Physalis is a genus of plants in the nightshade family (Solanaceae), native to warm temperate and subtropical regions throughout the world. The genus is characterised by the small orangey fruit similar in size, shape and structure to a small tomato, but partly or fully enclosed in a large papery husk derived from the calyx. Commonly, it is called cape gooseberry or ground cherry but many species are well-known to humans and have more fanciful names.
They are herbaceous plants growing to 0.4-3 m tall, similar to the common tomato - a relative - but usually with a stiffer, more upright stem; they can be either annual or perennial. Most require full sun and fairly warm to hot temperatures. Some species are sensitive to frost, though others such as P. alkekengi (Chinese Lantern) tolerate severe cold when dormant in winter.
These plants grow in most soil types and do very well in poor soils and in pots. They need lots of water throughout the growing year, except towards fruit-ripening time. Plants are susceptible to many of the common tomato diseases and pests; other pests such as the False Potato Beetle (Leptinotarsa juncta) also attack them. Propagation is by seed.
The typical Physalis fruit is similar to a firm tomato (in texture), and like strawberries or other fruit in flavor; they have a mild, refreshing acidity. The flavor of the Cape Gooseberry (P. peruviana) is a unique tomato/pineapple-like blend. Physalis fruit have around 130 kcal for 100 grams, and are rich in cryptoxanthin.
Its uses are similar to the common tomato or to fruits with a refreshing taste. Once extracted from its husk, it may be eaten raw or used in salads, desserts, as a flavoring, and in jams and jellies. They can also be dried and eaten much like figs, apricots or grapes.
The Cape Gooseberry is native to the Americas, but is commonly grown and feral in many subtropical areas including South Africa (the "Cape" in the common name). Another important commercial type is the tomatillo (P. philadelphica). Physalis fruit are significant as an export product e.g. for Colombia.
Physalis have some medical relevance; they are sometimes used in herbalism as a remedy for sore throats. Smooth Groundcherry (P. subglabrata) is considered a hallucinogenic plant by some and its cultivation for other than ornamental purposes is outlawed in Louisiana by State Act 159. However, its use as a hallucinogen does not appear widespread.
The extinct Dacian language has left little traces, but in De Materia Medica by Pedanius Dioscorides, a plant called Strychnos alikakabos (Στρύχνος άλικακάβος) is discussed, which was called kykolis (or cycolis) by the Dacians. Some have considered this plant to be Physalis alkekengi, but Ashwagandha (Withania somnifera) has been proposed as an alternative candidate and indeed this widely-traded medical plant seems to be a better match.