Taphrina pruni being larger than the healthy one. As a fungus, cool and wet weather conditions promote the germination of spores, whilst warm and dry weather results in infection rarely taking place. Colonisation can become extensive and eradication very difficult. The disease can to some degree be controlled by carefully removing infected branches, witch's brooms and fruit before the infective air borne spores are produced. Applications of copper-containing fungicides have a degree of control over the fungus. Taphrina pruni Taphrina pruni is a fungal plant pathogen of blackthorn (Prunus spinosa) that causes the Pocket or bladder Plum gall, a chemically induced distortion
Prunus pumila leathery, long, with a serrated margin. The flowers are in diameter with five white petals and 25–30 stamens. They are produced in small clusters of two to four. The fruit is a small cherry diameter, ripening dark purple in early summer. "Prunus × cistena" (purple leaf sand cherry) is a hybrid of "Prunus cerasifera" (Cherry Plum) and "Prunus pumila". It was developed by Niels Ebbesen Hansen of South Dakota State University in 1910. Prunus pumila Prunus pumila, commonly called sand cherry, is a North American species of cherry in the rose family. It is widespread in eastern and central Canada