The poplar tree has two main species that are common to the boreal forest: balsam poplar (or black poplar) and trembling aspen (or white poplar). Balsam poplar is the smaller of the two species, growing up to twenty-five metres tall if it is very old, but usually reaching heights of ten to fifteen metres. Balsam poplar grows in moist areas, particularly on the banks of streams or rivers. It has thick pointed leaves that are deep green on top, but pale green beneath, and bark that is dark and deeply furrowed when the tree matures.
Trembling aspen favours rich, moist soils, and is widespread throughout the forests of the northwest. It is usually the first tree to colonize an area of the forest that has been destroyed by forest fire. It can range from twenty to thirty metres in height. The bark of the trembling aspen is smooth and white, while its leaves are almost circular in shape, and flutter at the slightest breeze, hence the “trembling” name.
Balsam poplar had a number of medicinal uses among various Aboriginal Peoples of the northwest. The layer of sap under the bark of the tree could be chewed and applied to open wounds. Drinking the sap was said to treat diabetes and high blood pressure. When boiled, both bark and sap could be made into a tea to treat asthma. While not used extensively for construction, the wood of the balsam poplar was used to craft smaller items, such as children’s toys and utensils.
Trembling aspen had similar traditional uses to the balsam poplar, medicinally speaking. It could also be used as an emergency food source. The white material layered under the bark of the trembling aspen could be scraped off and eaten, and the leaves could be boiled to make a tonic used by elderly for treatment of liver and kidney problems.