GRAMINEAE. 87 



38. Panicum viscidum Ell. VELVETY PANICUM. (I. F. f. 266.) Culms 

 erect, 6-12 dm. tall, simple, or at length much branched above, villous. Sheaths 

 villous; leaves softly pubescent, those of the culm 10-17.5 cm - l n g) 10-16 mm. 

 wide, distant, those of the branches 2.5-6.25 cm. long, 4-10 mm. wide, crowded; 

 primary panicles 7.5-15 cm. long, ovoid, branches ascending; secondary panicles 

 much smaller; spikelets ovoid to oval, about 2.5 mm. long, pubescent; fourth scale 

 oval, apiculate, 2 mm. long. Moist soil, N. J. to Ind. and the Ind. Terr., south 

 to Fla. and Tex. Not viscid. June -Aug. 



39. Panicum Addisonii Nash. RIGID PANICUM. (I. F. f. 2676.) Culms 

 2.5-3.75 dm. tall, rigid, tufted, erect, or decumbent at the base, at length much 

 branched, the- branches erect, pubescent with long, nearly appressed hairs. Sheaths 

 appressed-pubescent, at least the lower ones; leaves erect, lanceolate, thickish, 

 smooth and glabrous on both surfaces, acuminate, 2.5-7.5 cm. long, 3-6 mm. 

 wide; panicle ovoid to oblong, 1.8-5.6 cm. long, its branches spreading or ascend- 

 ing; spikelets obovoid, 2mm. long; second and third scales densely pubescent with 

 long, spreading hairs. Sandy soil, southern N. J. May -June. 



40. Panicum Commonsianum Ashe, COMMONS' PANICUM. Culms tufted, 

 erect, 2 5-5 dm. tall, densely appressed-hirsute below and puberulent above, or 

 rarely somewhat hirsute. Sheaths, especially the lower ones, appressed-hirsute; 

 leaves erect or nearly so, firm, glabrous on both surfaces, ciliate toward the base, 

 4-10 cm. long, 3-6 mm. wide; panicle open, 5-7 cm. long, broadly ovate, its 

 branches spreading; spikelets 2.5 mm. long, obovate, pubescent. On dry, 

 sandy ridges along the coast, Del. to N. Car. June-July. 



41. Panicum Wilcoxianum Vasey. WILCOX'S PANICUM. (I. F. f. 260.) 

 Culms erect, 1.5-2.5 dm. tall, sparingly pubescent. Sheaths papillose-pubescent; 

 leaves 3.75-7.5 cm. long, less than 4 mm. wide, long-acuminate, strongly pubes- 

 cent with long hairs; panicle about 3.75 cm. long, oblong to ovoid, compact; 

 branches less than 2.5 cm. long, ascending, flexuous; spikelets about 2.5 mm. long, 

 ellipsoid; first scale about one-quarter as long as the spikelet; second and third 

 scales about equal, pubescent; fourth scale about as long as the third, obtuse. In 

 dry soil, Neb. (and Kans. ?). July -Aug. 



42. Panicum Liebergii (Vasey) Scribn. LIEBERG'S PANICUM. (I. F. f. 2593.) 

 Culms erect, slender, glabrous, roughish, especially near the nodes, 3-6 dm. tall, 

 at length branched. Sheaths papillose-hirsute with spreading hairs; leaves erect 

 or ascending, lanceolate, 5-10 cm. long, 6-12 mm. wide, acuminate at the apex, 

 papillose-hispid beneath and sometimes sparingly so on the rough upper surface; 

 panicle oblong, 5-10 cm. long, its branches erect or ascending; spikelets 3-4 mm. 

 long, oval, the outer three scales papillose-hirsute with long, spreading hairs. Dry 

 soil, Ohio to Minn, and S. Dak., south to Mo. and Neb. June -July. 



43. Panicum Scribnerianum Nash. SCRIBNER'S PANICUM. (I. F. f. 259.) 

 Culms erect, 1.5-6 dm. tall, simple, or late in the season dichotomously branched 

 above, sparingly pubescent. Sheaths strongly papillose-hispid; leaves 5-10 cm. 

 long, 612 mm. wide, more or less spreading, smooth above, scabrous beneath; 

 panicles small, the primary one ovoid, 3.75-7.5 cm. long, the secondary ones much 

 smaller ani more or less included; branches of the primary panicle spreading, 

 1.6-3.7 cm. long, often flexuous; spikelets turgid, obovoid, about 3 mm. long. In 

 dry or moist soil, Me. and Ont. to Minn., south to Va., Kans. and Ariz. June- Aug. 



44. Panicum xanthophysum A. Gray. SLENDER PANICUM. (I. F. f. 258.) 

 Culms erect, 3-6 dm. tall, simple. Sheaths sparingly papillose-hirsute; leaves 

 7.5-15 cm. long, 8-18 mm. wide, long-acuminate, erect, smooth and glabrous; pan- 

 icle !ong-exserted, linear, 3.75-10 cm. long, its branches appressed; spikelets few, 

 about 3 mm. long, obovoid, pubescent or glabrate ; first scale about one-half as long 

 as the nearly equal obtuse second and third; fourth scale indurated and shining, 

 elliptic or oval. Dry soil, Me. and Ont. to Manitoba, south to N. J. and Penn. 

 Plant light green, becoming yellowish in drying. June-Aug. 



45. Panicum calliphyllum Ashe. Plant yellowish-green. Culms single or a 

 little tufted, simple, 4-5 dm. tall, minutely pubescent; sheaths glabrous, excepting 

 the ciliate margins; leaves ascending, 9-11 cm. long, 912 mm. wide, lanceo- 

 late, smooth and glabrous, ciliate at the base; panicle 6-9 cm. long, its ascending 

 scabrous branches 3-4 cm. long; spikelets few, 3 mm. long, elliptic, pubescent. In 

 dry soil, central N. Y. June-Aug. 



