Physalis (/ˈfaɪsəlɪs/, sometimes /faɪˈseɪlɪs/, from physalis = bladder) is a genus of flowering plants in the nightshade family (Solanaceae), which grow in warm temperate and subtropical regions of the world. Most of the species, of which there may be 75-90, are indigenous to the New World. Cultivated species and weedy annuals have been introduced worldwide. A notable feature is the formation of a large papery husk derived from the calyx, which partly or fully encloses the fruit.