Volkartia (Volkartia rhaetica) photo and description

Volkartia (Volkartia rhaetica)

Volkartia (lat. Volkartia rhaetica) is a unique mushroom. It is the only fungus of the genus Volkartia. This is a genus of ascomycete fungi (family Protomycium). This fungus often parasitizes plants of the genus Skerda.

The genus Volkartia was discovered and put into use by R. Mair back in 1909, but for a long time it was synonymous with the genus Taphridium. But in 1975, this genus (and fungus) was again made independent by Reddy and Kramer. Later it was accepted to include in this genus some other fungi that previously belonged to Taphridium.

Volkarthia is considered a parasite. The fungus causes dark spots on the leaves of a plant affected by Volcarthia. The fungus itself is usually located on both sides of the leaf. Volkarthia has a grayish-white color and occupies a fairly large part of the leaf of the plant.

A few words about the internal structure of the fungus.

Ascogenous cells create a layer of highly cellular order under the epidermis. Usually they are spherical, the size is 20-30 microns. They grow as synasci, there is no dormant period. It is the appearance of synascos that is a distinctive feature that allows us to separate Volkarthia from fungi of the Tafridium genus. The location of ascogenous cells can be considered as a difference between this fungus and representatives of protomyces, in which the cells under the epidermis are scattered. It can be added that in protomyces, the formation of synasces occurs after a dormant period. If we talk about synasces, then in Volcarthia they are cylindrical, their size is approximately 44–20 µm, the thickness of the colorless shell is about 1,5–2 µm.

Spores, like the shell, are colorless, 2,5–2 µm in size, round or ellipsoidal in shape, can be either straight or curved. Ascospores are often formed already at the ascogenous cell stage. Spores tend to grow mycelium after the dormant period is over.

This fungus usually parasitizes Crepis blattarioides or other similar skerda species.

The fungus is found in Germany, France, Switzerland and Finland, and also comes across in Altai.