222 NORTH AMERICAN FLORA [VOLUME 17 



loose, sometimes longer than the internodes, papillose-hispid; blades drying yellowish- green, 

 more or less pilose on both surfaces, or glabrate, as much as 30 cm. long and 2 cm. wide, rounded 

 at base, gradually narrowed to the apex; panicles usually more or less included at base, 10-30 cm. 

 long, more or less nodding, usually rather compact, the numerous branches narrowly ascending, 

 very scabrous, spikelet-b earing toward the summit; spikelets 4.5-5 mm. long, ovate, acuminate, 

 strongly many-nerved ; first glume half the length of the spikelet or more, acuminate ; second 

 glume and sterile lemma subequal, a small palea in the sterile floret; fruit 3 mm. long, 2 mm. 

 wide, elliptic, stramineous to reddish-brown. 



Typb locality: India. 



Distribution: Introduced at various points in the United States; widely distributed in the 

 Old World. 



Illustrations: Jacq. f. Eclog. Gram. pi. 31; Trin. Ic. pi. 221; Vasey, Agr. Grasses U. S. ed. 

 2. pi. 13; Bull. U. S. Dep. Agr. Agrost. 20: /. 23; Contr. U. S. Nat. Herb. 15: /. 54; Britt. & 

 Brown, 111. Fl. /. 272; ed. 2./. 320; Hitchc. Text-book Grasses/. 21. 



33. Panicum cayennense Lam. Tab. Encyc. 1: 173. 1791. 



Panicum fioribundum Rich.; Lam. Encyc. 4: 742, as synonym. 1797. 

 Panicum peduncular e Willd.; Steud. Syn. Gram. 77. 1854. 

 Panicum cayennese patulum Doell, in Mart. FL Bras. 2 2 : 220. 1877. 



Plants erect, or, when much-branched at the base, spreading; culms 20-50 cm. high, often 

 zigzag, glabrous or more or less papillose-pilose below the pilose nodes; leaf -sheaths papillose- 

 pilose, ciliate; blades linear, 10-20 cm. long, 4-10 mm. wide, rather stiffly ascending, rounded 

 at the scarcely narrowed base, rather sparsely papillose-pilose on both surfaces or sometimes 

 nearly glabrous; panicles terminal and axillary from the upper 2 or 3 sheaths, rarely fascicled, 

 approximate and forming an elongate inflorescence from two thirds to almost the entire height 



of the plant, the individual panicles included at the base, 8—20 cm. long, half to two thirds as 



wide, the slender, scabrous branches and branchlets and the long, flexuous pedicels divaricate; 



spikelets 2.2-2.3 mm. long, 1.2 mm. wide, ob ovoid, turgid; first glume about half the length of 



the spikelet, acute ; second glume and sterile lemma equal, slightly exceeding the fruit, abruptly 



short-pointed, strongly 5-7-nerved, the sterile palea about half the length of its lemma; fruit 



1.7 mm. long, 1.1 mm. wide, oval, turgid. 



Typ3 locality: Cayenne. 



Distribution: Cuba; Costa Rica to Brazil. 



Illustration: Contr. U. S. Nat. Herb. 15: /. 56. 



34. Panicum capillarioides Vasey; Coult. Contr. U. S. Nat. Herb. 



1: 54. 1890. 



Plants in tufts of few to several culms from a knotted crown, erect or ascending, 30-55 

 cm. high; culms stiff, simple or sparingly branching, appressed-pubescent or sometimes gla- 

 brate, the nodes densely ascending-pubescent; leaf -sheaths mostly equaling or exceeding the 

 rather short internodes, papillose-pubescent; ligule about 1.5 mm. long; blades rather stiff, 

 ascending, 10-30 cm. long, 2-10 mm. wide, scarcely narrowed to the rounded base, flat or 

 drying somewhat involute, harshly papillose- pubescent on both surfaces, usually sparsely so 

 beneath; panicles short-exserted, usually nearly equaled by the upper blades, diffuse, 

 few-flowered, 10-20 cm. long, as wide or wider, the capillary branches stiffly spreading 

 at maturity, bearing rather short-pediceled spikelets toward the end, the axis and 

 branches scabrous, the rather conspicuous pulvini pubescent; spikelets 5-6 mm. long, 1-1.2 

 mm. wide, lanceolate, long-acuminate; first glume one third to half the length of the 

 spikelet, acute, 7~nerved; second glume and sterile lemma subequal, many-nerved, at least 

 three times as long as the fruit, usually more or less inflated above it; fruit 1.6-1.8 mm. long, 

 0.8-0.9 mm. wide, elliptic. 



Typb locality: Point Isabel, Texas. 



Distribution: Southern Texas and adjacent Mexico. 



Illustrations: Bull. U. S. Dep. Agr. Agrost. 17: /. 348; Contr. U. S. Nat. Herb. IS: /. 57. 



35. Panicum diffusum Sw. Prodr. 23. 1788. 



Panicum caespititium Lam. Tab. Encyc. 1; 173. 1791. 



Plants in small, dense tufts, spreading, or ascending from a decumbent base, simple or 

 sparingly branching, rarely repeatedly branching, 25-50 cm. high; culms slender, wiry, glabrous, 



