Both azalea gall and camellia gall are fungal diseases, as opposed to most galls, which are caused by insects.
Azalea galls are fleshy, irregular shaped growths (galls) that appear on the surface of the leaves, or flowers, of azaleas and rhododendrons. Initially, they are pale green, or sometimes pinkish, turning white as the summer progresses due to the formation of a floury covering, or bloom, of fungal spores.
The galls vary in size from pea-sized, all the way up to 7.5cm (3in). The affected leaf or flower is more-or-less totally replaced by the gall. Several galls will appear on affected plants.
Camellia galls look quite alarming. They are creamy-white swellings that develop during the summer, replacing the leaves. Most commonly only one or two galls appear on each plant.
These galls can be up to 15cm (6in) in size and very variable in shape. At first, they have a firm texture, becoming spongier or softer as they age, and are green, turning creamy-white as the spores are produced.