Strange fleshy white hollow forms like miniature hats are growing on a few wild rhododendron leaves in a rhododendron slick that skirts the west river trail. No insects were around. After studying and drawing them I googled them and have concluded they are rhododendron galls, also called azalea leaf galls and pinkster galls.. They differ from insect galls in that they are made by the spores of a fungus. Early settlers reportedly pickled them and considered them to be a delicacy.