GRAMINEAE. 



VOL. I. 



20. Panicum perlongum Nash. Long-stalked 

 Panic-grass. Fig. 330. 



Panicum perlongum Nash, Bull. Torrey Club 26: 575. 

 1899. 



Culms 8'-i6' tall, simple; sheaths hirsute with long 

 ascending hairs ; blades elongated, linear, erect, 

 papillose-hispid beneath, i"-ii" wide, the upper one 

 commonly 3'~5i' long; primary panicle long-stalked, 

 much-exserted, generally extending beyond the apex 

 of the upper leaf, ii'-2i' long, its branches erect or 

 nearly so; spikelets about ii" long, about i as wide, 

 glabrous or pubescent with a few scattered long 

 hairs, strongly nerved. 



On praries and in dry soil, Michigan to South Da- 

 kota, Manitoba and Texas. June-Au . 



21. Panicum linearifolium Scribn. Low 

 White-haired Panic-grass. Fig. 331. 



Panicum Enslini Nash, in Britt. Man. 83. 1901. 



Not Trin. 1826. 

 Panicum linearifolium Scribn. ; Nash, in Britt. & 



Br. 111. Fl. 3: 500. 1898. 



Culms tufted, slender, erect, smooth and gla- 

 brous, simple, 6'-i6' tall. Sheaths glabrous 

 or pilose with long white hairs, longer than 

 the internodes; ligule a ring of short hairs; 

 blades elongated, smooth or rough, glabrous 

 or more or less pilose, especially upon the 

 lower surface, 3'-io' long, i"-2" wide, the 

 uppermost leaf the longest and often extend- 

 ing beyond the panicle ; primary panicle loose 

 and open, often long-exserted, \\'-^ long, its 

 branches lax, ascending, secondary panicles 

 small and contracted on very short culms and 

 partly concealed by the bases of the long 

 culms: spikelets i"-i|" long, obtuse or acutish, 

 pubescent with spreading hairs. 



Dry soil, especially hillsides, Nova Scotia to Michigan, south to Georgia, Arkansas and Texas. 

 May-July. 



22. Panicum Werneri Scribn. Werner's 

 Panic-grass. Fig. 332. 



Panicum Werneri Scribn. ; Nash, in Britt. & Br. 111. 

 Fl. 3: 501. 1898. 



Smooth and glabrous, light green. Culms tufted, 

 erect, slender, simple or later sparingly branched, 

 io'-i8' tall ; sheaths equalling or shorter than the 

 internodes ; ligule a ring of short hairs ; blades erect, 

 elongated, linear, acuminate, ~2\'-$ long, \\"-2\" 

 wide, panicle finally long-exserted, loose and open, 

 2i'-3i' long, its branches ascending; spikelets about 

 i" long on longer hispidulous pedicels, oval, minutely 

 and sparsely pubescent, the first scale orbicular, 

 about one-quarter as long as the spikelet, i -nerved, 

 the second and third scales 7-nerved, the fourth scale 

 oval, slightly apiculate. 



Dry knolls in swamps. Maine to Ontario, Ohio, Mis- 

 souri and Texas. June-July. 



