OCT., 1809.1 PLANTS. 137 



Pinus lambertiana l^ouglas. Sugar IMiie. 



Fairly common in most parts of the Transition zone forest of ]»on(lerosa 

 pines, and occurring liere and tliere in tiie immense areas of chaparral 

 that cover the lower slo])es on the south and west sides of the mountain. 

 (See pp. 3L>-3;i.) 



Pimis albicaulis I'.ugeliiiann. White-bark I'ine. 



The timberline tree of Shasta, which it encircles at altitudes ranging, 

 according to slope, from about 7,()i)() up to 8,001) feet, and i^ushing up 

 on the warmest ridges to an extreme elev^atiou of 0,800 feet. In its 

 distribution therefore it tills the IIu<lsonian zone except in places 

 uusuited to tree growth. The only tree competing witli it on Shasta 

 is the black alpine hemlock, which, requiring more moisture, is at a 

 disadvantage and is coutined to special localities, as explained in full 

 under that species. (See pp. o9-4li.) 



Pinus ponderosa Laws. Ponderosa or Yellow Pine. 



The most abundant and characteristic tree of the lower slopes and 

 basal plane of Shasta, where, tilling the Transition zone, it forms a con- 

 tinuous open forest of wide extent. (See pp. 30-32.) 



Pinus murrayana Balf.>ur. Lodge-pole Pine. 



Confined to the northeast quadrant of Shasta, where it occupies the 

 lower part of the Canadian zone. (See pp. 38-.")9.) 



Pinus attenuata Lemmon. Knobcone Pine. 



Common in a limited area in the Transition zone on the south side of 

 Shasta, where it is confined to the lower slopes (from abont 4,000 to 

 5,000 feet altitude) from Panther Creek easterly to between the 

 branches of Mud Creek. (See pp. 33-34.) 



Tsuga mertensiana (Bong.) Carr.' ]>lack Alpine Hemlock. 



A characteristic tree of the Hudsoniau zone, where, however, it is 

 not generally distributed for the reason that the upper slopes of vShasta 

 are in most places too dry for it. It occurs in the same belt with rhius 

 albicauUsj but does not reach so high, and, requiring more moisture, is 

 confined to disconnected localities, usually in canyons and gulches or 

 along the shady sides of buttes or ridges. (See pp. 42-40.) 



Pseudotsuga mucronata (llaf.). Sudw. Douglas Fir or Spruce. 



Common, scattered througli the less arid parts of the forest of pon 

 derosa pines which clothes the lower Transition zone slopes of Shasta 

 and extends away in all directions (see p. 32). A subspecies pendula 

 (Engelm.) Sud worth, with "branches, at least tlie lower ones, very 

 slender and long pendent," has been described from Sisson (Lot. Calif., 

 II, 483, 1880; Sudworth, Check List Forest Trees of U. S., 24, 1898), 

 and is common thence westerly to tlie coast, (See pp. 34-35). 



' For change t)t'iiaiiie from Tsiuja pattmti to 2\ incrtensiana, isee lootnote p. 42. 

 21753— No. 16 18 



