Sweet potatoes gained the wrong reputation somewhere back in their history. Somehow these versatile, nutritious vegetables, distinct in color and delicate in flavor, came to be thought of as coarse, bulky peasant food.

And if you thump them down, whole and baked, or even candied, alongside a massive meal of meat and other vegetables, it's true. Sweet potatoes do seem to weigh their side of the plate down.

But there are other things to do with sweet potatoes: ways to take full advantage of that warm orange color, that subtle spicy sweetness, their nutrients and availability. Maybe sweet potatoes have a bad reputation because we haven't fully probed our imaginations for ways to incorporate them into the more elegant dishes we know how to serve.

They are originally a tropical find. European explorers learned of them during early passages to Central America. They were reportedly cultivated in the southern reaches of Europe only from the 16th century on, then brought to North America by early settlers. Virginia's colonists grew them in the early 1600s.

Today, the state of North Carolina tops the list of American sweet potato producers, with an annual yield of more than 5 1/2 billion pounds, according to 1985 crop report figures cited by USDA statistician Arvin Budge. Louisiana and California come in second and third in the nation, while Virginia was 12th. All the states growing sweet potatoes share the sort of climate conditions that this originally tropical plant demands: a long, warm growing season, to let the leafy tops grow and flourish, then die back and send plenty of sugars into the underground tubers, which are of course the portion of the plant we eat.

Grocery store labels tend to differentiate between the orange-fleshed tubers, calling them sweet potatoes, and the yellow-fleshed tubers, calling them yams. But in fact that nomenclature doesn't follow botanical tradition. Both the orange- and yellow-colored tubers are sweet potatoes, members of the Morning Glory family of plants. Yams, in another botanical family altogether, are technically Asian plants that grow massive and highly fibrous roots.

But these botanical distinctions should be ignored as one searches cookbooks and recipe files for ways to use sweet potatoes. Cooks have used the words "sweet potato" and "yam" interchangeably for years, just as one can use the orange- and yellow-fleshed tubers interchangeably in any recipe calling for one or another.

To enhance a recipe with the flavor and color of sweet potato, one can either work with a sweet potato pure'e or grated raw sweet potato. The pure'e works up easily from either baked or boiled sweet potatoes. Bake or boil in their own jackets: Bake at 350 degrees for about 45 minutes, or boil gently for about 20.

Whole cooked sweet potatoes can then be stored in a covered container in the refrigerator for about a week, ready to mash into a pure'e for use at any time.

Finely grated raw sweet potatoes are so tender that, when added to a recipe for baking, they just soften up and seem to melt. Raw sweet potatoes are delicious on their own, as well. Peeled thin slices add character to a raw vegetable platter, and grated sweet potatoes can combine with or substitute for carrots in salad recipes.

As one comes to appreciate sweet potatoes' esthetic possibilities, it's an added pleasure to recognize their nutritional riches as well. Sweet potatoes, compared with other vegetables, are high in plant protein, vitamin A (a cup of pure'e offers four times the U.S. RDA), vitamin C, calcium, phosphorus and potassium.

It's said that George Washington Carver came up with 118 uses for sweet potatoes. Certainly we can find a few more than the old tried-and-true ones. And maybe, with that little boost of culinary imagination, sweet potatoes will regain the respect they deserve. SWEET POTATO SYLLABUB (8 to 10 servings)

Juice of 1 pink grapefruit

1 cup sweet potato pure'e (from 2 large or 4 small cooked sweet potatoes)

2 tablespoons Triple-Sec

1 tablespoon sugar

1/4 teaspoon nutmeg, plus a few sprinkles more

1 pint whipping cream

Blend together strained grapefruit juice, sweet potato pure'e, Triple-Sec, sugar and nutmeg. Beat to create an even consistency.

