A gall (caused by an insect, I presume) on Buttercup (Ranunculus). Anyone identify it, please?
No identification made yet.
No interactions present.
The overall appearance of the large gall and the presence of a series of smaller versions (perhaps) suggest this is a fungal gall. Buttercup leaves are host to only 2 insects galls, both of which are leaf edge rollers.
I have a list of UK Plant Galls from 2012 (see http://www.british-galls.org.uk/) which shows 10 fungi and 4 insects which cause galls in Ranunculus. None of the insects seem to be leaf rollers. I wonder if you have a more complete list?
You are very sharp-eyed to see the smaller galls - I had missed them both on the leaf itself and in the original photo. Perhaps it might be worth moving the observation to Fungi and Lichens?
Redfern and Shirley 2nd ed give -
Dasineura ranunculi = "leaf edge rolled, bulged and thickened" See
Epitrimerus rhyncothix = "marginal roll narrow" not recorded since 1928
2 other insects mentioned gall flowers.
Are either Puccinia magnusiana or Uromyces dactylidis (both fungi)possible at an early stage?
Lat/Lng: 55.4737, -3.2026
OS grid ref: NT240206