. 



1. BRACK YSTACHYAE. 



Spikes several, short and few-flowered, sessile, remote, light-green; scales 

 hyaline ; perigynium erect, several-nerved, spongious at the base. 



Spikes gynaecandrous (i. e., pistillate above, staminate below) ; bracts inconspic- 

 uous ; perigynium light-green, ovate, tapering into a short, almost entire beak. 



1. C. canescens. 

 Spikes androgynous (i. e., staminate above, pistillate below) ; bracts narrow, but 



conspicuous ; perigynium shining reddish-brown, abruptly-beaked. 



2. C. tenella. 



2. NEUROCHLAENAE. 



Spike single, androgynous, shining reddish-brown ; perigynium erect, ob- 

 long, faintly nerved, scabrous along the short hyaline beak, with the orifice 

 slit on the convex face. 



One species. 3. C. nardina. 



