Earth

Dead man’s fingers are our creepy lifeform of the week

Dead man's fingers: Grassy surface with a group of greyish shapes that look like fingers coming from the ground.
View at EarthSky Community Photos. | David Hoskin from Halifax, Nova Scotia, Canada, took this photo of dead man’s fingers (Xylaria polymorpha) on June 25, 2024. Thank you, David. Are the dead awakening?!

What is that? Don’t worry, the dead are not rising from their graves nor has the zombie apocalypse arrived. As far as we know …

You will not be the first nor the last person to see human fingers in these images. Despite its disturbing appearance, there is nothing to fear. I present to you a very curious fungus called Xylaria polymorpha.

This fungus has a humorous but accurate nickname of dead man’s fingers.

Has the zombie apocalypse arrived?

Imagine one day you’re walking through the peaceful countryside and you see this. You’re welcome, I saved you from having a heart attack. Now you know it’s not what it looks like.

The roots of this fungus emerge from the ground to obtain light. These beings are just trying to live.

Black and dark gray fungus that looks like a hand with fingers coming from a surface with brown leaves and green plants.
These fungi look like human fingers coming from the ground. That’s why they are known as dead man’s fingers. Image via leeannbambalam/ iNaturalist (CC BY-NC 4.0).

Where to find these living fungi

You can find these fungi in wooded areas of all six inhabited continents. They’ll be on stumps and the dead wood of trees, especially beech trees. They grow inside rotten or cracked wood.

The fungus does not kill the tree. It only grows on already dead or dying wood and feeds on dead matter. This process is saprotrophy or saprotrophic nutrition.

Fungi already existed 400 million years ago. They are essential for breaking down dead plants and animals into nutrients that can be used by new plants growing in the soil.

A group of dark gray cylindrical fungi with a white top around a stump.
This fungus grows on already dead or dying wood and feeds on dead matter. Image vie Birchblanket/ iNaturalist (CC BY-NC 4.0).

Can you eat dead man’s fingers?

Surely, when you see this creepy plant, you’re probably not thinking, I’m going to prepare a delicious dish with these dead man’s fingers. Trust your guts. They look deadly, and indeed they are. These fungi are poisonous. All Xylaria contain amatoxin and phallotoxin, which are two compounds found in some of the world’s most poisonous mushrooms.

They become toxic when they enter your digestive system. And even if you see mushrooms that look colorful and beautiful, this might be a trick. Think of those frogs that look beautiful but are also poisonous.

On the other hand, humans try to find a use for everything. Scientists are investigating these fungi for medicinal and other pharmacological applications thanks to their antimicrobial, antibacterial and antioxidant properties.

3 long and thin structures coming from the ground. They look gray with a white top.
Dead man’s fingers don’t look delicious, and also, they are poisonous. Image via Aarongunnar/ iNaturalist (CC BY 4.0).

More on the dead man’s fingers

The word Xylaria comes from the Greek xýlon and means wood. The genus Xylaria includes about 100 species of fungi. Furthermore, the word Polymorpha means many forms.

Thus, these fungi can have domed or cylindrical shapes to more elongated or slender ones. Sometimes they can be somewhat deformed, with various protuberances. They have a smooth to rough external surface that only cracks over time.

The most developed specimens can measure up to 4 inches (10 cm) high. In terms of thickness, they reach 1.2 inches (3 cm) at their widest.

Many small, thin, greenish structures with a white top; a human hand at the side for size comparison.
These fungi are tiny and grow in groups. Image via Mamma Raz/ iNaturalist (CC-BY-NC-4.0).

In general, they’re dark colored, usually black or brown. Sometimes they have bluish or greenish tones. Unlike its exterior, the interior is white. If you cut them in half, you can see a spike-shaped interior.

This fungus tends to grow in groups. Rarely will you find a single dead man’s finger.

Long, thin white structure on a black surface. Has a wing-like structure, with filaments growing from the bottom.
In general, they’re dark colored, but the interior of the fungus looks white. Image via Siju/ iNaturalist (CC-BY-4.0).

Bottom line: Zombies are not awakening, as far as we know … If you see what looks like dead man’s fingers in the forest, you probably saw a creepy type of fungus.

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Posted 
July 8, 2024
 in 
Earth

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