Features: The scientific name of the Kentucky Coffeetree (Gymnocladus dioica)means "naked branch", because this tree spends up to 9 months of the year without leaves! When the doubly compound leaves appear in late spring, they are very large, up to one metre long and 60 cm wide. A legume, the Coffeetree produces long, dark brown leathery pods that contain up to seven rounded, dark, hard-coated seeds. Although early settlers are reported to have used the seeds as a coffee substitute, this practice is highly inadvisable as the beans contain poisonous substances called saponins. The Kentucky Coffeetree prefers sunny locales in rich woodlands and at the edges of marshes. However, it tolerates a wide variety of growing conditions in full sun.

Status: Threatened Provincially and Nationally

Range: This species is rare throughout its range, which extends from the southern Great Lakes region east to New York in scattered localities, south to Oklahoma and Arkansas, and west to Kansas and Nebraska. Its primary range is in the United States midwest. In Canada, it occurs only in extreme southwestern Ontario, at the northern limits of its natural range. Coffeetrees planted for horticultural purposes survive far beyond this range, however. There are fewer than 20 natural stands of mature trees (containing fewer than 200 mature individuals) in southwestern Ontario. Range Maps

Threats: Although this species has probably always been rare in Ontario, extensive deforestation and wetland drainage have occurred in the southwestern tip of the province. It is reasonable to conclude that a number of Coffeetree stands have been lost. As this is a "tough", fast-growing species that has been grown successfully in Ontario beyond its natural range limits, the question might be posed: "Why is it not more common?" One possible answer lies in the species' reproductive biology. Individual trees produce either male or female flowers, rarely both. In order for fertile seeds to be produced, pollen from flowers on male trees must be transported to flowers on female trees by insects. Range expansion in Ontario is probably hampered because of infrequent seed production, resulting from widely spaced trees, and the fact that both male and female trees must become established in a new locality in order for seed production to occur.

Protection: Under Ontario's Endangered Species Act 2007, the Kentucky Coffeetree is listed as a threatened species. The Act prohibits harming or killing the species. The Natural Heritage component of the Provincial Policy Statement under Ontario's Planning Act provides for the protection of significant habitat of threatened species. As many Coffeetree stands in Ontario are on private land, the interest of landowners will be essential if conservation efforts are to succeed. The potential exists to establish new stands of the species in suitable protected areas as it can be easily propagated from seeds and root cuttings.

Text Sources: Ambrose 1982; Waldron 1997

Last Modified Date: October 2008