paper birch

paper birch, (Betula papyrifera), ornamental, shade, and timber tree of the family Betulaceae, native to northern and central North America. See also birch.

The paper birch is usually about 18 metres (60 feet) tall but occasionally reaches 40 metres (131 feet); it can also be small and sometimes shrubby in certain conditions. It has ovate to nearly triangular dark green sharp-pointed leaves up to 10 cm (4 inches) long. The leaves are borne alternately along the stems. The bark, brown at first, whitens and peels into paper-thin layers, marked by narrow horizontal pores, or lenticels. On the copper-coloured inner bark, the pores are bright orange. Short pendulous branches and their numerous flexible twigs create a lacy silhouette in winter. The coloration of the twigs and bark varies throughout the tree’s geographical range. The male and female flowers are borne separately on catkins.

Paper birch is fast-growing but short-lived and is susceptible to borers when cultivated south of its natural range. The close-grained almost white wood is used for turned articles, woodenware, pulp, and fuel. North American Indians used the thin water-impervious bark for roofing and canoes.