Spots on a plant with a diameter of up to 6 mm, usually located near the veins, angular, yellowish-brown. There are no thickenings at the lesion sites.
Mycelium develops under the cuticle of fern.
The marsupial layer (“ hymenia ”) has the appearance of a whitish coating on both sides of the spots, but is more developed on the underside.
Eight -spore asks, with sizes (13) 18-25 × 6-7 (10) microns, club-shaped, with a truncated, less often rounded apex. Basal cells ( see Tafrin's article ) with sizes of 5-8 × 4.5-8 microns, almost isodiametric.
Ascospores are ellipsoidal, 4-5 × 2-3 microns, often budding.
Taphrina athyrii is known in Europe - on the British Isles , the Scandinavian Peninsula ( Norway ), in Switzerland , and also in Asia - in Abkhazia .
The fungus was first discovered in Abkhazia near Pshu on the Cartesian thyroid ( Dryopteris carthusiana ), it also affects the male thyroid ( Dryopteris filix-mas ) and female coydisciphy ( Athyrium filix-femina )
