FLORA OF THE SANTA CATALINA MOUNTAINS. 39 
fornia and only one of them has been reported from Colorado. These 
plants are: 
Quercus oblongifolia. Arctostaphylos pungens, Cal. | Pinus cembroides, Tex. 
Quercus arizonica. Garrya wrightii, Tex. Mimosa biuncifera, Tex. 
Quercus emoryi, Tex. Dasylirion wheeleri, Tex. Chrysoma laricifolia, Tex. 
Vauquelinia californica. Agave palmeri. Eriogonum wrightii, Col., Tex. 
Juniperus pachyphlea, Tex. | Nolina microcarpa. 
The Encinal likewise comprises a number of plants which reach their 
maximum occurrence on the Great Plains or else possess areas of dis- 
tribution which are chiefly to the northeast of Arizona. Among these 
are Bouteloua obligostachya, Bouteloua hirsuta, Bouteloua curtipendula, 
Polygala alba, Artemisia ludoviciana, Artemisia dracunculoides, and 
Stephanomeria runcinata. 
The elements which are common to the flora of California are few, 
as is true of the Desert, and are almost solely comprised in the follow- 
ing: Zauschneria californica, Amorpha californica, Bouvardia triphylla, 
and Brickellia californica, not to add Arctostaphylos pungens, which has 
its maximum extension southward into Mexico. The Encinal contains 
a number of forms which have been but recently segregated from well- 
known species, among them Rhus racemulosa, Rhamnus ursina, and 
Prunus virens. So little is known of the ranges of these species that 
it is impossible to state in how far they may represent contributions 
from distant floras or to what extent they represent forms that have 
been differentiated in the Arizona-Sonora region. 
The only northern element in the Encinal flora seems to be that 
which has been mentioned as occurring also in the Great Plains, while 
the mountainous regions of Colorado and Utah have contributed even 
fewer species than has the Californian region. 
THE FOREST FLORA. 
The Forest region of the Santa Catalinas possesses strong floristic 
affinities both with the Mexican cordillera and with the Rocky Moun- 
tains of Colorado and their southern extension in New Mexico. The 
majority of the plants which take a conspicuous place in the vegetation 
of the Forest are members of northern genera. Many of these members 
are identical with Rocky Mountain species, while many others have 
their chief range in the mountains of northern Mexico. There are also 
representatives of a few genera which are distinctively Mexican, a few 
species of northwestern relationship, and a few apparently of restricted 
range in the desert mountains of Arizona and New Mexico. 
As examples of the large Rocky Mountain contingent in the Forest 
flora may be mentioned: 
Abies concolor. Acer glabrum. Erigeron macranthus. 
Pseudotsuga mucronata. Jamesia americana. Heuchera rubescens. 
Disporum trachycarpum. Symphoricar pos oreophilus. Brickellia grandiflora. 
Salix scouleriana. Frasera speciosa. Gilia thurberi. 
Populus tremuloides. Dugaldia hoopesii. Achillea lanulosa. 
