The Kentucky Coffeetree, Gymnocladus dioicus, is a tree in the subfamily Caesalpinioideae of the pea family Fabaceae, native to the midwest of North America. The range is limited, occurring from the far south of Ontario, Canada and in the United States from Kentucky (where it was first encountered by Europeans) and western Pennsylvania in the east, to Kansas, eastern Nebraska, and southeastern South Dakota in the west, and to northern Louisiana in the south. It was formerly the state tree of Kentucky.
Varies from 18 to 21 meters (60-70 feet) high with a spread of 12-15 meters (40-50 feet) and a trunk up to one meter (3 feet) in diameter. A 10-year-old sapling will stand about 4 meters (13 feet) tall. It usually separates 3 to 4 1/2 meters (10-15 feet) from the ground into three or four divisions which spread slightly and form a narrow pyramidal head; or when crowded by other trees, sending up one tall central branchless shaft to the height of 15-21 m (50-70 ft). Branches stout, pithy, and blunt; roots fibrous.
Like the Sumac, branches are totally destitute of fine spray; smaller branches are thick, blunt, clumsy and lumpish. While other trees lose their leaves, along their twigs and branchlets are borne the buds, the hope and the promise of the coming year. But the Gymnocladus seems so destitute of these that the French in Canada named it Chicot, the dead tree. Even when spring comes, it gives no apparent recognition of light and warmth until nearly every other tree is in full leaf. The casual observer says it bears no winter buds, but there is a tiny pair, wrapped in down and wool, lying sleeping in the axil of every last year's leaf.
The Kentucky Coffeetree has immense bipinnate leaves, 60-90 cm in length, and about two-thirds as broad. The leaves emerge later in the spring than those of most other deciduous trees, and fall earlier in the autumn.
Among the trees of the eastern United States, there are two others with similarly large leaves: the Honey locust (Gleditsia triacanthos) and the Devil's Walking-Stick (Aralia spinosa). The expanding leaves are conspicuous because of the varied colors of the leaflets; the youngest are bright pink, while those which are older vary from green to bronze.
The bark is ash-gray and scaly, flaking similarly to black cherry, but more so. The flowers are dioecious, and the fruit is a hard-shelled bean in heavy, woody, thick-walled pods filled with sweet, thick, gooey pulp. The shape of the pods varies somewhat: pod length ranges from about 12.7 to 25.4 cm; unfertilized female trees may bear miniature seedless pods. The beans contain the toxin cytisine.
Gymnocladus is of Greek derivation and refers to the stout branches destitute of spray.
It is one of three species in the genus Gymnocladus, the other two being native to eastern Asia. These are Chinese Coffeetree Gymnocladus chinensis in central China, and Burmese Coffeetree Gymnocladus burmanicus in Myanmar.
The name is sometimes hyphenated as 'coffee-tree'; the form 'coffeetree' used here is as used officially by the United States Forest Service.
Widely dispersed, but rare.
This tree usually occurs as widely dispersed individuals or small colonial groups with interconnected root systems. This tree is found in floodplains and river valleys but is also sometimes seen on rocky hillsides and limestone woods. In the northeastern part of its range, seemingly natural groves of this tree are actually associated with known prehistoric village sites.
A Kentucky coffeetree can be found at the Wisconsin Welcome Center on I-90 in Beloit, Wisconsin.
Kentucky Coffeetree is easy to grow from seed. Filing the seedcoat by hand with a small file, and then soaking the seeds in water for 24 hours will ensure rapid germination. Propagation is also easy from dormant root cuttings.
It forms large clonal colonies, reproducing by shoots sprouting from roots.
Prefers bottom lands, and a rich moist soil. This tree is bothered little by heat, cold, drought, insects, disease, road salt, ice, and alkaline soil.
Toxic to animals. See veterinary link: http://www.library.uiuc.edu/vex/toxic/kentucky/kentucky.htm
When Kentucky was first settled by the adventurous pioneers from the Atlantic states who commenced their career in the primeval wilderness, almost without the necessaries of life, except as they produced them from the fertile soil, they fancied that they had discovered a substitute for coffee in the seeds of this tree; and accordingly the name of Coffee-tree was bestowed upon it. But when communication was established with the sea-ports, they gladly relinquished their Kentucky beverage for the more grateful flavor of the Indian berry; and no use is at present made of it in that manner.|||A. J. Downing
In pleasure grounds it is not uncommon, since it is often planted because of its unique appearance and interesting character.
The peculiarly late-emerging and early-dropping leaves, coupled with the fact that the large leaves mean few twigs in the winter profile, make it a tree that is ideal for urban shading where winter sunlight is to be maximized (such as in proximity to solar hot-air systems).
The common name "coffeetree" derives from the use of the roasted seeds as a substitute for coffee in times of poverty. They are a very inferior substitute for real coffee, and caution should be used in trying them as they are poisonous in large quantities.