Breonadia is a monotypic genus of flowering plants in the family Rubiaceae (order Gentianales), described by Colin Ernest Ridsdale in 1975. It contains a single species, Breonadia salicina — commonly known as matumi, African teak, or wild-oleander.
This is a medium to large evergreen tree reaching 10–40 m in height, with a straight trunk covered in grey to grey-brown, longitudinally ridged bark. Lateral branches are arranged in groups, forming a dense, narrow crown. The leaves are simple, lanceolate to narrow elliptic (80–300 × 20–90 mm), arranged in whorls of 3–5 (typically 4) and crowded at branch ends. They are tough and leathery, glossy dark green above and pale below, with a prominent pale yellowish-green midrib and lateral veins.
Flowers are produced in spherical, compact heads 15–25 mm in diameter, made up of numerous minute, pale mauve blooms. Each flower has a tubular, five-lobed corolla widening to a funnel-shaped throat; they are sweetly scented and appear in summer (November to March). The fruit develops as a ball of small, brown, two-lobed capsules (2–3 mm long), densely packed into rounded heads with a rough, bristly appearance, maturing in winter (June to July).
The tree grows in riverine fringe forest along permanent streams and rivers in tropical and subtropical Africa, from Mali and Benin in the west, east to Ethiopia, south through Malawi, Zimbabwe, Mozambique, and northeastern South Africa, as well as in Yemen, Saudi Arabia, and Madagascar. It is a protected species under South African law and its wood — hard, heavy, durable, and termite-resistant — has been highly valued for furniture, flooring, boat building, and historically for railway sleepers. The bark is used in traditional African medicine for stomach ailments, and leaf extracts have demonstrated antibacterial and antifungal properties.
Etymology
The genus name Breonadia has an obscure origin, but it possibly honours Jean N. Bréon (1785–1864), a French horticulturist. The species epithet salicina means "with willow-like leaves", derived from the genus name Salix for the willow.
Distribution
Breonadia salicina is native to tropical and southern Africa — from Mali and Benin in West Africa, east to Ethiopia, and south through Malawi, Zimbabwe, Mozambique, and northeastern South Africa (KwaZulu-Natal, Mpumalanga, Limpopo) — as well as Yemen, Saudi Arabia, and Madagascar. It inhabits riverine fringe forest, growing along or in the water of permanent streams and rivers at low altitudes, typically up to 2,000 m above sea level.
Ecology
The roots of Breonadia salicina tend to grow towards flowing water, making it characteristic of riverine habitats. Populations are small and fragmented, with low genetic diversity within individual populations but high diversity between populations — a pattern consistent with genetic drift in isolated groups. The seeds are eaten and dispersed by the Rameron Pigeon (Columba arquatrix). The tree occurs in subtropical to tropical climates and is sensitive to frost, though it can tolerate cold conditions.
Conservation
Breonadia salicina is a protected tree under Section 15(1) of South Africa's National Forests Act, 1998, which prohibits cutting, damaging, or possessing the tree or its products without a license. It has been Red Listed as Least Concern (LC) by SANBI. However, populations are small and fragmented, affected by genetic drift, deforestation, and logging.
Cultural Uses
Breonadia salicina has significant traditional and practical uses across its range. The bark is widely used in traditional African medicine to treat diarrhoea and digestive ailments; it is rich in tannins that inhibit E. coli growth, while leaf extracts show activity against both gram-negative and gram-positive bacteria. Antifungal compounds isolated from the plant have demonstrated efficacy in protecting stored produce.
The wood is hard, heavy, durable, and termite-resistant, with a yellow to light brown colour and a distinctive smell. Its natural oils prevent cracking when washed, making it prized for chopping boards, furniture, parquet floors, boat building, and outdoor benches. Historically, the wood was heavily used for railway sleepers in South Africa, and in Malawi trunks are hollowed into dugout canoes.
Taxonomy Notes
Breonadia was described by Colin Ernest Ridsdale in 1975 and is monotypic, containing only Breonadia salicina (Vahl) Hepper & J.R.I.Wood. It belongs to the gardenia family (Rubiaceae), the fourth largest flowering plant family globally (615 genera, ~13,150 species). The quinine tree Rauvolfia caffra is a common lookalike but differs by its milky sap, drooping leaves, and fleshy fruits.
Propagation
Breonadia salicina grows relatively fast from seeds. Fresh seeds are sown on coarse bark (for drainage) topped with river sand, kept moist. Germination rates are 60–80%. Seedlings are transplanted at the 3-leaf stage into a 5:1 river sand and compost mix, then hardened off in partial shade before moving to full sun. The tree requires ample water and well-drained soil; it can grow with its roots in water but not in waterlogged soil. It is frost-sensitive in youth.
