Betulaceae

Deciduous trees or shrubs, widespread in temperate to boreal regions in Northern Hemisphere. Species occur in early successional habitats or wetlands, or as dominant forest trees.

Bark smooth to scaly or papery, sometimes with horizontal markings (lenticels).

Leaves alternate, oval and simple, with toothed edges and veins from both sides of the central vein.

Male and female flowers occur separately on the same plant in early spring, the male flowers in conspicuous elongated drooping catkins and the female flowers drooping or erect, in catkins, heads, or conelike structures. Sepals none or two-parted. The fruit is an achene, a nut, or two-winged (samara); shape of lobes in the seed wings is an identifying characteristic among birches.