Gall, on Alder

Gall, on Alder

Observation - Gall, on Alder - UK and Ireland. Description: Single large raised blister on upper side of Alder leaf and hollow on under side. Blister is paler t

Single large raised blister on upper side of Alder leaf and hollow on under side. Blister is paler than the rest of the leaf. Quite a few around.