36 SOUTHERN CALIFORNIA ACADEMY OF SCIENCES. 



the New York Botanical Garden, under the direction of Dr. 

 Britton; the drawings for the other plates were made by Miss 

 Clara P. Colgan. 



Cyperaceae. 



Grass-like or rush-like herbs, with triangular, quadrangu- 

 lar, terete, or flattened, mostly solid, culms, and alternate, 

 mostly radical, leaves with closed sheaths, or leafless. Flowers 

 perfect or imperfect, solitary (rarely 2) in the axles of imbri- 

 cated bracts (scales), in 1-many-flowered, solitary or clustered 

 spikelets. Perianth hypogenous, of bristles or inner scales, 

 or wanting. Stamens usually 1-3 ; anthers basifixed, 2-celled. 

 Style 2-3-cleft, rarely simple or 2-toothed. Ovary 1-celled, ses- 

 sile or stipitate, containing a solitary erect anatropous ovule. 

 Fruit a lenticular or 3-angled achene. Embryo minute, at th*^ 

 base of the copious endosperm. 



A family of over 60 genera, and some 3,000 species : of 

 world-wide distribution, but most abundant in the temperate 

 portions of the northern hemisphere. 



The two families, the Gramineae, or true Grasses, and the 

 Cyperaceae, or Sedges, constitute the order Graminales, char- 

 acterized by the production of the flowers in the axles of 

 chaffy scales, which are arranged in spikes or spikelets. In 

 the Gramineae the fruit is a caryopsis, or grain, and the calms 

 are, with few exceptions, hollow; in the Cyperaceae the culms 

 are mostly solid, and the fruit is an achene. 



Key to the Genera. 



Flowers all perfect ; spikelets all similar. 



Scales of the usually flattened spikelets 2-ranked. 



Kachis straight. 1. Cyperus. 



Rachis flexuous above. 2. Schoenus. 



Scales of the spikelets spirally imbricated all around. 

 Dilated base of the style persistent as a tubercle. 



3. Eleocharis. 

 Style wholly deciduous. 



Perianth wanting ; style ciliate. 4. Fimbristylis. 



Perianth of 1-6 bristles, rarely 0; style glabrous. 



5. Scirpus. 



Perianth a minute hyaline scale. 6. Hemicarpha. 



Only the terminal flower perfect. 7. Cladium. 



