This is a very attractive shrub with striking red and green flowers. The genus name is derived the Greek "erythros" = red, referring to the bright red flowers typical of many species in this genus. Acanthocarpa is also derived from Greek, "akanthos" meaning thorn and "karpos" meaning fruit, in reference to the spiny pods.

This attractive shrub occurs naturally in the Queenstown district in the Eastern Cape Province, South Africa, an area once known as Tambukiland (hence tambookie thorn). The plant is endemic to this and possibly adjacent districts and occurs nowhere else in the world. In its natural habitat, the plants often form low thickets and covered large tracts of land. Early travellers reported these areas to be a blaze of red during spring and early summer when it is flowering, but sadly the plant is no longer as common.

The tambookie thorn is a much branched, deciduous, thorny shrub reaching up to 2m in height. The striking flowers are scarlet with the upper petal edged with green and are held in heads up to 10cm long and about 12cm wide.

The leaves are compound with three leaflets and bear numerous hooked, sharp, purplish-black prickles. The brown pods are up to 12cm long, constricted between the seeds and are armed with prickles (hence the specific name "acanthocarpa"). The seeds are brown and larger than those of other local Erythrina species. They are reportedly used as a charm against evil.

An interesting feature of this plant is its greatly enlarged undergound rootstock. There are reports dating from the 1860s that the succulent underground "root" is extremely light when dry, and in this state was sometimes made into light summer hats, hence the name pith helmets.

Growing Erythrina acanthocarpa

This is a very attractive shrub when in flower and makes an excellent garden specimen. Care should be taken not to plant it alongside paving as the large underground rootstock may cause the paving to lift. It performs best in a full sun position planted in well drained soil. Do not overwater and keep relatively dry in winter. It is frost hardy.

The tambookie thorn was introduced into cultivation in greenhouses in England in the early 1800s. It is reported to be long-lived in cultivation. Unfortunately this very attractive shrub is difficult to find in nurseries. It is fairly easily grown from seed, but cuttings are difficult to strike.

References

• Batten,A & Bokelmann,H (1966) Wild flowers of the Eastern Cape Province. Books of Africa : Cape Town
• Gledhill, E. (1981). 2nd ed. Eastern Cape Wild Flowers. Cape Provincial Administration : Cape Town.
• Hennessy, E.F (1972). South African Erythrinas. Natal Branch Wildlife Protection Society : Durban.
• Jackson, W.P.U. (1990). Origins and Meanings of Names of South African Plant Genera. Cape Town.
• Pole Evans, I.B.(ed)(1926) Flowering Plants of South Africa. Plate 203. Speciality Press : Johannesburg.
• Smith, C.A. (1966). Common Names of South African Plants. Botanical Survey Memoir No. 35. Dept of Agricultural Technical Services: Pretoria.

Sharon Turner
Witwatersrand National Botanical Garden
August 2001