HITCHCOCK AND CHASE — NORTH AMERICAN PANICUM. 



43 



DISTRIBUTION. 



River banks and moist places, Mexico to Argentina. 

 Mexico: Colima, Palmer 149 in 1897; Lodiego near Culiacan, Palmer 1660 in 1891; 



Saltillo, Brandegee 17 in 1893 (Univ. Cal. Herb.); Yucatan, Schott 592 (Field 



Mus. Herb.). 

 Guatemala: Agua Caliente, Beam 6143. 

 Brazil: Piauhy, Gardner 2353, 2361; Prov. Ceara, Gardner 1876 (all in Gray 



Herb.). 

 Argentina: Cordoba, Stuckert 11719, 56 in Kneucker Gram. Exs. 366. 



13. Panicum adspersum Trin. 



Panicum adspersum Trin. Gram. Pan. 146. 1826. Trinius states as to the origin of 



his specimen, "V. sp. Doming. (Sprengel, 

 sub nomine Pan. caespitosi.)" The type, 

 in the Trinius Herbarium, is labeled, "Pani- 

 cum adspersum m. St. Domingense s.[ub] 

 n.fomine] P. caespitosum Lam. (!) mis. cl. 

 Sprengel." This specimen was afterwards 

 figured by Trinius. a The spikelets are 3.2 

 mm. long. 



Panicum thomasmnum Steud.; Doell in 

 Mart. Fl. Bras. 2 2 : 188. 1877. This is men- 

 tioned as a synonym under P. adspersum 



Trin. The type, collected by Duchaissing 

 Fig. 24.— P. adspersum. From type specimen. . „. „, . . ,, a , , , TT , . 



in St. Thomas, is in the Steudel Herbarium. 



This species has been referred by many authors to P. grossarium L., but that name 



is a synonym of P. reptans. 



description. 



Plants light green, glabrous except as noted, ascending or spreading from a decum- 

 bent base, rooting at the lower nodes, commonly rather freely branching; culms 30 to 

 100 cm. high, compressed; sheaths shorter than the internodes, rather loose, densely 

 ciliate at least toward the summit; ligule a ciliate-membranaceous ring scarcely 1 mm. 

 long; blades ascending or spreading, 5 to 15 cm., rarely as much as 20 cm. long, 8 to 20 

 mm. wide, abruptly acuminate, sometimes ciliate at the rounded base, scabrous on 

 the margin; panicles rather short-exserted, 6 to 15 cm. long, composed of few to 

 many ascending spike-like racemes, 3 to 10 cm. long, the slender axes angled, 

 scabrous, usually pubescent in the axils, bearing approximate, short-pediceled spike- 

 lets singly or two or three together on short branchlets along the under side; spikelets 

 3.2 to 4 mm. long, 1.5 to 1.8 mm. wide, fusiform, turgid, abruptly acuminate; first 

 glume clasping, about one-third the length of the spikelet, subacute, 5-nerved, glabrous; 

 second glume and sterile lemma exceeding the fruit and pointed beyond it, 5 to 

 7-nerved, hispid at least toward the summit, or sometimes hispidulous only, rarely 

 glabrous, sometimes obscurely reticulate; fruit 2.2 to 3 mm. long, obovate, obtuse. 



This species varies much in size and habit. The Florida specimens are more robust 

 than many of those from the West Indies, including the type specimen. There ap- 

 pears, however, to be no characters by which these can be separated. Some of the 

 Cuban specimens, such as Curtiss 748, are equally robust. In a specimen from St. 

 Croix, Eggers in 1876, the spikelets are strongly papillose-hispid. 



a Gram. Icon. 2: pi. 169. 1829. 



