Polypodium vulgare, the common polypody, is an evergreen fern of the family Polypodiaceae. Polypodium vulgare is an allotetraploid species, believed to have arisen by chromosome doubling of a sterile diploid hybrid between two ferns which are not known in Europe. The fern's proposed parents are the northern Asian and northern North American and western North American Polypodium glycyrrhiza. Biochemical data point to a species from eastern Asia as the second possible parent. The name is derived from poly (many) and pous, podos (a foot).Polypody has traditional uses in cooking for its aroma and sweet taste, and in herbal medicine as a purgative and vermifuge.