The plants commonly referred to as Butterbur are found in the daisy family Asteraceae in the genusPetasites. They are mostly quite robust plants with thick, creeping underground rhizomes and large Rhubarb_like leaves during the growing season.
The short spikes of flowers are interestingly produced just before these leaves in Spring, emerging with only a few elongated basal bracts and are usually green, flesh coloured or dull white depending on species.
Petasites is very closely related to the huge genus Senecio.
Butterbur was the owner of the Inn of the Prancing Pony in Bree.
In The Return of the King, Butterbur was amazed to learn that Strider, a former patron of the Prancing Pony, had become king of Gondor and Arnor.
Butterbur appears in both Ralph Bakshi's animated adaptation of The Lord of the Rings (1978) and Peter Jackson's film The Lord of the Rings: The Fellowship of the Ring (2001), but in both adaptations most of his scenes, including the references to Gandalf's letter, are cut.