Brown agaricus mushrooms include cremini and portobellos, though they're really the same thing: Portobellos are just mature cremini.

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More Mushroom Facts

Cultivated mushrooms are agaricus mushrooms grown on farms. Exotics are any farmed mushroom other than agaricus (think shiitake, maitake, oyster). Wild mushrooms are harvested wherever they grow naturally--in forests, near riv

Many edible mushrooms have poisonous look-alikes in the wild. For example, the dangerous "yellow stainer" closely resembles the popular white agaricus mushroom.

Toadstool is the term often used to refer to poisonous fungi.

In the wild, mushroom spores are spread by wind. On mushroom farms, spores are collected in a laboratory and then used to inoculate grains to create "spawn," a mushroom farmer's equivalent of seeds.

A mature mushroom will drop as many as 16 billion spores.

Mushroom spores are so tiny that 2,500 arranged end-to-end would measure only an inch in length.

Mushroom farmers plant the spawn in trays of pasteurized compost, a growing medium consisting of straw, corncobs, nitrogen supplements, and other organic matter.

The process of cultivating mushrooms--from preparing the compost in which they grow to shipping the crop to markets--takes about four months.

The small town of Kennett Square, Pennsylvania, calls itself the Mushroom Capital of the World--producing more than 51 percent of the nation's supply.

September is National Mushroom Month.

One serving of button mushrooms (about 5) has only 20 calories and no fat. Mushrooms provide such key nutrients as B vitamins, copper, selenium, and potassium.

Some experts say the taste of mushrooms belongs to a "fifth flavor"--beyond sweet, sour, salty, and bitter--known as umami, from the Japanese word meaning "delicious."

This article was adapted from "The Book of Incredible Information," published by West Side Publishing, a division of Publications International, Ltd.