SOUTHERN CALIFORNIA ACADEMY OF SCIENCES. 37 



Spikelets monoecious, androgynous, or rarely dioecious; 



achene inclosed in a utricle. 8. Carex. 



1. Cyperus, Linn. Sp. PI. 44. Galingale. 



Annual or perennial herbs with simple triangular or sub- 

 terete culms, leafy at base. Infloresence subtended by conspic- 

 uous leafy involucres, irregularly umbellate with unequal raya 

 and a sessile central spike, or capitate. Flowers in flattened or 

 subterete spikelets of few or many scales. Scales concave, more 

 or less carinate, 2-ranked, deciduous or persistent, 1-2 of the 

 lowest usually empty. Perianth none. Stamens 3. Style 2-3- 

 cleft, wholly deciduous froni the summit of the 3-angled or 

 lenticular achene. 



About 650 species are recognized, natives of temperate and 

 tropical regions. 



Key to the Species. 



Styles 2-cleft; scales deciduous from the persistent rachis. 

 Achenes little flattened. 



Achenes oblong. 1. C. melanostachyus. 



Achenes ovoid. 2. C. bromoides. 



Achenes plano-convex. 3. C. laevigatas. 



Styles 3-cleft; achenes 3-angled. 



Scales deciduous from the rachis of the flattened spikelet. 

 Scales with incurved setaceous tips. 4. C. inflexus. 



Scales destitute of setaceous tips. 



Wings of the rachis separating to the base ; annuals. 

 Wings persistent on the rachis. 5. C. erythrorhizos. 

 Wings readily deciduous. 6. C. Parishii. 



Wings whole adnate to the rachis ; perennial. 



7. C. esculentua. 

 Spikelets decidous from the axis of the spike. 

 Spikes oblong, compact: spikelets slender. 



8. C. speciosus 

 Spikes short, loose and spreading; spikelets broader. 



9. C. long-ispicatus. 



