Taphrina

Taphrina is a fungal genus within the Ascomycota that causes leaf and catkin curl diseases and witch's brooms of certain flowering plants. One of the more commonly observed species causes peach leaf curl. Taphrina typically grow as yeasts during one phase of their life cycles, then infect plant tissues in which typical hyphae are formed, and ultimately they form a naked layer of asci on the deformed, often brightly pigmented surfaces of their hosts. No discrete fruit body is formed outside of the gall-like or blister-like tissues of the hosts. The asci form a layer lacking paraphyses, and they lack croziers. The ascospores frequently bud into multiple yeast cells within the asci. Phylogenetically, Taphrina is a member of a basal group within the Ascomycota, and type genus for the subphylum Taphrinomycotina, the class Taphrinomycetes, and order Taphrinales....read more on Wikipedia.