XXXIIIL 
THE BIRCH. 
THE Bircu.— Betula belongs to Monecia Polyandria in the 
Linnean system, and to Betulacee in the natural order of 
plants. The tree is indigenous throughout the north, and on 
high situations in the south of Europe. It is extremely hardy, 
and only one or two other species of trees approach so near 
to the North Pole. There are two tree varieties natives of 
Britain, Betula alba (L.), and B. a. pendula (Smith) ; the latter 
is by far the more valuable and ornamental. When a plant, 
it may readily be distinguished by the touch; its bark being 
covered over with rough exudations, while that of the com- 
mon tree is soft and velvety. Each variety is found exclu- 
sively in some districts, but frequently they are interspersed. 
Throughout the most remote parts of the Highlands of Scot- 
land, the birch is often found in extensive coppice on rocky 
elevations, where no other ligneous plant is to be met with. 
It also stands in glens and ravines, adorning the margins of 
lakes and rivers, where the silvery whiteness of its trunk, and 
the light and airy habit of its spray, form scenes beautiful 
and interesting, even in the absence of every other tree. 
Though it is often found associated with the alder on 
swampy ground, yet few trees more successfully resist drought. 
Adapting itself to various soils and situations, it possesses a 
wider range than any other plant. It is well suited to form 
a cover on ground from which Scotch pine timber has been 
recently removed ; the exuvize which always overspread such 
places, though hostile to plants in general, are favourable to 
the birch, which commonly springs up and becomes the suc- 
cessor of the pine. The common tree, where it grows wild, 
U 
