1908] Grinnell—Biota of the San Bernardino Mountains. 3) 
Salix Bigelovii Torrey. 
This was a conspicuous and easily recognized species, by its 
peculiar growth in circumscribed clumps, with bare grayish 
trunks and leafy crowns. The leaves were grayish green and 
obovate. This willow appears to be wholly confined to the upper 
half of the Transition zone, and occurred south of the Santa Ana 
from 6500 feet (sparingly) up to 9000 feet. It grew in pockets 
on the mountain side, and at the edges of the cienagas. The 
above determination was made by Dr. J. N. Rose. (See pl. 14.) 
Salix lasiandra Bentham. 
This willow grew to large trees, a grove of which grew on the 
upper Santa Ana a mile below the mouth of the South Fork, 
6000 feet altitude. I saw black willows elsewhere along the 
upper Santa Ana, and on Fish ereek at about 6900 feet. (Be- 
sides the three willows here listed I saw others, but their names 
are in doubt.) 
Alnus rhombifolia Nuttall. 
Alders grew luxuriantly along the water-courses of the Pacific 
slope of the mountains. Hither side of the upper Santa Ana was 
lined with alders, meeting overhead to form a dense and almost 
continuous canopy. In deep canons, such as Mountain Home 
creek, sheltered from the wind, these trees became exceedingly 
tall and straight. In broad open valleys they were more scrubby. 
Alders extended up Fish creek, Lost creek, and South Fork 
canons to about 7500 feet altitude, where they became smaller, 
and within a short distance disappeared. (See pl. 22.) 
Castanopsis sempervirens (Kellogg) Dudley. 
The chinquapin was an important brush plant occupying a 
belt overlapping the Transition and Boreal zones, only the upper 
margin of the former and the lower division of the latter. South 
of the Santa Ana all along the lofty San Bernardino ridge, it 
formed dense but low thickets from 8500 to 10,000 feet altitude. 
At the latter elevation it was prostrate and more scanty. On 
the north side of Sugarloaf above 8500 feet it was abundant. as 
it also was in the vicinity of Bluff lake and eastward. In the 
