(320) 



4. Scirpus L. BULRUSH. 



Spikelets $ , co-flowered. Palets imbricate 

 all round, the lowermost empty. Perigonium 

 6-setaceous. Style articulate with its base. 



1. S. LACUSTHIS L. Inflorescence apparent- 

 ly lateral, with a single erect involucral leaf; 

 stem almost terete; bristles of perigonium 6, 

 slender, with scattered barbs 2. Common. 

 Summer. 



2. S. TATOKA Kunth. Inflorescence appar- 

 ently lateral, with a single erect involucral leaf; 

 stem almost terete; bristles of perigonium less 

 than 6, stout and retrorsely plumose. 1C . Be- 

 nicia. Summer. 



3. S. OLNEYI Gray. Inflorescence appar- 

 ently lateral, with a single erect involucral leaf; 

 stem triquetrous. It. Presidio. Summer. 



4. S. MABITIMUS L. Involucre spreading; 

 spikelets large in a sessile cluster or sparingly 

 umbellate. 1. Common. Summer. 



5. S. SYLVATICUS L. Involucre spreading; 

 spikelets small in a supra-decompound inflores- 

 cence. 1. Common. Summer. 



6. S. ACICULABIS L. (EleocJiaris R. Br.). 

 Spike distichous or 3-ranked, few-flowered, 

 terminating a leafless stem. 0. Common. 

 Spring. 



7. S. PALUSTRIS Eeichenb. (Ekocharis E. 

 Br.). Spike terete, oo-flowered, terminating a 

 leafless stem. It. Common. Summer. 



