60 



,^ 



Fig. 54. PANICUM VIRGATXJM L. Sp. PL 59. 1753. SWITCH-GR ASS.-A 

 Stout, erect perennial 9-15 dm. (3°-50) high, usually forming large tufts, with 

 strong, creeping rootstocks, long, flat leaves, and ample, spreading panicles 

 15-50 cm. (6'-20') long. Spikelets (a,?)) ovate, acuminate, 4-5 mm. (2"-3i") 

 long: outer glumes acuminate,. the first one-half to two-thirds as long as the 

 .spikelet, the second and third glumes (6) a little longer than the fourth or 

 flowering glume (c).— Sandy soil, usually along streams and about ponds and 

 lakes, Maine and Ontario to North Dakota, Colorado, Arizona, Texas, and 

 Florida. (Mexico.) July to October. 



In luxuriant forms the panicle is very diffuse and 6 dm. (2°) or more in length. 

 In variety conferta Va.sey, Contr. U. S. Nat. Herb. 3 : 36 1892, which occurs 

 along the Atlantic coast, the panicle is narrow and densely flowered. Forms 

 occur with spikelets containing two perfect flowers, and in Texas there is a 

 form with much elongated panicles with the spikelets strictly l-flowered or 

 imperfect. 



This grass is a good sand-binder and on good lands it yields a large amount 

 of hay of fairly good quality. 



