Physic nut (Jatropha curcas) is an upright shrub or small tree that is of the spurge family, Euphorbiaceae. It is native to Mexico, the Caribbean, Central America, and South America. It was introduced to many tropical and subtropical areas for its use as a garden ornamental, and is commonly found in southern Florida, Hawaii, southern Africa (Mozambique, Zambia, Transvaal, Natal), and throughout the warmer parts of Asia. Physic nut also grows in parts of Australia, where it is considered to be an invasive weed.
Physic nut has thick, often greenish bark which exudes a watery sap when cut. It produces small, 5-petaled greenish-yellow flowers, borne in branched clusters. It develops dull yellow, hairless, capsule-like round fruits that turn dark brown when ripe; capsules split open to release two or three black seeds.
Physic nut, like other members of the Jatropha genus contain highly toxic compounds. The main toxins in physic nut are curcin (similar to ricin in the castor oil plant, a type of phytotoxin (Phytotoxins or toxalbumins are large, complex protein molecules that resemble bacterial toxins, and as such are equally as toxic) and a purgative oil. When eaten, the toxins are released from the plant which are known to inhibit protein synthesis. Once the toxins are absorbed into the horse's blood stream, rapid multi-system organ failure follows close behind. Ingestion of physic nut is quickly fatal; within 15 to 20 minutes signs of toxicity start to appear. There is no antidote. Treatment is essentially symptomatic and supportive.
Physic nut is usually avoided by horses, except during periods of drought and/or little other food is available to eat.
- Appetite Loss
- Weight Loss
- Dilated Pupils
- Elevated Heart Rate
CHEMICAL CONTROL: Herbicides for bellyache bush that are being used and/or researched may also be effective on physic nut.
- Langrand J, Médernach C, Schmitt C, Blanc-Brisset I, Villa AF, de Haro L, Garnier R. Poisoning with Jatropha curcas: 24 cases reported to Paris and Marseille Poisons Centers]. Bull Soc Pathol Exot.. 2015.
- Physic Nut Queensland Government Department of Agriculture, Fisheries and Forestry. 2014.
- Early Detection & Distribution Mapping System Available online at http://www.eddmaps.org/; last accessed August 5, 2014. The University of Georgia - Center for Invasive Species and Ecosystem Health.. 2014.
- Liberalino, A. A. A.; Bambirra, E. A.; MoraesSantos, T.; Vieira, E. C. jatropha curcas L. seeds: Chemical analysis and toxicity. Arq Biol Tecnologia, 31(4), 539-550. 1988.