Climbing herbs or lianes. Stipules 2 or 0. Leaves alternate, lobed or simple; petiole often with glands. Tendrils usually solitary in leaf axils, rarely 0. Flowers usually large and handsome, axillary, solitary or in racemes, bisexual, 5-merous. Bracts often 3, forming an involucre below the fl. Sepals often coloured inside, sometimes with horns on the back just below apex. Petals 5 or 0, membranous, more vividly coloured than the sepals. Corona present, variously shaped, simple or usually composed of filaments. Androgynophore usually distinct. Stamens 5, free. Styles 3. Fruit usually indehiscent, ± berry-like, spherical or ellipsoid, or rarely fusiform.

The structure of the flower is described in this labelled image of Passiflora subpeltata. Species of the genus were called "Calvary Lesson" by Catholic missionaries in S America (Mabberley, 1997) and the explanation of that is also given on the same page.