Aristolochiaceae

Abstract

The Aristolochiacea, the birthwort family, in the order of Piperales, is a family of flowering plants in clade of Magnoliids, consisting of about 7 genera with approximately 400 species, primarily in tropical and subtropical regions. Plants are usually herbaceous, shrubs, rarely subshrubs, or trees. Stems are often shorten or twining. Leaves are nearly basal or alternate, blades entire, rarely 3–5-lobed, basal often cordate. Veins are mostly palmate, pinnate, or petiolate. Stipules are absent. Inflorescences are terminal or axillary, racemes, cymes or corymbs, sometimes with solitary flowers. Flowers are bisexual, zygomorphic, or actinomorphic. Perianths are usually colorific, campanulate, or tubular. Limbs are 3-lobed, trumpet-shaped, or middle segment stretching to one side, ligulate, rarely 6-lobed or arranged to 2 whorls. Stamens are 6–12 and rarely more. Filaments are adnate to ovary or style column with anthers free, or filaments and anthers fully adnate to style column to form gynostemium. Anthers are 2-loculed, dehiscence longitudinal. Ovary is inferior or subinferior, rarely superior, and 4–6-loculed. Several to numerous anatropous ovules are on per locule. Style apex are 3–6-lobed, or adnate to stamens forming gynostemium. Fruit a capsule, dehiscent, or indehiscent. Seeds are flat or dorsal convex, abdominal concave, or with spongy wings around. Two species, belonging to different genera, are illustrated in this chapter.