Found on Dock leaf (Rumex sp.). 2 comments.
Caution: Do NOT use iSpot to identify fungi to eat!
Some fungi are very poisonous so a mistaken ID could have serious consequences.
No interactions present.
When recording I always check I can see the tiny white tufts of the fungus itself, as other things can cause similar lesions on dock leaves. Also, there are two other Ramularia species that can occur on R. crispus, R. obtusifoius, etc. However, these photos show the typical appearance so well that I am adding agreement with reasonable confidence.
N.B. From what we can see, the host here is more likely to be Broad-leaved Dock, R. obtusifolius.
I have decided I was over-confident in adding agreement to this post. I agree the leaf lesions are most likely caused by a Ramularia, but what we see here are simply the lesions and not the fungus itself. Ramularia rubella is the most likely cause, but the lesions of R. pratensis on Broad-leaved Dock look identical and are not rare on this host.
Thanks for the useful info Alan. Out of interest, what is it about the appearance of the dock leaves that leads to the likelihood of it being R. obtusifolius? I spent a wee while trying to decide whether it was obtusifolius or crispus and obviously got it wrong.
What we see of the leaf-shape matches R. obtusifolius.
Lat/Lng: 57.16, -2.2
OS grid ref: NJ880076