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

Wednesday, October 30, 2013

Poison Star-apple (Diospyros dichrophylla)

Family Ebenaceae
Description
The poison star-apple is a shrub or tree, 2-3(-13) m high, It is single or multi-stemmed with branches that grow straight up, forming a dense canopy.

The bark is grey to brown, and rather smooth or sometimes wrinkled. The young branches and the new growth are covered in soft, yellowish to pale brownish, velvety hairs. The leaves are simple and arranged alternately or spirally. They are narrowly oblong, egg-shaped or oval with bluntly pointed or rounded tips, the base of the leaf narrowing, are glossy, leathery, dark green and hairless above and pale green and sparsely to densely covered with hairs below. The margin is often tightly rolled under, entire and not wavy. The central vein is raised below.

The flowers are borne singly, on long, lax, leaf stalks, are bell-shaped, drooping and creamy white and can be seen from November to March. The 5-lobed calyx and petals curl backwards. The male and female flowers are on separate plants.

The fruit appears from March to October and is an almost round, slightly flattened berry with dense orange-yellow, velvety hairs. The persistent calyx has 5 narrow lobes that usually curve backwards.

There are 3-8 dark, shiny brown seeds.
Distribution and habitat
The poison star-apple is found in coastal scrub, coastal sandy flats, in open grassland, wooded ravines, on wooded rocky hillsides and along forest margins. This species is confined to a wide coastal belt all the way from Montagu in the west, eastward and northwards through the Eastern Cape and along the Kwa-Zulu Natal coast. It is one of the most common plants on top of the Lebombo Mountains ( Palmer & Pitman 1972). Some specimens have been collected in Limpopo, but it does not seem to occur further north of the Soutpansberg. This plant can tolerate some frost, and temperatures ranging between 8º and 39º C, but predominantly prefers the more moist areas with a high rainfall of 1 000 mm per year in the summer rainfall areas of South Africa. This plant does well in the Pretoria National Botanical Garden and can tolerate much more drought than indicated from its distribution.
Ecology
The flowers are pollinated by insects. It is said that the fruit is taken by birds although it is alleged to be poisonous.

Uses and cultural aspects
The wood of this plant is hard and black, but is used only for firewood. Since it is claimed that the fruit is poisonous, it is not used for human consumption. It seems that it has only been grown as a garden plant. It makes a lovely little shrub or small tree and can be trimmed to form a hedge like its cousin, Diospyros whyteana. Aside from the edible D. khaki mentioned above, ebony is obtained from a number of tropical species. The more famous South African species is the jakkalsbessie, D. mespiliformis. Another South African species with attractive red fruits is the bluebush, D. lycioides.