Carex Cyperaceae 213 



Spikes numerous, yellowish or brownish at maturity; leaf sheaths often red- 

 dotted ventrally. 

 Perigynia plano-convex, thin, yellowish; bracts mostly much exceeding the 

 spikes ; leaf sheaths usually transversely rugulose ventrally 



5. § MULTIFLORAE, p. 224. 



Perigynia thick-plano-convex or unequally biconvex, brown; bracts mostly 



shorter than the spikes; leaf sheaths not transversely rugulose 



6. § Paniculatae, p. 225. 



Perigynia tapering into the beak or, if abruptly contracted, culms flaccid and 



flattening in drying 7. § Vulpinae, p. 226. 



Terminal or all spikes gynaecandrous or, if androgynous, perigynia subterete and 

 spikes 1-3-flowered. 

 Perigynia without winged margins, at most thin-edged. 

 Perigynia 2-4 mm long. 



Perigynia not thin-edged, ascending or appressed, elliptic 



8. § Heleonastes, p. 229. 



Perigynia thin-edged, spreading, ovoid, usually broadest below the middle 



9. § Stellulatae, p. 230. 



Perigynia 4-5 mm long, narrowly lanceolate, appressed. .10. § Deweyanae, p. 232. 

 Perigynia with winged margins 11. § Ovales, p. 232. 



Subgenus Eu-Carex 

 Style articulated with the achene, at length deciduous; achenes apiculate or blunt at 

 the apex; perigynia closely enveloping the achenes or moderately inflated. 

 Spikes solitary, androgynous; perigynia beakless, rounded at the apex, glabrous. 



12. § POLYTRICHOIDEAE, p. 237. 



Spikes one to many, when one the perigynia not as above. 



Lower pistillate scales bractlike; achenes rounded at the apex, strongly con- 

 stricted at the base 13. § Phyllostachyae, p. 238. 



Lower pistillate scales not bractlike; achenes apiculate-tipped, not strongly con- 

 stricted at the base. 

 Achenes with sides convex above, closely enveloped by the perigynia; bracts 



sheathless, scalelike or setaceous 14. § Montanae, p. 238. 



Achenes with flat or concave sides; bracts from sheathless to long-sheathing. 

 Achenes closely enveloped by the perigynia; bracts, when present, strongly 

 sheathing. 

 Perigynia pubescent or puberulent, at least at the base of the beak. 

 Bracts either reduced to sheaths or absent. 



Culms not dioecious; spikes more than one; bracts bladeless 



15. § DlGITATAE, p. 242. 



Culms dioecious; spike solitary, bractless 16. § Pictae, p. 243. 



Bracts with well-developed blades 17. § Triquetrae, p. 243. 



Perigynia glabrous 18. § Albae, p. 243. 



Achenes not closely enveloped by the perigynia except at the base. 



Bracts long-sheathing (except in C. prasina of § Gracillimae, a species with 

 sharply triangular perigynia which are long- and flat-beaked, nerveless 

 except for the prominent lateral pair of nerves) ; achenes triangular 

 (except in § Bicolores, species with pulverulent or golden yellow 

 perigynia) . 

 Beak of perigynium entire, emarginate, or obliquely cut and at length 

 bidentate. 

 Pistillate spikes short, oblong to linear, erect or, if drooping, the 

 perigynia acutely triangular. 



Achenes lenticular; stigmas two 19. § Bicolores, p. 244. 



Achenes triangular; stigmas three. 



Perigynia with few to many strongly raised nerves. 



Perigynia tapering at the base, triangular; achenes usually 

 closely enveloped. 



