Butterbur is a genus of flowering plants in the sunflower family, Asteraceae, that are commonly referred to as butterburs and coltsfoots They are perennial plants with thick, creeping underground rhizomes and large rhubarb-like leaves during the growing season.
The short spikes of flowers are produced just before the leaves in late winter (e.g. Petasites fragrans or spring, emerging with only a few elongated basal bracts and are usually green, flesh coloured or dull white depending on the species.
Butterbur has been used for over 2000 years to treat a variety of ailments including fever, lung disease, spasms, and pain. Currently, butterbur extract is used for migraine prevention and treatment of allergic rhinitis, which have the most evidence for its effectiveness.