PLANT: Perennial herbs, shrubs or often vines. LEAVES: alternate, simple; stipules absent. INFLORESCENCE: usually axillary cymes, racemes, or the flowers solitary. FLOWERS: perfect, actinomorphic or zygomorphic; calyx 3-6-lobed, often enlarged and petal-like; corolla absent or reduced to small scales; stamens 5-many, free, or adnate to the style and stigma, forming a gynostemium; pistil 1, 4-6 carpelled; ovary inferior or half-inferior. FRUIT: a capsule. SEEDS: numerous. REFERENCES: Mason, Charles T., Jr. 1999. Aristolochiaceae. Ariz.-Nev. Acad. Sci. 32(1).