Also, a little more to add from our resident from-preteens mycologist:D
When harvesting a mushroom, take a little substrate with you, as well as samples of the vegetation from nearby (trees within several meters, and small woody shrubs the distance from the latter I advise depends on the plant species, some have shallow root beds that spread out some distance, others go deep into the ground, such as a taproot, although the latter morphology is really more common in herbaceous stuff)
Many fungi are what is called mycorrhizal, from 'myco-' meaning 'fungus' and 'rhizome' I.E roots, lit. 'mushroom roots', where the hyphae of the fungus form a symbiotic, closely intertwined composite between the fine roots of a plant, supplying and taking nutrients, such as the silver birch or pine species and the fly agaric, A.muscaria. Other examples include the deathcap, Amanita phalloides, which likes to grow in broadleaved, deciduous woodlands, particularly around oak, and beech trees, or the much sought-after matsutake (Tricholoma matsutake), which has a few really nasty lookalikes, such as the kidney-failure-inducing Amanitas in the subsection Lepidella, in the genus Amanita (representative members of which include A.thiersii, A.smithiana, A.abrupta (which contains aminohexanedieneoic acid derivatives and some funky aminoacids, which are hepatotoxic and nephrotoxic, although chemically totally unrelated to the cyclopeptide amatoxins)
Cut puffballs in half. Most are saprophytic, growing on rotten wood, rather than in free soil, although the giant puffball is an exception there, as far as I know, at least, those of small to moderate size, some, such as some Calvatia species, and the giant puffball, grow simply too massive to possible be confused, but its happened that egg-stage Amanitas of various kinds, including deadly ones have been taken in mistake of edible puffballs (and very, very delicious-I love giant puffball sliced, dipped in whipped egg, and fried in batter, sort of like eggy bread)
The Amanitas are nearly always, if not always (I know not of any saprophytic species, although A.thiersii does grow in places where there is a high cellulose, rather than lignin content in the local plantlife and is believed to break down cellulose in order to form sugars to feed off, although it may well be an ectomycorrhizal fungus, however, it grows on lawns...grass as a symbiote perhaps? it would be most strange to find a non-mycorrhizal Amanita)
Dig up the mushroom with a spoon or knife, don't yank it up or snap the caps off etc, unless it is a very distinct species you are harvesting, such as A.muscaria, I take the caps of these, and leave the stems, as I don't want anything but cap tissue for curing and drying, this however is a rare exception, for a very distinct species which grows in massive profusion where I make my annual harvest, with very specific habitat, and is specifically being looked for.
If you pull a mushroom up or cut it off at the ground, you risk leaving the base of the stem in the ground, which is a most foolish proposition, lazy, and stupid, once one knows better. The stem base in many species is a very important characteristic, such as in the Amanitas-does it have a bulb? a big sack-like volva? just a few scales? this is information which with some mushrooms, means the difference between life and death, or spending the rest of your life on dialysis and anti-rejection immunosuppressant medication.
Just do it!
And in the case of Clavicipitacea, of course taking the sclerotia, and taking some still in the grass/grain seedhead, in fact, I take the entire grass plant, just one is needed per type of grass, if there are different species growing then I take a sample, sclerotia still in situ within the host, of the entire grass, leaves, stem and sometimes the roots, although the latter is really not nescessary, I am, by nature, just extremely thorough)
Black mushrooms-good advice. Although there are a few species which do blacken not as a sign of age. Such as certain Hygrophorus (the waxcaps) species, notably the conical waxcap and blackening waxcap, these go quite literally jet black as they grow out of infanthood. And certain Russulas and Lactarius, Russula nigricans is edible, but ugly as sin, and reputedly not very tasty. Although not to be confused with the similar looking R.subnigricans, which contains a really, really nasty poison, cycloprop-2-ene-1-carboxylic acid, this is the same toxin found in the sought after 'edible' species Tricholoma equestre, the man-on-horseback or knights's shield, and causes severe rhabdomyolysis-basically your muscle tissue melts and the breakdown products flood your kidneys and shut them down....very unpleasant indeed. T.equestre does this too, although has a long history of being eaten, tends to do so only if multiple meals are eaten within a few days, or a glut is consumed at once. I avoid the species entirely however.
Chemical reagents are also very valuable in identifying mushrooms. And are indispensable, absolutely indispensable when dealing with the two genuses Russula and Lactarius in particular, and valuable when IDing Amanitas.
Tell you what, I shall start a thread, on the fundamentals of mushroom IDing, sound like a good idea?
It isn't quite true that the only way is to learn from a master, it is a very good way, and advisable, but I can well imagine that it isn't always possible. I had nobody to learn from. I have had one nasty episode of GI distress, in all the time I have been foraging, and that was not from a misidentified mushroom, but eating one not toxic, but known to be edible, but poor, at least according to Roger Phillips et al. Phallus impudicus, the stinkhorn. Eat the egg stage, and suffered for it, they really didn't agree with me, although I couldn't stomach more than a little to begin with. (The eggs of these are very, very different in cross section, and much bigger than unopened Amanita buttons, and are surrounded with a layer of gelatinous slime-perhaps t is this I should have eaten rather than the inner core, I don't know, but I won't be trying it again)
The only person who has ever been with me on a foray, are the bitch ex housemate, an old friend of mine from childhood, picking libs, cyans and fly agarics, and my old man, when I was of an age that I wasn't really able to go places other than the local playing fields where I used to live, as I was too young to have my own transport. He has learned a couple of things, but that, was from me, and is nowhere near my level of competence/experience I am sure.
