> 
ax 
ba 
8 
Associated in small depressions near melting snow are Trillium ovatun, 
Erythronium grandiflorum, Polygonum bistortoides var. linearifolium, 
Ranunculus Eschscholtzii and Trollius laxus var. albiflorus. 
Talus slopes at high elevations are frequent, resultant from the disin- 
tegration of cliffs. The most common entrant on these is Xerophyllum 
tenax and associated with it is often Polygonum alpinum, Arabis Sparsi- 
ee 
flora, Spiraea corymbosa, Amelanchier florida, Juncus Parryi, Vaccinium 
membranaceum, V. scoparium and Prunus enarginata. After soil is estab- 
lished by these agents, the slope is often Slowly taken over by Abies 
lasiocarpa and Tsuga Mertensiana. Xerophyllum tenax is characteristic 
of high ridges and open slopes. 
Frequent on rounded peaks or in moist depressions at hi elevations 
= ] 
there occur pastures of varied size in which Luzula glabrata is almost 
the sole innabitant or very abundant. 
in a few restricted areas on northerly moist benches at higher eleva- 
tions , (somet imes) pure stands of Picea Engelmannii with abundant repro- 
eee eee This species, with Abies lasiocarva, often descends to 
the margins of boggy meadows ét elevations 4s low as 2000 feet. 
Pinus elbicauvlis is usually found. It con- 
™ 
hest elevation 
monly cccupies ridges above cO00C feet, intermixed with Abies lasio- 
caroa or Tsuge Mertensiana, or “corms pure stancs. Associated with it 
are often Touné Vaccinium myrtillus, Xerophyilum tenéx, Vaccinium sco- 
slsbella, Luzula glabrata and Juncus Parry:. 
mo 
neriun, Menziesic. 
