This species is often considered merely a subspecies of the scarce swallowtail, though recent authors are increasingly counting it a separate species. Its distribution is restricted to the Iberian peninsula south of the Pyrenees. It is very similar to the scarce swallowtail but usually a more papery white, with noticeably more kite-shaped wings and a more distinct yellow line along the costa of the forewing. Another useful but not 100% diagnostic feature is the third bar from the wing base on the forewing, which is typically blunt on the vein, not tapered to a point: