The bark of all birches is characteristically marked with long
horizontal lenticels, and often separates into thin papery plates,
especially upon the Paper Birch. It is practically imperishable, due
to the resinous oil which it contains. Its decided color gives the
common names Red, White, Black, and Yellow to different species.
The
buds form early and are full grown by midsummer, all are lateral, no
terminal bud is formed; the branch is prolonged by the upper lateral
bud. The wood of all the species is close-grained with satiny texture
and capable of taking a fine polish; its fuel value is fair.
The leaves of the different species vary but little. All are
alternate, doubly serrate, feather-veined, petiolate, and stipulate.
Apparently they often appear in pairs, but these pairs are really
borne on spur-like two-leaved lateral branchlets.[1]
