On Sunday, the weather forecast for today said that the very heavy rain and high winds would move up from the south to give us a pretty unpleasant day. So, it seemed like a good idea to get out in the garden and do some tidying up as well as making sure that high winds would not lead to things, like plastic flower pots, flying around.
I had a walk around, in the character of the head gardener of a big estate. That is to say, I was walking around looking favourably on some things and very unfavourably on others. The only problem is I get to play all the other characters as well; the assistant head gardener, the gardener, the under-gardener and all the way down to the unpaid trainee who gets to do most of the unpleasant jobs for no reward.
During this tour, I spotted a mushroom and thought it might be instructive to see if I could positively identify it. I immediately found a key problem with mushroom identification. All the photos published are of perfect specimens whereas mine was a long way short of perfect.
I started with my mushroom book. This is the book that spends 160 pages describing and picturing mushrooms before concluding that the only truly reliable way to identify mushrooms is to go foraging with someone who knows what they look like. I wasn’t expecting to get very far and, sure enough, none of the images looked anything like my mushroom.
Then I remembered my interactive CD from Kew Gardens and Guys and St Thomas’ Hospital. Because it doesn’t work with Windows 7 I had to root out an old laptop with Windows XP persuade it to come to life after being neglected for so long.
The CD works by asking structured questions about the appearance of the fungus you want to identify. Things like colour, shape and texture of the cap (see above). What the underside of the cap looks like and, after stating that it has gills, what colour and type of gills it has.
Moving down, the next block of questions are about the stem; size shape, appearance and presence/absence of any type of collar.
Then there are questions that require the mushroom to be sliced through; colour/appearance on the inside, does it exude any juice, does its appearance change when exposed to air?
Then, finally, some questions about the gills and their attachment to the stem.
Once the program has reduced the possibles to five or fewer it asks if you want to look at the contenders. My mushroom was said to be from one of four genera; Russula, Entoloma, Boletus or Tricholoma. The images of these fungi on the CD didn’t help so I tried various online searches to see if I could narrow the field.
Maybe it's just me but I found I was tempted to go for the nearest match even if there was something fundamentally different. 'It looks just like X except that the cap is the wrong colour'. Or, 'I'd say it was Y but the stem hasn't changed colour after being cut'.
But, just to take one of the genera, Boletus, various species are described as ‘edible’, ‘inedible’ or ‘poisonous’ so, clearly, that could be a fairly rash judgement to make. I would need to narrow my identification from one of four genera to a particular species of one of them before I could be sure of what I had found.
But my searches didn’t not provide a better answer so I was left wondering both precisely what it was I had found in the garden and, if identification is really this difficult, how is it that there are so few cases of mushroom poisoning?
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