voL. Iv.] Southern Extension of California Flora. 201 
El Rosario to Calamujuet, no considerable range impedes the 
traveler. 
The climate of San Pedro Martir is cold in winter; ice is 
formed on standing water even during the month of May, and 
like most elevated regions the rainfall is greater than on the 
neighboring lower lands. 
The ridges traversing the plateau have a barren, desolate 
appearance, and the large rounded rocks with which they are 
covered form a striking feature of the landscape. Between these 
ridges little brooks arise and find their way at first through 
extensive green meadows, then run rapidly down the very steep 
mountain sides toward the Pacific Ocean. Trees of good size 
are found almost over the whole plateau and in some places are 
very abundant. Pinus /effreyz is the most common, but on the 
ridges a few sugar pines (?. Lamdertiana) and along the streams 
some cedars (Libocedrus) keep them company. In a few locali- 
ties some ‘‘ quaking asp,’’ ‘‘cypress’’ and silver fir can be found 
but they are not common, and at the lower elevations one of the 
pifion pines, P. Parryana, is almost the only tree. Oaks that 
never become large enough to be called trees are plentiful and 
form part of the underbrush that in many places, especially on 
ridges, is so thick as to be almost impenetrable; this chaparral is 
made up mainly of Manzanita and Ceanothus. Other bushes are 
scattered about and often in some localities they are abundant; 
the most noteworthy of these being: Garrya Veatchii at lower 
and Garrya Wrightii at higher elevations, Rhamnus Californica 
in almost every place and a willow common along the streams. 
Our present knowledge of the vegetation of Northern Lower 
California has been mainly derived from several collections by 
Mr. C. R. Orcutt, who has traveled from its northern boundary 
as far south as El Rosario and San Fernando; and from the 
explorations of Dr. Edward Palmer about San Quentin and 
Lagoon Head. Mr. Orcutt has published a catalogue containing 
names of plants growing in Lower California, but no definite 
localities are given. The results of Dr. Edward Palmer’s collect- 
ing have been published by the Department of Agriculture, and 
the California Academy of Sciences has printed in its Proceed- 
ings an account of the plants found on the trip between Magdalena 
