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| Human World on Nov 20, 2009

How can I tell if a mushroom is poisonous?

All the old wives’ tales about how to tell if a mushroom is poisonous – such as whether it tarnishes silverware or turns blue when bruised – are dead wrong.

There’s a saying that there’s no such thing as an old, bold mushroom hunter.

That’s because there are no outward characteristics that all poisonous mushrooms have in common, so picking and eating wild mushrooms requires the utmost caution. To be absolutely safe, the only mushrooms you should eat are those found at supermarkets and restaurants!

Of the thousands of mushrooms found in North America, only about 5 percent are edible. Only about 5 percent are poisonous, too. And the rest just aren’t fit to be eaten.

Poisonous mushrooms run the gamut of shapes – from a cup to a tongue to a sponge. All the old wives’ tales about how to tell if a mushroom is poisonous – such as whether it tarnishes silverware or turns blue when bruised – are dead wrong.

The number one rule for enjoying the fruits of a mushroom hunt is to eat only those mushrooms which you can absolutely, positively identify as edible. But even experienced mushroom hunters can be fatally fooled, since many edible mushrooms have toxic lookalikes. For example, when a dreaded mushroom known as the Destroying Angel is in its early stage, it can look like the harmless Puffball. So – when eating wild mushrooms – take care.

Experts also caution that even once you’ve positively identified a wild mushroom as edible, you should taste only a small bit and wait 24 hours. Some people have adverse reactions. Finally, cook all mushrooms thoroughly to be on the safe side.