Ongaonga - tree nettle - Urtica ferox
Ongaonga, is a nettle that is endemic to New Zealand. Sometimes known as the 'tree nettle', ongaonga has woody stems and unusually large stinging spines, emanating from the leaves and every branch, and can grow 5 metres tall. Even the lightest touch can result in a painful sting that lasts several days. 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. There has been one recorded human death from contact—a lightly clad hunter who died five hours after walking through a dense patch.
Crowe (Which Native Forest Plant) says:
“Considering just how dangerous this shrub is, it is surprising how few New Zealanders know the plant. Not only have several dogs and horses died by coming into contact with it, it has killed at least one tramper who pushed through a thicket of this plant.”
The stinging hairs are very obvious on this nettle being some 6mm or more in length. Crowe describes them as being like a hypodermic syringe. “The slightest touch knocks off the tip of the needle leaving a slanting point that drives into the skin. The elastic barrel at the base of the needle immediately shrinks, pumping its venom into the victom. The extract from just one of these long, fat stinging hairs is sufficient to kill a guinea pig.”
Ongaonga contains the same poison as common garden nettle but also has another, as yet unidentified, poison. In severe cases of poisoning artificial respiration and injection of atropine may be necessary. Pain can be eased somewhat with calamine or antihistimine medication. Common along edges of forest (including forest tracks!) and regenerating scrub.
This photograph taken on Kapiti Island.