178 SUMMER FLOWERS. 



72. Cyperaceous Plants. Cyperace^e. 



* Flowers unisexual, tlie stamens and ovat^ies within separate 

 glumes. 



(298) Carex — flowers in imbricated spikes, each covered by a 



glume ; ovaries enclosed in bottle-shaped utricles formed 

 of the persistent perigones. 



** Flowers perfect, the stamens and ovaries within the same 

 glume. 



t Glumes or hracts distichous or two-ranked. 



(299) SchoBnus — spikelets 2-4-flowered ; glumes 6-9, the lower 



ones smaller, empty. 



tt Glumes or hracts regularly imbricated. 



X Lower glumes empty or larger than the fertile ones, some- 

 times all fertile. 



§ Bristles not so long as the glumes, or wanting. 



(300) Blysmus — bristles 3-6 ; nut plano-convex, tipped with the 



base of the style, which is not dilated ; spikelets in two- 

 ranked spikes. 

 (801) Eleocharis — bristles 3-6 ; ' nut compressed, crowned with 

 the persistent dilated base of the style ; spikelets solitary. 



(302) Scirpus — bristles about six or none ; nut plano-convex or 



trigonous, tipped with the filiform base of the style, which 

 is not dilated ; spikelets solitary clustered or panicled. 



§§ Bristles at length much longer than the glumes. 



(303) Eriophomm — bristles (in the fruiting state) silky; nut 



trigonous ; spikelets solitary or umbellate. 



%X Lower glumes empty, or smaller than the fertile ones. 



(304) Rhynchospora — bristles about six ; nut compressed, con- 



vex on both sides, crowned with the dilated base of the 

 style. 



