This is a small tree of great character which grows in the eastern parts of South Africa. It is a very versatile addition to the indigenous garden.

The generic name (Leucosidea) is derived from the Greek words for "white or grey appearance", while the species name (sericea) is the Latin for "silky" in reference to the silky hairs on the leaves of the tree.

The ouhout is often a straggly shrub or a dense, small, evergreen tree, which grows up to 7m tall to 5m wide. It is single or multi-stemmed and branches low down. The bark is rough, reddish brown in colour and flakes off to reveal a smooth light brown under-bark. The leaves are alternately arranged, compound and covered with silky, silver hairs. Each leaf possesses 3 to 4 pairs of leaflets. The veins on the leaves are deeply sunken on the upper surface and protrude on the lower surface. The leaves are a dark green colour above and a lighter green colour below. The margins of the leaflets are deeply serrated. When the leaves are crushed they have a strong herb-like smell. The flowers are greenish-yellow in colour, star-shaped, and grow in spikes at the ends of young shoots in spring (August to September). The fruits are nut-like and about 3 mm in diameter (December to January).

This tree is usually found growing in dense thickets at altitudes above 1000 metres. It can be found growing in open grassland, along river banks and on wooded, rocky ridges. It is usually found growing in damp conditions, on deep, sandy or clayey and often rocky soil. Leucosidea sericea occurs in the Eastern Cape, Lesotho, western KwaZulu-Natal, the eastern Free State, North West, Gauteng, Mpumalanga, and Limpopo provinces, Swaziland and Zimbabwe.

The flowers and young shoots of this plant are browsed by cattle and goats in spring. It forms dense thickets on overgrazed, eroded or otherwise disturbed areas and can, therefore, become a problem plant on farm lands. The ouhout produces nectar which is probably utilised by bees and other insects.

The wood makes good, durable fence posts in permanently wet soil even though it is soft. Apparently in mountainous areas where the ouhout occurs near streams it is an indication that they are suitable for being stocked with trout. Zulu people use a paste made from the crushed leaves of Leucosidea sericea for treating ophthalmia (an eye ailment). The tree is used by the local people as a charm to protect the inhabitants of homesteads. The wood of this tree burns slowly and produces a lot of smoke like old and decaying wood. This together with the appearance of the flaky bark has given rise to the tree's common name of "oldwood".

Growing Leucosidea sericea

Leucosidea sericea is a frost resistant, evergreen tree, which makes it an ideal species to use to protect less frost hardy plants during winter. Because it is fast growing it can be used to establish an evergreen canopy relatively quickly while slower growing trees can be used around it and ultimately take its place once they have developed sufficiently. The tree can also be used to provide shade in summer if low branches are trimmed off. The ouhout is a dense plant that can be used to provide a screen against noise, objectionable views and wind. This tree can be very successfully utilised near water sources such as rivers and dams since it enjoys living in damp areas. It possesses a slightly weather beaten and untidy general appearance due to its gnarled, flaking trunk and irregular form and these qualities can be utilised well when trying to create a naturalistic, indigenous, African style garden. Due to the concentration of silver hairs on the leaf edges, the tree possesses a silvery sheen in the sunlight. The ouhout is also suitable for use as a bonsai tree.

The ouhout is propagated easily and quickly from either seed or cuttings. Seeds should be sown in a good seedling medium and kept moist. Seedlings can often be found underneath parent plants and may be carefully removed and placed in nursery bags with a suitable medium.

Leucosidea sericea belongs to the family Rosaceae (the Rose family). This is a very large and economically important family. It is mostly found occurring naturally in the temperate regions of the Northern Hemisphere. It comprises 120 genera with 3000 species worldwide. This family includes some common fruit crop plants such as the apple, peach, plum, prune, nectarine, pear, apricot, almond, cherry, loquat, quince, blackberry, raspberry and strawberry. This family also includes one of the most popular ornamental plants in the world namely the Rose. Rose oil is one of the world's most valuable oils and is used as a base for most perfumes. Rosaceae is however a poorly represented family in southern Africa with fewer than eight native tree species and a number of naturalised aliens.

References

• Coates Palgrave, K. 1983 TREES OF SOUTHERN AFRICA. Struik: Cape Town.
• Joffe, P. 1993. THE GARDENER'S GUIDE TO SOUTH AFRICAN PLANTS. 1st edition, Cape Town: Tafelberg Publishers Limited.
• Pooley, E. 1994. THE COMPLETE GUIDE TO TREES OF NATAL, ZULULAND & TRANSKEI. Durban: Natal Flora Publications Trust.
• Thomas, V. & Grant, R. 1998. SAPPI TREE SPOTTING HIGHVELD AND THE DRAKENSBERG TREE AND SHRUB IDENTIFICATION MADE EASY. Johannesburg: Jacana.
• Van Wyk, B. & van Wyk, P. 1997. FIELD GUIDE TO TREES OF SOUTHERN AFRICA. 1st edition, Cape Town: Struik Publishers.

Marc Stern
Witwatersrand National Botanical Gardens
June 2002