62 CYPERACEAE. 



1. Perigynia compressed; scales very dark. 



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

 times in C. misandrd). 

 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. Aeorastachyae. 

 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. Spieostachyae. 

 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. 



23. 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. 



I. Brachystachyae. 



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

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



Spikes gynaecandrous (t. 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. b., 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 shor^ hyaline beak, with the orifice 

 slit on the convex face. 



One species. 3. C nardina. 



