Common polypody, rock polypody

The dried rhizome is used as an expectorant in treating bronchitis and chronic coughs.
The rhizome of Polypodium vulgare, a very similar European species (considered the parent plant by some botanists), contains a large number of chemical compounds, including a non-violent purgative that stimulates bile secretion, an essential oil, a sweet mucilage, a bitter resin with vermifuge properties, osladin (a substance 300 times sweeter than sugar) and glycyrrhizin (which has a licorice-like taste).