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Brown Roll-rim (Paxillus involutus)

Brown roll rim mushroom growing beside moss on woodland floor Brown roll rim mushroom growing among fallen woodland leaves Brown roll rim mushroom underside showing crowded brown gills

The Brown Roll-rim (Paxillus involutus) is a woodland mushroom commonly found near birch trees and was once believed to be edible. It has a brown cap with a distinctive rolled-in edge when young, which flattens as it matures. The gills bruise dark brown when damaged, a key identification feature. It appears in late summer and autumn in woodland, parks, and gardens.

This mushroom is now known to be dangerous because it can cause a severe immune reaction after repeated consumption. The toxins trigger the destruction of red blood cells, leading to haemolytic anaemia, kidney failure, and in some cases death. Alarmingly, people may eat it several times without issue before suddenly becoming seriously ill.

Identification Features:

  • Cap colour yellow-brown to reddish-brown
  • Cap surface smooth, sometimes slightly sticky when damp
  • Cap margin strongly rolled inward (involute) when young
    • This rolled rim is a key feature
  • Cap becomes flattened or depressed in the centre with age
  • Gills are crowded, yellowish to brownish
  • Gills are decurrent (run down the stem)
  • Gills bruise or darken brown when touched
  • Stem is short, thick and brownish, often slightly off-centre
  • Flesh is pale yellowish, turning brown when damaged
  • Spore print is brown
  • Grows in woodland, especially with birch, pine and spruce
  • Often found in groups or scattered
  • Fruits summer through autumn in the UK

Foraging Safety:

  • Poisonous - never eat
  • Previously considered edible, now known to be dangerous
  • Can cause a rare but serious immune reaction called paxillus syndrome
  • Repeated consumption can trigger:
    • Sudden severe allergic reaction
    • Destruction of red blood cells
    • Kidney failure
  • Poisoning can occur even after previous safe meals
  • Cooking does NOT make it safe
  • Symptoms may include:
    • Vomiting
    • Abdominal pain
    • Dizziness
    • Collapse in severe cases
  • Often mistaken for:
    • Brown woodland mushrooms
    • Some edible milkcaps
  • Key warning signs:
    • Strongly rolled cap margin
    • Gills that bruise brown
  • Beginners should avoid all brown gilled woodland mushrooms
  • Dangerous to children and pets
  • If ingestion is suspected:
    • Seek urgent medical attention
    • Inform medics of possible mushroom poisoning
  • Best practice:
  • Learn to recognise and leave undisturbed

Identification video:

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