Gymnocladus dioica
Kentucky Coffee Tree
a perennial woody deciduous member of the Gymnocladus genus in the family Leguminosae.
Taxonomy and growth
- Family
- Leguminosae
- Genus
- Gymnocladus
- Life cycle
- perennial
- Foliage
- deciduous
- Woodiness
- woody
- Growth rate
- slow
- Height
- 20 m
- Spread
- 15 m
- Fertility
- self sterile
- Flower type
- dioecious
Uses
Toxicity
Toxicity warning. The historical record reports a hazard for this plant. Do not use it to decide which parts are safe to eat or use medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
The ripe seed contains hydrocyanic acid. This toxin can be destroyed by thoroughly heating the seed for at least 3 hours at 150°c[5]. The seed contains saponins[9]. Although toxic, these substances are very poorly absorbed by the body and so tend to pass through without causing harm. They are also broken down by heat so a long slow baking can destroy them. Saponins are found in many plants, including several that are often used for food, such as certain beans. It is not advisable to eat large quantities of food that contain saponins. Saponins are much more toxic to some creatures, such as fish, and hunting tribes have traditionally put large quantities of them in streams, lakes etc in order to stupefy or kill the fish[K].
Edible uses
This section contains historical Plants For A Future notes marked noncommercial.
Seedpod - raw or cooked. The roasted seeds can be eaten like sweet chestnuts[13]. The pulp is sweet[6][18]. A flavour like caramel[9]. The pods are up to 25cm long and 5cm wide[11]. The roasted seed is a caffeine-free coffee substitute[6][2][15][19][8]. A bitter flavour[10]. Thorough roasting for at least 3 hours at 150°c is necessary in order to destroy the poisonous hydrocyanic acid that is found in the seed[5]. Seed - roasted and eaten like a nut[3][8][10]. The seed contains toxic substances, see notes above.
- Product or use
- Coffee
- Plant part
- Seed
- Plant part
- Seedpod
Medicinal uses
Historical medicinal uses. These records describe reported uses. They do not establish safety or effectiveness. Ask a qualified health professional before using any plant medicinally.
This section contains historical Plants For A Future notes marked noncommercial.
The pulverised root bark is used as an effective enema[8][9][13]. A tea made from the bark is diuretic[9]. It is used in the treatment of coughs due to inflamed mucous membranes and also to help speed up a protracted labour[9]. A snuff made from the pulverized root bark has been used to cause sneezing in comatose patients[13]. A tea made from the leaves and pulp from the pods is laxative and has also been used in the treatment of reflex troubles[9]. A decoction of the fresh green pulp of the unripe fruit is used in homeopathic practice[18].
- Product or use
- Homeopathy
- Product or use
- Miscellany
Material uses
This section contains historical Plants For A Future notes marked noncommercial.
The fruit is high in saponins and is used as a soap[7]. The leaves are used as a fly poison[9]. Trees are planted on the spoil tips of mines to stabilize and reclaim the soil[7]. Wood - coarse-grained, heavy though not hard, strong, very durable in contact with the soil, finishes to a fine lustre. A handsome wood, it weighs 43lb per cubic foot and is used for cabinet work, furniture, construction, fencing etc[15][16][18][4][11][12].
- Product or use
- Insecticide
- Product or use
- Soap
- Product or use
- Wood
Ecology and functions
- Ecosystem niche
- Canopy, Secondary canopy
Environment
- Range
- Eastern and Central N. America - New York to Tennessee, west to Arkansas and South Dakota.
- Habitat
- Prefers deep rich soils in bottomlands, deep ravines and moist lower slopes[11].
- Light
- full sun
- Shade tolerance
- no shade
- Water
- moderate
- Hardiness
- Zone 4+
- Soil textures
- sandy, loamy, clay
- Soil pH
- acid, neutral, alkaline, very alkaline
- Drainage
- well drained
- Tolerances
- drought
- Tolerates Nutritionally Poor Soil
- No
- Drought
- tolerant
- Salinity
- tolerant
Propagation
This section contains historical Plants For A Future notes marked noncommercial.
