The open plant encyclopedia
Snap a photo or search by any name to see how to care for it, where it comes from, whether it's safe, and a 3D model you can turn.
The plants people record most in your country, and ones that grow there wild.
Filter by what you want to do, shape, origin, country, care and safety.
Urtica ferox
Tree nettle (ongaonga) is a New Zealand endemic shrub or small tree up to 3 m tall, covered in stinging hairs. It is grown mainly in gardens and restoration plantings for its role as a host plant for the New Zealand red admiral butterfly, and should be handled with care.
Urtica ferox, commonly known as tree nettle and ongaonga, is a species of nettle endemic to New Zealand. A member of the Urticaceae, the plant is covered in trichomes (hairs), which contain toxins that are poisonous to humans and other animals. It is a large woody shrub or small tree that can grow to a height of 3 metres (10 feet). Its trichomes can cause painful stings, with effects that can last several days or weeks; the sting is strong enough to kill cattle, dogs, and horses. Two human deaths have been caused by contact with the plant.
The plant was first scientifically described by German naturalist Georg Forster in 1786. U. ferox is wind-pollinated, and its seeds are later dispersed by gravity or the wind. The plant serves as a host for several moth species, and it is the primary source of food for the larvae of the New Zealand red admiral butterfly.
Like all Urtica species, U. ferox is wind-pollinated, although bees may visit the flowers to collect nectar. U. ferox's seeds are dispersed by gravity and the wind. During winter in some southern localities, U. ferox can be semideciduous (losing some of its leaves) or entirely deciduous (losing all of its leaves). This characteristic is uncommon in the native plants of New Zealand.
Urtica ferox is usually avoided by people, but it has had some traditional and medicinal uses for the indigenous Māori people. In traditional medicinal practices, the bark of U. ferox and the leaves of kawakawa (Piper excelsum), boiled together, were used to treat eczema and sexually transmitted infections. The plant was also a traditional Māori food source. The inner stems were consumed after the leaves and outer bark had been removed. The thin film that makes up the inner bark was also eaten raw and had a sweet taste. In Māori mythology the plant was placed in forests to prevent people moving freely and to irritate people. In one legend the Polynesian explorer Kupe is said to have placed several obstacles, including this plant, to slow down those chasing him. In the Māori language ongaonga can be used to describe something annoying, and a frustrating or irritating person can be called he tangata ongaonga, meaning "a prickly person".
Text excerpted from the Wikipedia article Urtica ferox by its contributors, under CC BY-SA 4.0; the excerpts and the care summary drawn from them are shared under the same licence.
The care summary was written by AI (Claude, Anthropic) from the sources on this page, with general growing knowledge where they are silent. Check before relying on it.
Life form, climate and native range: World Checklist of Vascular Plants, Royal Botanic Gardens, Kew (CC BY 3.0), reformatted; see Plants of the World Online.
