The Purple Emperor (Apatura iris) is a species of butterfly of the brush-footed butterflies (Nymphalidae) family, noted for its iridescent, metallic, violet-blue sheen which occurs on the wings of the male. It is found in damp, deciduous forests in the vicinity of streams, rivers and ponds where it settles on tree foliage overhanging the water. Found on http://www.probertencyclopaedia.com/browse/BPA.HTM