Arkansas Tree Database

Black Locust

Black Locust

Scientific name:

Robinia Pseudoacacia


40'-60' tall, up to 80' tall


alternate, pinnately compound, 8"-14" long with 7-19 oval leaflets, with somewhat triangular spines at the base of the leaf, untoothed


creamy white with yellow blotch inside, pea-shaped, in drooping 4"-8" clusters, sweetly scented


flat pod, 3"-5" long and containing 4-10 seeds

Fall Interest:

yellow; deciduous


sun; dry to moist soil; adaptable; can fix atmospheric nitrogen in the soil


locust borer


aggressive spreader and good for land reclamation; important source of honey; wood exceptionally resistant to decay, used for posts, crossties



twigs and branches have sharp strong spines, borne in pairs at the nodes; root bark was chewed by Native Americans to induce vomiting or relieve toothache; a valuable source of spring nectar, flowers are visited by bees, butterflies, and hummingbirds; all parts of the tree are considered toxic; native to Arkansas


Click thumbnail to enlarge images

Black locust bark on trunk Black locust bark on trunk Black locust paired spines at stem node Black locust flowers Black locust flowers in 4"-8" raceme Black locust flowers in 4"-8" raceme Black locust leaf, pinnately compound and 8"-14" long Black locust seeds in pods Black locust seed pods Black locust root nodules Black locust stem, showing spines in pairs at nodes Black locust tree in bloom