Coriaria arborea var. arborea

Poisonous plant

Tutu is the classic poisonous plant of NZ. It is a widely distributed native species found throughout New Zealand, particularly along stream banks and in regenerating native bush. Some of the first animals introduced to NZ by Captain Cook in the 18th Century were poisoned by it. The plant caused losses in cattle and sheep. All parts of all Coriaria species are poisonous except the succulent black, soft fleshy petals surrounding the seeds (the seeds themselves are also poisonous). Poisoning is usually through eating the seeds, berries or poisonous honey.

Tutin acts on the central nervous system leading to symptoms of nausea, vomiting, burred vision, weakness and seizures or convulsions and can lead to a comatose state. Breathing is usually affected, so too is memory.

Toxic honey is contaminated as a result of bees visiting tutu (Coriaria arborea) with honey dew being excreted onto the leaves of the plant by the tiny toxic sap sucking passion vine hopper (Scolypopa australis) and then bees gathering the honeydew.

Tutin, and its derivative, hyenanchin are extremely toxic to humans, but only a few areas in NZ regularly produce toxic honey. These include the Coromandel Peninsula and Eastern Bay of Plenty and the Marlborough Sounds.

A number of people have been killed, incapacitated and hospitalised over the years from eating toxic honey. The last recorded case from commercial honey was in 1974 involving 13 patients. There have been 9 cases since 1974 with the last known poisonings occurring in 1991 in the Eastern Bay of Plenty area and 2008 in the Coromandel.

See also the 2008 news item about toxic honey causing illness in the Coromandel.

Click on this link for more information about Poisonous native plants.