58 UNIVERSITY OF MISSOURI STUDIES [206 



A form, undoubtedly native, with somewhat narrower 

 leaves, slenderer stems, which are branched from the root, 

 the sheaths less hairy and less prominently papillose, the 

 spikelets acute and greenish, or the uppermost purplish, 

 occurs in swales in the plains region, 5100-5500 ft. (Daniels, 

 985). An analogous, or perhaps identical form, gathered by 

 P. A. Rydberg in the sand-hills of Nebraska, is referred by 

 him (somewhat doubtfully) to P. capillare agreste Gatt. with 

 the remark that the form is named var. occidental* in the 

 National Herbarium with no published description (Rydberg 

 U. S. Nat. Herb. Cont. 3, 186). 



Throughout Southern Canada and the United States. 



43. P. virgatum L. Tall switch grass. 



Frequent on the plains and mesas, 5100-6000 ft. (Daniels, 



397)- 



Maine to Assiniboia; Florida to Arizona. 



43^. P. Tennesseense Ashe. Tennessee panic-grass. 



Collected by Jones at South Boulder (Hitchcock and Chase). 

 Maine to Minnesota and Utah ; Georgia to Arizona. 



44. P. Scribnerianum Nash [P. scoparium Auct, not Lam.]. 

 Scribner's panic-grass. 



Common among rocks on the foot-hills, but occurring oc- 

 casionally on the mesas and plains, 5400-7000 ft. (Daniels, 99). 



Maine to British Columbia; Virginia to Arizona and 

 Oregon. 



32. ECHINOCHLOA Beauv. Barnyard grass. 



45. E. Crus-galli (L.) Beauv. [Panicum Crus-galli L.]. 

 Cockspur grass. 



Common in waste places and along irrigation ditches, 

 5100-6000 ft. (Daniels, 741). 

 Europe, thence to North America. 



45a. E. Crus-galli mutica (Vasey) Rydb. 

 With the type (Daniels, 997). 

 Range of the type. 



