Ongaonga, Urtica ferox, is a nettle that is endemic to New Zealand. Sometimes known as the 'tree nettle', ongaonga has woody stems and unusually large stinging spines, and can grow 5 metres tall. Even the lightest touch can result in a painful sting that lasts several days. It has killed at least one person who blundered into it, as well as several dogs and horses.

In Maori folklore, Kupe was said to have placed several obstacles to hinder pursuers whose wives he had stolen, one of which was the ongaonga.

Ongaonga is the main food plant for larvae of the New Zealand Red Admiral butterfly or Kahukura, Bassaris gonerilla.

References

Trees of New Zealand

Urtica ferox | Ongaonga