Annual or perennial herbs, glabrous to pubescent. Leaves usually alternate, petioled, entire or lobed, texture soft. Flowers solitary. Calyx 5-cleft, enlarged, bladder-like and 3-angled in fruit. Corolla campanulate, white or yellow. Stamens 5, attached near the base of corolla tube. Ovary bilocular. Fruit a globose berry, surrounded by the inflated calyx. Seeds many, compressed.