As far back as 1830 botanists made sketches of the Rooibos plant and published their work. Since then scientists around the world have published their Rooibos research findings in a wide variety of leading scientific journals. In 2008 Professor Lizette Joubert of the Agricultural Research Council and Professor Wentzel Gelderblom of the Medical Research Council, along with two more collaborators, published an overview of existing knowledge about the history, cultivation, traditional uses, composition and biological activity of Rooibos and other South African herbal teas. Their 37-page review article was published in the Journal of Ethnopharmacology*. Key facts about the composition of Rooibos, and the importance of its compounds, can be summarised as follows: Rooibos contains a complex mix of many flavonoids (compounds widely found in plants that are known to have health benefits). Its composition is unique, because it contains aspalathin – to date only isolated from Aspalathus linearis (the botanical name for Rooibos). Aspalathin is the major flavonoid of unfermented Rooibos. It decreases during fermentation, but is still a major flavonoid constituent of fermented Rooibos (the tea with the characteristic red-brown colour and flavour). Aspalathin is important, not only because it is a novel compound, but also because it is the most active antioxidant in Rooibos in many cases. Rooibos also contains the rare flavonoid glucoside nothofagin. Other major phenolic compounds are orientin and iso-orientin, with smaller amounts of vitexin and isovitexin and many more compounds. The flavonoid composition of Rooibos varies between different regions and seasons, probably due to different soil and climate conditions, as well as genetic variations in the seeds used to propagate the plant. Rooibos is naturally caffeine free. It is considered a low tannin beverage, especially when compared to Camellia sinensis (black) tea.