For the identification of insects and other fauna and flora of South Africa.

Friday, December 20, 2013

Cape Chestnut (Calodendrum capense)

Family Rutaceae
Birds do not find the nectar-filled flowers inviting, but butterflies do feed on them. Samango and vervet monkeys, and rameron and olive pigeons, cinnamon doves and Cape parrots eat the seeds. The larvae of several butterfly species, including the orange dog (Papilio demodocus) which also uses other citrus family trees, breed on the foliage.
 
In a forest environment, this tree can reach heights of up to 20 m, but at the forest margin or in the open it is shorter, approx. 7 m, with a more spreading canopy. At the coast this tree is often evergreen, but inland it is deciduous with rich yellow autumn colours. The flowers are large and striking, faintly sweet-scented and carried in conspicuous terminal panicles during early summer (October to December).
The timber is white or light yellow, fairly hard but bends well and is easily worked. It is used for tent bows, wagon-making, yokes, planking, shovel handles, and furniture, and is considered one of the most generally useful hard woods. The bark is used as an ingredient of skin ointments and is sold at traditional medicine markets. Seeds are crushed and boiled to obtain oil that is suitable for making soap. The Xhosa believe that the seeds have magic properties, and hunters used to tie them around their wrists when hunting to bring them skill and good luck.
Calodendrum capense got its common name because William Burchell (1782-1863) thought that the flower and fruit resembled the horse chestnut. It is, however, not closely related to the chestnuts, Castanea species, which belong in the Fagaceae, the beech & oak family. And Carl Peter Thunberg (1743-1828), pupil of Linnaeus and the 'father of South African botany', was so excited at the sight of a tree in flower when he visited Grootvaderbosch in 1772, that he fired his gun at the branches until one broke and delivered the blooms into his hand. He was the one who named it Calodendrum.
Calodendrum capense is a member of the Rutaceae, the buchu & citrus family, a family of ±160 genera and ±1650 species that occur in warm temperate regions of the world, with 22 genera and 290 species in southern Africa. One of the diagnostic features of this family is the presence of oil glands on the leaves, visible as tiny translucent dots when held up to the light. Another common feature, caused by the oil, is the strong scent of the leaves, particularly when they are crushed.