328 George E. Nichols, 



there seems little question that in former days, in so far as they 

 were then represented in this region, the majority of the plants 

 popularly classed as weeds, and which to-day thrive in a variety 

 of open situations created by man's activity, were restricted to 

 situations such as gravel slides ; boulder plains, sandy flood plains 

 and rocky banks along streams ; and sea beaches. Excluded 

 through competition from situations edaphically more favorable 

 to them, the weeds, which as a group are essentially pioneers, 

 have always flourished in these open situations. 



In addition to the weeds, the grasses are well represented on 

 the upper beach by such species as Ammophila arenaria, Dan- 

 thonia spicata, Pea compressa, Poa pratensis, Festuca rubra, 

 and occasionally Elymus arenariiis, while the sedge, Carex 

 silicea, is seldom absent. Other common herbaceous species 

 here are Fragaria virginiana, Potentilla tridentata, Geranium 

 Rohertianum, Oenothera muricata, Ligusticum scothicum. Cam- 

 panula rotundifolia, and Anaphalis margaritacea. Various 

 xerophytic mosses, notably Ceratodon purpureus, Racomitrium 

 canescens, Brachythecium albicans, Polytrichum juniperinum, 

 and Polytrichum piliferum, thrive in open, gravelly soils, while 

 the foliose lichens, Cladonia rangiferina, C. sylvatica, and 

 Stereocaulon coralloides may also be represented. But the 

 vascular vegetation is by no means restricted to herbaceous 

 forms, for even on rocky and quite exposed parts of the beach 

 there usually are scattered shrubs and trees. In stony situations 

 the plants may secure a foothold in patches of gravel between 

 the cobbles, but very frequently a favorable substratum is created 

 by the decomposition of logs which have been cast up by storms. 

 Of the shrubs, Junipcrus communis dcpressa, Myrica carolinensis, 

 Rubus idaeus canadensis, Empetrum nigrum, Gaylussacia 

 baccata, and Vaccinium pennsylvanicum are quite characteristic 

 of shingle beaches, and Vaccinium Vitis-Idaca grows well in 

 grassy, gravelly or sandy areas. The commonest tree is the 

 white spruce, though the balsam fir is scarcely less frequent. 

 Both of these trees often exhibit a weather-beaten aspect, but 

 this is especially true of the balsam fir. On the beach at English- 

 town (Fig. 29) grow specimens of the latter which measure 

 less than two feet in height but sprawl out on the ground over a 

 radius of more than six feet. Their low stature is due to the 

 repeated killing off of the leader, and this in turn is probably 



