16 BOTANY. 
of its having been long known. It was first settled by the Spaniards soon after the dis- 
covery of this part of the continent. It is well wooded and watered. We had not time to 
examine the timber of the mountains in this vicinity on account of our hasty march. In the 
preceding portion of our route we mentioned the trees seen at Cajon Pass ; and as we passed 
down Cajon creek we saw the California sycamore, (Platanus Mexicanus,) alder, (Alnus,) of 
quite a respectable size, and cotton-wood ; and as we proceeded on to the plains there were 
collected two other species of oaks which grew in great abundance; neither of them in fruit, 
however, at the time we passed. The base of the mountains to our right was covered with this 
timber. 
Grass and wild oats are abundant in the valley from one end to the other. Nature has 
peculiarly favored this region, and adapted it to grazing, by furnishing it with a succession of 
plants, which come on in regular succession ; so that no trouble or expense is experienced in 
raising cattle and horses, except for salting and keeping them tame. The first crop is called 
** pin-grass,”” (Erodium cicutarium,) belonging to the family of Geraniacee ; the next is a crop 
of leguminous plants, such as Medicago, and several species of clover, (Zrifolium,) which 
spring up one after another; then follow wild oats (Avena) and other species of grass in great 
abundance. 
At the Cajon valley there are several species of cactaceee, both flat-jointed and cylindrical, 
with a woody axis, which are somewhat different from those passed in the Colorado valley. 
At Cocomungo, in this valley, we found vast and dense patches of an Opuntia, nearly akin 
to O. Engelmanni, which had the appearance of having been introduced ; but whether it really 
is so, cannot be determined. The Spanish Tuna, (Opuntia Tuna,) which is cultivated for its 
fruit, forms hedges fifteen or twenty feet high. The Indians and Mexicans are very fond of 
the fruit, which serves them for food during its season. 
At the mission of San Gabriel we saw large orchards of orange trees laden with its golden 
fruit, which ripens perfectly in the open air, (22d May.) We could say nothing more favorable 
of the climate of this delightful region. "There are many other exotic plants that would succeed 
with very little trouble; the tea plant especially we think would do well, and deserves a 
thorough trial. The grapes cultivated here are said to be equal to any in the world. 
