Not frequently recorded, but the species is inconspicuous and certainly overlooked. No formal conservation assessment has been made.
Similar to A. veneta, but ascospores with a somewhat larger lower cell and less tapered apex. Specimens on Fagus have ascospores 15-17 x 3.5-4 µm in size, formed within asci measuring 40-45 x 10-12 µm.
A paraphyletic taxon with A. veneta nested within it; further molecular studies may confirm recognition of further segregate species; A. quercina and A. tiliae are provisionally recognized here.
The teleomorph is primarily known from dead leaves of Fagus species. Records from other woody plants (including Quercus and Tilia) are likely to belong to separate taxa although the molecular evidence does not currently support their exclusion. The species seems to occur exceptionally on herbaceous tissues, but further research is needed. The anamorph is known from lesions on living leaves and more rarely twigs.
Widespread in north temperate regions including the northern USA and Canada and many European countries including Russia and Georgia. It may be introduced elsewhere.
A weak and non-specific pathogen, with asexual spores formed in lesions in living leaves, and sexual spores produced following death of the host tissues.