358 GERTRUDE P. NORTON 



The crevice plants common along the shores of the lake are : 



Polemonimum humile R & S. 



Arabis hirsuta. 



Artemisia discolor Dougl. 



Cerastium alpinum L. 



Sedum stenopetalum Pursh. 



Heuchera cylindrica var. glabella T. & G. = H. glabella. 



Viola adunca Smith. 



Geum triflorum Pursh. 



Erigeron speciosus DC. 



Pentstemon spp. 



Aster spp. 



Arctostaphylos uva-ursi L. is the most important plant in form- 

 ing the heath mat and holding moisture. Berberis re-pens Lindl. 

 soon gets a foothold. These two are also pioneer plants in the 

 stony beach succession. The shrubs are also much the same in 

 both successions. The common shrubs are: 



Shepherdia canadensis (L) Nutt. 



Opulaster opulifolius var. paucifiorus T. & G. 



Symphoricarpos occidentalis Hook. 



Acer glabrum Torr. 



Amelanchier alnifolia (Nutt) T. &. G. 



Philadelphus lewisii Pursh. 



Betula occidentalis Hook. On the beach. 



Alnus tenuifolia Nutt. 



Primus demissa Nutt. 



Cornus stolonifera Michx. 



Symphoricarpos racemosus Michx. 



Holodiscus ariaefolia. (Smith) Green. 



Ribes saxosum Lindl. 



Ribes irriguum, Dougl. 



Ribes cereum Dougl. 



Rosa nutkana Presl. 



Rosa pisocarpa Gray. 



B. The stony beach succession 



The beach is composed of rounded water-worn rocks of all 

 sizes from large boulders to the small pebbles of the gravel 

 beaches. Between these stones many plants find a foothold 

 and some large trees. 



