GRAMINEAE. 



VOL. I. 



38. Panicum microcarpon Muhl. Barbed Panic-grass. Fig. 348. 



P. barbulatum Nash, in Britt. & Br. 111. Fl. i: 120. 



1896. Not Michx. 1803. 

 P. microcarpon Muhl. ; Ell. Bot. S. C. & Ga. I : 127. 



1817. 



Culms at first simple, erect, 2-3 tall, later pro- 

 fusely branched for their whole length, 3-4 long, 

 prostrate or leaning, the nodes strongly barbed; 

 blades smooth and glabrous, generally truncate or 

 rounded at the base, the primary ones 3'-$' long, 

 about \' wide, widely spreading, the lower ones 

 usually reflexed, those of the branches V-2 f long, 

 i "-2" wide; primary panicle 3'-$' long, exserted, 

 ovoid, its branches ascending, rigid ; secondary 

 panicles smaller, lax, not exceeding the leaves, the 

 branches bearing few spikelets; spikelets about I" 

 long, ellipsoid, purple, glabrous; first scale about 

 one-third as long as the spikelet, acute. 



Moist soil, Massachusetts to Missouri south to Florida 

 and Texas. Bearded Joint-grass. June-Aug. 



Panicum nitidum Lam., differing by its larger pubescent 

 spikelets, ranges from Virginia to Florida, the Bahamas and 

 Texas. 



39. Panicum annulum Ashe. Ringed Panic-grass. 



Fig- 349- 



P. annulum Ashe, Journ. E. Mitch. Sci. Soc. 15: 58. 1898. 



Culms i6'-2i tall, glabrous or sparingly pubescent, 

 tufted, finally branched, the nodes densely barbed with 

 spreading hairs, appearing like a ring; sheaths glabrous 

 or the lower ones softly pubescent ; ligule less than \" 

 long; blades 2i'-5' long, 3" -7" wide, velvety pubescent on 

 both surfaces; panicle 1^-4' long, open, its branches erect- 

 ascending or ascending, rarely spreading; spikelets about 

 i" long and nearly i as wide, elliptic, strongly pubescent 

 with spreading hairs. 



In dry rocky woods, New Jersey and Pennsylvania to 

 Georgia, Missouri and Mississippi. June and July. 



40. Panicum boreale Nash. Northern Panic-grass. Fig. 350. 



Panicum borcnlc Nash, Bull. Torr. Club, 22: 421. 1895. 



Culms at first erect and simple, i-2 tall, later de- 

 cumbent and somewhat branched, smooth and glabrous. 

 Sheaths shorter than the internodes, usually smooth, 

 ciliate; ligule short, ciliate; blades 3' -5' long, \'-\ f wide, 

 erect, truncate or rounded at the sparsely ciliate base, 

 acuminate; panicle 2'~4' long, ovoid, its branches i'-2' 

 long, spreading or ascending; spikelets i" long, about 

 equalling the pedicels, ellipsoid, somewhat pubescent; 

 first scale ovate, obtuse, about one-third as long as the 

 spikelet; second and third scales oblong-ovate, 7-ncrved, 

 pubescent, equalling the fourth, which is oval, acute, and 

 slightly more than ']" long; palet of third scale usually 

 empty. 



Moist soil, Newfoundland to Ontario south to New York, 

 Indiana and Minnesota. June and July. 



