H8 GRAMINEAE. 



15. Panicum clandestinum L,. Hispid Panicuin. (Fig. 257.) 



Panicum clandestinum L. Sp. PI. 58. 1753. 

 Panicum pedunculatum Torr. Fl. U. S. 141. 1824. 



Culms erect or ascending, i^-4 tall, rather 

 stout, simple at first, much branched later in the 

 season. Sheaths longer than the internodes, much 

 crowded on the branches, papillose-hispid, especi- 

 ally the upper ones; leaves 2'-8' long, J^'-iX' 

 wide, cordate-clasping at base, acuminate, smooth 

 and glabrous, the margins ciliate at base ; primary 

 panicle sometimes long-exserted; panicles of the 

 branches below included in the sheaths, rarely 

 slightly exserted; spikelets \"-\W long, ellipsoid; 

 first scale about one-third as long as the spikelet; 

 second and third oval, acutish, g-nerved, the fourth 

 oval, obtuse, apiculate, whitish, shining. 



*"" In thickets. Quebec to Michigan, south to Georgia, 

 Missouri and Texas. June-July. 



16. Panicum xanthophysum A. Gray. 

 Slender Panicum. (Fig. 258.) 



Panicum xanthophysum A. Gray, Ann. Lye. X. Y. 3: 

 233- 1835. 



Culms erect, i-2 tall, simple. Sheaths spar- 

 ingly papillose-pubescent; ligule very short; leaves 

 3 / -6 / long, */$'-}' wide, rounded at base, long- 

 acuminate, erect, smooth and glabrous; panicle 

 long-exserted, linear, 1^2'-^' long, its branches ap- 

 pressed ; spikelets few, about \y z " 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, Maine and Ontario to Manitoba, south to 

 New Jersey and Pennsylvania. Plant light green, 

 becoming yellowish in drying. June-Aug. 



17. Panicum Scribnerianum Nash. Scribner's Panicum. (Fig. 259.) 



Panicum scoparium var. minor Scribn. Bull. Univ. Tenn. 



7:48. 1894. Not P. capillare var. minus Muhl. 1817. 

 Panicum scoparium S. Wats, in A. Gray, Man. Ed. 6, 632. 



1890. Not Lam. 1797. 

 Pamcum pauciflorum A. Gray, Man. 613. 1848. Not 



Ell. 1817. 

 Panicum Scribnerianum Nash, Bull. Torr. Club, 22: 421. 



1895- 



Culms erect, 6 / -2 tall, simple or late in the season 

 dichotomously branched above, sparingly pubescent. 

 Sheaths strongly papillose-hispid, sometimes glabrate ; 

 leaves 2 / -4 / long, 3 // -6 // wide, rounded or truncate at 

 base, acuminate, more or less spreading, smooth above, 

 scabrous beneath ; panicles small, the primary one ex- 

 serted, ovoid, 1%'-$' long, the secondary ones much 

 smaller and more or less included ; branches of the 

 primary panicle spreading, S"-!^ long, often 

 flexuous; spikelets turgid, obovoid, about i%" long. 



In dry or moist soil, Maine and Ontario to Minnesota, 

 south to Virginia, Kansas and Arizona. June-Aug. 



