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, Deam 6143. 
Brazit: Piauhy, Gardner 2353, 2361; Prov. Cearé, Gardner 1876 (all-in Gray 
Herb.). 
ARGENTINA: (6rdoba, 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. caespitost.)’? The type, 
in the Trinius Herbarium, is labeled, ‘‘ Pani- 
cum adspersum m. St. Domingense s.[ub] 
n.[omine] P. caespitosum Lam. (!) mis. cl. 
Sprengel.” This specimen was afterwards 
figured by Trinius.¢ The spikelets are 3.2 
mm. long. 
Panicum thomasianum Steud.; Doell in 
Mart. Fl. Bras. 27: 188. 1877. This is men- 
tioned as a synonym under P. adspersum 
Trin. The type, collected by Duchaissing 
in St. Thomas, is in the Steudel Herbarium. 
This species has been referred by many authors to P. grossarium L., but that name 
isa synonym of P. reptans. 
Fic. 24.—P. adspersum. From type specimen. 
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: pl. 169. 1829. 
