Are you looking for a fabulous shade tree, rich in a unique cultural history and adored by elephants and butterflies alike? Then look no further than the spectacular flat-crown albizia to add a year-round talking point to your garden!
As the common name of this magnificent tree suggests, Albizia adianthifolia has a conspicuous flat crown, which makes it unmistakable in the coastal and low-altitude forest, forest margins, open forest and ravines where it occurs in South Africa. It can reach a height of over 40 m. The bark is grey to reddish brown and rough. Branchlets and peduncles have grey to brown hairs with the young tips tinged pinkish red.
Leaves are very characteristic; the 4-8 pairs of pinnae bear 6-12 pairs of leaflets each. Every leaflet is obliquely rhombic-quadrate (rectangular) with the midrib diagonally across it. The petiole has a gland at the base.
The flowers are striking, forming relatively large, half-spherical heads. Petals are white or greenish white and joined for at least two thirds of their length. Stamens are fused partly to form a tube and reddish pink or green at the tips. These lax inflorescences appear in different months of the year, but in South Africa the tree flowers in spring during the months of September-November.
The fruit is a thin pod with a conspicuous margin and veins. As the pod dehisces and opens up, the margins often persist as the centre parts fall off. The seeds are flat and brown.
Although this species is not threatened at the moment, over exploitation and ringbarking of trees for the medicinally important bark are becoming more and more common.
Distribution and habitat
The flat-crown albizia usually occurs in moist and tropical areas such as forests as well as areas that are transitional to woodland. Geographically it is distributed from the northern parts of the Eastern Cape in South Africa throughout the tropical countries up into Senegal in the west and Ethiopia in the east of Africa. It also occurs on Madagascar.
Derivation of name and historical aspects
The genus is named in honour of Filippo degli Albizzi, an Italian naturalist, who brought seeds from Constantinople to Florence. By doing so in 1749, he effectively introduced a species of this genus (the Asian species A. julibrissin) to European horticulture. The specific epithet refers to the resemblance of the leaves, folia, to the maidenhair fern, genus Adiantum.
This species is particularly fond of tropical environments and is especially prevalent in the more moist areas of eastern parts of South Africa and northern Limpopo. Because the tree flowers with such spectacular profusion, it attracts many butterflies that come to feed off the nectar and sap that slowly seeps out of the branches. Several impressive butterfly species lay their eggs on the tree and the larvae of, amongst others, Charaxes cithaeron and C. ethalion, feed off the foliage. The tree is also popular with elephants which relish its foliage.
Uses and cultural aspects
It is unbelievable how many uses this tree has! The golden-yellow wood is light and soft-grained and used for naves; however, it may be used for many other general purposes as well. A sauce is said to be made from the seeds for use over food. The sweet-smelling gum or resin of this tree is used in cosmetics in some African countries, however it is of a somewhat inferior quality. Medicinally the tree has many uses. An emetic prepared from the bark are used to treat skin diseases and bronchitis. Extracts from the roots are applied to inflamed eyes and in some northern African countries the plant is one of the ingredients in a remedy for snakebite. The bark is also said to be effective in humans and animals for anthelmintic or tapeworm treatment as well as headaches and sinusitis when powdered. In western African countries, the plant is used to ward off evil spirits, whereas Zulus sometimes make a love charm emetic from it. The tree is also planted in some areas to conserve soil and control erosion. It is also valued for the shade and shelter it provides in tea and cacao plantations and because of its handsome shape, it is a most adored ornamental species.
Growing your own umbrella
Nothing can be easier than cultivating this handsome tree as it can simply be grown from seeds. Soak the seeds in warm water overnight to allow water to penetrate the leathery testa (seed coat) and the next morning sow in seedling trays containing a 5:1 mixture of river sand and compost. Make sure that you harvest healthy seeds and at the very least, 60% of your seeds will germinate. One should take care when transplanting the young seedlings because they immediately form taproots and damage to it could result in slower-growing trees. The seedlings can either be transplanted into black nursery bags when they have two leaves, or directly into the ground. It will grow optimally in humus-rich, sandy soil and requires watering every second or third day depending on weather conditions. Naturally the tree occurs in frost-free areas, therefore tree lovers of the Highveld and other cold parts of the country should rather opt for some of the better adapted Acacia species from their region.
References and further reading
- Germishuizen, G., Meyer, N.L., Steenkamp, Y. & Keith, M. (eds) 2006. A Checklist of South African plants. Southern African Botanical Diversity Network Report No. 41. SABONET, Pretoria.
- Glen, H.F. 2004. SAPPI What's in a name? The meaning of the botanical names of trees. Jacana, Johannesburg.
- Lewis, G., Schrire, B., Mackinder, B. & Lock, M. (eds). 2005. Legumes of the world. Royal Botanic Gardens, Kew.
- Ross, J.H. 1975. Flora of southern Africa 16, 1: 138-150. Botanical Research Institute, Pretoria.
- Smith, C.A. 1966. Common names of South African plants. Memoirs of the Botanical Survey of South Africa No. 35.
- Van Wyk, B-E. & Gericke, N. 2000. People's plants: a guide to useful plants of southern Africa. Briza Publications, Pretoria.
- Venter F. & Venter, J-A. 2002. Making the most of indigenous trees. Briza Publications, Pretoria.
- Watt, J.M. & Breyer-Brandwijk, M.G. 1962. The medicinal and poisonous plants of southern and eastern Africa, edn 2. Livingstone, London.
National Herbarium, Pretoria