Monte L. Mitchell, age 12, of Peterboro, Ontario, Canada, for his question:

What exactly are artichokes?

Artichokes are served as vegetables and a helping may be either a glorified thistle bud or small tubers that resemble potatoes. This is enough to make a person wonder which is the real artichoke. The problem would be solved if the two very different edible portions came from the same plant. But they do not. The thistle type vegetable comes from the globe artichoke. The tasty little tubers are donated by the Jerusalem, alias the sunflower artichoke.

Almost everybody has sampled a steamed or boiled globe artichoke. Its globular head sits in a small soup plate while we peel off its fat scales, dip them in melted butter and use our front teeth to slide the fleshy greenery from the tough fibers. The delicious flavor resembles a subtle blend of asparagus, nuts and a special artichoke tang of its own. The flavor gets better and the scales get softer as we nibble our way to the center. The best part is the tender heart    the thick, flat base to which the scales are attached.

The wild relatives of globe artichoke are sturdy cardoon thistles that thrive in the warm moist climate of Mediterranean Europe. For ages, people ate their fleshy stems as cooked vegetables and used the juices to curdle milk to make cheese. About 500 years ago, they began cultivating these wild thistles and the pampered strains produced huge, globular buds of fleshy scales. This aristocratic artichoke was taken westward to the New World. It now thrives in mild, moist regions of North America.

Meantime, the Amerindians were cultivating an artichoke of their own. It produces a bright yellow daisy, just for appearance, and does its real chores underground. There it grows edible tubers that resemble bumpy potatoes. This vegetable was taken eastward to Europe, where the Italians named it the "girasol", or sunflower artichoke. But this name was mis translated to Jerusalem artichoke.

Our native artichoke was neglected in favor of the aristocratic artichoke of Europe. This is a pity, because its tasty tubers are high in food value and low in calories. When sliced, they add crunchy, nut flavored bites to raw salads. When cooked they are soft and mealy. They contain calcium, phosphorus and iron, plus A, B and C vitamins. They also contain levulose, a form of sugar permitted on the diets of diabetics. They are low in calories because, unlike potatoes, they contain no starchy food.

Jerusalem artichokes prefer coolish climates with a summer growing season of about 125 days. They thrive in a wide region across the middle of North America. The tubers are harvested when the shaggy tops wither in the fall, and it would be nice if we harvested more of them.

Both the edible artichokes are members of the daisy family, Compositae. Both plants sprout tall, wide tufts of coarse and hairy leaves. Neither produces worth¬while seeds. The globe multiplies from spreading root suckers. The Jerusalem sprouts new plants from last year's tubers left in the ground. It is an annual herb. A perennial globe artichoke plant produces its thistle buds year after year.