Like dabs of soot on the backs of old blackberry leaves.
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.
At this size it will almost certainly be P. violaceum. Strictly you should look at spores, but P. bulbosum spore-masses are much smaller than these.
recording wildlife with The Recorder's Year on www.hbrg.org.uk/TRY.html.
Thanks for ID. Have just googled it and find it can be used as a biological control against brambles. There are acres of brambles where I took this photo - does the presence of Phragmidium violaceum mean they might be at risk?
Blog - Loose and Leafy - http://looseandleafy.blogspot.com/
No - it is everywhere, abundant, and there is no sign of Brambles dying off. It is a natural native fungus, specific to Brambles. I don't know how you would use it as a practical way to get rid of Brambles - reading the papers on the subject, I think you would be better just getting a spade!
Lat/Lng: 50.5, -2.5
OS grid ref: SY6677