20 University of California rxliUcafions. [botany 



beginnino- with those of the h)wei' edge of the tiiiilxn- helt and 

 pi'oeeediug' to those of the siiinmit. 



Big-cone Spruce {F^(u<lo1snga macrocarpa .) — The Big-cone 

 Spruce, with its slender trunks and long, spreading branches, is 

 found only in a few well watered canons of the west side, below 

 the range of the pines. It is common in the canons of all three 

 forks of the San Jacinto River, running down to an altitude of 

 8000 feet , but is entirely lacking in those canons Avhich open onto 

 the Colorado Desert. That this species requires considera])le 

 moisture is shown l)y the way in which the individuals are 

 huddled along the streams and on north slopes, often the south 

 side and bottom of a caiion being forested with groves of the 

 Big-cone Spruce, while the north side will support only a 

 chaparral formation, as shown in plate iii, where the abrupt ter- 

 mination of the forest will also be noticed. 



Coulter Pine {Pinus Conlieri) . — This pine, remarkable for 

 producing the largest cones known, is commonly met with on the 

 south and west sides of the mountain, where it forms small 

 groves and narrow strips along the lower edge of the Yellow 

 Pine belt. It is also found scattered among the other pines up 

 to 6500 feet altitude on south slopes, l)ut not in the higher 

 valleys nor on those sides of the mountain facing the Colorado 

 Desert. It has been reported* that the seeds, being large and 

 rich, were eagerly sought liy the Indians, who prized them as an 

 article of food; but on account of their strong, oily taste, the 

 Saboba and Santa Rosa Indians do not gather them. The nuts 

 of the Pinon Pine (P. monopJiylla) , which is abundant on the 

 desert ranges to the southeast of San Jacinto Mountain, and of 

 the Parry Pinon (P. Parry ana ) , which grows sparingly in the 

 neighborhood of Toro Mountain, are much preferred. 



Yellow Pine and Jeffrey Pine {Pinus ponderosa and its 

 variety Jeffrey i) f . — This characteristic Transition Zone i)ine is l)y 



*Newberry, Pop. 8ci. Mo. xxxii. 35 (1887). 



tExplanations of some of the irregularities in the boundaries of the Yellow Pine 

 belt will be given in the discussion of Slope exposure, and desert winds. 

 On the life zone map the blue area corresponds to the region in wliicli 

 either this pine or the White Fir is the dominant tree, except tliat in the 

 canyon of the middle fork of the San Jacinto River the Big-cone Spruce is the 

 principal tree, and that there is a narrow fringe of Coulter Pino along the lower 

 edge on the west side. The Wliite Fir liecomes ddiiiinant only in the tapper 

 Transition Zone. 



