348 Trees of Southern California. [ZOE 
Salix lasiolepis Benth. ‘‘ White Willow.’ Arborescent, or 
sometimes a small tree, 20 feet high, the trunk 10 inches in 
diameter. Fis. December and January, many of the leaves 
persisting later. Common by streams and in meadows, from 
3000 feet altitude on the southern slope of the San Bernardino 
Mountains to the Coast. 
Populus trichocarpa T. & G. “Black Cottonwood.” Small 
tree, 40 feet high, the trunk 18 inches in diameter. Fs. March. 
Along mountain streams from 3000 feet altitude on the southern 
slope of the San Bernardino Range to the Coast; also on Santa 
Catalina Island. 
Populus Fremonti var. Wislizent Wats. ‘Spreading tree 80 feet 
high, the trunk 4 feet in diameter; or in the desert region often 
reduced to a straggling, misshapen tree 25 feet high, with trunk 
not exceeding 18 inches in diameter. Fis. February, March. 
Three trees on sandy loam at San Bernardino measure respec- 
tively 12 feet 4 inches, 11 feet ro inches, and 8 feet 5 inches in 
circumference, each being about 70 feet in height. Prevalent 
throughout the entire region, mostly in the neighborhood of 
water. It ascends the southern slope of the San Bernardino 
Range to 2000 feet altitude, and the northern slope to 3500 feet. 
In the San Bernardino and San Jacinto Valleys there were 
formerly extensive groves of large trees now nearly destroyed. 
There is also a narrow fringe of large trees along the Mojave ~ 
River from opposite Hesperia to Camp Cady. Elsewhere in the 
desert region the tree is sparsely present along water courses in the 
cafions, or, where the water is permanent, fringing its borders, as 
at Morongo Creek. 
The species is reported in the roth Census Report (ix, 175) 
as collected at ‘‘Colton, Parry,” but I have been unable to 
detect it, and the late Dr. Parry was not aware of its existence at 
that station.* 
Yucca baccata Torr. Occasionally 15 feet high, with trunk 
less than a foot in diameter, or acaulescent, branches short, stiff © 
* Populus monilifera Ait. Trees referred to this species by Prof. Sargent, 
are in cultivation at Colton as street shade trees, Their origin is uncertain, 
and the species has never been found in a wild state in this region. 
