Calodendrum capense aka Cape Chestnut

Calodendrum capense, or Cape chestnut, belongs to the Rutaceae family. This African tree grows from Kenya south to South Africa. Its range also includes Uganda, Rwanda, and eastern DR Congo. It grows in forests beside rivers and at higher elevations. It also occurs in wooded ravines, forest edges, and scrub. People grow it as an ornamental tree beyond its native range.

The tree grows slowly and forms a dense, rounded crown. Reported heights range from 16–66 feet [5–20 metres]. The evidence does not give a separate garden size range. Trees in forests tend to develop straight trunks, sometimes with buttresses. In hot, dry valleys, they stay lower and become gnarled. These trees also bear smaller leaves and flowers. The bark is pale grey, and the leaves are large. Trees shed some leaves but can remain evergreen near the coast.

Pink to mauve flowers form showy masses across the crown. Their sweet scent draws bees and butterflies, which pollinate them. The supplied sources do not state a flowering season. The fruit has a knobbly surface and forms a capsule. Ripe capsules split open to reveal black seeds. Flowers, fruit, bark, and leaves give the tree value as a specimen. Gardeners also plant it for shade and as a windbreak. Its roots are not aggressive, which suits street and car park planting.

Cape chestnut grows in tropical and subtropical climates. It accepts full sun or light shade. It grows best with annual rainfall of 800–1,500 millimetres. The reported wider tolerance spans 600–2,000 millimetres each year. Trees can withstand frost down to about −5°C. Well-established trees in sheltered groups may survive about −8°C. Cold winters can prevent reliable flowering, even when trees survive. Fresh seed gives more reliable results than old seed. Young plants transplant well, and cuttings offer another means of propagation.

People harvest the seeds for oil and the wood for timber. The bitter, yellow seed oil serves in soap and skin care. It can soften skin and has potential as fuel or lubricant. People also use the bark in skin cosmetics. The tough wood bends well and is easy to work. The source lists no known edible uses or hazards. This does not establish safety for people or pets.