[QUOTE=vetbridge]
Any budding mycologists out there? What are the odds that random mushrooms found in Pennsylvania will:
[ul]
[li]kill me[/li][li]cause gastroenteritis[/li][li]cause delirium/hallucinations/etc[/li][li]be unappetizing[/li][/ul]
[/quote]
In order of most likely: 1.) Be unappetizing - most mushrooms don’t really taste that great.
2.) Cause gastroenteritis - many mushrooms ( even some ‘edible’ species for some people ) will cause tummy aches.
3-20.) NA
21.) Cause delirium/hallucinations - psychotropic mushrooms are way down the list in terms of how common they are. Odds are rather low you’d randomly get ahold of one, though in my area one rather potent ( but unappetizing looking ) critter isn’t that uncommon on second or third-year wood chips used in gardens.
22.) Kill you - Contrary to popular opinion the vast majority of mushrooms are non-fatal. Make you feel a little sick, common - kill you, rare. The comment that “poisonous mushrooms are very toxic” is, by and large, fairly true. But most mushrooms are not poisonous in any real sense.
That said some really nasty ones DO come up on lawns and every admonition you’ve gotten up to now is spot on. NEVER mess with a mushroom that hasn’t been reliably identified. The half-assed, semi-educated guess I’m about to give you should not in anyway be considered reliable.
As far as I know the best general guide is still Daniel Aurora’s Mushrooms Demystified, though it really is more Pacific coast oriented. However no truly definitive general field guide exists - the topic is too huge. It would be like a field guide to insects of North America. I have the best available keys as of ten years ago to most of the North American genera and they fill two massive binders ( and would require a good microscope and some minor chemistry ) and are quite incomplete.
But if you were asking me casually, my best GUESS ( assuming dark gills, but they are still not really identifiable from a photo ) is some species of Agaricus, the same genus as the species that includes your store-bought crimini, button and portabella mushrooms ( all the same specis - A. bisporus ). Which doesn’t mean it’s edible by any stretch, even if I’m right. Many Agaricus, including some of the most common on lawns, are in the inedible, gastrointestinal upset group. A very general rule of thumb for that genus is that if it has a yellow or yellowish stain when you score it with your fingernail ( at the base of the stipe is often best ) and has a phenolic odor, it is more likely to be inedible. If it stains reddish brown and smells of almonds/marzipan it is more likely to be edible.
But DO NOT take that as gospel. Please.