actually i don't think there is a way of physically knowing, you probably need to search it up, and compare pics, becarefull some mushrooms look very similar and not all good.

G'day Libra278, Thank you for your question. Identifying mushrooms is fairly tricky. You need to get a guide to safe and poisonous mushrooms in your area. These are some guides to picking mushrooms from Wikipedia: * Never consume a mushroom for which a positive identification to species has not been made (see mushroom poisoning). * Never try to convince anyone else to eat a mushroom that you have identified. * Simplistic rules-of thumb such as: "it's edible if it discolors when cut", or "if it doesn't stain a silver spoon" are often dangerously inaccurate. Species identification is a must. * An identification should be made with no less than size, color, gill connectivity, environment, a cross section, bruising color, odour, and a spore print. * In no case should you eat a mushroom when something about the mushroom contradicts available information about what one suspects the mushroom is. * Always attempt to use multiple sources for identification. * Be able to tell what distinguishes this mushroom from its closest sister species * Learn what the death cap, destroying angel, Galerina species, small Lepiota species and the deadly webcap and some of its relatives look like in all stages of their development; those kinds cause the majority of deadly poisonings. Other species can cause permanent kidney failure or make you severely ill but do not often kill. * Until you can be considered an expert, stay away from all difficult to identify groups, such as amanita, cortinarius, and "little brown mushrooms". * Always identify each specimen during preparation. * Deaths due to an inexperienced collector gathering a button-stage amanita along with edible mushrooms have occurred, or when a group of collectors unwisely combines their mushrooms. * Novices should start with more easily identifiable and less dangerous groups, such as boletes (being aware of the Devil's bolete) and bracket fungi, completely avoiding standard agarics. B* e careful to use information relevant to your area. Some mushrooms that are safe in Europe, for example, have deadly lookalikes in North America. * Only consume a small amount of the mushroom the first time. Like every other food that you taste for the first time, certain types of popular edible mushrooms, such as sulphur shelf, cause an allergic reaction in about half of the people who eat them. Some species, such as Paxillus involutus, can be eaten several times without ill effect and then cause severe distress when consumed again. Your first taste should be just a taste (to see if you actually care for it), and your second should be about a teaspoon full. Space tastings far apart - poisoning from the highly deadly destroying angel doesn't even produce symptoms until ten hours after consumption and can take over a week to kill its victim. You should never "taste" an unidentified mushroom; mushrooms such as the deadly webcap, commonly found throughout Europe, are so poisonous that even putting a small piece in the mouth and spitting it out can cause a severe poisoning. * Do not allow young children to gather mushrooms for consumption. If they hunt with you, keep any mushrooms they find separate and identify them yourself. As always, if in doubt, throw it out. * If you do eat your mushrooms, remember to keep a piece or even better a mushroom for each specimen you have picked. If you have misidentified the fungus and are poisoned by it, this can help expert mycologists make a proper identification and diagnosis. * Only consume specimens that are freshly picked (or properly preserved) and not too old. Like all food, even a perfectly edible mushroom will eventually rot and cause stomach upsets if ingested. " Personally, I prefer to buy my mushrooms from the fruit and veg shop so I know its safe. I have attached sources for your reference. Regards Reference Wikipedia Mushroom Hunting http://en.wikipedia.org/wiki/Mushroom_hunting Edible and Poisonous Mushrooms http://mdc.mo.gov/nathis/mushrooms/mushroom/ Poisonous fungi http://www.naturallist.com/fungipoi.htm Wild Mushrooms and Poisoning http://www.ces.ncsu.edu/depts/pp/notes/General_Principles/gpin004/gpin004.htm

It is very difficult, as many mushroom species closely resemble each other. Even people who are used to eating them can get confused, and every now and then there are mass poisonings. One of the most sensational cases was the local Oregon poisoning of Amanita phalloides that occured October 22, 1988 (see Readers Digest, July 1989, pp. 43-48). A Korean woman had picked mushrooms that looked similar to ones that she used to pick as a child in Korea. Isun Pak had mistaken the deadly Amanita phalloides with what she thought were edible Paddy Straw mushrooms (Volvariella volvacea). Out of five people that had eaten these mushrooms one evening, four received liver transplants and will take medication for the rest of their lives, and one was seriously ill, but recovered fully and didn't have to receive a transplant. I wouldn't go picking myself, but would stick to what was available in supermarkets. There is a great choice these days, which can be widened by visiting specialist markets (eg Chinese, Korean etc)

You can look it up in a book or you can try it..

-Buy a field guide to the mushrooms of your area. -Feed the mushrooms you find to a goat, they won't eat poisonous items.

nope. Guess I shouldn't be walking around eating mushrooms!

you have to learn them individually, there is no set distinguishing features feeding them to an animal is not foolproof. many animals can eat death caps , or fail to show symptoms for days. know the difference between juvenile puffballs and juvenile destroying angels