Eastern Cottonwood

About Eastern Cottonwood in Alberta

Eastern Cottonwood, at the species level Populus deltoides, is represented in Alberta most defensibly by plains cottonwood, Populus deltoides subsp. monilifera, a native southern Alberta riparian tree. The Alberta story is not a generic eastern-forest tree story; it is a prairie river and floodplain story tied to large old cottonwoods, flood-dependent regeneration, and southern river corridors. For ARA, wild mature plains cottonwoods can be among the most important heritage deciduous trees in southern Alberta.

Identification: Leaves are broad, triangular to deltoid, coarsely toothed, and attached to flattened petioles that make the leaves flutter in wind. Basilaminar glands near the leaf base can be useful in the species complex, especially when separating Populus deltoides from other poplars and cottonwoods.

Alberta range and habitat: Alberta's native Populus deltoides is primarily a southern riparian tree, best treated as plains cottonwood. It belongs to major river valleys, floodplains, and alluvial systems rather than upland forest.