One fine day walking through the fields, you could get a scare when you trip over these dead man’s fingers sticking out of the ground.
Don’t let the alarms go off, it’s not a buried zombie wanting to get out. You have come across the fungus Xylaria polymorpha , a saprophytic fungus of the Ascomycota division belonging to the order of the Xylariales.
You have most likely found it on the ground, in the remains of wood from normally flat trees such as oaks or beech , feeding on rotten wood or wounds on the trunks of the trees, during the autumn especially in November-December.
When the fruiting bodies are young they have a light brown appearance, sometimes mealy, darkening as they age to a black color when they are mature and towards the end with a warty appearance because the bottle-shaped ascomas already have their ostiolus. Sometimes they can be green or light blue as in the photograph, which gives them a more terrifying appearance.The dead fingers that are observed is the fruiting body of the fungus that appears when it is going to perform sexual reproduction. During spring, this fungus disperses conidia for dispersal by asexual reproduction.
The spores have a tonsil-shaped, irregular shape and are flattened on one side, smooth and brown in color. Asci are octosporic (they have 8 spores) with spores that have an apical ring that appear in the sexual phase of the biological cycle of this fungus.
There are not only dead fingers
There is another very similar fungus belonging to the same genus, Xylaria longipes, which should not be confused with. This is known in English as Dead Moll’s Fingers, something that would roughly translate as the fingers of the dead Moll. Its main difference with Xylaria polymorpha is the long peduncle that it presents and that is somewhat slimmer than the previous one.
As a curiosity, it is thought that the wood affected by this fungus may have better properties for making violins, due to the chemical compounds that have been isolated from them, such as the antifungal xylaramide, tyrosol and sordarin.
