Spirostachys africana

Spirostachys africana is a medium-sized (about 10 metres tall) deciduous tree with a straight, clear trunk, occurring in the warmer parts of Southern Africa. Its wood is known as tambotie, tambootie or tambuti.

It prefers growing in single-species copses in deciduous woodland, often along watercourses or on brackish flats and sandy soils.

Description

The leaves are small, elliptic with crenate margins, and turn bright red in winter before dropping. The petiole has 2 small glands at the distal end. The grey-black rough bark is distinctively split into neat rectangles. The catkin-like flowers appear in early spring before the leaves. Male and female flowers are borne separately on the same tree (monoecious). The small 3-lobed capsules split into three equal segments when ripe; on a warm day this splitting (dehiscence) can sound like a fusillade of shots.

Wood

Despite its being prone to heart-rot, it is prized in the furniture industry for its beautiful, dense and durable timber, which is reddish-brown with darker streaks, a satin-like lustre and extremely fragrant sweet, spicy smell. The oily timber exudes a white, poisonous latex when freshly cut, and campfires that burn tambuti fuel give off noxious fumes contaminating meat or other food grilled on the flames or coals. The latex is used as a fish poison, is applied to arrow-tips and is used as a purgative by the Ethnic inhabitants. The active principle is the diterpene excoecarin, named for the Indian Euphorbiaceous mangrove Excoecaria agallocha.

Jumping beans

The fruits are frequently parasitised by the larvae of the small grey moth Emporia melanobasis (Pyralidae: Phycitinae). These larvae jack-knife inside the fallen segments, causing them to move about erratically and vigorously, to the surprise of the uninitiated. This has led to the name "Jumping Bean Tree". The Mexican jumping bean, Sebastiania sp., also belongs to the Euphorbia family and is parasitised by the moth Cydia deshaisiana.

References

• Medicinal and Poisonous Plants of Southern and Eastern Africa - John Mitchell Watt & Maria Gerdina Breyer-Brandwyk (E&S Livingstone 1962)

See also

• List of Southern African indigenous trees