Any mycologists out there? DS has a question...

[Fishandjam]

Why are some toadstools toxic, and others aren't?

DS is slightly obsessed with fungi. He's 3 1/2 and a bit weird. He asked me this earlier (obvs didn't say "toxic" - "yucky poyzuss" were his exact words) and I was stumped. A Google search later and I'm still stumped, though scarily well informed as to just how the Death Cap or Destroying Angel kills you .

[magnumicelolly]

Same reason some plants are and other plants aren't. Some contain chemical compounds that for e.g. destroy your liver. Others don't!

[SummerRain]

It's an evolved protective strategy, just as with any poisonous lifeform; plant, fungi, bacteria or animal.

Organisms which mutate to form a poisonous compound are eaten less than their non-poisonous relatives and thus contribute more genetic material to the next generation. Thus natural selection favours the new mutated form as it's fitter in an evolutionary sense.

[EauRouge]

As soon as I saw the thread title, I knew it would be you . Have you seen the children's activities on the Woodland Trust website? There's some free spotter sheets you can print out here. I'm planning to sign DD1 up to their children's club for her birthday.

[EauRouge]

Haven't they got fantastic names? I can't decide if chicken of the woods or King Alfred's cakes is my favourite.

[EdwiniasRevenge]

And...if you want to take it a step further...some look like poisonous ones to scare predators away but aren't.

Don't know any fungal examples but there is a snake which has very similar markings to tge very poisonous coral snake to help it avoid predators.

Things that are poisonous tend to be very brightly coloured as a warning.

[Fishandjam]

I don't know what you mean eau

My favourite toadstool name is Slippery Jack. Sounds like a pirate of some sort. Though Elfin Saddles is also rather poetic.

Summer, I did wonder if it was an evolutionary thing but I am puzzling as to whether it's the whole story. I can understand why it's advantageous for some fungi to be toxic, but in that case, why are some not only non-toxic, but positively tasty? I get why other fruiting plants have evolved to have seeds that are attractive to herbivores/omnivores, but that surely doesn't apply to fungi as I can't see how their spores would survive a transit through an animal's digestive system. (And of course fungi tend to rely on wind dispersal anyway, I think...) And if it's an advantage to be toxic, why are some non-toxic varieties pretty widespread whereas many of the toxic varieties are quite rare?

Or is it that we as humans can recognise that some are toxic and some aren't, whereas other animals don't and so don't risk eating them (and therefore from the fungus' point of view, it doesn't matter whether it is or isn't)? But then some animals do eat fungi, so that knocks that line of reasoning out. (Reindeer get sozzled on fly agaric, though that's another discussion in its own right. The links to Santa Claus in particular are fascinating.)

Questions, questions!

edwinia, unfortunately many of the really horrible toadstools look quite innocuous. See the Death Cap here and the Destroying Angel here. Some of the little bastards also look like edible species e.g. the False Morel.