American Mountain Ash

About American Mountain Ash in Alberta

American Mountain Ash is a small deciduous tree or large shrub in the rose family, valued for white spring flowers, compound leaves, red-orange fruit clusters, and bird habitat. It is native in Canada overall, but the Alberta evidence supports treating it as a planted ornamental tree rather than a native wild Alberta species. For ARA, notable examples are most likely to be older or unusually successful planted rowans in parks, yards, institutional landscapes, and curated urban settings.

Identification: Leaves are alternate and pinnately compound, usually with 9-17 sharply toothed leaflets. The compound leaves give the tree a fine, feathered texture compared with simple-leaved ornamental trees. Leaf undersides may appear paler, and new growth can be somewhat downy before becoming smoother.

Alberta range and habitat: American Mountain Ash is native farther east and northeast in North America and is native in Canada overall, but Alberta wild occurrence was not confirmed. Alberta evidence points to planted use rather than native stands.