Veterinary Medicine Library

Kentucky Coffee Tree (Gymnocladus dioica ( L. ) Koch)

Other common names include: American coffee berry, Kentucky mahogony, nicker treet, stump tree.

| Description | Distribution | Conditions of poisoning | Control | Toxic principle | Clinical signs | References

Kentucky Coffee Tree


Kentucky coffee tree is a large round-barked tree belonging to the legume family and reaches heights of 60 to 100 feet. Its short trunk, 1 to 2 feet in diameter, divides into several large branches that end in contorted, stout twigs. Twice-compound leaves are arranged feather-fashion in 3-7 pairs of leaflets which are more or less ovalish without marginal teeth and 2-4 inches long. The tree is most easity identified in fall and winter for its large deressed leaf scars. The leaf which emerges late in spring is made up of a hundred or more separate oval leaflets arranged on the branches of the rib.

The flower, which blooms in May, is inconspicuous, greenish-white in terminal racemes, and has a tubular base about 1/2 inch long. Male and female flowers are found on the same tree. The fruit is a thick, flat pod, containing 4-7 flat broad seeds with a sticky pulp between them. The pulp dries at maturity and the seeds become olive-brown, 1/2 - 3/4 inches in diameter.

Kentucky Coffee Tree Foliage Kentucky Coffee Tree Bark
      Leaves       Bark


The Kentucky coffee tree grows in moist woods, creek banks, and flood plains. It is mainly found in the Midwest from western Ohio to eastern Kansas and Oklahoma, southern Michigan to northern Alabama and Tennessee. The tree was much planted around farm houses and may now be maintained as ornamentals around newer buildings.

Conditions of poisoning

The leaves, seeds and pulp are poisonous and have affected sheep, cattle, horses, and humans. Sprouts eaten in the spring have produced toxicosis. Pods and seeds on the ground eaten in the fall or winter have produced poisoning. Leaves, young sprouts and seeds with the gelatinous material around them contain the toxin.


Until spring grasses and herbage are abundant, animals should not be grazed in woods where the Kentucky coffee tree grows or where it has been cut and allowed to sprout. Since there are never more than a few of these trees in any woodland, sprouts can be grubbed out periodically, and thus poisoning from them can be prevented.

The pods cling to the tree through the winter and are shed in the spring. To prevent animals from eating the fallen pods, large fruiting trees can be fenced in. Although the tree has little commercial value, it is so rare that unnecessary cutting of it is not recommended.

Toxic principle

The toxic principle of this plant is uncertain. It is possibly the quinolizidine alkaloid, cytisine, which acts like nicotine.

Clinical signs

Clinical signs include rapid onset (within 1 hour) of intense gastrointestinal irritation, profuse diarrhea and straining, vomiting, hypertension, bradycardia, respiratory depression, muscle paralysis, and convulsions. Animals often display depression. Death usually occurs within a day after clinical signs appear.

Other References:

Gymnocladus dioicus entry in Wikipedia

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Last updated on Nov 24, 2009