With the spread of bird flu prompting fears of an epidemic or even pandemic that could kill humans by the million, a Chinese spice hitherto associated with the pleasures of aperitifs has suddenly assumed key medical significance. For the fruit known as star anise has an ingredient vital to a drug to fight the strain of avian flu that has already killed more than 60 people in Asia.Harvested in China and Vietnam and used as a spice, it provides flavouring for candies, pastis drinks and tobacco.But it also has a key pharmaceutical asset - shikimic acid, described by experts as the world’s only weapon against bird flu.Star anise, the dried, star-shaped multiple fruit of a small oriental tree which is a member of the magnolia family, is a traditional ingredient of oriental cuisine with its pungent, liquorice-like flavour.It also serves as the main flavouring of the liqueurs Pernod and Anisette.But its medical significance had already been noted before bird flu arrived, including potential cancer-fighting properties.