Natural History of Nova Scotia, 653 



growth ; and the roots of the maple are never injured when 

 the stem is killed by fires, or cut down ; and, consequently, 

 always throw out a number of shoots, which, in the course of 

 one summer, after a fire, form clumps of shrubbery 3 ft. or 

 4 ft. in height. The white birch and the poplars, always 

 with a mixture of fir and maple, and often of oak and spruce, 

 form the shelter of the white pine. The hemlock is sheltered 

 by the yellow birch, mixed with fir, spruce, and maple ; and 

 these young groves of birch, and all other groves of young 

 hardwood, are protected on the open side, if such there should 

 be, by a thick belt of firs. Wherever, also, the edge of an 

 old grove of beech or fir is exposed, by the destruction of the 

 wood on the adjoining barren, a very thick belt of fir springs 

 up ; which, in the course of a few years, completely shelters 

 it from the wind and sun. The red larch, or hacmetac [Pursh 

 has given Pinus pendula, now Zarix pendula Lamb., as the 

 " hacmatack ; " and Lkrix microcarpa Lamb, is given, in one 

 work, as the red larch], forms a portion of the shelter for black 

 spruce on rocky barrens. The alder, mixed with withrod, 

 dwarf willows, and shoots from the roots of the red-flowering 

 maple, serves to shelter the white birch, poplar, spruce, fir, 

 and hacmetac. The seedling plants of the alder require the 

 shelter of the kalmia, or of the evergreen, and dead leaves of 

 the common plants of poor land; the hawkweeds [//ieracium 

 sp.], the golden rods, the trailing evergreens, the Mitchells, 

 &c. The kalmias, spiraeas, and rhodora [22hodora canaden- 

 sis L.~] have seeds so minute, that the young plants are 

 scarcely visible to the naked eye, and perish in a few hours if 

 exposed to sun or wind. They are sheltered by the may- 

 flower and other plants. The rhodora (the shrub which 

 produces such an abundance of red flowers in the spring) 

 usually vegetates upon the roots of the horse fern, which it 

 finally destroys. The tough creeping roots of the mountain 

 tea serve to bind the rotten wood and the coarser parts of the 

 turf, and prevent them from being displaced by frost. The 

 creeping vines of the linnea cover broken stones, and preserve 

 the moisture of the small portion of turf or soil beneath them. 

 The lichens and mosses are necessary to the other plants of 

 barren soils : their roots form a sward, and they prevent the 

 ground from freezing early, or to a great depth, and from thaw- 

 ing easily when frozen ; while naked patches of poor gravel 

 freeze suddenly, and, thawing with every mild spell in winter, 

 imbibe a great quantity of water, which is retained by the 

 frozen subsoil, till, freezing again, by its increased volume it 

 so shakes and overturns the ground, as to throw T out the roots 



