Gray Birch

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

A close-up view of the white bark of a Gray Birch tree. Below an old branch opening, there's a dark, flat, rounded triangle shape taking up its side. The bark also has small, cut-like lines running down it, revealing the darker gray layer underneath.

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

Three green, triangular Gray Birch leaves with sharp ridges along its sides hang from light green stems.

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 range of this species delineated in light green on a gray map of the northeastern United States and Canada. Native range includes eastern Pennsylvania most of New Jersey, the eastern half of New York, all of Connecticut, Massachusetts, Rhode Island, Vermont, New Hampshire, and the southern half of Maine. The range also includes a small band along the border of Quebec and the United States, and include most of eastern New Brunswick and all of Nova Scotia. Small pockets of native range are dotted throughout Pennsylvania, with a couple of small populations in Virginia and western North Carolina.

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

Towson University