My ID of T. pruni on P. padus is incorrect, the collection is of T. pruni from P. domesticus (hybrid). This needs to be and will be amended in the FRDBI.
In recent communication with Paul Cannon at Kew, much of the information that Brian lays out was corroborated by him.
Microscopically and Morphologically the two species are difficult to tell apart. However, as Taphrina species are deemed as being strongly host specific, it is unlikely that T. padi would turn up on P. domesticus or P. spinosa. P. padus (its host) is in a different section of the genus. Likewise, T. pruni is unlikely to turn up on P. padus. Due to suggestions in past papers, that these two species were synonymous, confusion over hosts has arisen.
Best
Andy