Ratiboř

This species belongs to saproparasitic wood-decaying fungi, which gradually kill the host tree and then continue to form fruiting bodies on its dead trunk for some time. This rare find was discovered by the leading Czech mycologist RNDr. Mgr. Jan Wipler, Ph.D.

The find is located on an old European ash tree (Fraxinus excelsior) between houses no. 250 and no. 381 (Mrs Jakubíková's wine shop and confectionery) in the cadastral area of Ratiboř (postcode 756 21). The exact coordinates of the location are 49.396459N, 18.055192E, on mapy.com here.

The fruiting bodies of the rust fungus are annual, without skeletal fibres, and disintegrate after ripening. A typical symptom of infection is a black cavity in the tree trunk, resembling a woodpecker's nest – this is where the species name nidus-pici comes from. An asexual stage (anamorph) appears at the edges of the cavity, characterised by the formation of chlamydospores and rust-coloured conidiophores. Fruit bodies in the sexual stage (teleomorph) appear only rarely.

An infected tree remains asymptomatic for a long time – the infection can remain latent for up to 5 years before it manifests itself in noticeable structures. An important diagnostic feature is gutation, when the fungus secretes drops of fluid to get rid of excess water and metabolites. The pathological process is a typical example of white rot, in which the fungus enzymatically breaks down lignin, thereby disrupting the structure of the wood. The root system remains undamaged and decomposition proceeds slowly, usually from the point of entry into the host tissue in both directions. Intervention in the tree is recommended only when the depth of the cavity exceeds the radius of the trunk at that point. Until then, there is no risk of the tree breaking.

The downy oak polypore is not listed in the current Red List of Macromycetes of the Czech Republic, yet it is a species that deserves attention and protection, especially given its occurrence mainly in natural and preserved forest stands.

Interesting fact

This fungus is commonly found in primeval forests, mainly on oak and beech trees. However, it can also be found in towns and villages in exceptional cases – and that is exactly what happened here! In recent years, it has also appeared sporadically in synanthropic habitats such as parks, cemeteries and gardens – often as a wound infection after lightning, a broken branch or a cut surface.

Although it is not officially classified as an endangered species, it is a rare fungus. Such a find right in the village is not only unique, but also a source of pride. Which village can boast such a natural rarity – and right next to a wine shop?

RNDr. Mgr. Jan Wipler, Ph.D. / mycologist