(15) 



2 . Lastarrisea. Perigonium tubular, coria- 

 ceous, 6-dentate. Ovary 1. Fruit an 

 akene. Involucre 0. 



3. Chorizanthe. Involucre 1-3 flowered, 

 coriaceous, 3-6 angular. Ovary 1. 

 Fruit, an akene. 



4. Tricerastes (Datisca). Calyx superior 

 Petals 0. Anthers extrorse. Ovary 3- 

 quetrous. Styles 3, each 2-cleft. Ovary 

 I -celled. Placentae parietal. 



5. Cyperus. Gluinaceous. Spiklets dis- 

 tichous. 



6. Eleocharis. Glumaceous. Spiklets im- 

 bricate. Perigonial bristles not exserted. 

 Caryopsis apiculate by the persistent 

 articulate base of the style. 



7. Fimbristylis. Glumaceous. Spikelets 

 imbricate. Perigonial bristles not ex- 

 serted. Caryopsis apiculate. Style 

 articulate above its base. Aquatic. 



8. Scirpus. Glumaceous. Spiklets imbri- 

 cate. Perigonial bristles not exserted. 

 Caryopsis apiculate by the persistent 

 continuous base of the style. Aquatic. 



9. Eriophorum. Glumaceous. Spikelets 

 imbricate. Perigonial bristles exserted, 

 considerably longer than the glumae. 

 Aquatic. 



