Dryas iulia (often incorrectly spelled julia), commonly called the Julia butterfly, Julia heliconian, the flame, or flambeau, is a species of brush-footed (or nymphalid) butterfly. The sole representative of its genus Dryas, it is native from Brazil to southern Texas and Florida, and in summer can sometimes be found as far north as eastern Nebraska. Over 15 subspecies have been described.

Its wingspan ranges from 82 to 92 mm, and it is colored orange (brighter in male specimens) with black markings; this species is somewhat unpalatable to birds and belongs to the "orange" Müllerian mimicry complex.

This butterfly is a fast flier and frequents clearings, paths, and margins of forests and woodlands. It feeds on the nectar of flowers, such as lantanas (Lantana) and shepherd's-needle (Scandix pecten-veneris), and drinks the tears of caiman, the eye of which the butterfly irritates to produce tears. Its caterpillar feeds on leaves of passion vines, including Passiflora affinis and yellow passionflower (P. lutea) in Texas.

Its mating behavior is complex and involves a prolonged courtship whose outcome appears to be controlled by the female. This raises questions pertaining to the occurrence of the evolution of sexual conflict.

The species is popular in butterfly houses because it is long-lived and active throughout the day. However, the caterpillars are spiky and may cause a skin rash.

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