Black Cottonwood (Populus trichocarpa)

Lushootseed names:

 Cottonwood: q̓ʷədiʔq̓ʷ (k-wah-dee-k)

Cottonwood Tree: q̓ʷədiʔq̓ʷac (k-wah-dee-k-watz)

Location: Standing in a grove of trees just to the north of Paccar Hall, this tree is on of the largest in terms of trunk size.

Summary: This specimen may represent the only mature Black Cottonwood growing on the main body of campus, although others grow in the nearby Union Bay Natural Area. Why might such a large and versatile tree with a wonderful shady canopy not have more specimens around campus? The answer lies in the weak nature of a Cottonwood's trunk and branches. Black cottonwoods are adapted to live mainly along rivers and streams, which are in a constant state of flux, eroding and flooding. Due to the dynamic nature of this species' preferred habitat, it has adapted to a lifestyle of quick establishment and fast growth, sometimes attaining heights of 60’ in less than ten years. While this fast growth ensures the tree will have access to sunlight and be able to create offspring before the next flood, growing fast is usually not the same as growing strong. The trunks and branches of P. trichocarpa are notorious for their often-catastrophic failure during storms, which is fine in the forest but a bit more dangerous in a high-density city like Seattle. They are, therefore, generally shunned as urban trees, in spite of their great beauty and capacity for providing wonderful shade and habitat.

Black Cottonwoods are trees of great importance for restoration in modern times. Not only does the species’ fast growth enable it to rehabilitate deforested patches of land quickly, this tree is also amazingly simple to propagate. By taking small cuttings from the branches of a live tree and burying them, one can create a new poplar, the buried branch sending out new roots and shoots to create a clone of the original. Cottonwood forests are usually very productive wildlife communities. They provide ample nesting sites for a multitude of birds, and a favorite food for beavers, which may be seen consuming the bark of these trees along the shores of Lake Washington just east of campus. The tree also has significant cultural importance as a traditional source of food and medicine. The inner bark of the species is edible, and the resin present in the buds of the tree can be turned into a powerful anti-inflammatory and antiseptic medicine. The tree also contains salicylic acid (like Aspirin), so is used for pain relief. The Cottonwood’s fast growth also makes it a great candidate for producing the pulp needed to mill paper.