1908] Grinnell—Biota of the San Bernardino Mountains. 29 
part of the whole flora of the region. Thesspecies listed were 
those which came to my attention either because they were food- 
plants of certain birds or mammals, or because their distribution 
seemed to coincide with that of certaim animals. It is to the 
plants that one must turn for the surest indexes of the zonal 
position of a locality. Though familiar with the appearance of 
the plants in the field, I know nothing of systematic botany, and 
must here acknowledge complete dependence upon the informa- 
tion as to names, given me by specialists in that department. 
During each of the three seasons I took in specimens of such 
plants as interested me, and in all some 600 sheets were obtained. 
Duplicate sets were given to the authorities who named the spe- 
cies. I am indebted for the determination of species to Miss 
Alice Eastwood, of the California Academy of Sciences, to Dr. 
Harvey M. Hall of the University of California, to whom I am 
also grateful for reading the manuscript of this portion of my 
report, and to Dr. J. N. Rose, of the United States National 
Museum. 
Juniperus occidentalis Hooker. 
The western Juniper was a common tree in the more arid parts 
of the region. It occurred sparingly on the upper Santa Ana, 
and more abundantly around Sugarloaf and the high ridge to the 
eastward as high as 9500 feet altitude, where very large examples 
were seen. In Bear valley it was conspicuous, because often 
isolated on the sage flats. Around Doble and Gold mountain and 
down the desert slope past Cactus Flat, 6000 feet altitude, it was 
common. I should consider it a native of arid Upper Sonoran 
and Transition. (See pl. 4:.) 
Abies concolor (Gordon) Parry. 
The white or silver fir was what may be called a typical Upper 
Transition tree. It was abundant alone the north side of the 
San Gorgonio-San Bernardino ridge up to 9000 feet altitude on 
south-facing slopes, and down as low as 5500 feet altitude alone 
the upper Santa Ana on shaded north slopes. It was an import- 
ant component of the woods around Bluff lake and all alone the 
