Also known as the White Birch or Canoe Birch

Location: Southeast corner of Thomson Hall, in the planter towards the HUB east of the last entrance steps.

Summary: The Paper Birch is significant in being one of the very few trees native to our state that can also be found growing naturally in such faraway places as the Midwest, Northeast and even down into the Carolinas in the South. It exhibits one of the widest geographical ranges of any tree on the continent, matched only by the Quaking Aspen. How did this tree achieve such breadth of habitat? The Paper Birch develops its numerous small seeds with winglike bracts, a feature that allows them to be spread far and wide on the wind, quickly colonizing open sites where they are available. This process is happening now in the high latitude tundra, where prevailing climate previously kept conditions too harsh for any trees to grow. As the planet warms, Birches are moving north and expanding the reach of the Boreal Forest, though they can be slowed by extensive browsing from deer, elk, and moose. 

An easy identifier of this species is its distinctive papery bark, white and smooth with lateral black lines marking it at regular intervals, peeling back in some places. There are very few look-alikes with which to confuse it. In the city however, the situation can be more difficult. European birches are more popular as an ornamental because they are more easily cultivated and look quite similar. The Paper Birch generally has significantly larger leaves, oval to round and tapering abruptly to a long-pointed tip, the bottoms paler and slightly hairy. Male and female reproductive bodies appear on separate flower structures called catkins, which are long hanging appendages with either a slightly fluffy or a waxy and grainy texture. Here in Washington this species grows only in the northern Cascades, and prefers to establish on recently disturbed land. However, it is quickly outcompeted by larger and more shade tolerant species since it only grows to a maximum height of around 100’. This means that the Paper Birch relies on continued disturbances to open new spaces for its growth.

The Native peoples of our region have a variety of traditional applications for the Paper Birch. The bark is waxy and therefore serves as an excellent fire-starter. The resin, which contains xylitol, is an effective tooth cleaner when chewed. Sap of the species can be drunk raw, and the waterproof nature of the bark is conducive to its use as a roofing material, as well as for buckets and baskets. The wood of the species is an excellent firewood. The lumber industry in the Canadian Pacific Northwest has not been a friend to the Paper Birch. Devalued due to having wood inferior in quality to that of larger conifers, many timber operations have actively worked to eliminate the species under the mistaken notion that Paper Birch was competing with plantation forest trees for resources. This misguided use of cutting and herbicide application ignores the fact that natural forests are diverse for a reason; monocultures of trees attract disease, and diversity of species leads to a healthier ecosystem. Paper Birch hosts fungi in its roots which help to repel other species of fungi that attack Douglas-fir trees. When the Birch is removed from the forest, the other trees are more susceptible, an important lesson to remember as we consider how to manage landscapes in the future.

Historical Background: Native people inland from the west coast use the waterproof papery bark for baskets, canoes, roofing tiles, and more. The wood can also be used as fuel and food. The Athabaskan Indians experienced a buzz from chewing on the birch gum, containing terpenes. Birch resin contains a disinfecting compound called zylitol and is sold as a teeth cleaner. In parts of North America, the sap is used in syrups, wine, and beer.

Native

Native Range: Northern North America: Canada, Alaska, B.C., Washington to Montana, and more

Identifying Features: The most distinctive feature of the birch is its white papery bark, peeling in papery strips and flecked with horizontal dark lines of raised pores. In the wet climate of the PNW it is not uncommon for the bark to be split by sections of rougher almost black thick bark which appears due to an abundance of water allowing the tree to swell. Leaves are ovular to round and toothed, tapering to a point and a dull light green on top, lighter and hairy on the bottom. Flowers appear in the form of long hanging catkins extending from twig tips.

Identifying Features In Depth:

1. Form: Small to medium sized tree, growing up to 100” (30m), often expressing medium apical control and open canopy.

2. Leaves: Oval to round and pointed on the tip with toothed edges and a dull green color on top (paler and hairy on bottom). Leaves are deciduous and alternate, up to 4’ (10cm) long, and occasionally have shallow lobes. Leave often turn a bright yellow in fall.

3. Bark: Birch bark often is generally quite distinctive, papery and white to coppery-brown, peeling in strips and covered with dark brown horizontal lines. Older trees or those in wetter climes may experience deep furrowing and thickening of the bark which exposes dark to almost black bark ridged bark (some of which may be seen on this specimen).

4. Reproductive Bodies: Male and female flowers both appear in separate catkins, hanging protrusions that look somewhat like a bushy cats tail. They are between about 1-2’ (2-4cm), sometimes smaller, and flower at the same time prior to fresh leaves. Catkins break up after flowering and females give way to opposite dual winged nutlets.