664 MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



or veined, o — Moist open ground, often a weed in fields, southern 

 Florida, southern Texas; tropical America, at low altitudes (fig. 1474). 

 Panicum fasciculatum var. reticulatum (Torr.) Beal. Differing 

 from P '. fasciculatum in having smaller more compact panicles, nar- 

 rower pubescent blades, less regular suberect racemes and larger, most- 

 ly mare yellowish spikelets 2 .6 to 3 mm long. Many intergrades occur. 

 © (This has been erroneously referred to P. fasciculatum var. 

 chartaginense (Swartz) Doell.) — Prairies, fields, 

 and waste ground, Arkansas and Louisiana to 

 Arizona; introduced in North Carolina and 

 South Carolina; Mexico. 



116. Panicum adspersum Trin. (Fig. 

 1475.) Culms ascending or spreading from a 

 decumbent base, rooting at the lower nodes, 30 

 to 100 cm tall; blades 5 to 15 cm long, 8 to 20 

 mm wide; panicle 6 to 15 cm long, the racemes 

 3 to 10 cm long; spikelets 3.2 to 4 mm long, fusiform, abruptly acu- 

 minate, hispid or hispidulous, sometimes only at the summit, rarely 

 glabrous, obscurely reticulate-veined, o — Moist open ground, 

 often on coral limestone, Florida; ballast, Philadelphia and Camden; 

 Mobile; West Indies. The Florida specimens, commonly more robust 

 than the typical form from the West Indies, have been described as P. 

 keyense Mez. 



Figuke 1477.— Distribution of 

 Panicum arizonicum. 



Figure 1478.— Panicum tcxanum. Panicle, X 1; two views of spikelet, and floret, X 10. 

 (Hitchcock 3187, Tex.) 



Panicum ramosum L. Kesembling P. adspersum, but spikelets 

 smaller, having a finely transverse rugose sterile lemma, in appearance 

 much like the fertile lemma, o — Ballast, Alabama (Mobile); 

 tropical Asia. 



117. Panicum arizonicum Scribn. and Merr. Arizona panicum. 

 (Fig. 1476.) Culms erect or sometimes decumbent at base, 20 to 60 

 cm tall; sheaths glabrous to papillose-hispid; blades 5 to 15 cm long, 

 6 to 12 mm wide, glabrous or papillose-hispid beneath, ciliate near 

 base; panicle 7 to 20 cm long, the branches rather loosely flowered, 

 finely pubescent and papillose-hirsute; spikelets 3,5 to 3,8 mm long, 



