Can anyone help me figure out what this is that is affecting my friend's Azalea. He said it is also affecting a nearby cherry tree. See photo.
Indeed the galls are caused by the fungus Exobasidium vaccinii. The galls are also known as "pinkster apples." This is a common problem on certain evergreen azaleas, primarily pink and white flowered types. Doubtful that the same organism is infecting the cherry tree. On the other hand, if the cherry tree is actually a peach, nectarine or almond tree, then it might have peach leaf curl (caused by an unrelated fungus, Taphrina deformans), which causes gall-like swellings and deformations of the leaves.
