VOL. IV.] Trees of Soul/iej-ji California. 



339 



Lyonothammis florilnmdtis, Qicercus Engclmanni, and Pimis 

 Torrcyana may be regarded as endemic. The bare projection 

 into this area of the Coast flora is indicated by isolated groups of 

 Myrica Califoryiica and Arbtctus Mcnziesii. yEscjdus Californica, 

 Quercus Douglasii, O. Wislizeni fridesce^is, and Pimis Sabinia7ia, 

 belonging to this flora barely enter our territory from the San 

 Joaquin region, and hence are forced into a narrow belt between 

 the desert and the mountains, over which they have been unable 

 to pass into a region better suited to them. 



DESERT AREA. 



Fremontia Calif ornica^ Chilopsis saligna^ 



Da lea spinas a Yucca baccafa* 



Olneya Tesota Yucca brevifolia 



Prosopis jiclifiora'^ Piniis mojiophyUa 



Prosopis piibescens Jimiperus Califoriiica'^ 

 Acacia Gregg ii^ 



The close connection between this and the intramontane flora 

 is shown by the fact that six of the above eleven species, desig- 

 nated by an *, pass to a greater or less extent into the intra- 

 montane district, while Populus Fremonti ]VisIi.zeni, of the former, 

 passes into this desert. Finns Parryana, which barely enters this 

 area, and perhaps M'asJiingfonia filifem, are prolongations of the 

 Lower Califorman subarea. 



In the following table is shown the distribution in the difi'er- 

 ent areas of the trees, separated according to their sizes: shrubs, 

 and trees that barely enter the district being omitted. It will be 

 seen that development is in accordance with the relative moisture 

 of the different areas. The paucity of arboreal growth in the 

 desert region is especially remarkable, when it is remembered 

 that it is geographically the most extensive of the three. 



