Culturally and Economically Important Nontimber Forest Products of Northern Maine
Paper Birch, Betula papyrifera
Other names: White birch, bouleau blanc (French), masqemus (Maliseet), maskwi (Mi'kmaq)
Immediately recognizable due to its striking white bark, paper birch is an exceptionally versatile tree. Paper birch is extremely cold tolerant, and has the widest range of any of our native birch trees, spanning from Maine to Alaska. Walking through the woods, you might come across white cylinders of rot-resistant bark left empty as the inner wood rots away. Rot resistance made paper birch bark a favorite material for canoe building, but this is only one of its many attributes. In addition to being aesthetically beautiful, paper birch is sometimes referred to as ‘the medicine tree’, because the leaves, bark, twigs and sap have a long history of use for curative purposes.
Physical Description: A fast growing, small to medium sized tree, paper birch can reach up to 90 feet tall, but is usually shorter. It is easily distinguished by its characteristic white, exfoliating bark that peels off in horizontal strips. Oval-shaped leaves have doubly-serrate margins and pointed tips. Twigs are slender, reddish-brown and dotted with lighter colored enlarged pores called lenticels. Individual trees have both male and female flowers in separate, cylindrical clusters known as catkins.
Habitat: Paper birch is commonly found in mixed hardwood-conifer forests and along riverbanks. It will sometimes form pure stands following disturbances such as logging or fire. Drought and shade intolerant, paper birch needs abundant light to become established. While it grows in a variety of soil types, paper birch does best in well drained soils such as sandy loams.
Uses: Winter bark of birch trees is used to make baskets, containers, decorative hair clips and other utilitarian items. Bark is actually made up of several thin layers, held together by a powdery white substance called betulin, which can be used as a painkiller. In addition, paper birch bark is highly rot resistant, and makes an excellent fire starter, even when wet. The leaves, twigs and sap of paper birch are used to treat skin conditions. Although not commonly done in Maine, the sap of paper birch (as well as yellow birch) may be used to make syrup.
Preparation: Winter bark must be warmed before shaping into containers and other items. Betulin from bark may be extracted in alcohol to make a tincture that is taken internally, or infused into warm oil to make a topical salve.
When to harvest: Harvest birch sap in the spring, leaves and twigs in the spring and summer. Bark can be harvested in the spring for certain applications, but one interviewee noted that in order to obtain a stiff, non-exfoliating bark, harvesting should take place in the winter:
"You have to collect [bark] in the winter, when the sap is down. If you collect it when the sap is up in the spring of the year, it’s very limber. You can make pouches out of it, but it exfoliates. It’ll just come apart layer by layer by layer. You know, you have to lash the edges of it and everything else, and it’s a pain in the neck to try to deal with. You collect [it] when the sap is down, and [it's] stiff."
Tips for Sustainable Harvesting/Management: Do not peel too much exfoliating bark off of any one birch- this can seriously harm or even kill the tree. Instead, first look for bark that has fallen off the tree on its own- it is just as potent. When done correctly (taking care not to peel off the inner bark, including the phloem where the sap runs), harvesting large pieces of winter bark will not harm birch trees. It will simply cause the bark to grow back much darker for several years, like tree in this photograph. But there is a trick to this, so it is best to learn from someone experienced.
Photos by Michelle Baumflek
Species information reference: 3
Information about medicinal plant uses is provided for educational purposes only. It should not be used for self-diagnosis or treatment and is not a substitute for consultation with a licensed physician.
Last Modified: 01/13/2011