GRASS FAMIL.Y. 



18. Panicum Wilcoxianum Vasey. Wil- 

 cox's Panicum. (Fig. 260.) 



Panicum Wilcoxianum Vasey, Bull. U. S. Dept 

 Agric. Bot. Div. 8: 32. 1889. 



Culms erect, 6 / -io / tall, sparingly pubescent. 

 Sheaths papillose-pubescent ; ligule a ring of hairs ; 

 leaves iK / -3 / long, less than 2" wide, long-acum- 

 inate, strongly pubescent with long hairs ; panicle 

 about \ l /t' long, oblong to ovoid, compact ; branches 

 less than i / long, spreading or ascending, flexuous ; 

 spikelets about i%" 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, Nebraska. July-Aug. 



119 



19. Panicum boreale Nash. Northern Panicum. (Fig. 261.) 



Panicum boreale Nash, Bull. Torr. Club, U: 471. 189,5. 



Culms at first erect and simple, i-a tall, later 

 decumbent and somewhat branched, smooth ^n4 

 glabrous. Sheaths shorter than the intcrnodrs, 

 usually smooth, ciliate ; ligule short, ciliate ; leaves 

 3 / -5 / long, }& f -yt' wide, erect, truncate or rounded 

 at the sparsely ciliate base, acuminate ; panicle -'- 

 4' long, ovoid, its branches i'-a' long, spreading or 

 ascending; spikelets i" long, about equalling the 

 pedicels, ellipsoid, somewhat pubescent ; first seal* 

 ovate, obtuse, about one-third as long as the spike- 

 let ; second and third scales oblong-ovate, 7-nerved. 

 pubescent, equalling the fourth, which is oral. 

 acute, and slightly more than X" long; palet of 

 third scale usually empty. 



Moist soil, Newfoundland and Ontario to New York, 



Vermont and Minnesota. Sumr 



20. Panicum laxiflorum L,am. Lax-flowered Panicum. (Fig. 262.) 



Panicum laxiflorum Lam. Encycl. 4: 748. 1797. 



Culms erect, %'-i6' tall, simple, pubescent or glab- 

 rate. Sheaths shorter than the internodes, hirsute; 

 leaves 2^-5' long, 2 // -5 // wide, erect, generally nar- 

 rowed at base, long-acuminate, pubescent or glabrate ; 

 panicle 2 / -4 / long, its axis and erect or spreading 

 branches sometimes hirsute ; spikelets about i" long, 

 ellipsoid or narrowly obovoid, strongly pubescent ; 

 first scale minute, i-nerved ; second and third about 

 equal, g-nerved, very pubescent, as long as the shining 

 obtuse minutely apiculate fourth one ; third scale 

 usually with an empty palet. 



Moist soil, Virginia to Kentucky, south to Florida. 

 Also reported from much further north. It has been con- 

 founded with the preceding species. June-Aug. 