Seed - best sown in a greenhouse as soon as it is ripe[7]. The seed can also be sown in early spring in a greenhouse[17]. Scarification and pre-soaking the seed for 24 hours in warm water, especially if it has been stored, will improve germination[7]. Make sure the seed has swollen after soaking, soak it again if it has not and, if it still does not swell, try filing away some of the seedcoat but be careful not to damage the embryo. As soon as they are large enough to handle, prick the seedlings out into fairly deep individual pots and grow them on in the greenhouse for at least their first winter. Plant them out into their permanent positions in late spring or early summer, after the last expected frosts. Consider giving them some protection against the cold for their first couple of winters outdoors Root cuttings 4cm long and 1cm thick in a greenhouse in December[7]. Plant the roots horizontally in pots[17]. Good percentage.
Cultivation
This section contains historical Plants For A Future notes marked noncommercial.
Requires a deep rich soil and a sunny position[1][7]. Tolerates drought, atmospheric pollution, salt and limestone soils[7]. A very cold-hardy plant, tolerating temperatures down to about -30°c[7]. A very ornamental[1] but slow growing tree[2], it rarely flowers in Britain, requiring more summer heat than it usually gets here[2][7]. Trees in the wild seldom live longer than 100 years[11]. The tree has a light canopy so does not cast much shade[7], making it a good tree to use for the top canopy of a woodland garden. Dioecious. Male and female plants must be grown if seed is required. Unlike most members of the Leguminosae, his species does not form nodules of nitrogen-producing bacteria on the roots[14].
References
F. Chittendon. RHS Dictionary of Plants plus Supplement. 1956 Oxford University Press 1951-00-00
Bean. W. Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement. Murray 1981-00-00
Yanovsky. E. Food Plants of the N. American Indians. Publication no. 237. U.S. Depf of Agriculture.
Hill. A. F. Economic Botany. The Maple Press 1952-00-00
Facciola. S. Cornucopia - A Source Book of Edible Plants. Kampong Publications 1990-00-00 ISBN 0-9628087-0-9
Hedrick. U. P. Sturtevant's Edible Plants of the World. Dover Publications 1972-00-00 ISBN 0-486-20459-6
Huxley. A. The New RHS Dictionary of Gardening. 1992. MacMillan Press 1992-00-00 ISBN 0-333-47494-5
Weiner. M. A. Earth Medicine, Earth Food. Ballantine Books 1980-00-00 ISBN 0-449-90589-6
Foster. S. & Duke. J. A. A Field Guide to Medicinal Plants. Eastern and Central N. America. Houghton Mifflin Co. 1990-00-00 ISBN 0395467225
Lauriault. J. Identification Guide to the Trees of Canada Fitzhenry and Whiteside, Ontario. 1989-00-00 ISBN 0889025649
Elias. T. The Complete Trees of N. America. Field Guide and Natural History. Van Nostrand Reinhold Co. 1980-00-00 ISBN 0442238622
Britton. N. L. Brown. A. An Illustrated Flora of the Northern United States and Canada Dover Publications. New York. 1970-00-00 ISBN 0-486-22642-5
Moerman. D. Native American Ethnobotany Timber Press. Oregon. 1998-00-00 ISBN 0-88192-453-9
Diggs, Jnr. G.M.; Lipscomb. B. L. & O'Kennon. R. J Illustrated Flora of North Central Texas Botanical Research Institute, Texas. 1999-00-00 http://artemis.austincollege.edu/acad/bio/gdiggs/NCTXpdf.htm
Uphof. J. C. Th. Dictionary of Economic Plants. Weinheim 1959-00-00
Usher. G. A Dictionary of Plants Used by Man. Constable 1974-00-00 ISBN 0094579202
Sheat. W. G. Propagation of Trees, Shrubs and Conifers. MacMillan and Co 1948-00-00
Sargent. C. S. Manual of the Trees of N. America. Dover Publications Inc. New York. 1965-00-00 ISBN 0-486-20278-X
Saunders. C. F. Edible and Useful Wild Plants of the United States and Canada. Dover Publications 1976-00-00 ISBN 0-486-23310-3