The emerald swallowtail has a wingspan reaching about 7.5 to 10cm. The dorsal sides of the wings are covered by a large set of green scales with a background colour varying from dark green to black, with a broad set of bright emerald green metallic bands in an almost V shape. The undersides are black with orange, white and blue spots along the edges of hind wings. The wings have extended parts to it and this is where swallowtails get their name. The iridescent green of this butterfly is not produced by pigments, it is caused by the colouration of the structure of the wings. They refract the light and give rise to blue and yellow visible reflections, producing the perception of green colour when additively mixed. The juvenile caterpillar is green with orange bands laid on top in a segmented fashion.