A tree with persistent, galled staminate flowers. Ash flower gall mite Eriophyes fraxinivorus causing deformation of staminate flower buds. This is a mite less than 0.5 mm in length. Galled flower buds never open, remain green, later turning black. Galls can persist for up to two years. Even though they are considered unsightly, the mite does not really harm the tree.