Kestrel was mushroom hunting one of her finds turned out to be quite interesting. I will let her take over from here.

©kestrel, all rights reserved. Click for full size.


I went on a foray looking for mushrooms and noticed this. It’s a hump in the duff, right in the middle of the photo.


It’s hard to see what might be in there! I went around to the other side of this shrump (a hump in the duff where a mushroom is emerging).


That looks pretty exciting. I cleared away some of the debris to see better what was in there.


Aha! It’s Hypomyces lactifluorum, also called the Lobster Mushroom. It’s so fascinating: this is a parasitic mold attacking another mushroom. The original mushroom is Russula brevipes (Short Stemmed Russula) which although edible, is rather bland and crumbly. H. lactiflulorum attacks and parasitizes it, causing it to become dense and firm. They are often quite large.


  1. jazzlet says

    Gosh, that’s amazing, I don’t think we have anything like it in the UK. Is the color from the orignal Russula or from the Lobster Mushroom?

  2. kestrel says

    @jazzlet: the color is from H. lactifluorum. R. brevipes is “white” (not a true white perhaps but pretty close). I guess they don’t occur in the UK although I hear they are in Europe.

  3. kestrel says

    Whoops! That was not clear at all. I guess H. lactfluorum does not occur in the UK. You probably have R. brevipes, but not sure.

  4. Onamission5 says

    So the part of the stem where one can see vivid white is the original mushroom, and the ring of yellow-gold around it is the parasite?

  5. kestrel says

    @Onamission5: Actually the entire thing is R. brevipes, but H. lactifluorum has changed the entire structure all the way through. You can’t really say that some part is unaffected. As I understand it (I AM NOT A MYCOLOGIST simply a very keen amateur) that colored part you see is the spore-bearing surface of H. lactifluorum and you can see that the original spore bearing surface (in this case gills) of R. brevipes have been severely distorted. The original gills on R. brevipes, before being attacked, are like the pages in a partially opened book: very packed together and quite deep.

    But yes, when you cut these up to cook them the insides are white and very firm. One of my favorite ways to prepare them is to cube them (about 1/2″ on a side) and use them as “clams” in “clam” chowder and use some other species (say, Leccinum insigne) as the “mushroom”.

  6. jazzlet says

    We certainly have Russulas, R.brevipes isn’t in my “How to Identify Edible Mushrooms”, although that may be because Patrick (the author) didn’t think it was worth eating, I’d have to check a more comprehensive tome to see whether we have it at all. Great Britain does not have as wide a range of fungi as many places in Europe, because of being an island.

  7. Onamission5 says


    Oh, interesting! Thanks.

    I found a shot on mykoweb of two R. brevipes, one infected, one not, which helped me visualize what you’re talking about. Pic here, fifth image down in “other descriptions and photos.” Very cool.

  8. rq says

    So basically H.lactifluorum ate R.brevipes‘ brains.

    Sadly, your link seems to be borked. Can you make it work?

  9. kestrel says

    @Onamission5: GREAT photos, wow! Yes, that’s what happens! Amazing. Who would imagine a fungus attacking a fungus? Delights my heart. I would SO LOVE to become a mycologist but fear I’ve left it a little too late… Still! So much out there to learn, can’t help but be excited by that!

  10. Nightjar says

    Oooh, beautiful! Very interesting find indeed. I miss mushrooms already but given current weather conditions I think it will be a while before the first show up.

  11. rq says

    It’s never too late to become a mycologist!
    Thanks for the links, Onamission5, wow!
    As per lumipuna’s comment, no more public swimming pools for me -- who knows what you can catch! ;)

  12. Saad says

    In light of recent events, I thought this post was going to be about something else. I’m glad it isn’t.

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