For the identification of insects and other fauna and flora of South Africa: please click on the following links:
Insects and related species: Antlions - Ants - Bees - Beetles - Bugs - Butterflies, Moths and Caterpillars - Centipedes and Millipedes - Cockroaches - Crickets - Dragonflies and Damselflies - Grasshoppers and Katydids - Mantis - Stick Insects - Ticks and Mites - Wasps - Woodlice
Plants, Trees, Flowers: (Note: Unless plants fall into a specific species such as Cacti, they have been classified by their flower colour to make them easier to find) Bonsai - Cacti, Succulents, Aloes, Euplorbia - Ferns and Cycads - Flowers - Fungi, Lichen and Moss - Grass - Trees
Animals, Birds, Reptiles etc.: Animals, Birds, Fish and Crabs - Frogs - Lizards - Scorpions - Snails and Slugs - Snakes - Spiders - Tortoise, Turtles and Terrapins - Whipscorpions
Other photography: Aeroplanes - Cars and Bikes - Travel - Sunrise - Water drops/falls - Sudwala and Sterkfontein Caves etc.

Saturday, August 17, 2013

Narrow-leaved Sand Olive (Dodonaea angustifolia)

Family Sapindaceae
This well known, drought and wind resistant, indigenous plant can grow into a shrub as it is usually multi-stemmed or a small tree when the lower branches are pruned. It is ideal for water-wise gardens.

Description
Dodonaea viscosa var. angustifolia is an evergreen shrub or small tree up to 5 m high. Its bark is light grey and finely fissured. The droopy leaves are shiny light green above and paler green below. Its flowers are small, yellowish green and are followed by decorative clusters of yellow or reddish fruits with papery wings. Flowers are produced from April to August (autumn–winter). This is a fast growing plant that prefers a sandy substrate; when given good soil and plenty of water it requires minimal water once established.
 
Distribution and habitat
Dodonaea viscosa var. angustifolia grows in a variety of habitats from arid, semi-arid to high rainfall regions and is frost-hardy. It is found in a wide strip along the coast from Namaqualand through the Western Cape, Eastern Cape to KwaZulu-Natal as well as further north in Mozambique and Zambia.
 Derivation of name and historical aspects

The genus Dodonaea was named after Rembert Dodoens. He was a Dutch physician and botanist who wrote a book on plants of the Middle Ages. He died in 1585. The specific epithet viscosa means sticky, referring to the young growing tips which contain surface flavonoids; this gives them a shiny appearance. In the genus Dodonaea there are 60 species widespread mostly in Australia. In South Africa there are two recognized taxa: Dodonaea viscosa var. angustifolia and Dodonaea viscosa var. viscosa.

Ecology
The dense bushy hedges which it may form are ideal bird nesting sites and the flowers attract butterflies. The seed has papery wings and is possibly dispersed by wind.

 Uses and cultural aspects

This shrub is grown worldwide, as the roots have soil-binding properties which are effective for the purpose of stabilizing sand dunes and to control erosion. The early Cape settlers used a decoction prepared from the new leaf tips for fever. In the rural areas Dodonaea viscosa var. angustifolia is still widely used for colds, influenza, stomach trouble and measles. For a sore throat and oral thrush it is used as a gargle. The Khoi-Khoi used a concoction of the root for colds and influenza. In Namaqualand the green leaves are boiled slowly, then left to steep, strained, and the extract is used for influenza, colds and also to induce sweating. It also used to relieve coughs and the congested feeling typical of influenza, croup and diphtheria. The same extract is considered to alleviate stomach ailments and fever. The leaves are used externally as a remedy for itchy skin and to treat skin rashes. An extract of the leaves is used as a mild purgative and for rheumatism, sorethroat and haemorrhoids. Other early uses of the plant include the treatment of pneumonia, tuberculosis and skin rashes. In southern Africa it is regarded as one of the most important traditional medicines and is used in combination with other medicinal plants, including Viscum capense (Willem Steenkamp, pers. comm.). Most of the Dodonaea viscosa var. angustifolia specimens found in the Karoo Desert National Botanical Garden are a host plant to the hemiparasitic shrub, Viscum capense which grows on them. Seeds of the parasite are deposited on the branches of the host as a result of birds feeding on the fruits of the parasite and cleaning their beaks on the branches of the host. In arid areas it is also a valuable source of firewood.