74 FLORA OF THE YELLOWSTONE NATIONAL PARK. 



Agropyrum repens, Beanv. 



Pelican Creek, 8000 ft. alt. (624); Upper Geyser Basin (Coulter); Yel- 

 lowstone Lake (Adams). 



Agropyrum Scribneri, Vasey. 



Rocky alpine and subalpine ridges and summits from 9000-10,500 ft. 

 alt. Generally distributed, but nowhere very common (270, 620). 



Hordeum nodosum, L. (H. pratense, Huds.). 



Rather frequent in moist meadows from 7500-9000 ft. alt. (247, 598). 



Hordeum jubatum, L. 



Upper Geyser Basin (Coulter). Yellowstone Park (Forwood). 



Elymus Sibiricus, L. 



Upper Geyser Basin (Coulter). 



Elymus Sitanion, Schult. 



Common over the open dry areas up to 7000 ft. alt. (626). 



CONIFERS. 



Juniperus communis, L., var. alpina, Gaud. 



Rocky bare slopes, up to 8000 ft. alt., especially over the hot spring 

 and geyser areas. Not common. 



Juniperus Virginiana, L. 



Common over the formation of the Mammoth Hot Springs, with 

 Pinus flexilis, and along Gardiner River, for a few miles above its mouth. 



Abies subalpina, Engelra. 



Common throughout, from 6500-9500 ft. alt. 



Pseudotsuga Douglasii, Carr. 



Common up to 9000 ft. alt. Forming a scattered growth on the lower 

 and dryer ridges. 



Picea Engelmanni, Engelm. 



Associated with Abies subalpina. 



Pinus flexilis, James. 



Common on gravelly ridges, from 7500 ft. alt., to the timber line. 



Pinus albioaulis, Engelra. 



With the preceding, but ranging higher. The timber-line tree. 



Pinus Murrayana, Balf. 



Common everywhere. Forming 65 per cent, of the forest area. 



