Aecidium petasitidis Sydow, 1901
A considerable number of rusts of the genus Puccinia that have their uredinia and telia on grasses make aecia on butterbur. Aecia cannot be identified on the base of external characters. Therefore they are collective addressed as Aecidium petasitidis.
Petasites albus, hybridus, paradoxus.
Blumer (1946a), Buhr (1965a), Gäumann (1959a), Pellicier (2001a), Roskam (2019a), Tomasi (2014a).