Tephrosia virginiana
Tephrosia virginiana
Safety & Hazards
Contact with the plant can cause dermatitis in sensitive people[1]. The seeds are toxic[1]. The plant contains rotenonoids and has been used traditionally as a fish poison - rotenoids kill or stun the fish making them easy to catch, but the fish remain perfectly edible for mammals. Rotenonoids are classified by the World Health Organization as moderately hazardous. They are mildly toxic to humans and other mammals, but extremely toxic to many insects (hence their use as an insecticide) and aquatic life, including fish. This higher toxicity in fish and insects is because the lipophilic rotenonoid is easily taken up through the gills or trachea, but not as easily through the skin or the gastrointestinal tract. The lowest lethal dose for a child is 143 mg/kg, but human deaths from rotenone poisoning are rare because its irritating action causes vomiting. Deliberate ingestion of rotenone, however, can be fatal. The compound decomposes when exposed to sunlight and usually has an activity of six days in the environment.
Cultivation Details
Tephrosia virginiana is hardy to about -25° when given a suitable position[2]. A deep rooted plant, requiring a dry to moist light or medium very well-drained soil in a sunny position[2]. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby[2].
Propagation
Pre-soak the seed for 12 hours in warm water and then sow in a greenhouse in spring. Prick out the seedlings into individual pots when they are large enough to handle and grow on in the greenhouse for their first winter, planting out in the following spring or early summer. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-21. <temperate.theferns.info/plant/Tephrosia+virginiana>
Pollinators
Insects
References
- [1]A Field Guide to Medicinal Plants. Eastern and Central N. America. — Foster. S. & Duke. J. A. · Houghton Mifflin Co. · 1990 · ISBN 0395467225 ↩︎A concise book dealing with almost 500 species. A line drawing of each plant is included plus colour photographs of about 100 species. Very good as a field guide, it only gives brief details about the plants medicinal properties.
- [2]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [3]The American Barbistyled Species of Tephrosia (Leguminosae) — Wood C.E. · 1949 ↩︎
- [4]The Leguminosae; A Source Book of Characteristics, Uses and Nodulation — Allen O.N.; Allen E.K. · University of Wisconsin · 1981 · ISBN 0-333-32221-5 ↩︎An amazing and comprehensive work, giving a brief guide to the many genera of the family Fabaceae and also the principle uses of the genus.
- [5]Gray's Manual of Botany.Eighth Edition — Fernald. M. L. · American Book Co.; New York · 1950 · ISBN 0442222505 ↩︎A bit dated but a good and concise flora of the eastern part of N. America.
- [6]The History and Folklore of North American Wild Flowers. — Coffey. T. · Facts on File. · 1993 · ISBN 0-8160-2624-6 ↩︎A nice read, lots of information on plant uses.
- [7]Native American Ethnobotany — Moerman. D. · Timber Press. Oregon. · 1998 · ISBN 0-88192-453-9 ↩︎Very comprehensive but terse guide to the native uses of plants. Excellent bibliography, fully referenced to each plant, giving a pathway to further information. Not for the casual reader.
- [8]Earth Medicine, Earth Food. — Weiner. M. A. · Ballantine Books · 1980 · ISBN 0-449-90589-6 ↩︎A nice book to read though it is difficult to look up individual plants since the book is divided into separate sections dealing with the different medicinal uses plus a section on edible plants. Common names are used instead of botanical.