The Dwarf Birch (Betula nana) is a distinct species, which occurs locally in the mountainous parts of Northumberland and Scotland. It is not a tree, but a bush, only two or three feet in height. Its firm-textured, round leaves have scalloped margins and short footstalks.
The foliage of the Birch in autumn turns to a yellow hue. At this period—and, indeed, for a month earlier—there may be
seen beneath the Birch-trees one of the most striking of our toadstools, the Fly Agaric (Amanita muscarius), so-called from its use as the lethal ingredient in the making of fly-papers. From a bulbous base a creamy yellow stem arises, decked about half its height with an ample hanging frill. The upper side of the spreading "cap" is painted with crimson, over which are scattered flecks of white or cream kid—the remains of an outer envelope that was ruptured by the expansion of the cap, and of which the frill represents the lower portion. This species is really poisonous, and the Kamschatkans are said to make their vodka superlatively intoxicating by the addition of this fungus to it. On the trunk of the Birch may sometimes be found a large fungus named Polyporus betulinus, whose root-like portion penetrates the bark and sucks up the sap.
Birch-bark is used for tanning certain kinds of leather, and the peculiar odour of Russian leather is said to be due to the use of Birch in its preparation. The Birch agrees with the Beech in two respects—it is of little value for timber, but as a nurse to young timber-trees it is of considerable importance. Its name is from the Anglo-Saxon beorc, birce, and signifies the Bark-tree.
