Vegetation of Northern Cape Breton. 359 



red maple ; but associated with these, in varying abundance, may 

 grow paper birch and yellow birch, white ash and black ash 

 (Fraxinus nigra), and occasionally white pine. 



The vegetation of wooded swamps may include various of the 

 herbaceous and shrubby species already listed, but in addition to 

 these a number of forms occur here which have not yet been 

 mentioned, although some of them may likewise grow in open 

 swamps. Such, for example, are the following: 



Phegopteris polypodioides Maianthemum canadense 



Aspidium novehoracense Coptis trifolia 



Osmiinda Claytoniana Mitclla nuda 



Taxus canadensis Oxalis Ac eto sella 



Carex trisperma Viola renifolia 



Carex tenella Circaea alpina 



Carex leptalea Camus canadensis 



Carex folliculata Linnaea borealis americana 



Clintonia borealis Aster acuminatus 



C. THE ASSOCIATION-COMPLEXES OF UNDRAINED SWAMPS 



Occurrence of bogs along the coast. — In the vicinity of Bad- 

 deck and in other localities where the clayey nature of the soil 

 retards drainage, bogs may develop in shallow depressions of 

 any description. They develop best, however, here as in regions 

 farther south, in fairly deep, closed, water-filled depressions. 

 Raised bogs, such as occur along the coast in New Brunswick 

 (see Ganong '98), and which are extensively developed on the 

 interior plateau in northern Cape Breton, are apparently absent 

 along the coast. The finest series of bogs discovered in the low- 

 land is situated near the mouth of the Barrasois River, where in 

 a tract of woodland less than a square mile in area there are 

 six or eight fine examples. All of these occupy closed basins, 

 presumably kettle holes in the drift, but possibly drift-covered 

 sink holes, range in size from less than one to more than three 

 acres, and bear a remarkable resemblance to certain Connecticut 

 bogs (see Nichols '15, pp. 202-217). The following observa- 

 tions relate more particularly to this collection of bogs, which 

 can be regarded as representative. 



The floating mat and its association-types. — The early stages 

 of bog development are best exhibited in the largest of these 



