Eastern Comma

The eastern comma is a brushfoot butterfly (Nymphalidae) belonging to the genus Polygonia, a group commonly known as anglewings for their irregular, angular, and scalloped wing margins that give them a jagged, leaf-like outline. It is found throughout much of eastern North America, favoring wooded habitats over the open fields and meadows preferred by many other butterflies.

The species gets its common name from a small, pale, comma-shaped mark on the underside of the hindwing, a feature shared with several related Polygonia species but useful, along with subtle differences in mark shape, hindwing color, and shape of the projections, for identification. Like the mourning cloak, the eastern comma overwinters as an adult, sheltering in bark crevices, hollow logs, or similar cover, and can be one of the first butterflies seen flying on warm days in late winter or early spring.

An old alternate name, "hop merchant," reflects a folk belief tied to the caterpillar's association with hop vines, an example of how vernacular names for butterflies sometimes carry historical or folkloric associations rather than purely descriptive ones.

• Wingspan roughly 4.5–6.5 cm; upperwings are orange with dark brown-black spots and blotches, deeper toward the wing bases.
• Wing margins are deeply notched and angular ("anglewing" shape) rather than smoothly rounded, giving a ragged silhouette.
• Underside is mottled brown and gray, closely resembling a dead leaf, with a small silvery-white comma-shaped mark near the center of the hindwing.
• Seasonal forms differ: summer-form individuals tend to have darker hindwings, while the overwintering fall/winter form is typically more orange overall.
• Lookalikes: the question mark butterfly (Polygonia interrogationis) is very similar but larger, with an added small dot next to the comma mark forming a "question mark" shape on the hindwing underside; the gray comma is another close relative distinguished by subtler differences in the underside pattern.

Found in deciduous woodlands, forest edges, streamside corridors, and wooded parks across much of eastern North America, generally avoiding wide-open treeless habitats. Adults overwinter in sheltered spots such as bark crevices or woodpiles and can be seen flying on unusually mild days in very early spring, well before most butterflies emerge. Activity continues through summer and fall, with the species often perching on tree trunks, fallen logs, or bare ground rather than flowers.

Adults feed mainly on tree sap, rotting fruit, and occasionally animal droppings rather than flower nectar, and are frequently seen basking with wings spread on sunlit tree trunks or the forest floor. When at rest with wings closed, the dead-leaf pattern on the underside provides effective camouflage against tree bark and leaf litter. Caterpillars feed on the leaves of host plants including elm, hop vines, and nettles, and are spiny with variable coloring, often resting along leaf edges or the undersides of leaves.

Complete metamorphosis, with two to three generations per year across most of its range. Eggs are laid singly or in small stacks on the leaves of host plants such as elm, hop, and nettle; caterpillars are spiny, variably colored from pale to dark, and feed through several molts before pupating in an angular, mottled chrysalis suspended from a leaf or twig. The final generation of the year emerges in the darker summer form initially before later individuals shift to the brighter overwintering form, which survives the cold months as a dormant adult sheltering in bark crevices or similar cover, emerging again the following spring.