A new natural hybrid in the genus Petasites: P. japonicus × P. pyrenaicus (Asteraceae)

A large clone of a Petasites found growing at Borde Hill, East Sussex in 2014, which had been identified as female P. pyrenaicus (P. fragrans), otherwise unknown in Europe as far as we are aware, has been shown by morphological and molecular studies to be the hybrid female P. japonicus × male P. pyrenaicus. The origin of this hybrid, new to science, is unknown, but it has evidently been growing at Borde Hill for several decades, and has now escaped into the wild beside an adjacent footpath.