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Dr. Arthur P. Kelley, of Rutgers University, addressed the 

 Club on "Plant communities of the Medicine Bow Mountains 

 in Wyoming". 



The Medicine Bow Mountains lie in south-eastern Wyoming, 

 within the borders of the Medicine Bow National Forest, and are 

 accessible by an excellent auto road from Laramie. The historic 

 Overland Trail skirts their base, and Fort Laramie, famous 

 during Indian days, is nearby. Rising sharply, a great meta- 

 quartzite ridge towers to 12,000 feet elevation above sagebrush 

 plains ; in reality the great mountain mass consists of an elevated 

 plateau or mesa upon which rises the final ridge, caused by a great 

 fault scarp. 



Upon this mountain mass are communities of plants which 

 exist in more or less definite zones according to elevation. The 

 elevation, of course, influences climate, for at the base the scanty 

 rainfall supports but sagebrush and cactus while at the summit 

 snow lies the year round. In between are two zones, the lower of 

 which is more arid and is clothed with pines, the upper more rainy 

 and clothed with spruce. Thus we may distinguish alpine, sub- 

 alpine, montane and plain communities. 



Within these larger communities are smaller and still smaller 

 ones; and these go through a regular process of development or 

 succession. Thus a lake is gradually invaded by sedges until a 

 meadow is formed, starred with blossoms, and the lake is gone; 

 and the meadow becomes dotted with spruce trees which grow up 

 into a forest. In each zone which has a definite climate the plant 

 communities go through such a succession and end with one 

 which we might call a climax. Thus the climax stage of the 

 alpine zone is a scrubby juniper community, the junipers being 

 shorn by the storms to a dwarf form so thickly branched that 

 one may walk on top of them as on a lawn. The alpine com- 

 munities are especially attractive because of the curious plants 

 growing in crevices of the rocks, quickly blossoming in the few 

 weeks of summer. Their colorings are marvelous — blue, purple, 

 gold, cream, and purest white. 



Arthur H. Graves, 



Secretary. 



