The caterpillars range in color from green and yellow to orange and are ornamented with black specks that give them the appearance of a bird dropping, which is useful for camouflage, or a large eye, a form of mimicry that is also efficient for protection.

[3] The butterfly is found in the eastern United States, specifically in the Appalachian Mountains, ranging from Pennsylvania to Georgia.

[3] Originally, researchers believed that P. canadensis and P. glaucus were distributed in distinct regions separated by a hybrid zone stretching east from Minnesota to southern New England and south along the Appalachian Mountains.

[3] Data collected about oviposition preferences and larval mortality rates further suggest hybridization between P. canadensis and P. glaucus.

[4] Due to shifting thermal landscapes, the ranges of both P. glaucus and P. canadensis have moved dramatically enough to overlay, leading to crossbreeding that has resulted in P. appalachiensis.

[3] Although hybrid speciation is often difficult to achieve, given the difficulty of finding a habitat separate from either parental species (competitive exclusion) and remaining genetically distinct from the parental species (reproductive isolation), P. appalachiensis accomplishes this by living in a separate habitat: a higher elevation in the Appalachian Mountains.

[9] In addition to their appearance, every caterpillar of the swallowtail family has an osmeterium, a special scent gland behind the head that, when disturbed, is everted from its pouch and releases a foul odor.

[9] The mimicry induced by the eyespots and forked gland give the caterpillar the appearance of a snake, adding to its defense mechanisms against potential predators.

[6] They prefer to remain in mid-level to high elevations in the southern Appalachian Mountains, and the species' range stretches from Pennsylvania to Georgia and Alabama.

[2] The adult butterflies tend to remain in the canopy of the Appalachian hardwood forest and mainly only leave when visiting flowers.

The Appalachian tiger swallowtail shares a delayed flight pattern and many other hybrid-like traits with P. glaucus and P. canadensis despite its genetic isolation.

[2] The Appalachian tiger swallowtail tends to fly directly up the western side of Spruce Knob towards the summit against strong westerly winds.

[8] The summit contains substantial vegetation within protected nooks where the adult butterflies rest and obtain nectar from various plants.