Tussilago farfara, commonly known as coltsfoot, is a plant in the groundsel tribe in the daisy family Asteraceae, native to Europe and parts of western and central Asia. It has had uses in traditional medicine. The name "tussilago" is derived from the Latin tussis, meaning cough, and ago, meaning to cast or to act on. However, the discovery of toxic pyrrolizidine alkaloids in the plant has resulted in liver health concerns.
Tussilago farfara is the only accepted species in the genus Tussilago, although more than two dozen other species have at one time or another been considered part of this group. Most of them are now regarded as members of other genera (Chaptalia, Chevreulia, Farfugium, Homogyne, Leibnitzia, Petasites, Senecio).
Coltsfoot is a perennial herbaceous plant that spreads by seeds and rhizomes. Tussilago is often found in colonies of dozens of plants. The flowers, which superficially resemble dandelions, appear in early spring before dandelions appear. The leaves, which resemble a colt's foot in cross section, do not appear usually until after the seeds are set. Thus, the flowers appear on stems with no apparent leaves, and the later appearing leaves then wither and die during the season without seeming to set flowers. The plant is typically 10–30 cm in height. The leaves have angular teeth on their margins.