VEGETATION OF THE BRAZOS CANYON, 

 NEW MEXICO' 



PAUL C. STANDLEY 



National Museum, Washington, D. C. 



During August and September, 1914, Mr. H. C. Bollman and 

 the writer camped for four weeks along the Brazos River, near 

 the mouth of Brazos Canyon, in Rio Arriba County, New 

 Mexico, some thirty miles south of the Colorado line. A large 

 collection of plants was secured, and a general study of the 

 vegetation was made, some of the results of which are stated here. 



The Canyon is reached from the railroad at Chama, New 

 Mexico, twenty-two miles distant on the Denver and Rio Grande 

 Railroad. The narrow gauge line starting from Alamosa, 

 Colorado, runs southwestward across the plains to Antonito, 

 then turns westward and begins a gradual ascent of the southern 

 spurs of the San Juan Mountains. The adjacent plains are 

 covered chiefly with sagebrush, rabbit-brush (Chrysothamnus 

 sp.), and blue grama (Bouteloua gracilis), no individuals of the 

 former shrubs exceeding perhaps three feet in height. After a 

 short distance, as the hills are reached, the ascent becomes 

 steeper and the road very tortuous. The foothills show many 

 evidences of comparatively recent volcanic activity; there are 

 many isolated cones surrounded by gently sloping lava beds 

 which end in abrupt cliffs. The first trees are seen here, pinyon 

 (Pinus edulis) and cedar (Juniperus scopulorum) , but they are 

 few and scattered. In one place there was noticed a large clump 

 of aspens, which, by some strange anomaly of distribution, are 

 two zones lower than they should be! Straggling pines (Pinus 

 brachyptera) soon make their appearance, and as the tops of the 

 lower hills are reached, the pinyon entirely disappears, to be re- 

 placed by a thin growth of pine. 



1 Published by permission of the Secretary of the Smithsonian Institution. 



179 



THE PLANT « (■HID, VOL. 18, NO. 7, 1915 



