153 



GRAMINEAE. 



Vol. I. 



62. Panicum Scribnerianum Nash. Scribner's 

 Panic-grass. Fig. 372. 



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



1890. Not Lam. 1797. 

 P. pauciflorum A. Gray, Man. 613. 1848. Not Ell. 1817. 

 P. 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; 

 blades 2'-4' long, 3" -6" wide, rounded or 1 truncate at 

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

 scabrous beneath ; panicles small, the primary one ex- 

 serted, ovoid, ii'-3' long, the secondary ones much 

 smaller and more or less included; branches of the 

 primary panicle spreading, 8"-ii' long, often flexuous; 

 spikelets turgid, obovoid, a little over \\" long. 



In dry or moist soil, Maine to British Columbia, south 

 to Virginia, Texas and Arizona. June-Aug. 



Panicum Helleri Nash, of the south-central states, dif- 

 fers in being glabrous or nearly so, and with smaller spike- 

 lets. It is recorded from Missouri. 



63. Panicum oligosanthes Schult. Few- 

 flowered Panic-grass. Fig. 373. 



P. paucif,orum Ell. Bot. S. C. & Ga. 1: 120. 1817. 



Not R. Br. 1810. 

 P, oligosanthes Schult. Mant. 2 : 256. 1824. 



Culms tufted, erect, l°-2i° tall, villous, finally 

 branched; sheaths, especially those on the 

 branches, papillose-hispid, ciliate on the margin; 

 blades erect or ascending, 2'-^' long, 2i"-s" wide, 

 lanceolate to linear, softly and densely pubescent 

 on the lower surface, the upper surface glabrous 

 or with a few long hairs near the base ; primary 

 panicle 2'-$' long, its branches ascending; spike- 

 lets i|"-2" long and about i as wide, oval, pu- 

 bescent. 



In dry soil, New Jersey to Florida, Illinois and 

 Texas. June-Sept. 



64. Panicum xanthophysum A. Gray. 

 Panic-grass. Fig. 374. 



Slender 



P. xanthophysum A. Gray, Ann. Lye. N. 

 P. calliphyllum Ashe, Journ. E. Mitch. 



Y. 3: 233. 1835. 

 Sci. Soc. 15: 31. 



Plant light green, becoming yellowish, in drying. 

 Culms erect, l°-2° tall, simple. Sheaths sparingly 

 papillose-pubescent; ligule very short; blades 3'-6' long, 

 ¥-¥ wide, rounded at base, long-acuminate, erect, 

 smooth and glabrous ; panicle long-exserted, linear, 

 l§'-4' long, its branches appressed, rarely somewhat 

 ascending; spikelets few, ii"-2" long, obovoid, pubes- 

 cent or rarely glabrous, 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, Quebec to Manitoba and Pennsylvania. June- 

 Aug. 



