The Grey Knight (Tricholoma Terreum) Identification

Grey Knight / Summer / Autumn / Toxic

Scientific Name

Tricholoma Terreum

Common Names

The Grey Knight, Dirty Tricholoma.




They are mycorrhizal with coniferous trees, most commonly pines and spruces.


A fairly common member of the Knight family, they were eaten a lot in the past. However some people do suffer adverse reactions to them, there are also some concerns about their effects on your kidneys. They could also easily be confused with more toxic mushrooms, so they are not a species that I personally eat.

Identifying Features:


Conical when young they flatten out with age and develop a raised, central umbo. They are grey to white in colour and have woolly fibres radiating outward from the centre.

Jerzy Opioła, CC BY-SA 3.0 <>, via Wikimedia Commons


Smooth and almost pure white, quite often hollow.

User:Strobilomyces, CC BY-SA 3.0 <>, via Wikimedia Commons


The gills are white when young becoming greyer with age. They are quite crowded and are sinuate.

Nico Hernandez, CC BY 4.0 <>, via Wikimedia Commons
sinuate gill


Mild mushroom aroma.


White to pale cream.


In food

They have a mild mushroom flavour but I don’t eat them myself for three reasons;

  • They are known to cause gastrointestinal issues in some people, even after they’ve been thoroughly cooked.
  • They can easily be mistaken for toxic lookalikes
  • There are concerns about there long term effects on your kidneys.

So they’re best avoided in my opinion.

Classiccardinal, CC BY-SA 4.0 <>, via Wikimedia Commons

Known hazards

A Chinese study found that the Grey Knight contains toxins that cause a disease called Rhabdomyolysis, which is normally caused by serious muscle trauma for example being crushed or being bitten by a snake. It causes your muscle fibres to die, releasing their contents into your blood stream, this can lead to serious kidney failure. I have however also read reports that say that only eating what they call an ‘abnormal’ amount would cause rhabdomyolysis, they say that eating up to 200 grams would be safe.

Potential lookalikes

Many members of the Tricholoma family look similar for example the Leopard Tricholoma (Tricholoma Pardinum) which is believed to be highly poisonous. The Leopard Knight tends to be larger, its cap scales are arranged in a concentric pattern and it prefers deciduous trees.

The Yellow Knight (Tricholoma Equestre) may also be mistaken for the Grey Knight but this has bright yellow gills.

Also the Sulphur Knight (Tricholoma Sulphureum) but this mushroom has a yellow cap and smells of sulphur.

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