Petasites Hybridus
 

Petasites Hybridus

This is Petasites Hybridus, known in Swedish as pestskråp (lit. "plague-butterbur"), as it was believed it could even cure plague. Its main use, however, was to cure convulsions, something it has been used for since the Middle Ages. This use, unlike curing plague, has a basis in science: The active substance, an alkaloid named petasin[a], was isolated from the plant the 1950's and is 15 times as powerful as papaverin[b], which is used to cure cramps.

[a]

http://en.wikipedia.org/wiki/Petasin

[b]

http://linnaeus.nrm.se/flora/di/astera/petas/petahyb.html