Scientific Name:
Robinia pseudoacacia
Toxic Parts:
Flower Color:
fields, woodlands, shade, roadsides, wasteareas, ornamental

Geographical Distribution

Black locust  distribution - United States

Black Locust

Robinia pseudoacacia

False acacia, Locust tree, Yellow locust, Robinia
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Black locust (Robinia pseudoacacia) is a fast-growing, deciduous tree. It is native to the Appalachian mountains from Pennsylvania to Alabama, and a secondary population in the Ozark Mountains, in the United States.
It is also often planted as an ornamental tree for its showy aromatic flowers and hard, durable wood. R. pseudoacacia's dark brown bark is rough with interlaced ridges. It produces fragrant white, pink or purple flowers in drooping pea-like clusters. Its fruit pods are smooth, 2 to 4 inches long, and contain 4 to 8 seeds.

Toxic components
All parts of R. pseudoacacia contain a number of toxins, with the most important being robin, a toxalbumin that is toxic to chickens if ingested. Toxalbumins are plant proteins that inhibit protein synthesis, and similar in structure to the toxins found in tetanus and botulinum. The toxin is particularly prevalent in the inner bark, seeds, and leaves. Ingestion of R. pseudoacacia bark, pruned or fallen branches, and young sprouts can result in black locust toxicity in poultry. Symptoms of poisoning present one to two hours after ingestion and result from hemorrhagic enteritis.


  • loss of appetite
  • diarrhea (possibly bloody)
  • weakness
  • depression
  • paralysis
  • death


FIRE CONTROL: Burning has not been effective in controlling black locust. Fire may kill main stems, but this will result in prolific sprouting. Fire also may stimulate seed germination and create favorable conditions for seedling establishment.

BIOLOGICAL: Black locust suffers considerable damage from insects, particularly the black locust borer, Megacylline robinine.

CHEMICAL: Black locust has been effectively controlled with herbicides. Herbicide applications should be most effective in spring, just after leaves are fully expanded. Smaller sprouts may be controlled by spraying all foliage with 4 percent glyphosate. Applying herbicide to freshly cut stumps is probably the most effective means of controlling black locust. Wiping the stump with 100 percent glyphosate within fifteen minutes of cutting should reduce or even eliminate subsequent root suckering