Xylaria polymorpha

Dead man’s fingers

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A fungus that feeds on dead organic matter, like rotting wood. The fungus is popularly called dead man’s fingers, because its fruiting body looks a lot like a dead hand emerging from the soil. Scary, right?

A fungus that feeds on dead organic matter, like rotting wood. The fungus is popularly called dead man’s fingers, because its fruiting body looks a lot like a dead hand emerging from the soil. Scary, right?

Polymorpha means ‘many shapes’. X. polymorpha is named like this, because the fruitbodies can take many forms. They can be found in black or blue colors, or covered in a layer of fluffy white spores.

Full circle

X. polymorpha is a saprotrophic fungus. This means that it feeds on dead organic matter, like dead tree trunks. The fungus breaks down the wood to its individual molecules. Those serve as food for other organisms like plants. In this way, fungi complete the circle of life.

Over 90% of the recycling of organic matter in nature is done by fungi. Without saprotrophic fungi and bacteria like X. polymorpha, a forest would suffocate in its own waste. Dead leaves, branches, trees and organisms wouldn’t decay, no new nutrients would be added to the soil and the soil would soon be depleted. Fungi are indispensable for all life on earth.

Inside the fungus

X. polymorpha is a member of the phylum Ascomycota, or sac fungi. Its spores are stored in sac-like structures. The mushroom of this fungus has already scared many people, because it looks like a dead hand emerging from the forest ground.

If you were to cut a dead man’s finger in half, you would find a sturdy, white material, surrounded by black dots. These dots contain the spore-sacs. The spores are ejected out of the fungus through holes in the surface of the mushroom. This process of developing and ejecting spores can take months for X. polymorpha, which is very long for a fungus.

Photo: Mike Roberts