PAXICE.E. 151 



A. Lciif-bliulcs plioato , 15 



li, Hristlos with fine teeth pointinj; downwards 1 



C. liristles witli lino ttoth jtointiiif,' upwards (a) 



a. I 'hints ;]-() meters lii«fli )t 



a. IMants 25-00 eni. higli. Slieaths eoniprossed. . 3. 4, 5, <! 



a. Plants usually S-:.M) cm. lii^jli (No. 7 often taller). Sheaths 



compressed little if any (}i) 



b. Exotic, cultivated, •^(»-4(> em. or more hiffh 



e>' 



t 



b. Native in Florida and 'IVxas 8 



a. Plants usually ;50-G0 em. hi<,di. Sheaths comjjressed little if 



any (c) 



c. Spikes tawny yellow when mature !) 



c. Spikes ffreen or reddish brown when mature. . . . (d) 



d. Fertile lloret stron<;ly wrinkled transversely, as \n ('. 



l//ii>trti 10, 11 



d. Fertile lloret not wrinkled transversely, or only as seen 



under a lens (e) 



e. Spikes dense I'l 



e. S|)ikes interrupted (i) 



i. Sp<ikelets 3 mm. long 13 



i. Spikelets 2 mm. long, bristles single. ... 14 



1. C. verticillata (L.) Porter, Bull. Torr. Club, 20:196 (1893). 



Panicum vertidUatHm L. Sp. PI. Ed. 2, 82 (1T62). Pcnnhe- 

 tum verticiUiitum R. Br. Prod. 1: 195 (1810). Setaria verticillata 

 Jieauv. Agrost. 51 (1812). 



Culms erect or ascending, brauching and cylindrical below, 

 30-60 cm. high. Sheaths smooth, loose; ligule ciliate: blades flat, 

 rough, twisted (?), broad at the base, of large specimens, 15 cm- 

 long, 12-15 mm. wide. Spikelike panicle green, often rather 

 loose and interrupted at the base, the s[)ikelets densely clustered, 

 each pedicel bearing 1-2 bristles twice as long as themselves 

 with the asi)erities directed downwards. Spikelets oval, aiiout 2 

 mm. long, first glume one-half the length of the spikelet, 1-nerveil, 

 second nearly as long as the third, broad. 7-nerved, the latter 5-7- 

 nerved; fertile floret smooth, the minute transverse wrinkles 

 scarcely visible, even under a lens. 



