White Birch

White Birch (aka. Paper Birch; Canoe Birch; American White Birch)

Betula papyrifera Marsh.

(Betula cordifolia is now a separate species)

Classification

  • Clade: Eudicots/Rosids
  • Order: Beech
  • Family: Cupuliferae (Birch Family)

Height

  • 20-30 m (50-70’)

Leaves

paper birch leaves leaf betula papyrifera

White Birch trees have deciduous, alternate leaves that turn pale yellow in Autumn. The leaves are born on a 3 cm long pubescent petiole. They show pinnate venation, an ovate shape, and double serrated leaf margins. Their matte leaves come to a point, but it isn’t drawn out into the narrow tail-like apex seen in gray birch. The underside of the leaf has lighter coloration with black dots and hairs on the midrib.

Twigs and Buds

White Birch twigs are reddish-brown and spotted or warty when young with short fuzzy hairs. They have numerous white lenticels – pores used for gas exchange. They do not give off the wintergreen smell when damaged like yellow birch does. The brown or green buds are hairless (8 mm).

Crown

The White Birch crown is open and airy with branches that tend to point upwards and not droop down.

Catkins (flowers)

White Birch flowers are classified as catkins. They resemble yellowish-green caterpillars.   White Birch trees are monoecious, having separate male and female flowers on the same tree from mid-April to May. The male catkins are 3-10 cm at maturity – larger than the female catkins. Female catkins are more upright, starting off as 1.5 cm and green and maturing to 2-4 cm “cones” of seeds when mature. The brown cone-like fruits (1- 1¾”) contain numerous winged nutlets. The wings on the nutlets are glabrous/smooth (not hairy like Betula nigra).

Bark

paper birch trunk betula papyrifera

White Birch is best known for its bright white bark that peels off in sheets when mature. This is in contrast to Yellow Birch Betula alleghaniensis that peels in thin shreds. Peeling White Birch bark reveals inner tints of yellow and orange on the underside of the peeled bark. It may be tempting to try to peel off huge sheets of bark, but removing bark that hasn’t peeled off naturally will injure the tree. Gray Birch trees also have white bark when mature, but their trunk has more numerous thick dark lines with dark chevrons (upside-down V’s). Saplings of White Birch have brown bark.

Habitat

White and Gray Birch are both considered pioneer species because they are among the first trees to pop up in cut over and recently burned localities. This is in contrast to Yellow Birch trees that prefer shade. White Birch trees are common in young forests and along roadsides. After ice storms, they can be seen bending toward the ground.

Other Notes

Native Americans and Canadian First Nations use to make Birch Bark Canoes, some capable of making the trip from Cape Breton, Nova Scotia to Newfoundland. Birch is an important source of lumber, pulp, and fuel. Many mammals, including moose, deer, and snowshoe hares consume twigs in winter and ruffed grouse consume buds. They are most noted for their white trunks and peeling bark that stands out beautifully in winter.

Similar Species:

  • Heart-Leaved Birch Betula cordifolia: differentiated from Betula papyrifera by the heart shaped base of its leaf
  • Gray Birch Betula populifolia: differentiated by its long tapered leaf apex

Range

  • Northern United States and Canada

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Biodiversity Exposed