322 



George E. Nichols, 



bluff itself, a plant cover is rapidly developed. Eqnisetum 

 arvense and Agrostis alba maritima frequently, and Elymus 

 arenarins occasionally are conspicuous pioneers, but for the most 

 part the pioneer species here are largely weeds and slump plants. 

 Sometimes a grassy sod is formed, but more commonly Almts 

 mollis (Fig. 23) comes in along with the grasses and forms 

 a dense thicket. Sooner or later, trees appear, mostly white 

 spruce and paper birch, and these may supersede the alders, 

 forming a low, scrubby forest along the bluff. The trees often 

 exhibit the same one-sided habit as those on headlands. 



Figure 24. — Exposed rocky headland at White Point ; scrubby forests, 

 mostly white spruce ; in right foreground a characteristically one-sided 

 spruce. Photograph by Dr. L. H. Harvey. 



Owing to the abundance of seepage water, soil conditions 

 locally, especially along clay bluffs, may be unusually favorable 

 for plants, and in such places it is a common thing to find the 

 vegetation made up in large part of species which are ordinarily 

 associated with swamps or flood plains : such, for example, as 

 Alnus incana, Calamagrostis canadensis, Junciis effusus and 

 various sedges, Hcraclcuvn lanatum, Eupatontni pnrpnreum, and 

 Aster piiniceus. Associations of this sort, though mentioned 

 here for convenience, should naturally be classed under the 

 hydrarch series. 



Association-types of exposed headlands. — Bleak headlands like 

 the one pictured in Fig. 24 are a prominent feature of the coast, 



