Warburgia salutaris (Bertol.f.) Chiov.
Common names: pepper-bark tree (Eng.); peperbasboom (Afr.); isibhaha (Zulu); manaka (Venda); shibaha (Tsonga)
SA Tree No: 488
This tree is a priority species for conservation and cultivation in gardens, as it is over-harvested in the wild for medicinal use and is a very popular item for sale at street markets.
This is an evergreen, slender tree that grows from 5 to 10 m tall. The dark green, glossy leaves are paler green below with entire margins. They are simple, alternately arranged, elliptic to lanceolate. The midrib is slightly off-centre with a tapering apex and base. The leaves have a bitter, burning, peppery taste.
The stem is covered by a rich brown bark marked with corky lenticels that is also bitter and peppery.
It has small, white to greenish flowers, up to 7 mm in diameter. The flowers are solitary, axillary, or in tight, few-flowered heads, borne on short, robust stalks in the axils of the leaves in autumn to winter (April to June).
These flowers develop into rounded, oval berries, about 30 mm in diameter, narrowing towards the base. They are dark green, turning purple when ripe, leathery in texture and covered with gland dots. They are on the tree from winter into early summer (July to December).
Warburgia salutaris is Endangered (EN). Due to its wide range of medicinal uses, this tree is over-harvested in the wild, which has caused an estimated 50% decline in the South African population, with some subpopulations nearly extinct.
Distribution and habitat
This is a tropical forest tree which extends southwards as far as north-eastern KwaZulu-Natal, Mpumalanga and Limpopo. It also occurs in Swaziland, Zimbabwe and Malawi. Its habitat is variable, and it is found growing in coastal, riverine, dune and montane forest as well as open woodland, thickets and in kloofs.
Derivation of name and historical aspects
The genus Warburgia was named after Dr Otto Warburg, 1859-1938, who was born in Hamburg. He lectured in botany at the University of Berlin, Germany, and was also the author of numerous botanical papers. The specific epithet salutaris is Latin meaning 'healthful'. The English common name, pepper-bark tree, relates to the pungent inner bark that tastes peppery. Isibaha is an old name in the history of Africa, and is thought to be based on an Arabian word which dates back to the days when the Arabs traded with Africa.
Leaves are browsed by Black Rhino and antelope.
Medicinally, the pepper-like, bitter stems and root bark are used to cure many ailments. As an expectorant or smoked, they are a widely used remedy for common colds. Dried and ground, they make a snuff used to clear the sinuses. Taken orally they are believed to cure spots in the lungs. Both stems and root bark are a remedy for malaria. Powdered and mixed with water, they are believed to cure sores in the mouth.
The wood is soft, oily and aromatic, but is not well known for timber in South Africa probably because of its rarity. According to Palmer & Pitman (1973), in Kenya the leaves of the pepper-bark are sometimes used to flavour food, added to curries, and the wood is sometimes used in building.
Growing Warburgia salutaris
Warburgia salutaris can be cultivated from seed as well as vegetatively from cuttings. Cuttings should be taken in spring. The tree grows in well-drained soil, with good aeration and moderate watering. Soil should be rich in organic matter in the form of well-rotted compost. The pepper-bark is an attractive evergreen tree for both small gardens and big estates, in full sun or semi-shade. It is also a suitable plant for hedge as it responds well to pruning. It is also a good container plant.
The pepper-bark tree is sensitive to frost and should be protected when young.
- Coates Palgrave, K. 1977. Trees of southern Africa, edn 2. Struik, Cape Town.
- Palmer, E. & Pitman, N. 1973. Trees of southern Africa. Vol. 3. Balkema, Cape Town.
- Pooley, E. 2003. The complete field guide to trees of Natal, Zululand and Transkei. Natal Flora Publication trust. Pp.188, 189.
- Van Wyk, B.E. & Gericke, N. 2000. People's plants. Briza Publications, Pretoria.
August 2004, updated May 2018
Plant Type: Shrub, Tree
SA Distribution: Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga
Soil type: Loam
Flowering season: Autumn, Winter
PH: Acid, Neutral
Flower colour: Green, White, Cream
Aspect: Full Sun, Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Average