HITCHCOCK AND CHASE—NORTH AMERICAN PANICUM. 37 
DESCRIPTION. 
Plants spreading, usually prostrate, or with a decumbent base, rooting at the lower 
nodes; culms slender, usually freely branching, ascending 10 to 30 cm. above the 
decumbent or creeping base, glabrous, the nodes usually puberulent; sheaths 
loose, glabrous, densely ciliate, shorter than the inter- 
nodes; ligule a dense ring of hairs 1 mm. long or less; 
blades lanceolate or ovate-lanceolate, 1.5 to 6 cm. long, 
4 to 12 mm. wide, cordate, glabrous or puberulent on 
both surfaces, the white, undulate margin hispid- 
scabrous, ciliate at base with long, stiff hairs; inflores- 
cence finally long-exserted, 2 to 6 cm. long, consist- 
SE esis Bonn type ing of 3 to 12 spike-like, ascending or spreading racemes 
specimen of P. prostratum Lam. tranged along a main axis; racemes solitary or some- 
times somewhat fascicled, the upper approximate and 
shorter, the lower rather distant and 2 or 3 cm. long; rachises and pedicels scabrous 
and usually sparsely pilose with long, weak hairs; spikelets borne on one side of the 
rachis, irregularly and rather densely clustered, on pubescent pedicels 1 mm. or less 
in length, elliptic, 1.9 to 2 mm. long, 0.9 to 1 mm. wide, acute, glabrous; first glume 
about one-sixth the length of the spikelet, rounded or truncate; second glume and 
sterile lemma slightly exceeding the fruit, strongly 5 to 7-nerved; fruit 1.7 mm. long, 
0.8 mm. wide, elliptic, apiculate. 
As a whole this species is very uniform, but the long hairs on the secondary rachises 
and pedicels are sometimes wanting. 
DISTRIBUTION. 
Moist open ground and a frequent weed in waste places and cultivated soil, Florida 
to Texas, Mexico, and the West Indies, south to northern South America; also in the 
tropical regions of the Eastern Hemi- 
sphere. 
_ Fuorima: Apalachicola, Biltmore 
Distr. Chapman Herb. 4276 
(Gray Herb.). 
ALABAMA: Mobile, Mohr in 1884. 
Louisiana: Pointe a la Hache, 
Langlois 45 in 1882, 154 in 
1883; Burnside, Combs 1431; 
New Orleans, Ridell in 1840; 
Algiers, Tracy 1837. 
Texas: Columbia, Bush 266, 1296; 
Industry, Wurzlow 6; Houston, 
Thurow 21 in 1903; Pierce, Tracy 7387; Lynchburg, Joor 39 in 1884; without 
locality, Nealley in 1884 and 1888. 
Mexico: Cuicatlan, Nelson 1622. 
Cusa: Habana, Curtiss 691, Hitchcock 146, Leén 276, 292, 297, 566, 576, 906, 910c; 
Madruga, Curtiss 536; San Antonio, Hitchcock 145; Herradura, Tracy 9103; 
Cienfuegos, Pringle 73; Baracoa, Pollard, Palmer & Palmer 19; La Magdalena, 
Earle & Baker 2455; Santiago, Leén 910; Guayabal, Leén 910b; without local- 
ity, Wright 3857. 
Jamaica: Hope, Harris 6845; Gordon Town, Hart 838. 
Porto Rico: Guanica, Millspaugh Pl. Utow. 726, Sintenis 3368; Salinas de Cabo, 
Sintenis 847; Coamo Springs, Goll 662; Ponce, Heller 497. 
DanisH West Inpizs: St. Croix, Ricksecker 77; St. Thomas, Hggers 293 (Hitch- 
cock Herb.). 
Fic. 18.—Distribution of P. reptans. 
