Onagraceae - Evening primrose family

Herbs, sometimes ± woody at the base, or shrubs. Stipules minute or 0. Leaves alternate or opposite, rarely whorled, simple, entire, lobed or pinnatifid. Flowers bisexual or (rarely) unisexual, actinomorphic, 4- or 5-merous (rarely 2-, 3- or 6-merous). A long hypanthium usually present (not in Ludwigia). Petals free, sometimes 0. Stamens usually twice as many as the sepals in 2 whorls. Ovary inferior. Style single, stigma variously shaped. Fruit usually a loculicidally or irregularly dehiscent capsule, 1-many-seeded.

Worldwide: 18 genera and 650 species, cosmopolitan, especially tropical and warm America.