Linda Kowalski, age 11, of Albany. N. Y., for her question:

How can you tell a mushroom from a toadstool?

Spring is dust around the corner and, with the first warm showers, a vast assortment of fungus plants will poke up their noses. These fungi are the mushrooms, the toadstools, the morels and the puff balls. It is a aceptable to call those good to eat mushrooms and those that are don’t  eat toadstools. Deciding which is which is serious, maybe a matter of life and death for some of the toadstools contain deadly poisons.

Andy thinks most of his readers are too young to separate the mushrooms from the toadstools for themselves. You have only two safe choices. You can buy them at the market, fresh or canned. Or you can take along an expert.

Market mushrooms are safest. They are grown from safe spores under conditions where they insect population is controlled. This last is important. Insects love to lay their eggs under the umbrella caps of the mushrooms. There is plenty of. food there for the young grubs and when the mushroom decays, the decaying process gives off heat to help the insect eggs hatch. In all wild mushrooms, you run the risk of eating insect eggs and larvae, perhaps too small for your eyes to see.

Fungi have no green chlorophyll. The body of the plant is a mesh of  fine threads below ground or buried in the bark of a tree trunk. This meshy web is called the mycelium and it feeds on rich decaying materials such as old rotting tree stumps. The little umbrella caps are the fruiting bodies and each may contain half a million little spores, or seedlets.

An expert botanist will tell you never to trust a young budding mushroom growing wild. Several of the safe and unsafe fungi look alike in the button stage. If he decides that one variety might do, he is careful to gather the whole stem. Certain deadly toadstools have a little cup which surrounds the chubby stem just below the surface of the soil.

Any fungi that has a milky juice is sure to be a toadstool. Another clue is in the spores, the powdery seedlets hidden in the folds under the cap. Mushrooms have dark spores; toadstools have white o r putty colored spores.

Your expert may test the spores with a sheet of half black, half white paper. He places the cap, spore side down,. and covers it with a glass.  The spores will fall out, some on the light and some on the dark paper. You can see then whether they are light or dark. This is a good trick, even if you are not seeking for mushrooms.  The spores leave a print, or design on the paper and every type of fungus leaves a different spore print. But, as we said before when comes to the ones, that may be eaten, it’s better to stick to the mushrooms from the supermarket!