24 University of California Pnhlieations. [botany 



of the White Fir, while on the higher slopes the Limber Pine is 

 very common, as noted below. The Murray Pine reaches its 

 normal development in the well watered valleys of the higher 

 part of the mountain, such, for example, as Round Valley and 

 the small, pocket-like valleys between Deer Springs and the main 

 peak, where this tree, with its straight, thin-barked trunks ris- 

 ing like collonades from the valley floors, forms quite dense for- 

 ests of greater or less extent. Beneath these forests there is but 

 little under-brush and the ground is thickly strewn with . the 

 smp.ll cones. Less symmetrical trees cover the drier slopes at 

 higii altitudes and run out along the north and east sides of the 

 highest ridges. The undulating, rock-strewn plateau between 

 San Jacinto and Marion Peaks, all of which has an altitude of 

 over 10,000 feet, is scantily forested with both the Murray and 

 Limber Pines. Here they take on those characters so common 

 to trees growing under similar conditions, — the low, thick trunks, 

 the twisted and gnarled branches reaching far out on the one 

 side and scarcely present on the other, and the general dwarfed 

 appearance always assumed by trees on exposed, wind-swept 

 ridges at high altitudes. (See plate vi) . 



It was noticed that on certain slopes many of the trees were 

 branched from near the ground, sometimes as many as six nearly 

 erect trunks arising from a single base. This is probably due to 

 a lack of soil moisture since it occurs only in trees growing along 

 the edges of forests bordering on barren areas, while on the 

 cooler slopes, kept moist by lingering snow-di-ifts, and in the 

 basins and canon bottoms the trunks are undivided. 



Limber Pine {Finns ffexilis) . — With the exception of the 

 Murray Pine this is the only tree that inhabits the higher slopes 

 and ridges of San Jacinto Mountain. It does not occur in the 

 lower part of the range of that species and may be considered as 

 a Hudsonian Zone species, as far as its distribution on this 

 mountain is concerned, although it occasionally reaches over 

 into the Canadian. It grows on the rocky summits just west of 

 Lake Surprise, at 9200 feet altitude, and extends down the west 

 side of Marion Peak nearly to Deer Springs. The lowest point 

 at which it was found Avas on the ridge between Marion and 

 Tahquitz Peaks, at an altitude of 8200 feet. 



