Gray Birch

Betula populifolia Marshall

Description

Gray birch (birch family, Betulaceae) is a deciduous, fast-growing (2 to 5 feet per year ⁴) tree that grows to 40 feet, often with several trunks.¹ It has white  bark a with dark, inverted Vs below the branches. ¹  The bark does not readily peel in horizontal strips.  The alternate leaves are triangular with long tips, 1.5 to 3 inches long with two sizes of teeth on the margin, and 6 to 9 pairs of veins ending in the large teeth. ¹  Twigs are rough warty. ³  Male and female flowers are on the same plant. ³  Yellowish male flowers are in catkins 1.5 inches long and female flowers are green in upright catkins 0.5 inches long. ³  The fruits are small cone-like structures. ³

Bark of gray birch.  Maryland Biodiversity Project, J. Solem ²

Leaves of gray birch.  Maryland Biodiversity Project, J. Solem ²

Distribution

Gray birch extends from Southeastern Canada to Virginia and is scattered west to Illinois. ³  It prefers growth in cool regions where summer temperatures are 75 F and snow covers the ground throughout the winter. ³  In Maryland gray birch is listed as S1 (highly state rare) and may have been introduced.  Records show its presence in Garrett, Allegany, Baltimore, Howard, Cecil and Kent counties. ²

Native distribution of gray birch.  Wikimedia Commons ⁵

Wildlife Importance

Seed-eating birds such as the American Goldfinch,  Pine Siskin and Black-capped Chickadee feed heavily on gray birch. ^4,7  Ruffed Grouse and White-tailed Deer feed on twigs and buds. ⁷  Beavers feed on the bark and wood. ⁷  Many insects use the leaves, fruits and wood for nourishment. ⁷  Caterpillars of the Morning Cloak and  Compton Tortoiseshell butterfly use gray birch. ⁷

Economic Importance

The wood of gray birch is soft but can buy used to make toothpicks, clothes pins and spools. ⁶ It can also be used for making paper. ⁶

Threats

The bronze birch borer can weaken the tree and the birch leaf miner can also affect gray birch. ³  It is intolerant of fire, but quickly recolonizes burned areas. ⁴

Interesting Facts

• Gray birch is frequently planted on mine spoils which is expanding its range. ⁷

References

1. Oregon State University Landscape Plants:  Betula populifolia
2. Maryland Biodiversity Project:  Gray birch
3. Missouri Botanical Garden: Betula populifolia
4. USDA NRCS Plant Fact Sheet:  Gray birch
5. Wikimedia Commons:  Betula distribution maps of North America
6. Illinois Wildflowers:  Gray birch
7. plant.org:  Gray birch

Contributed by J. Hull

Towson University Glen Arboretum