1780 GLIi. CYPEEACE^. [Cyperus. 



Glumes -with 1 or 2 nerves on each side near the keel and broad 

 nerveless margins. Leaves almost filiform. 



Spikelets clustered. Nuts more than halt the glume 14. C. enervis. 



Spikelets solitary or 2 together. Nuts scarcely half the glume . . 15. C. debilis. 

 Glumes with 1 nerve on the middle of each side. Leaves linear, 



often 1 line broad . . , 16. C. Icevis. 



"Spike'ets numerous, clustered or capitate, the clusters or heads solitary 

 or in an umbel of few rays. Glumes with a prominent straight or 

 recurved point. Small annuals (S(lua,rrosi.) 

 Keel of the glumes ending in a short slightly recurved point, with a 



nerve on each side. Nuts narrow 17. C. castaneus. 



Keel of the glumes ending in a long recurved point, the sides nearly 



nerveless. Nuts rather broad 18. G. caspidatus. 



Glumes 3 or 5-nerved, tapering into a long recurved point, without 

 nerveless margins. Nuts broad 19. C squarrosus. 



Spikelets dark-coloured, clustered or capitate in an umbel of few rays or 

 clusters rarely solitary. Nuts broad, as long as the glume (Ni- 

 gricantes.) 

 Spikelets small and numerous in dense globular heads. Glumes 



orbicular not J line long 20. C. difformis. 



Spikelets spreading, in clusters of 3 to 6. Glumes above 1 line long . 21. G. tetraphyllus. 

 Spikelets pale or brown, clustered capitate or solitary on the rays of an 

 umbel. Nuts broad, not above J the glume (except G. filipes) 

 (Compressi.) 

 Involucral bracts few, unequal, 1 or 2 longer than the inflorescence 

 or all short. 

 Umbel-rays few. Stems .weak. Spikelets oblong. Glumes acutely 



keeled, with 1 nerve in the middle of each side 22. C. trmervis. 



Umbel-rays numerous. 



Stems erect, very angular or fiat. Spikelets small, linear, acute . 23. C. Haspan. 

 Stems angular. Spikelets about IJ line long, less the J line broad 24. G.fiavidus. 

 Stems erect, leafy at the base. Spikelets very flat, ovate or 



oblong. Glumes brown with white edges • 25. C. condnnus. 



Involucral bracts 6 or more long leafy and unequal. Umbel rays long 

 numerous and slender. 



Spikelets solitary on each ray 26. C. filipes. 



Spikelets in clusters of 3 or 4 on each ray 27. C. pedunculosus. 



Involucral bracts about 6, nearly equal, rigid, erect or spreading. 



Umbel many-rayed or reduced to a dense cluster. Stem leafless . . 28. G. vaginatus. 



Spikelets pale or dark brown, clustered on the rays of an umbel. Nut 



narrow, nearly or quite as long as the glume (Fulvi.) 

 Spikelets small and few-flowered, in little globular clusters in a com- 

 pound umbel 29. C. holosehcenus. 



Spikelets very flat, long and narrow linear, clustered in a compound 



umbel. Glumes mostly obtuse 30. (7. dactylotes. 



Spikelets very flat, linear, clustered in a simple umbel or compound 



cluster. Glumes tipped with fine points . ' . . . . .'..■. 31. C, Gilesii. 

 Spikelets rather thick, oblong or lanceolate. Glumes obtuse or scarcely 

 acute. Stems obtusely triquetrous. 



Spikelets 8 to 12-flowered. Glumes imbiicate though rather loose. . 32. G.falvus. 



Spikelets 10 to 30-flowered. Glumes spreading scarcely imbricate . 33. G. carinatus. 

 Spikelets of G. carinatus. Stems stout, acutely 3-angled. Involucral 



bracts 1 or 2 very long and scabrous 34. C. alteriMorus. 



Spikelets usually numerous, in loose spikes along the rays of a simple or 



compound umbel (Ornati.) 

 Spikelets flat, usually pale, the rhachis of the spike minutely hairy . . 35. C. pilosus. 

 Spikelets flat, of a rich brown. Glumes bordered by a scarious hyaline 



membrane ...... Z&. 0. ornatus. 



Spikelets flat, pale brown or yellowish green, very irregularly spicate. 



Glumes very obtuse, loosely imbricate 37. C. Iria. 



Spikelets flat, pale, densely spicate. Glumes loosely imbricate, the 



keel produced into a short point 38. c. eUiisimides. 



Spikelets very narrow-linear, loosely spicate and spreading, the glumes 



very narrow and distant ■ 39. C. distans. 



Sect. IV. Papyrus. — Spikelets fiat or terete, the rhachis tordered hy scarious wings, either 

 .persistent or at length more or le3s detached as small scales. Glumes imbricate. I^tyle Z-eleft. 

 -Nut equally triquetrous. 



