Kentucky coffee tree

Article By:

Graves, Arthur H. Connecticut Agricultural Experiment Station, New Haven, Connecticut.

Davis, Kenneth P. School of Forestry, Yale University, New Haven, Connecticut.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.362700

A large, strikingly distinct tree, Gymnocladus dioica. The Kentucky coffee tree usually grows to a height of 80–90 ft (24–27 m), but sometimes attains a height of 110 ft (33 m) and a diameter of 5 ft (1.5 m). The species name, dioica, means that the tree is dioecious; that is, male and female flowers are on different individuals. It grows from eastern Nebraska, Kansas, and Oklahoma to southern Ontario, western New York, and Pennsylvania, and southwestward to Louisiana. It can be recognized readily when in fruit by its leguminous pods, which contain hard, heavy, red-brown seeds (Fig. 1), which were used by early settlers as a substitute for coffee—hence the name coffee tree. The branches are stout and thick, and the bark has thin, twisted ridges. The leaves are twice pinnate, and the winter buds, sunken in the bark, are superposed, two or three together (Fig. 2). Never a common tree, it is cultivated sometimes in parks and gardens of the eastern United States and northern and central Europe. It is used occasionally as a street tree. The wood is hard and reddish, and is used for construction. It is durable in contact with the soil and is used also for railroad ties and fence posts. The Janka hardness for the Kentucky coffee tree is 1390 lb-force (630 kg-force); its density is 37 lb/ft³ (593 kg/m³). See also: Fabales; Forest and forestry; Tree

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