The avocado tree is 'transgender ' and has overnight sex changes , a botanist has discovered . Professor John Warren discovered avocado trees switch from male to female in a matter of hours . Professor Warren , based at the University of Aberystwyth , Wales , said the avocado tree displays 'unique flowering behaviour ' . He found that during the day the trees , which grow in tropical and Mediterranean climates , flower with their 'female parts ' ready to be pollinated by bees . Professor John Warren discovered avocado trees switch from male to female in a matter of hours . The flowers close for the night and then the next morning they reopen - but now they use their 'male anthers ' to spread their pollen . Professor Warren said : 'The whole elaborate exercise seems to have evolved to increase the chances of cross-pollination , while limiting the amount of self-pollination . 'The trees are usually successful in avoiding the 'sin ' of inbreeding . ' Professor Warren has written about the avocado in his book called the Nature of Crops . The botanist , from the University of Aberystwyth , pictured , said the plants limited the amount of self-pollination .
Professor John Warren discovered avocado trees switch gender in hours . The botanist said the tree displays 'unique flowering behaviour ' However , trees are usually successful in avoiding polinating themselves .