This one was spotted today on a small feral rose branch growing out of a rock wall by the driveway. ‘Galls result from an intricate interaction between two living organisms. The gall-maker (insect disease, mite) causes the plant to change the course of normal growth and modifies growing tissue into a special swelling that surrounds the gall-maker. In the case of mossy rose galls it is a small cynipid wasp. Despite their unsightly appearance, most insect galls do not seriously affect the vigor of healthy plants. Mossy rose galls formed on the leaves of the rose are harmless.’ More from Iowa State University https://hortnews.extension.iastate.edu/2008/7-2/mossyrosegall.html It was a nice day for gardening, overcast and about 25 C.