CYPERACEAE 43 



at each angle, and with several intermediate ribs, all connected by trans- 

 verse ridges. In marshes and mud-holes in the northern part. Not un- 

 common. May-September. 



5. STENOPHYLLUS Raf. 



Slender annuals, with spikelets solitary, umbelled or capitate and sub- 

 tended by one-several leaves. Base of the style persistent as a tubercle 

 on the achene. 



1. S. capillaris (L.) Britton. Much tufted, 2MO' high : culms and 

 leaves capillary : spikelets few, ovoid, 2" or less long : achene 3-angled, 

 transversely wrinkled. Locally very abundant in sandy fields and woods 

 four miles south of <Grain Valley. June-July. 



6. FIMBRISTYLIS Vahl. 



Annual or perennial with umbellate or capitate spikelets Flowers as 

 in Stenophyllus, save that the enlarged base of the style is not persistent 

 at maturity as a tubercle. 



Perennial from a thickened base. 1. F. castanea. 

 Annual. 



Achene lenticular. 2. F. laxa. 



Achene 3-angled. 3. F. Frankil. 



1. F. castanea (Michx.) Vahl. l-3 high, from a bulbous thickened 

 base : leaves involute : umbel simple or somewhat compound : spikelets 

 oblong, l^ // -2 // thick, 3 // -5 // long : achene lenticular, longitudinally 

 minutely striate and reticulated. Rich prairies around Lee's Summit 

 and Grand View ; adventized at Atherton. June-July. 



2. F. laxa Vahl. 6 X high : umbel subsimple : spikelets l x/ wide, 3 X/ 

 long: achenes longitudinally ribbed, the ribs connected by fine cross 

 lines, and conspicuously tubercled. Quite abundant in a wet, sterile, 

 open place about one mile north of Greenwood. August-October. 



3. F. FrankiiSteud. 2 / -12 / high: umbel somewhat compound : spike- 

 lets numerous, less than 1 // wide and 2 /x long : achene obovoid, 3-angled, 

 reticulated. Sand-bars along the Missouri River at Courtney and Sibley. 

 Rare and local. 



7. SCIRPUS L. BULKUSH. 



Spikelets from few- to many-flowered, one to very many, solitary or in 

 spikes or umbels. Flowers perfect. Bristle present. Scales imbricated 

 all around. Style 2-3-cleft, not swollen at the base and wholly deciduous, 

 or its base persistent as an awl-like tip. Achenes lenticular or triangular. 



Spikelets 1-7, appearing lateral. 1. S. Americanus. 



Spikelets 7-many. 



Culms terete, leafless. 2. S. lacustris. 



Culms three-angled, leafy. 

 Bristles downwardly barbed. 



Spikelets 8"-12" long, 1-5 together. 3. 8. fluviaiilis. 



Spikelets l"-3" long, 6-75 together. 4. 8. atrovirens. 



