The Kentucky coffeetree, Gymnocladus dioicus,[4] is a tree in the subfamily Caesalpinioideae of the legume family Fabaceae, native to the Midwest and Upper South of North America. The seed may be roasted and used as a substitute for coffee beans; however, unroasted pods and seeds are toxic. The wood from the tree is used by cabinetmakers and carpenters. It is planted as a street tree.
Gymnocladus dioica, commonly called Kentucky coffeetree or coffeetree, is a tall deciduous tree with rough, scaly gray-brown bark and large bipinnate compound leaves. It is native to the Midwest, primarily southern Michigan and Ohio southwest to Iowa, Kansas, Oklahoma and Arkansas. It grows 60-80β (less frequently to100β) tall with an irregular open oval to obovate crown. In Missouri, it typically occurs in low or rich woods, bluff bases and along streams (Steyermark). Large leaves to 3β long, divided into 3-7 pairs of pinnae, with individual leaflets (1-3β long). Leaflets are blue-green in summer, turning an undistinguished yellow in fall. Larger trees typically cast light shade. As the specific epithet suggests, the species is dioecious (separate male and female trees). Greenish white flowers appear in late spring (May-June). Male flowers in clusters to 4β long. Female flowers in panicles to 12β long. Female flowers are fragrant. Fertilized female flowers give way to flattened reddish brown pods (to 10βlong) which ripen in October and persist well into winter. Native Americans and early American settlers, especially those in the Kentucky territory, roasted and ground the seeds to brew a coffee-like beverage (albeit no caffeine), hence the common name. Native Americans roasted the seeds for food. Seeds are very toxic prior to roasting, and should never be eaten fresh off the tree. Trees are late to leaf out in spring and are one of the first to drop leaves in the fall.