116 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
DESCRIPTION. 
Plants more or less spreading, often rooting at the nodes of the decumbent base; 
culms simple or sparingly branching, 40 to 100 em. or more high, sheaths shorter than 
the elongated internodes, ciliate and hirsute at the juncture with the blade, otherwise 
glabrous or papillose-hirsute toward the summit, ligules fimbriate, about 0.5 mm. 
long; blades erect or ascending, conduplicate or flat, 10 to 25 cm, 
long, 5 to 15 mm. wide, rarely wider, narrowed to the rounded or 
subcordate base, glabrous or with a few scattered hairs on the upper 
surface; panicles oblong in outline, 5 to 30 cm. long, composed of 
many slender, raceme-like branches, the lower distant, spreading, 
sometimes as much as 10 cm, long, the upper ascending; branchlets 
very short, mostly secund on the lower side of the branches, bearing 
2 or 3 spikelets, or a few toward the base of the lower branches 5 to 
10 mm, long; spikelets 1.1 to 1.5 mm. long, about 0.7 mm. wide and 
as thick or thicker; first glume one-third to half the length of the spikelet, sub- 
acute, 1 to 3-nerved; second glume slightly shorter than the sterile lemma, the 
latter subtending a palea of nearly equal length, this becoming subrigid at maturity 
forcing open the spikelet; fruit 1 to 1.1. mm. long, about 0.5 mm, wide. 
This widely distributed species is variable in appearance. The following excep- 
tionally robust specimens from Mexico and Guatemala have comparatively short, 
cordate blades 1.5 to 1.8 em. wide, and very turgid spikelets 1.5 mm. long, a few 
stiff hairs on the branchlets: Finck 3, Liebmann 419, Purpus 2159, 2160,4 Tuerckheim 
1254. 
Tonduz’s no. 3071 and his no, 4868, in the Costa Rica Herbarium, have pubescent 
spikelets as in the Spruce specimen upon which Doell bases his variety pubescens. 
These appear to be merely exceptional specimens. 
Fic. 109.—P. laz- 
um. Fromtype 
specimen. 
DISTRIBUTION. 
Savannas and open woods, Mexico, West Indies, and south to Paraguay. 
Mexico: Culiacdn, Palmer 1558 in 1891; Mirador, Liebmann 412, 419; Cérdoba, 
Finck 3; Mayito, Rovirosa 427; Zacualpan, Purpus 2159, 2160 in part; Oriz- 
aba, Bottert 688. 
GuaTeMALA: Dept. Alta Vera Paz, Tuerckheim 1254, 8803; Santa Rosa, Feyde 
> & Lux 3900; Puerto Barrios, Pitter 361. 
Honpuras: San Pedro Sula, Thieme 5587 in part. 
Costa Rica: Buenos Aires, Tonduz 4864, 4871; Rio Tilirf, Tonduz 3071; Turri- 
alba, Pittier 16123; Las Mesas, Pittier 3117. 
Banamas: Turk Island, Madiana (Gray Herb.). 
Cua: Herradura, Caldwell & Baker 7136, Hitchcock 177, Tracy 9054, 9062, 9072, 
9099; Wajay, Earle d: Wilson 343; Santiago de las Vegas, IMitchcock 178, 
Tracy 9114; Retiro, Wright 759; Guanabacoa, Ledn 914; Sancti Spiritus, Leén 
907, 909; without locality, Wright 3751 in part, 3863 in part; Isle of Pines, 
Curtiss 464, Palmer & Riley 1069, Taylor 37. 
Porro Rico: Utuado, Britton & Cowell 394; Cayey, Heller & Heller 522; Catatio, 
Heller & Heller 1378; Ponce, Heller in 1902; Mayaguez, Sintenis 360; Fajardo, 
Sintenis 1254; Mount Morales, Britton & Marble 1068; without locality, 
Eggers 1329. 
Danisu West Inpres: St. Thomas, Hggers 165 (Gray Herb.). 
Lreewarb IsLanps: Guadeloupe, Duss 3179. 
Winpwarp Istanps: St. Lucia, U.S. Fish Com. in 1887; Barbadoes, Dash 450; 
Granada, Broadway in 1905. 
a Panicum viseidellum Scribn. was also distributed under this number. 
