Japanese star anise

The Japanese star anise (Illicium anisatum) is a tree similar to Chinese star anise. It is highly toxic, therefore it is not edible; instead, it has been burned as incense in Japan, where it is known as shikimi. Cases of illness, including "serious neurological effects, such as seizures", reported after using star anise tea may be a result of using this species.

I. anisatum is native to Japan. It is similar to I. verum, but its fruit is smaller and with weaker odor, which is said to be more similar to cardamom than to anise. While it is poisonous and therefore unsuitable for using internally, in Chinese medicine it is used for treatment of some skin problems.

Japanese star anise contains anisatin, shikimin and sikimitoxin, which cause severe inflammation of the kidneys, urinary tract and digestive organs. Other compounds present in toxic species of Illicium are safrole and eugenol, which are not present in I. verum and are used to identify its adulteration.

Anisatin and its derivates are suspected of acting as strong GABA antagonists.

It is impossible to recognize Chinese and Japanese star anise in its dried or processed form by its appearance only, due to morphological similarities between the species.

There are cases of product recalls when products containing star anise were found to be contaminated by Japanese anise. Cases of consumers admitted to hospital with neurological symptoms after ingesting excessive doses of star anise or smaller doses of products adulterated with Japanese anise were described as well.