Btish — North American Species of Triodia. 77 



ing scales about 6 mm. long, obtuse at the scabrous apex , 3- 

 nerved, the lateral nerves vanishing at or below the apex, the 

 mid-nerve usually excurrent as a short tip. Barrens and 

 rocky prairies. Common south westward. June to October . 

 Perennial. 



Upper Sonoran area. Missouri and Kansas to Arkansas, 

 Indian Territory, Oklahoma, Texas, Colorado and Arizona. 



Type locality not ascertained. 



Specimens examined.— Missouri : Eagle Rock, Barry County, Bushy 



639, 1896 Texas: Dallas County, Beverchon, 446; same locality. Bush, 



1134, 1900; same locality, Beverchon, 1109, 1900 — San Antonio, Bush, 842, 

 1901.— Kansas: Chautauqua County, Hitchcock, 919. 1896 — Colorado: 

 Caaon City, Brandegee, 360, 1874. 



EXPLANATION OF ILLUSTRATIONS. 



Plates X.-XI. 



Plate X.— Tiiodia congesta, habit, reduced one-half, andspikelet, X 2. 

 Plate XL— Triodia Nealleyi, habit, reduced one-half, and spikelet, X 3 • 



Issued June 9,1902. 



