C.YLVI. CYPERACE.E. 



853 



Oyary compressed; style short or long or obsolete; stigmas 2 or 3. 

 Fruit trigouous, triquetrous, obovoid, or plano-couvex. — Disteib. All 

 warm and temperate regions ; species about 360. 



I have followed Boeckeler in including under the genus Ci/penis the genera Pycreus, 

 Juncellus, and Mariscus, a course followed by Pas (Engl. & Prantl, Pflanzenf.). Tlw 

 late Dr. Trimen in his 'Flora of Ceylon' continued by Sir Joseph Hooker includes the 

 first two genera in Cyperus, but retains Mariscus as a distinct genus. The generic 

 distinction in that genus, however, viz. the disarticulation of the rhachilla of the 

 spikelets above the 2 lowest glumes, cannot be applied in the field, but maybe said to 

 be limited to herbarium specimens. In a recently publislied pamphlet by Dr. N. L. 

 Britton, Director-in-Chief of the New York Botanical Grardens, " The Sedges of 

 Jamaica " [Bulletin of the Department of Agriculture of Jamaica, vol. 5, Supplement 1 

 (1907)], that botanist makes the following remarks on j)age 1 : — "I have accepted the 

 generic limits outlined by Mr. Clarke with the exception of his treatment of Cypenis 

 and its segregates, where I have accepted the view of previous authors in taking 

 Cyperus in its broad sense rather than recognizing the genera Pycreus, Mariscus, and 

 Torulinium, as I believe the characters depended on by Mr. Clarke for the maintenance 

 of these genera are too vague for satisfactory use." 



Stigmas 2. 



Fruit a laterally compressed nut. 



Siiperflcial cells of the nut longitudinally oblong or 

 elliptic. Nut often appearing zonate or murieate 

 by reason of the thickened ends of the cells running 

 into an undulating or broken horizontal line. 



Spikelets lanceolate, 20-60-flowered ; nut obovoid 



black 1. C. latespicatus. 



Spikelets liuear-oblong with exactly parallel sides, 



20-flowered ; nut globosely ovoid, brown 2. C. malaharicus. 



Superficial cells of the nut nearly square. Nut often 

 appearing regularly dotted by reason of the light 

 reflected from the convex surface of each cell. 



Stems often clotlied for :J-f of their length by 

 leaf-sheaths, decumbent at the base ; I'hizome 



creeping, 4-1 in. long 3. C. sanguinolentus. 



Stems enveloped in leaf-sheaths only a little way 

 above the base, erect ; roots fibrous. 

 Annuals. 



Stems tufted. 



Spikelets 6-10-flowered ; rhachilla winged ; 



stamens 2-3 4. C. hyalinus. 



Spikelets 20-50-flowered ; rhachilla not 

 winged. 



Stamen 1 ; nut yL in. long 5. C. pitmilus. 



Stamens 2 ; nut g^ in. long 6. C. globosus. 



Stem robust, solitary or subsolitary. 



Nut y'jf in. long, rounded at the apex ; 

 glumes with conspicuous white margins ; 

 bracts reaching 16 in. long ; stamens 



usually 3 7. Ca Ibonuirginatus. 



Nut tV in. long, obcordate at the apex ; 

 margins of glumes not conspicuously 

 white ; bracts reaching 9 or 10 in. long ; 



stamens 3 8, C. pmncticulatus. 



Perennial ; nut ^V in. long ; stamens usually 2. 9. C. odoratus. 

 Fruit a dorsally compressed nut. 



Spikelets many, densely packed iu a terminal head; 

 stems reaching 10 in. long; bracts 1-6 in. long; a 



dwarf annual herb 10. C.pygmcBus. 



Spikelets 1-30 in 1 apparently lateral head ; stems 



reaching 2 ft. long ; bracts 1-3 in. long 11. C. lavigatus. 



Spikes umbellate ; stems reaching 3 ft. long; bracts 



reaching 18 in. long; a stout perennial herb 12. C. alopecuroides. 



