A wild banana that may hold the key to protecting the world's edible banana crop has been put on the extinction list. It is found only in Madagascar, where there are just five mature trees left in the wild. Scientists say the plant needs to be conserved, as it may hold the secret to keeping bananas safe for the future. Most bananas consumed around the world are of a type known as the Cavendish, which is vulnerable to a plant pest. (BBC News)