Fabaceae: Gymnocladus dioicus
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Family Name
Fabaceae
Common Name
Kentucky coffee tree
Description
Gymnocladus dioicus is a large, deciduous, perennial tree with rough bark and growing to 23 m tall. The young twigs are brown, hairless with light brown to orange lenticels. The large leaves are alternate, bipinnate, 30-90 cm long, 30-60 cm wide, with each leaf having 3-7 pairs of pinnae (branches), the branches up to 10 cm long and having 4-7 pairs of leaflets on each branch. The leaflets are 4-7 cm long, 2-3 cm wide, rounded at the base, pointed at the tip with entire margins. The inflorescence consists of terminal racemes or panicles, 5-30 cm long. the flowers have a tubular-obconic hypanthium 6-10 mm long, with 5 oblong sepals, 3-5 petals 4-5 mm long, 10 stamens with those opposite the petals slightly longer than those opposite the sepals. The trees generally produce either male or female flowers,but usually also produce some perfect flowers.The fruit is a flattened, oblong, indehiscent legume 5-15cm long and 3-5 cm wide, containing dark seeds, 15-20 mm in diameter. The fruit is green in the summer and turns purplish-brown as it dries. Kentucky coffee blooms in May and June in woodlands along streams and on open hillsides in southeastern South Dakota. This species has been planted in windbreaks and urban landscapes throughout SD and can be found in many regions as an introduced species.
Horticulture Notes
Seed collection: The fruit mature in in late summer and can be collected when the pods turn dark or after they fall to the ground.
Germination: Dormancy is imposed by the seed coat. Make a small opening with a file or hacksaw before planting.
Light: Full sun.
Soil: Rich, loamy soil is best, but they will tolerate a wide range of soils.
Water: Moist conditions produce the most robust trees, although they can withstand some drought.
Additional Notes
Kentucky coffee is a stately tree that make a dramatic showing as a single specimen or as a component of a woodland planting. The fruit are large and heavy and can be difficult if the trees are planted in a mowed lawn. Planting male trees reduces the number of fruit produced and they are often marketed by commercial nurseries.