Maya MacDonald, age 12, of Salt Lake City, Utah, for her question:

How many edible mushrooms are there?

Every summer, a certain number of people are fooled into sampling the wrong mushroom. You know for sure that it is the wrong mushroom if the meal is followed by severe stomach gains and'the patient turns bluish. But the information is now too late unless a doctor can be reached at once.

There are at least 38,000 types of mushrooms and about 1000 of them are edible. Ordinary folk often classify the poisonous and the non edible types as toadstools. But scientists group all the mushrooms and toadstools together and all of them, of course, are fungus plants. The edible types are delicious when broiled or boiled, stewed or sauteed. They also tend to add their savory flavor and bring out subtle tastes in certain meaty dishes. But, oh my, the mushroom clan is full of deadly tricks. Maybe you think that you have a good chance of finding one of the 1000 safe types. But remember, for every edible type,. there are 37 inedible types and some of these are deadly poison.

There is a long list of rules for selecting the safe mushrooms from the dangerous ones. A nonexpert could never remember them all and sometimes even an expert is fooled. The . edible amanitopsis mushroom has a flat, pale umbrella with a brownish daisy type center. It looks like a sister of the death cup mushroom that is as deadly dangerous as its name suggests. The shaggy mane mushroom has a tall white dome with shaggy brown tufts and black spores. These mushrooms are edible only when ripened and freshly cooked.

Many mushrooms are safe only at certain stages of their development and no expert would dream of sampling a batch of any baby mushrooms found in the wild. Many safe and i dangerous types look exactly alike in the button stage. What's more, many edible mushrooms are dangerous during the button stage and lose their poisonous chemicals only as they mature. The fairy ring mushroom is one of the best, but a variety of bugs enjoy it as much as we do. Growing in the wild, it often is full of insect eggs and infected with assorted germs. This also is true of the chunky puffballs and morels that wear high, pointed cap$, the buried truffles and other varieties of wild, edible mushrooms.

We have a large number of native mushrooms to avoid, ranging from the mildly harmful to the deadly dangerous. The deadly death cup and its snowy white cousin, the destroying angel, carry fatal poisons that dissolve the blood cells. One of our most handsome mushrooms is the fly amanita. Its 12 inch umbrella is a blend of soft yellow and apricot, usually spotted with primrose spots. But the big beauty is a sneaky killer. There are enough edible mushroom rules to fill a fat book. The safest rule is to choose a reliable market and buy mushrooms that have been grown under hygienic conditions. Unless you have a qualified expert along, it is plain silly to sample your own selections from the wilds.

Many mushrooms, however, deserve to be admired. The bird's nest is a pale cup holding a match of round button eggs. The coral is a spiky tuft of citrus yellow. The jack o'lantern is like a flat cluster of primrose yellow pansies. The magpie is a black pixie hat with white dots. Some types grow from logs and trunks looking like fluted shells and folded fans. The assorted~morels look like fat fairy trees in various shades of brown, orange and apricot, often spotted with bumpy polka dots.