AristolochiaceaeThe Aristolochiaceae are a family of flowering plants. Wild ginger is included here, among others. The Aristolochiaceae are closely related to the Piperales, and may be placed there, but are more often given their own order (Aristolochiales).
Aristolochia and Asarum are two genera in this family. Many members of the Aristolochia genus and some members of the Asarum genus contain the toxin aristolochic acid, which discourages herbivores and is carcinogenic in rats. Aristolochia itself is carcinogenic to humans.
Pipevine swallowtail butterflies lay their eggs on pipevine (Aristolochia species), and the larvae dine on the plant but are not affected by the toxin, which then offers the adult butterfly protection against predators.