Taphrina amentorum (Sadeback) Rostrup. Fruit body consists of asci, about 30-50 x 10-20µ, which cover both surfaces of swollen catkin scales and malform the infected scales so that they become curved, tongue-like outgrowths; light green when fresh, and stained or streaked with red. Ascospores often budding in the ascis, 3-5 x 4-5µ. Habitat densely on female catkins of alders. Frequent. Found in southwestern North America. Season June-September. Not edible.