Paxillus involutus

Timebomb Toadstool – The Brown Roll-Rim

The words ‘Mushroom’ and ‘Toadstool’ are not truly scientific names, but general common usage describes these as edible or inedible (and poisonous) fungi respectively. But there is a grey area, (internationally speaking) regarding this mushroom or should I say toadstool?. It is still sold in eastern Europe markets, where-as here at home in the UK, it is strongly advised to be avoided. Over time, this fiendish toadstool can release it’s toxins and seriously poison you…

Brown roll-rimThe Brown Roll-Rim (Paxillus involutus) is a very common toadstool found throughout the UK and Europe. I have come across it many times in mixed woodland. If picked for eating it can lose it’s toxicity once thoroughly cooked, but over time and if eaten on a regular basis, it’s toxin will enter the bloodstream and systematically cause the destruction of the red blood cells. Not very pleasant and definitely not worth the risk. There’s no real timescale for when and if this will happen, but I think it’s best described as a ticking time-bomb!

The common name helps describe this naughty toadstool quite well. Naturally a brown toadstool, it’s rim remains ‘inrolled’ although less so when expanded as it grows – see picture on the left – excuse long fingernails!). The texture when younger is finely felted and later becomes smooth (slimy when wet).

Size-wise, it can grow from 5 – 15cm in diametre when fully mature and has a distinct hazel brown colour (tawny brown / olive when younger), often dotted with darker orange/brown blotches and the margin may become very wavy.

The crowded, decurrent gills are a reliable feature for identification also. They ‘bruise’ dark brown on handling are easily separated from the cap flesh.

Being very common in broad leaved and sometimes coniferous woodland (even parks and gardens), you will most likely stumble across these toadstools during late summer to late autumn. They have been classed as deadly poisonous and therefore, to repeat myself again, just avoid them. Several deaths have been reported from Europe. Better the devil you know – to coin a phrase!

Note: See comments boxes below. To eat or not to eat! I know I won’t be eating them!

Paxillus involutus

The Brown Roll-Rim Toadstool – Viscid when wet and brusing dark brown on the gills (top). Younger examples are more finely felted when young before becoming smoother.

PS. If you want to get scientific – check out this eco-news on the study of this very mushroom (and related species): http://www.jgi.doe.gov/sequencing/why/99182.html

QUICK ID TABLE: BROWN ROLL-RIM Paxillus involutus

CAP / FLESH

5-15cm across. Inrolled margin. Ochre – hazel-brown colour (often with darker rain post marks). Downy texture when younger, becoming smoother. Slimy when wet.

STEM

8cm x 0.8-1.2cm. Similar but lighter colour as cap. Stains darker with age.

GILLS / SPORE PRINT

Crowded and decurrent. Light ochre to sienna. Bruises darker.
Spore Print: Sienna brown (see how to take a spore print here).

HABITAT / SEASON

In broadleaved woodland and on heaths. Late summer – late autumn.

EDIBILITY

Poisonous. Can be deadly. Regular consumption build up toxins within the body. Avoid.

5 replies
  1. gaz
    gaz says:

    A Polish gentleman had a jar of these on a foray. And was adamant he had eaten them all his life. They were pickled. He actually ate one in front of the group? Hope is ok? Who knows?

    Reply
    • J C Harris
      J C Harris says:

      Well. It’s a life choice I guess. Some guidebooks didn’t label it as poisonous until 1990, yet an Italian guidebook labelled it as edible in 1998. It has complex ‘back-story’. Wide scale suspicion was first aroused when in October 1944 a German mycologist Julius Schäffer died after eating one. More concern in later years was when several unexplained deaths occurred in the same place (I think Polish Village). Eventually it was understood that they had all died from an autoimmune reaction (after many years of eating Paxillus involutus) causing the body’s immune cells to consider its own red blood cells as foreign – and attack them. Nasty!

      The antigen in the mushroom that causes this is still not fully understood. Perhaps some people are immune or do not have long term side effects. One thing I do know is that I will not be eating any at all…

      Reply
  2. Tom Roe
    Tom Roe says:

    Hi, I ate a couple of these just over a year ago cooked (fried quite well), and am starting to worry quite a bit after hearing/reading various things on them..some worse than others..but all seem to say that the real danger is from repeated consumption..would you say i should not be at great risk having had them just the once? Or could you recommend anyone else who may know a bit more about it all perhaps? I am considering a hospital visit but dont know if they will even be able to help. I am thinking that i may be over-worrying, but still understandably concerned.

    Reply
  3. J C Harris
    J C Harris says:

    Hi Tom
    I understand your concern about eating these mushrooms, but I would tend not to worry too much. Evidence of serious poisoning and death has been recorded from people who have consumed these particular mushrooms often and regularly, over a long period of time. From what I have read and have been told, this is the case. Eating them once would not supply much toxin to your system (a lot of which may have been destroyed on cooking well), otherwise a lot more people would be seriously ill from them. But I’m not a complete expert on the subject, and I think a trip to your GP or hospital won’t do any harm – they would have a much better idea of who to go to for further help.
    All the best
    John

    Reply
  4. Tom Roe
    Tom Roe says:

    You dont know how good that is to hear and thanks for the quick reply!, im sure i will be fine..i just wasnt sure if the ‘acumulation’ they talk about is like the toxin multiplying over time, not necessarily doing it regular, but sounds like its not. I’m normally so careful and not sure how i let these slip but ill be cross-referancing twice as much from now..not nice at all thinkin ya days could be numbered.

    Reply

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