Tephrosia multifolia
Tephrosia multifolia
Safety & Hazards
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.
Botanical Description
Tephrosia multifolia is an erect, much-branched perennial plant growing from heavy, woody roots. The stems become more or less woody and persist; the plant growing 1 - 2 metres tall[ 1615 Title The American Barbistyled Species of Tephrosia (Leguminosae) Publication Contributions from the Gray Herbarium of Harvard University 170, 1949 Author Wood C.E. Publisher Year 1949 ISBN Description ]. The plant is a potential source of insecticidal compounds and is sometimes cultivated by native peoples for use as a fish poison.