Phylum: Ascomycota Family: Incertae Sedis
Gymnosporangium cornutum Arthur ex F. Kern
Rowan Crown
A northern species, infrequently recorded. The aecial stage is found on leaves of rowan (Sorbus aucuparia), but other hosts also used. The telial stage is on juniper
References:
Ellis & Ellis (1997) - Microfungi on Land Plants;
Termorshuizen & Swertz (2011) - Dutch Rust Fungi;
Wilson & Henderson (2011 reprint) - British Rust Fungi