11 February, 2012

A Couple of Winter Mushrooms: One Edible and One Deadly

In my last post, I had some photos of the edible wood ear fungus, Auricularia auricula, that I spotted in the woods next to Lake Russell in Georgia over the Christmas holidays.  There were a couple of other mushrooms out, too.  The oyster mushroom, Pleurotus spp., shown below is another good edible that is easily identified and has no poisonous "look-alikes". 
Lovely, pale yellow Pleuortus growing on a fallen pine tree.  You can see the gills of the specimen on the left.


That is not the case with the mushrooms in the next two photos.  These are an Amanita spp., either A. phalloides, known as Death Cap  or A. bisporigera, known as Destroying Angel or Death Angel.  You get the idea.  These are deadly mushrooms, the ones that have given wild mushrooms a bad rap as a food source.
This young specimen still has a closed cap, but you can see some of the volva, or full veil, on the right of the base of the stipe, that used to cover the entire mushroom before the stipe began elongating.   After I took the photo, I dug down and found the underground part of the volva that encapsulated the mushroom like an eggshell at an earlier stage of development.  I neglected to get a picture of that.  :-(
If you enlarge the photo by clicking on it, you can see flecks of the volva on the left side of the cap.






I took photos of a more mature specimen in which the cap had expanded a bit and the stipe had elongated even more.The slightly yellowish color of the cap and top of the stipe make me think that this might be A. bisporagera instead of A. phalloides, which is usually solid white.  But A.p. has some color variability and also some of the color on the cap of this one is probably just bruising.  In all practicality, it doesn't make too much difference, as both are deadly poisonous.  This website has good descriptions and photos.
Here you can see the annulus or ring around the stipe which is a remnant of the partial veil that covered the gills before the cap opened.  You can also see part of the volva at the base of the stipe where I pulled back part of the leaf litter.
As described here, most cases of deadly mushroom poisoning in North America are due to confusion of these 2 species of Amanita with the wonderfully edible padi straw mushroom.   The main reason is because Asian immigrants to North America are very familiar with collecting padi straw mushrooms from the wild and these poisonous Amanitas do not grow in the same habitat.  When they move to North America, they are not aware that poisonous Amanitas are common, so they pick the "impostor" padi straws without looking at them carefully.  If they had looked carefully, they would have seen a partial veil, which that is not present on the padi straws.  Normally, padi straws are collected when they are quite young; the partial veils of the Amanitas are hidden at this stage, so you have to look for it deliberately.  It is an easy difference to see - if you know to look for it.  Read here for an interesting account of surviving a poisoning that occurred this way.



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6 comments:

  1. Interesting post Wilma.
    Glad I don't eat mushrooms though. No chance of a slip-up lol

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    1. Commercially cultivated mushrooms are safe, Keith. You should give them a try. :-)

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  2. Wilma,
    Thanks for the Sunspot link :-) Very interesting! The photo there looked to have the spot position exactly the same as in my photo.

    Enjoy your Mushrooms :-)

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    1. Those sunspots looked exactly like your photos in your blog.

      I dried a small handfull of the wood ear, but didn't pick any of the oyster. I think I'll put some of the wood ear in my omelet this morning. I'll let you know how they were.

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  3. When I was growing up in the UK there was only one type of edible mushroom in the shops (the so called 'button' mushroom) and of course there were the 'magic' ones which we (ahem) occasionally harvested.

    Loads in the shops here in Japan and I love eating them, I had 3 different kinds yesterday actually. But I have to say I would never pick a wild mushroom to eat.......I'm just too much of a coward.

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    1. These days you can get such a great variety in the shops at reasonable prices that there is not much call to go "shrooming", as we called it. But back in my destitute graduate school days, it was a different story; free, wild mushrooms were a welcomed treat. Of course feeling comfortable with the IDs was helped by the fact that I was studying mycology in school. :-)

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