Black Locust

About Black Locust in Alberta

Black locust is a non-native, naturalized North American legume tree that is rare in Alberta and best interpreted through planted, historic, shelterbelt, specialty, or occasional escaped contexts rather than as a native or common municipal tree. It is recognizable by pinnately compound leaves, paired nodal spines, fragrant white pea-flower racemes, flat pods, and dark ropey bark. For ARA, black locust becomes notable when an Alberta specimen is old, large, locally remembered, tied to older planting history, or showing long-term clonal persistence from an earlier planting.

Identification: Leaves are alternate and pinnately compound, with multiple oval leaflets. The leaflets are usually entire or nearly entire rather than sharply serrate, giving the foliage an open, fine-textured look compared with many broad-leaved Alberta trees.

Alberta range and habitat: Black locust is not native to Alberta. Alberta wild or escaped occurrences should be treated cautiously and documented as localized persistence or escape from planting unless stronger evidence is available.