The Ulysses butterfly (Papilio ulysses), also known as the blue mountain butterfly, is a large Australian swallowtail. The Ulysses butterfly has a wingspan of about 14 cm (5.5 inches). It lives in northeastern Australia along the coast of Queenslan. It inhabits tropical rainforest areas and suburban gardens. The Ulysses butterfly's favourite food plant is euodia (Melicope elleryana), a tree with clusters of small pink flowers growing straight out of the branches. The upperside the wings are an iridescent electric blue; the underside is a more subdued black and brown in colouration. The colours are produced by the microscopic structure of the scales.