Aristolochia

Aristolochia is a genus of flowering plants in the family Aristolochiaceae, commonly known as birthwort or pipevine. The genus comprises several hundred species of herbs, shrubs, and woody climbers found in tropical and temperate regions worldwide. Most species are climbing vines with heart-shaped leaves and distinctive pipe- or urn-shaped flowers, often with mottled interiors and an odor that attracts specific pollinators. The flowers employ a trap-and-release mechanism, temporarily ensnaring visiting insects to achieve pollination.

Fruits are typically capsules containing winged seeds. Aristolochia species vary in size from groundcovers to vigorous climbers; one well-known horticultural species is Aristolochia macrophylla, the Dutchman's pipe, valued as a shade-tolerant vine in gardens. Ecologically, Aristolochia species serve as host plants for certain butterflies, such as the pipevine swallowtail in North America.

The plant has a controversial medicinal history. Several species were used in traditional medicine, notably for diuretic or purgative properties. However, many Aristolochia species contain aristolochic acids, compounds that are nephrotoxic and carcinogenic. Exposure or ingestion has been linked to aristolochic acid nephropathy and urothelial cancers, and products containing Aristolochia are restricted or banned in several countries.

Cultivation requirements vary by species but many prefer shaded to partly shaded, moist soils and can tolerate a range of climates. Taxonomically, Aristolochia is the largest genus in Aristolochiaceae and includes about 500 species, many of which are cultivated ornamentally or studied for their distinctive floral structure and chemical properties.