Annual or perennial herbs, glabrous or pubescent with simple hairs. Leaves mostly equal, sometimes paired, simple, membranous, entire, denticulate or sinuate, petiolate. Inflorescences solitary or few flowers in leaf axils or branch forks. Flowers radially symmetrical, 5-merous; calyx campanulate, lobed, often ribbed; corolla yellow or white, often with a contrasting eye, rotate or rotate-campanulate, mostly subentire; filaments inserted at base of corolla tube, often pubescent, sometimes basally expanded, anthers dehiscing longitudinally; ovary 2-locular. Fruit a juicy, globose berry; fruiting calyx green (in our species), inflated, entirely enveloping the berry, membranous or leathery with 5 or l0 longitudinal ribs, the base often invaginated; seeds numerous, compressed, discoid or reniform, minutely pitted; embryo coiled, subperipheral.
About 75 species mostly in the Americas, a few in Eurasia. Three species in Taiwan.
