286 NORTH AMERICAN FLORA [Volume 17 



lemma in the pubescent spikelets usually glabrous, the midnerve sometimes indistinct; fruit 

 2.8-2.9 mm, long, 1.1-1.2 mm. wide, apiculate. 



Type locality: C6rdoba, Mexico. 



Distribution: Southern Mexico to Panama. 



Illustrations: Ark. Bot, ll 4 : pi. 3,f. 1; Contr. U. S. Nat. Herb. 17: /. 135, 136. 



205. Panicum chiriquiense Hitchc. & Chase, Contr. U. S. Nat. Herb. 



17: 527. 1915. 



Plants perennial, olivaceous; culms straggling, creeping and rooting at the lower nodes, 

 softly papillose-pilose, freely branching, the leafy fertile branches ascending, 20-30 cm. high; 

 nodes pilose; leaf -sheaths nearly as long as the internodes or the upper overlapping, softly 

 papillose-pilose; ligule short, 0.5 mm. long; blades flat, somewhat spreading, 4-7 cm. long, 

 7—10 mm. wide, narrowly lanceolate, asymmetric at base and often somewhat falcate, acumi- 

 nate, softly papillose- villous beneath, rather sparsely pilose on the upper surface; panicles short- 

 exserted or included at base, 2.5-3.5 cm. long, half to two thirds as wide, the few branches ascend- 

 ing, the axis and few nearly simple branches slender, villous; spikelets short-pediceled, 2.6-2.8 

 mm. long, about 1.1 mm. wide, elliptic; first glume about three fourths as long as the spikelet, 

 acute, 3-nerved, villous; second glume and sterile lemma equal, covering the fruit, the glume 

 villous, minutely apiculate, the lemma usually subindurated, smooth and shining in the two 

 middle internerves, the midnerve suppressed or evident at the summit only, the lateral inter- 

 nerves villous; fruit 2.1 mm. long, 1 mm. wide, minutely apiculate. 



Type locality: El Boquete, Panama. 

 Distribution: Known only from the type collection. 

 Illustration: Contr. U. S. Nat. Herb. 17: /. 138. 



206. Panicum obtusum H. B. K. Nov. Gen. & Sp- 1: 98. 1815. 



Panicum polygonoides C. Muell. Bot. Zeit. 19: 323. 1861. 



Panicum repente Buckl. Prel. Rep. Geol. & Agr. Surv. Tex. App. 3. 1866. 



Brachiaria obtusa Nash, in Britton, Man. 77. 1901. 



Plants perennial, usually tufted from a more or less knotted rootstock, and producing 

 widely creeping stolons, sometimes 2 meters long or more, with long internodes, and geniculate, 

 swollen, conspicuously villous nodes, these often with a knob-like cluster of hairy scales at the 

 base of the extravaginal, erect branches, the clusters produced sometimes when the branch is 

 not developed; culms wiry, compressed, 20-80 cm. high, simple, usually decumbent at base, 

 glabrous, the nodes glabrous; leaf -sheaths shorter than the internodes, glabrous, or the lower 

 and those of the stolons sometimes villous; ligule membranaceous, about 1 mm. long; blades 

 3-20 cm. long, 2-7 mm. wide, erect, firm, usually involute-setaceous toward the tip, glabrous 

 on both surfaces or sometimes with a few long hairs on the upper surface at the base; panicle 

 usually short-exserted, 3-12 cm. long, about 1 cm. wide, the few, appressed, raceme-like branches 

 densely flowered; spikelets short-pediceled along one side of a slightly flattened rachis, 3-3.8 

 mm. long, 1.5-1.8 mm. wide, and about 2 mm. thick, obovoid, blunt, glabrous, usually brown- 

 ish; first glume nearly as long as the spikelet, 5 -nerved; second glume and sterile lemma sub- 

 equal, 7-9-nerved, the lemma subtending a rather firm palea and a staminate flower; fruit 

 3-3.5 mm. long, 1.5-1.7 mm. wide, subacute, smooth and shining, but very obscurely pubescent 

 at the apex. 



Type locality: Near Guanajuato, Guanajuato. 

 Distribution: Missouri to Arizona, and south to central Mexico. 



Illustrations: Bull. U. S. Dep. Agr. Agrost. 7: /. 45; Contr. U. S. Nat. Herb. 15: /. 361; 

 Britt. & Brown, 111. Fl. /. 246; ed. 2. /. 312. 



207. Panicum grande Hitchc. & Chase, Contr. U. S. Nat. Herb. 17; 



529. 1915. 



Plants perennial, gregarious, producing extensively creeping or floating leafy stolons about 

 5 mm. thick; culms 1.5-2 meters high or more, erect from a long decumbent base with papery 

 sheaths and tufts of fibrous roots, 1-2 cm. thick, simple or sparingly branching, succulent, the 

 nodes densely appressed-hirsute ; leaf-sheaths overlapping except toward the summit, glabrous, 



