338 Trees of Southern California. [ZOE © 
PHYTOGRAPHIC RELATIONS. 
The region here under consideration presents three distinct 
floras; that of the mountains, that of the desert, and that of the 
district between the main range and the sea coast, which may be 
called the intramontane. Adopting Dr. Merriam’s phytographic 
areas, the mountain flora belongs to the Nevadan subzone, the 
desert to the Sonoran proper, and the intramontane to the Cali- 
fornian, or in a more general view the whole territory may be 
regarded as a part of the great Sonoran life area, into which pro- 
jects, along the axis of mountains, a narrow arm of the Boreal. 
These relations become evident from a tabulation of the trees, 
and would be further enforced by an examination of the distribu- 
tion of the shrubs and herbs. 
MOUNTAIN AREA, 
Acer glabrum Pinus albicaulis 
Prunus emarginata mollis Pinus ponderosa 
Cornus Nuttallit Pinus Jeffreyi 
Salix flavescens Pinus Coultert 
Quercus Kelloggii Pinus Murrayana 
Castanopsis chrysophylla Abies concolor 
Pinus Lambertiana Libocedrus decurrens 
This zone is connected with the intramontane flora by a belt 
of Pseudotsuga macrocarpa, and with the desert flora by a belt of 
Cercocarpus ledifolius and Juniperus occidentalis. Negundo Calt- 
Sornica and Pinus tuberculata also occur on the edge of this zone- 
INTRAMONTANE AREA. 
Rhamnus Californica Juglans rupestris 
R. Californica tomentella _ Quercus chrysolepis 
Acer macrophyllum Quercus agrifolia 
Negundo Californicum Quercus lobata 
Prunus ilicifolia Alnus rhombtfolia 
Prunus demissa Populus Fremonti Wislizent 
Cercocarpus parvifolius Salix laevigata 
Heteromeles beg Salix lasiolepis 
Sambucus glau Salix lasiandra lancifolia 
Umbellularia Ca, lifornica Platanus racemosa 
