Aspalathus linearis, the source of rooibos tea, is a shrub found in the western mountainous parts of the Western Cape. Rooibos tea is a most popular drink for health-conscious people, as it contains no colourants, additives or preservatives and is free of caffeine.
Aspalathus linearis is an erect to spreading, highly variable shrub or shrublet up to 2 m high. Its young branches are often reddish. The leaves are green and needle-like, 15-60 mm long and up to about 1 mm thick. They are without stalks and stipules and may be densely clustered. The yellow flowers, which appear in spring to early summer, are solitary or arranged in dense groups at the tips of branches. The fruit is a small lance-shaped pod usually containing one or two hard seeds.
The species is reported to be not under threat but a number of factors are causing areas with natural populations to decrease. Due to the great demand for rooibos tea, both nationally and internationally, more of the land is converted to plantations of this plant. Other factors influencing natural growth are overgrazing by stock, alien plant invasion, climate change and the uncontrolled harvesting of wild rooibos.
Distribution and Habitat
Aspalathus linearis is naturally distributed in the winter rainfall area from about Vanrhynsdorp in the north to the Cape Peninsula and the Betty's Bay area in the south. The area experiences cold wet winters and hot dry summers with about 300-350 mm of rain per annum. Rooibos tea is made from selected forms of the species found mainly on the Cederberg Mountains. It is cultivated on sandy soils in the valleys of the Olifants, Breede and Hex Rivers (Dahlgren 1988).
Derivation of name and historical aspects
The genus name Aspalathus is derived from the Greek aspalathos, which was the name of a scented bush that grew in Greece. The epithet linearis is derived from the Latin word for linear, which in this case refers to the shape of the leaves.
Uses and cultural aspects
Aspalathus linearis is of great economic value. It was first used by the indigenous people of the Cederberg area and is currently a very popular tea. It is considered healthy as it is caffeine-free, low in tannins and rich in anti-oxidants. It is not only enjoyed as a herbal tea, but is also used as an ingredient in cosmetics, in slimming products, as a flavouring agent in baking, cooking and cocktails and even as a treatment for infants who are prone to colic.
Growing Aspalanthus linearis
Although many of the plants in the genus Aspalanthus are attractive, they have apparently seldom been grown in gardens. This is thought to be due to the difficulty in propagation by seed or root cuttings and in providing the optimal growing conditions for the plants. In order to grow Aspalathus linearis successfully, seeds must first be scarified and then planted in acid, sandy soils.
There are commercial plants of rooibos at the Cape. According to Mr S de Beer of Lambertshoek farm, Clanwillian, seeds which are obtained from the local rooibos tea management board have been treated and germinate easily. They are planted in seedbeds in March to a depth of 5-10cm and are ready for planting out by July. Plants are generally rainfall dependent and the plants prefer not to be too wet. No fertilizing is required and the plants grow quite well in nutrient poor conditions. The most common pest is Loopers or “Landmeter wurmpies” (the larvae of the family Geometridae and of the order Lepidoptera)
Generally farmers plant seeds in February and March and then transfer the seedlings to plantations. It takes 12- 18 months before the shrubs are ready to be harvested. The plants are harvested once each year, from December through April. They are harvested up to period of five years and then pulled out and new plants are planted.
The basic method of rooibos harvesting has remained largely the same as the process used centuries ago. An environmentally friendly way of harvesting tea is used that involves cutting only the young branches. Once they are cut, they are neatly bound and transported to the process yards. The older branches are left on the tree and the bushes get slightly taller every year. The tea cuttings are chopped very fine and then bruised to ensure that the important chemical reaction which develops the characteristic colour and flavour of the tea can take place. After watering and airing, the tea is left to "sweat" in heaps and it at this point that the tea acquires its typical reddish brown colour and develops its sweet flavour. After the sweating process has been completed, it is spread out in a large drying yard to dry in the sun.
The rest of the process involves sorting and grading the tea according to length, colour and flavour. The finished Rooibos is finally weighed, bagged, and sold to companies who pack the product in either teabags or in loose leaf form under their own brand names.
References and further reading
- Dahlgren, R. 1988. Crotalarieae (Aspalathus ). Flora of southern Africa 16,3: 1-423.
- Gess, S. 2000. Rooibos - Refreshment for Humans, bees and wasps. Veld and Flora 86, 1 : 19-21
- Heiveld organic rooibos tea: produced with pride. 2003.
- Louw, R. & Huntly, P. 2006. Poor man's cup of tea no longer. Veld and Flora 92, 3 : 1541-56
- Jackson, W.P.U. 1990. Origins and meanings of South African plant genera. University of Cape Town Ecolab.
- Leistner, O.A. (ed.). 2000. Seeds plants of southern Africa : families and genera. Strelitzia 10. National Botanical 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.