Paper birch (Betula papyrifera)

Paper birch photograph; ? MN DNR, Welby Smith
Paper birch leaf closeup photograph; ? MN DNR

Form

Height 65' to 70', diameter 14" to 20"; twigs dull orange or red during first winter, later become brown; open crown; grows singly or in clusters.

Bark

Thin, papery; becomes pure white with age, marked by many pores or "lenticels"; separates into thin sheets that often roll up; bark thickens on old trees, becoming dark (nearly black) and scaly.

Leaf

Simple, alternate on stem, length 2" to 3"; oval or heart shaped, pointed, rounded at base, irregularly toothed; becomes thick and leathery in texture; dull on upper side and yellowish green on lower side; turns light yellow in autumn.

Fruit (seed)

Nutlet resembles a cone and contains many tiny seeds; nutlets are tightly grouped in a 1" to 1-1/2" long catkin; ripens in August and September.

Range

Generally abundant throughout the state except the southwest; shade intolerant, fast growing.