. Results of a biological survey of mount Shasta, California. Probably 9,300 to 9,500would be a fair average for their upi)er limit on the warmer southerlyslopes. On the cold northeast slope, just south of Brewer Creek, they descend21753—No. 16 6 42 NORTH AMERICAN FAUNA. [N-n. 16. on a biirrou ])umice slo])e to 7,000 lect, where, sparingly mixed withalpiue hemlocks, they meet tlie iii)]>er limit of Sliasta liis and silverpines. ]Jlack Alpine nE:\(K {rsinia mrrtensland^).—lUit the wliite-bark pine, although the dominant and most widely distributed tree ofthe up])er timber belt, is not th
. Results of a biological survey of mount Shasta, California. Probably 9,300 to 9,500would be a fair average for their upi)er limit on the warmer southerlyslopes. On the cold northeast slope, just south of Brewer Creek, they descend21753—No. 16 6 42 NORTH AMERICAN FAUNA. [N-n. 16. on a biirrou ])umice slo])e to 7,000 lect, where, sparingly mixed withalpiue hemlocks, they meet tlie iii)]>er limit of Sliasta liis and silverpines. ]Jlack Alpine nE:\(K {rsinia mrrtensland^).—lUit the wliite-bark pine, although the dominant and most widely distributed tree ofthe up])er timber belt, is not the only tree, for in i)laees it is mixedwith or re])laced by the black alpine hemlock. Shasta is a Yevy drymountain, and yet the white-bark pine thrives on its driest slopes andgrows among the bare, naked blocks of lava where tree life seemsirai)ossible. The hemlock re(iuires more moisture, and therefore is at adecided disadvantage. It never reaches as high as ri)nis !(((uJisand attains its best development along the lower border of the Hud-. FlG. 24. — alpine lieiiilocks mar Scjuaw (i sonian /one, where it occurs iu disconnected sheltered localities—usually in canyons or on the shady east or northeast sides of buttes orridges, where there is more moisture than on the exposed slo])es. Sincethese shady easterly slopes are always cold, tlie hemlocks that occupy This is the species heretofore coiiiinoiily laiowii as Tsin/a jxtltoni ov Ti^mia patio-niana. It lias been recently discox-crod lliat the name Tniuja mcricnsiana, commonly:ij)]ilie(l to the racilif lowland hemlock, wiis first <;iveii to the jjrcseut aljiiiie 8])ccies,iiecessitatinj; a most nnhajiiiy change oi name. Fortunately, however, the commonKnglish names of the two ami Ihcir widely diflerent /one ranges—one restricted tothe low Transition licit ncai- the inast, the other to the high lludsoniau zone on theloftiist mountains—may ]ire\ciit the confusion that otherwise would result from thechange of n
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Keywords: ., binomial=tsugamertensiana, bookcentury1800, booksubject, taxonomy
