Part 3, 1915] POACEAB 



243 



10-30 mm. wide, somewhat asymmetric at the rounded or slightly cordate, sometimes ciliate, 

 base, softly pubescent, or sometimes velvety, on both surfaces to glabrate except near the 

 margin and at the base; panicles short-exserted, finally loose and rather few-flowered, 10-20 

 cm. long, about two thirds as wide when expanded, the rather few, slender branches stiffly as- 

 cending or spreading, bearing toward the ends short, appressed branchlets with 1-3 rather 

 short-pediceled spikelets; spikelets 2-2.3 mm. long, 1-1.2 mm. wide, obovate, obtuse, turgid, 

 at maturity olivaceous or brown, glabrous or more commonly papillose-hispidulous; first glume 

 about two thirds as long as the spikelet, acute ; second glume slightly shorter than the sterile 

 lemma, exposing the summit of the fruit at maturity, both 5-nerved, in glabrous spikelets the 

 nerves bordered by interrupted rows of minute papillae; fruit 1.9-2.1 mm. long, about 1 mm. 

 wide, elliptic, obscurely pointed, papillose-roughened, becoming dark-brown at maturity. 



Type locality: Cayenne. 



Distribution: Mexico and the West Indies to Paraguay. 



Illustrations: Kunth, Rev. Gram. pi. 27; Trin. Ic. pi. 238; Contr. U. S. Nat. Herb. 15 : /. 131. 



91. Panicum glutinosum Sw. Prodr. 24. 1788. 



Panicum obtusiflorum A. Rich, in Sagra, Hist. Cuba 11: 305. 1850. 

 Panicum Lindenii Griseb. Cat. PI. Cub. 233. 1866. 



Plants perennial, somewhat glaucous; culms erect from a geniculate or decumbent base, 

 often rooting at the lower nodes, 1-2 meters high, robust, compressed, glabrous ; leaf-sheaths 

 often longer than the internodes, somewhat keeled, especially the lower, glabrous or sometimes 

 pilose, densely bearded at the juncture with the blade; ligule obsolete; blades elongate-lan- 

 ceolate, acuminate, 15-50 cm. long, 15-25 mm. wide (the uppermost reduced), abruptly or 

 gradually narrowed at the base, more or less ciliate along the lower portion, glabrous or some- 

 times very sparsely pilose; panicles rhomboid in outline, 15-30 cm. long, about as wide, the 

 lower branches verticillate, nearly as long as the main axis, stiffly ascending, the axis and 

 branches glabrous, sometimes viscid, bearded in the axils, bearing slender, flexuous, scabrous 

 branchlets, with rather long-pediceled spikelets, mostly along the upper half; spikelets 3 mm. 

 long, 1.5-2 mm. wide, turgid, obovoid, obtuse, olivaceous to brown, the faintly nerved, very 

 viscid glumes whitish on the margin; first and second glumes about equal, slightly shorter than 

 the fruit, the sterile lemma thinner in texture, mostly entirely concealed beneath the first 

 glume, the sterile palea wanting; fruit 2.6 mm. long, 1.2-1.5 mm. wide, obovoid-elliptic, olive- 

 brown, densely minutely puberulent at the summit, otherwise smooth and shining, the margins 

 of the lemma toward the summit scarcely inrolled. 



Type locality: Jamaica. 



Distribution: Mexico and the West Indies to Paraguay and Bolivia. 



Illustration: Contr. U. S. Nat. Herb. 15: /. 132. 



92. Panicum Rudgei R. & S. Syst. Veg. 2: 444. 1817. 



Panicum scoparium Rudge, PI. Guian. 1: 21. 1805. Not P. scoparium Lam. 1798. 



Panicum Rudgei brasiliense Raddi, Agrost. Bras. 48. 1823. 



Panicum dasytrichum Spreng. Syst. 1 : 317. 1825. 



Panicum hirsutum Willd.; Spreng. Syst. 1: 317, as synonym. 1825. Not P. hirsutum Sw. 1797. 



Panicum rhigiophyllum Steud. Syn. Gram. 76. 1854. 



Panicum rigens Salzm.; Steud. Syn. Gram. 76, as synonym. 1854. Not P. rigens Sw. 1788. 



Panicum cayennense divaricatum Doell, in Mart. Fl. Bras. 2 2 : 220. 1877. 



Plants perennial, yellow-green or tawny; culms robust, 30-100 cm. high, erect or somewhat 

 geniculate at base, often zigzag, especially above, densely and harshly villous; leaf -sheaths 

 nearly equaling the internodes or overlapping, densely papillose- villous or hirsute; ligule mem-- 

 branaceous, ciliate, about 1 mm. long, the hairs of the ligule blending with the hairs of the 

 upper surface of the blade; blades thick, linear, 15-40 cm. long, 5-10 mm. wide, rather rigidly 

 ascending, flat or folded, slightly narrowed toward the base, gradually long-acuminate, densely 

 short-hirsute on both surfaces or glabrate; panicles terminal and in the axils of the approximate 

 upper 2-6 leaves, forming an oblong inflorescence one third the height of the plant, or more, 

 each more or less included at base in the subtending sheath; branches pilose in the axils, branch- 

 ing freely from the base, the branches and branchlets angled, scabrous, the lower branchlets 

 stiffly ascending, the upper and the long pedicels divaricate, somewhat flexuous; spikelets 

 about 3.5 mm. long, 1.5 mm. wide, turgid, somewhat attenuate at base, strongly nerved, 



