1. Cyperus. CYPERACEAE. 87 



F. Spikelets paniculate. 



Lowest flower fertile Cladium 9. 



Lowest flower sterile Gahnia 10. 



F. Spikelets solitary Caustis 11. 



E. Hypogynous scales 6 Lepidosperma 12. 



A. Flowers unisexual ; glumes imbricate all round. 



Nut enclosed in a utricle Carex 13. 



Nut not enclosed in a utricle Chorizandra 8. 



1. CYPERUS, L. 



(Latin, from Greek kypeiros, some species of Sedge.) 

 Spikelets several flowered, with distichous glumes ; stamens 1-3 ; styles 2- or 3-fid ; 

 no hypogynous bristles. Usually perennials with simple stems ; spikelets in sessile heads, 

 or on the rays (branches) of an umbel, having at the base an involucre of leafy bracts. 



A. Style 2-cleft ; rhachilla not winged. 



B. Nut compressed laterally (with 1 edge next rhachilla) G. Eragrostis 1. 



B. Nut compressed dorsally (with the flat or concave face 



next rhachilla). 



Dwarf annual ; spikelets numerous in a head G. pygmaeus 2. 



Perennial ; spikelets 1 or 2 together C. distachyus 3. 



A. Style 3 -cleft ; rhachilla not or scarcely winged ; spikelets 

 capitate or clustered. 



C. Spikelets few, pale-colored in a single sessile cluster ; 



small annuals. 

 D. One involucral bract erect G. tenellus 4. 



D. Involucral bracts spreading. 



Glumes nerveless on sides G. enervis 5. 



Glumes nerved on sides G. gracilis 6. 



C. Spikelets numerous ; glumes with recurved points ; 



annual C. squarrosus 7. 



C. Rather tall perennials. 



E. Nut not \ as long as glume ; bracts 3-9, almost 



equal G. vaginatus 8. 



E. Nut as long as glume ; spikelets small, capitate ; 



bracts 1-3 C. difformis 9. 



E. Nut shorter than glume ; stems trigonous ; 2 in- 

 volucral bracts long. 



Spikelets in umbellate heads C. fulvus 10. 



Spikelets in sessile heads G. Gilesii 11. 



A. Style 3-cleft ; spikelets spicate on the umbel-rays. 



F. Rhachilla not winged ; spikes loose C. Iria 12. 



F. Rhachilla with scarious wings (persistant bases of the 



glumes). 



G. Stems stout, acutely 3-angled. 



Umbel small ; spikelets 10-30 mm G. alterniflorus 13. 



Umbel large ; spikelets 8-12 mm G. exaltatus 17. 



G. Stems slender, acutely 3-angled. 



Rootstock bearing tubers ; spikelets flat G. rotundus 14. 



Rootstock without tubers ; spikelets scarcely 



flattened C. subulatus 15. 



G. Stems stout, bluntly 3-angled ; spikelets flat, 



reddish-brown C. Gunnii 16. 



1. C. Eragrostis, Vahl. Leaves shorter than stem ; spikelets usually in a compound 

 umbel, with 2-4 involucral bracts ; spikelets flat, dark-brown, 12-24-flowered, 6-12 mm. 

 long ; glumes obtuse with a green keel and nerveless sides ; nut less than | the length 

 of the glume, biconvex. 



Recorded by Bentham for " Torrens River, F. Mueller," but does not appear to have 

 been found since. 



2. C. pygmaeus, Rottb. Low annual, with narrow leaves ; spikelets small and numerous 

 crowded into a globular compound head with 3-5 broad-based involucral bracts far sur- 

 passing it ; style 2 or rarely 3-cleft ; nut ovoid, shorter than glume, plano-convex or 

 trigonous. 



River Murray, on moist ground. Summer. 



3. C. distachyus, All. Slender perennial ; leaves very short or reduced to sheaths at 

 the base ; spikelets solitary or twin, dark-brown, 6-24-flowered ; involucral bracts 2, 

 the lower one long, erect ; nut much shorter than glume, plano-convex. 



Country about Lakes Torrens and Eyre. Spring. — Also in the Mediterranean region. 



