Vegetation of Northern Cape Breton. 



305 



folia, Anaphalis margaritacea, and Solidago hicolor. Most of 

 the weeds found in pastures and along roadsides thrive on gravel 

 slides. Of the herbaceous plants, the grasses, particularly Dan- 

 thonia spicata, commonly play an essential role, contributing to 

 bring about increased stability in the substratum through the 

 formation of a more or less continuous sod. Shrubs, notably 

 Ruhns idacus canadensis, and trees, especially the white spioice, 

 are also important in this respect. 



Figure 15. — Gj'psum ("plaster") outcrop along shore of Ingonish Har- 

 bor. 



Sometimes a xerophytic weed stage in the succession, in which 

 the plants are scattered and the vegetation open, is followed by a 

 definite grass stage, in which the ground is completely carpeted 

 by vegetation. But more commonly trees are present from the 

 outset, and the first continuous plant cover is dominated by trees, 

 which form an open grove, the ground between the trees being 

 grassed over or else occupied by colonial herbaceous species, such 

 as Dicksonia and Anaphalis, or by Riihus. The white spruce 

 invariably stands preeminent among the trees, but there is a 

 scattered representation of balsam fir, paper birch, balsam poplar^. 



