Obetia radula (stinging-nettle tree)

Obetia radula is known from only a rather narrow geographic band, stretching from eastern Congo-Kinshasa, through Rwanda, Burundi, Uganda, Kenya and north Tanzania, to Madagascar. It has been found at 500–2,000 m above sea level.

Leaves of Obetia radula (Image: Henk Beentje)

A tree 5–13 m tall, with a sparsely-branched trunk up to 50 cm across, covered in stinging hairs. The leaves are clustered at the branch ends, and are much lobed, 15–25 × 15–25 cm, with stinging hairs all over. The flowers are yellow-green and the male and female flowers are usually borne on separate trees in the axils of leaves. The male flowers are borne in groups up to 10 cm long, and are about 2 mm across. The female flowers are borne in groups up to 30 cm long, and are up to 8 mm across. The fruits are minute (less than 2 mm long).

Stinging-nettle tree occurs over a wide area, and there are no specific threats to either its habitat or the species itself. Hence, although an official conservation assessment has not been carried out, it is thought likely this species will be assessed as of Least Concern.

The stem fibres of Obetia radula are used to make rope and baskets. Some tribes use the roots as a remedy against barrenness (female infertility). The leaf is used in East Africa to deter rats and moles, as contact with the stinging hairs on the leaves causes intense itching in animals. In Madagascar the bark fibre was formerly used to ignite fires.

Pressed and dried specimens of Obetia radula are held in the Herbarium, where they are available to researchers from around the world by appointment. The details of some of these specimens, including images, can be seen on-line in the Herbarium Catalogue.

Search Kew's databases for more information on this species

Kew botanist Henk Beentje’s blog post: Stinging-nettle tree from Ngurdoto crater wall, Tanzania

Find out more about the stinging nettle (Urtica dioica)