Rhytisma umbonatum. A. Habit on leaf. B. Stromata with ascomata viewed through a hand lens. C. Stroma with single ascoma viewed with a dissecting microscope. D. Stroma in vertical transverse section (low power). E. Part of stroma in vertical transverse section (high power), note old conidioma in upper wall of stroma. F. Asci, ascospores and paraphyses. G. Conidioma in vertical transverse section. H. Conidiogenous cells and conidia.
