A deciduous tree up to 12m high, exceptionally 25m, with an oval or rounded crown and bark that is dark brown and deeply furrowed. It suckers freely and often forms thickets. Young stems and branchlets have short spines. Small, bright green leaves above and paler beneath which become yellow in autumn. White, fragrant flowers in drooping sprays from September to November. Reddish-brown pods. The seeds, leaves and inner bark are poisonous seeds.
- Common name Black locust
- Scientific name Robinia pseudoacacia
Alternative common names
False acacia, locust tree, yellow locust (English); witakasia, valsakasia (Afrikaans)
- Where does this species come from? North America
- What is its invasive status in South Africa? Existing legislation: CARA 2002 – Category 2 Proposed legislation: NEMBA – Category 1b
- Where in South Africa is it a problem? All provinces in South Africa
- How does it spread? Seed dispersal and suckering.
- Why is it a problem? Competes with and replaces indigenous species. Dense stands are formed mainly by suckering from the roots and can cover vast areas; stands along watercourses restrict access to water by domestic and wild animals. Poisonous to humans and domestic livestock.
- What does it look like? General description: A deciduous tree reaching up to 25m high, but often smaller with dark brown and deeply furrowed bark. Leaves: Small, bright green leaves above and paler beneath which become yellow in autumn and rounded at the tips. Flowers: White, fragrant flowers in drooping clusters appear from September to November. Fruit/seeds: Reddish-brown pods.
- Does the plant have any uses? Timber, fuel, fodder, ornament, shade, donga reclamation; honey source.
Plant me instead alternatives
Ankle thorn (Acacia robusta), hook thorn (Acacia caffra), weeping wattle (Peltophorum africanum).