310 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Dr. Edward Palmer, Lieut. C. F. Pond, and Dr. J. N. Rose—have 
confined their attention mainly to thé coasts. Several important 
mountain ranges along the backbone of the Peninsula—the Sierra de 
Calamahué, Sierra de Santa Lucfa, Sierra de San Francisco, and the 
Sierra de la Giganta—remain unexplored, and they doubtless bear on 
their upper slopes many new and interesting plants. New light on 
distribution is also to be expected, as a number of species now known 
only from near the summits of the Victoria Mountains will probably 
be found to range farther north in the Sierra de la Giganta. 
Lower California was not included in the botanical treatment of 
Mexico in the Biologia Centrali-Americana and has been given no 
place in any general flora of North America, except the as yet incom- 
plete North American Flora. The most important papers dealing 
with the flora of the Peninsula are those published by Brandegee, 
mainly in the Proceedings of the California Academy of Sciences and 
Zoe; by Bentham in the Botany of the Voyage of the Sulphur; and, 
as scattered articles, by Rose, Gray, Watson, Greene, and Hitchcock 
and Chase. 
The flora of the Peninsula is readily separable into two main divi- 
sions: One, identical with that of southern California, which entering 
from the north occupies the northwest coast and the Sierra del Pinal 
and San Pedro Mértir mountain regions, comprising species which 
disappear rapidly to the southward, a few reappearing on the summits 
of the high mountains in the Cape District south of La Paz; the other, 
a more austral flora, derived from or related to that of the adjacent 
mainland coast of Mexico, occupying the entire southern part of the 
Peninsula except the summits of the higher mountains and extending 
northward in a narrowing strip east of the San Pedro Martir Moun- 
tains. Brandegee* states that the greatest change in the flora takes 
place in about latitude 28°. While a rough division may be made in 
the vicinity of this parallel, many austral species reach much farther 
northward along the coast of the Gulf of California. 
The region as a whole is of unusual interest, owing in part to its 
configuration and to the inclusion within its borders of these widely 
differing floral areas. The higher mountains are crowned by familiar 
appearing forests of oak and pine. In the more arid desert sections 
a number of species in adapting themselves to their environment 
have developed into monstrous forms which so prevail as to give the 
landscape an aspect of unreality. Several remarkable genera seem 
to be peculiar to the Peninsula and numerous species belonging to 
genera ranging widely in tropical America are here rather narrowly 
restricted in range. 
* Southern Extension of California Flora. Yoe 4: 199-210. 1893. 
