16 



A low, spreading, much-branched annual, 1 to 8 dm. high, with short, cylindrical 

 spikes and lanceolate leaves 3 to 6 cm. long. Culms compressed, geniculate, 

 decumbent, very glabrous; nodes smooth; sheaths very loose, striate, compressed, 

 glabrous, margins smooth, shorter than their internodes; ligule short, densely 

 ciliate-f ringed with white hairs; leaf-blades 3 to 6 cm. long, 4 to 8 mm. wide, cor- 

 date at the base, long-acuminate at the apex, scabrous and sparingly papillate cili- 

 ate on both sides, especially below, margins cartilaginous, serrulate-scabrous. Inflo- 

 rescence dense, cylindrical, 1 to 3 cm. long, about 1 cm. in diameter, purplish; com- 

 mon axis angular, scabrous; branches very short, subverticillate, densely flowered; 



setae 1 or 2, purple, stout, 

 flexuous, retrorserly scab- 

 ous, 3 to 8 mm. long. Spike- 

 lets 1.5 to 2 mm. long, nearly 

 sessile, elliptical-ovate; first 

 glume triangular - ovate, 

 acute or obtuse, 3-nerved, 

 about one-third the length of 

 the spikelet ; second glume 

 ovate, obtuse, 5 to 7-nerved, 

 nearly equaling the 5 to 7- 

 nerved, acute third glume, 

 which bears a short palea in 

 its axil; flowering glume 

 about 1.5 mm. long, elliptical- 

 ovate, acute, striate, nearly 

 smooth or very finely trans- 

 versely wrinkled below. 

 Palea similar in texture and 

 markings, about as long as 

 the glume. 

 Alabama, Louisiana, Mexico, 



South America, Europe. 

 Specimens examined. — Louisi- 

 ana: Port Eads, Langlois 

 1885, on "billast." Ala- 

 bama: Mobiie, on "ballast," 

 Mohr 1888. Mexico: Gua- 

 dalajara, 484 r.^lmer 1886. 

 Very readily distinguished 

 from C. verticillata bj' its 

 smaller size, more spreading 

 habit, short cylindrical 

 spikes, and smaller spikelets. 

 6. Cheetocliloa verticillata 

 (L.) Scribn. U. S. ':)ept. 

 Agr., Div. Agros. Bui. i : 39 

 (1897). Panicum vertldllatum. L. Sp. PL ed. 2, 82 (1762). Setaria vcrik-iUafa 

 Beauv. Agrost. 51 (1812) . Chamseraphis verticillata Porter Bui. Torr. Bot. Club. 

 20: 196 (1893). Ixophorus veriiciUatus Nash Bui. Torr. Bot. Club. 22: 422 

 (1895). (Fig. 6.) 

 An erect or ascending, glabrous, somewhat csespitose annual, 3 to 6 dm. high, with 

 linear-lanceolate leaves and interrupted subspiciform panicles 5 to 10 cm. long. 

 Culms geniculate, glabrous, compressed; nodes brown or black, smooth; sheaths 

 loose, shorter than their internodes, smooth, striate, margins glabrous below, 



Fig. 6. — Ghcetochloa verlieillata : o, 6, views of the spikelet, 

 showing the setae. 



