Name requested: Microsphaera penicillata var. extensaMycologia 44 (4): 573.
Homotypic synonym: Microsphaera extensaAnnales Mycologici 12 (1): 9. Mycotaxon 15: 130.
Homotypic synonym: Microsphaera alni var. extensaMycologia 32 (3): 340. 44 (4): 573.