282 CYPERACEAE 



13. CAREX- L. Sp. PI. 972. 1753. 



Grass-like sedges, perennial by rootstocks. Culms mostly triangular, often strongly 

 phyllopodic or aphyllopodic. Leaves three-ranked, the upper (bracts) elongate or short, 

 and subtending the spikes of flowers, or wanting. Plants monoecious or sometimes dioeci- 

 ous. Spikes one to many, either wholly pistillate, wholly staminate, androgynous or gynae- 

 candrous, sessile or peduncled, the base of the peduncle often with a perigynium-like or 

 spathe-like organ (cladoprophyllum) surrounding it. Flowers solitary in the axils of 

 scales (glumes). Perianth none. Staminate flowers of three (or rarely two) stamens, 

 the filaments filiform. Pistillate flowers of a single pistil, with a style and two or three 

 stigmas. Style either (1) jointed with the apiculate-tipped or rounded achene and wither- 

 ing and at length deciduous ; or (2) continuous with achene, persistent, indurated and not 

 withering. Achene triangular, lenticular or plano-convex, completely surrounded by the 

 perigynium or rarely rupturing it in ripening. Rhacheola occasionally developed. [The 

 classical Latin name, probably derived from the Greek, to cut, referring to the sharp leaf- 

 blades of some species]. 



Species more than 1000, all continents, but least developed in the tropics. Type species, Carc.v pulicaris L. 



Spike one. 



Stigmas two; achenes lenticular. 



Perigynia many-striate. 1. Aardinae. 



Perigynia nerveless ventrally. 5. Capitatae. 



Stigmas three; achenes triangular. „ j ■ .,, 



Perigynia strongly inflated, sessile, not becoming reflexed; pistillate scales persistent. 



2. Inflatae. 

 Perigynia not inflated. 



Pistillate scales deciduous; perigynia stipitate, at least the lower reflexed at maturity. 



Perigynia dark-tinged; style jointed with achene. 3. Athrochlaenae. 



Perigynia straw-color; style continuous with achene. 39. Pauciflorae. 



Pistillate scales persistent; perigynia not reflexed at maturity. 



Perigynia rounded and beakless at apex, many-nerved. 19. Polytrichoideae. 



Perigynia not rounded at apex, beakless or beaked. 



Perigynia lanceolate. 6. Circinatae. 



Perigvnia not lanceolate. 



Perigynia finely striate. 1. Nardinae. 



Perigynia 2-keeled, otherwise nerveless. 



Culms dioecious or nearly so. , 22. Scirpinae. 



Spikes androgynous. 



Perigynia pubescent or puberulent, 2.5-4 mm. long. 21. Filifoliae. 



Perigynia glabrous, 5-7 mm. long. 20. Firmiculjies. 



Spikes more than one. 



Stigmas two; achenes lenticular. 



Lateral spikes sessile, short (rarely somewhat elongated), the terminal one androgynous or gynae- 

 candrous. 

 Perigvnia not white puncticulate. 



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



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



6. FOETIDAE. 



Spikes, at least the lower, distinct. 



Perigynia plano-convex, sharp-edged, the beak obliquely cut, bidentulate in age. 



7. DiVISAE. 



Perigynia much flattened, wing-margined at least above, the beak deeply bidentate. 



8. Arenariae. 

 Cespitose or rootstocks short-creeping. 



Spikes androgynous. 



Perigynia with body abruptly contracted into the beak. 



Spikes few (usually ten or less) ; perigynia green or tinged with reddish brown. 



10. Muhlenbergianae. 

 Spikes numerous; perigynia yellowish or brownish. 



Perigynia yellowish; opaque part of leaf-sheaths usually transversely rugulose. 



11. MULTIFLORAE. 



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



12. Paniculatae. 

 Perigynia with body tapering into the beak. 13. Stenorhynchae. 



Spikes gynaecandrous. 



Perigynia at most thin-edged. 



Perigynia spreading or ascending at maturity. 14. Stellulatae. 



Perigynia appressed. 15. Deweyanae. 



Perigynia narrowly to broadly wing-margined. 16. Ovales. 



Perigynia white puncticulate. 17. Canescentes. 



Lateral spikes elongated, peduncled or sessile; terminal spike staminate, or if rarely gynaecandrous, the 

 lateral spikes peduncled. 

 Lowest bract long-sheathing, jiistillate spikes not very many-flowered. 26. Bicolores. 



Lowest bract sheathless or. if more or less sheathing, the pistillate spikes very many-flowered. 

 Achenes not constricted in the middle. ^^- Acutae. 



Achenes constricted in the middle; scales sharp-pointed, three-nerved. 36. Cryptocarpae. 

 Stigmas three; achenes triangular. . 



Lateral spikes very numerous, sessile, short; perigynia plano-convex, strongly lacerate-winged. 



9. Macrocephai.ae. 



Lateral spikes not very numerous, usually not sessile; perigynia not lacerate-winged. 

 Perigynia pubescent or at least puberulent. 



Pistillate spikes with from few to about 25 perigynia. 



Bracts of non-basal pistillate spikes sheathless or very nearly so. 23. Montaxae. 



Bracts of non-basal pistillate spikes sheathing. 



Bracts more or less purplish-tinged, the blades absent or rudimentary. 



24. Digitatae. 



* Text (except zonal distribution) contributed by and illustrations (with a few exceptions) 

 prepared under the direction of Mr. Kenneth K. Mackenzie. 



