228 



WILLIAM S. COOPER 



The vegetation of the first and oldest moraine merits a de- 

 tailed description. The whole extent is uniformly covered by 

 what is apparently an open forest in which Picea Engelmanni 

 is greatly predominant. Pinus albicaulis and Abies lasiocarpa 

 are occasional. The trees are small, ranging up to thirty feet 

 (6 meters) in height, and in age to 116 years, as far as investi- 

 gation went. They stand on the average perhaps thirty feet 

 apart. No old dead trees were seen. There is nearly every- 

 where between the trees a dense thicket growth made up of 



Fig. 5. Moraine II. Thicket of Salix and Bctula glandulof-a; a single young 

 spruce. In the background, Moraine III. 



several species of Salix, Betula glandulosa, Shepherdia canadensis, 

 and Juniperus sihirica. In occasional openings among the 

 trees and shrubs are patches of herbs and creeping shrubs: 

 Dryas octopetala and Arctostaphylas rubra (Rehder and Wilson) 

 Fernald [Mairania alpina of authors], most abundant; Dryas 

 Drummondii, Hedysarum Mackenzii Arctostaphylos Uva-ursi, 

 Castilleja pallida, Pyrola uliginosa, Moneses uniflora, and a few 

 mosses and cladonias. Humus is fairiy abundant in depressions, 

 but scarce in other places. There are frequent small areas, 



