Part 3, 1915] POACEAE 279 



188. Panicum scoparium L,am. Encyc. 4: 744. 1797. 



Panicum pubescens Lam. Hncyc. 4: 748. 1797. 



Panicum viscidum Ell. Bot. S. C. & Ga. 1: 123. 1816. 



Panicum pauciflorum Bosc; Spreng. Syst. 1: 313, as synonym. 1825. 



Vernal plants grayish -olive, velvety-pubescent throughout except as noted; culms 80-130 

 cm. high, stout, erect or ascending, usually geniculate at base, the nodes villous with reflexed 

 hairs, a glabrous, viscid ring below; leaf -sheaths about half as long as the long internodes, the 

 velvety pubescence wanting on the back toward the summit, the surface here viscid when fresh ; 

 ligule 1 mm. long; blades rather thick, ascending or spreading, often reflexed late in the season, 

 12-20 cm. long, 10-18 mm. wide, long-acuminate, slightly narrowed to the rounded base, the 

 uppermost leaf often much reduced; panicles finally long-exserted, 8-15 cm. long, nearly as 

 wide, many-flowered, the axis, branches, and pedicels with viscid blotches, the branches as- 

 cending or spreading, spikelet-bearing to the base; spikelets 2.4—2.6 mm. long, 1.4-1.5 mm. 

 wide, obovate, turgid at maturity, abruptly pointed, papillose-pubescent with spreading hairs; 

 first glume one fifth to one fourth the length of the spikelet, acute to truncate; second glume and 

 sterile lemma strongly nerved, the glume obtuse, shorter than the fruit at maturity, the lemma 

 abruptly pointed and equaling it; fruit 2 mm. long, 1.4 mm. wide, obovate-elliptic, apiculate. 



Autumnal phase leaning or spreading, branching from the middle nodes after the maturity 

 of the primary panicle, the branches usually longer than the primary internodes, repeatedly 

 branching, often more or less scorpioid, the ultimate branchlets in flabellate fascicles, the 

 sheaths often swollen toward the summit, contracted at the throat, the blades much reduced, 

 overtopping the small, partially included panicles. 



Type locality : Carolina. 



Distribution: Massachusetts to Florida, and west to Oklahoma and Texas. 



Illustrations: Ell. Bot. S. C. & Ga. pi. 7,f. 3; Bull. Tenn. Exp. Sta. 7: pL 11, f. 44; Bull. 

 U. S. Dep. Agr. Agrost. 17: /. 386; 21: /. 11; Contr. U. S. Nat. Herb. 15: /. 333; Britt. & Brown, 

 III m.f. 266; ed. 2./. 377. 



189. Panidum viscidellum Scribn. Circ. U. S. Dep. Agr. Agrost. 19: 



2. 1900. 



? Panicum refiexopilum Steud. Syn. Gram. 84. 1854. 



Vernal culms ascending from a decumbent, widely spreading or creeping base, rooting at 

 the lower nodes, softly villous or nearly glabrous, the nodes more or less short-bearded; leaf- 

 sheaths shorter than the internodes, villous or, especially the uppermost, glabrate; ligule ciliate, 

 2-4 mm. long ; blades spreading, rather thick, more or less velvety-pubescent or villous on both 

 surfaces, the uppermost 5-13 cm. long, 9-13 mm. wide, linear-lanceolate, subcordate, the lower 

 lanceolate, more cordate, shorter and wider; panicles 4-1 1 cm. long, half to two thirds as wide, 

 usually densely flowered, the numerous branches spikelet-bearing from the base; spikelets 

 1.8-1.9 mm. long, 1 mm. wide, elliptic, acute, sparsely pubescent; first glume about one third 

 as long as the spikelet, pointed ; second glume and sterile lemma slightly exceeding the fruit at 

 maturity; fruit 1.5 mm. long, 0.8 mm. wide, elliptic, abruptly pointed. 



Autumnal phase branching from the middle and upper nodes, the branches erect or as- 

 cending from the decumbent primary culm, the densely villous sheaths often overlapping on 

 the shortened internodes, the blades more or less oyate-lanceolate and strongly cordate-clasp- 

 ing, velvety-pubescent, the panicles similar to the primary ones but smaller. 



Type locality: Jalapa, Vera Cruz. 

 Distribution : Mexico to Colombia; Cuba. 

 Illustration: Contr. U. S. Nat. Herb. 15: /. 335. 



190. Panicum aculeatum Hitchc. & Chase; Hitchc. Rhodora 8: 



209. 1906. 



Vernal plants in large clumps; culms slender, 70-100 cm. high, ascending, scabrous, 

 harshly pubescent below; leaf-sheaths papillose-hispid with stiff, sharp-pointed hairs, a puberu- 

 lent ring at the summit, the uppermost usually glabrous; ligule minute, membranaceous, 

 ciliate; blades firm, stiflly ascending or spreading, 12-20 cm. long, 9-13 mm. wide, acuminate, 

 involute-pointed, scarcely narrowed to the rounded base, very scabrous on the upper surface 

 and toward the apex beneath; panicles 8-12 cm. long, about as wide, few-flowered, the slender, 