Whip cream until soft peaks form. Fold sweet potato mixture into cream. Spoon into goblets or glass dessert dishes. Sprinkle with nutmeg. Chill in refrigerator at least 2 hours before serving. WINTER MORNING MUFFINS WITH BRAN AND SWEET POTATOES (Makes 12 to 16 muffins)

2 cups unbleached flour

1 cup bran

1/4 teaspoon salt

1 teaspoon baking soda

2 tablespoons brown sugar

1 egg

1 cup milk

1/3 cup molasses

3 tablespoons melted butter

1 cup grated raw sweet potato (from 1 large or 2 small sweet potatoes)

Blend dry ingredients together, then sift or stir thoroughly with fork, breaking up any clusters of soda or brown sugar. Beat egg, then beat in all remaining ingredients except grated sweet potato. Make a well in dry ingredients and pour in wet ingredients, add grated raw sweet potatoes and briskly stir. Do not overstir. Spoon into greased muffin tins to 2/3 full. Bake in a 400-degree oven for 20 minutes. SUNNY-SIDE BISCUITS (Makes about 16 2-inch biscuits)

2 cups unbleached flour

1/2 teaspoon baking soda

1 tablespoon baking powder

1/2 teaspoon salt

1/2 cup (1 stick) cold unsalted butter

1/3 cup sweet potato pure'e (from 1 small cooked sweet potato)

1/2 cup buttermilk (or milk)

Blend together dry ingredients by sifting or forking thoroughly, breaking up any clusters. Add butter by cutting small chunks into dry ingredients. Blend in sweet potato pure'e and then, using pastry blender, 2 knives or fingers, work biscuit dough quickly until chunks of butter are no bigger than peas. Pour in just enough buttermilk or milk to make the dough stick together.

Turn out onto floured board. Flatten dough to 1/2-inch thick, then fold over twice. Repeat this process 2 more times, then flatten once more to 1/2- to 3/4-inch thickness. Use round biscuit cutter or top edge of drinking glass to cut 2-inch biscuits. Bake on ungreased sheet at 400 degrees for 20 minutes. GEORGE WASHINGTON CARVER MEMORIAL SOUP (4 servings)

2 onions

4 garlic cloves

2 tablespoons olive oil

2 tart cooking apples, cored and peeled

1/2 teaspoon curry powder

1/4 teaspoon cayenne pepper

1/2 teaspoon thyme

1/2 teaspoon salt

1/2 cup peanut butter

2 cups sweet potato pure'e (from 2 large or 4 small cooked sweet potatoes)

2 1/2 cups chicken broth

Sprig fresh parsley

Mince onions and garlic coarsely. Let them begin to soften slowly over low heat in the olive oil, then add coarsely chopped apples. Stir in curry powder, cayenne pepper, thyme and salt. Cook all slowly until onions are transparent and apples begin to soften.

Put seasoned cooked onions, garlic and apples, along with peanut butter and sweet potato pure'e, into blender or food processor.

In saucepan over low heat, stir together sweet potato mixture and chicken broth. Keep hot but do not allow to boil. Sprinkle with minced fresh parsley to serve. CHOCOLATE SWEET POTATO MARBLE CAKE (Makes a 10-inch tube cake)

4 ounces semisweet chocolate

1 teaspoon vanilla

3 cups flour

1 1/2 cups sugar

2 teaspoons baking powder

2 teaspoons baking soda

2 teaspoons cinnamon

1/2 teaspoon ginger

1/4 teaspoon cloves

1/4 teaspoon nutmeg

1 teaspoon salt

2 cups mashed cooked sweet potatoes (2 to 4 sweet potatoes)

1 1/2 cups vegetable oil

4 eggs

1 cup chopped nuts (optional)

Butter and lightly flour a 10-inch tube pan. Place chocolate and vanilla in small saucepan and set, covered, in a larger pan that you've just filled with boiling water.

Sift together all dry ingredients and set aside. In a large bowl, beat the sweet potatoes and oil together, then beat in eggs one by one until well blended. Slowly add dry ingredients and mix well. Stir in nuts, if desired. Put one-third of batter in another bowl and stir in melted chocolate and vanilla.

Place batter into tube pan, alternating large spoonfuls of sweet potato and chocolate. When all of the batter is in the pan, swirl gently by running blade of knife through and around once.

Bake at 350 degrees for 1 to 1 1/4 hours, until cake tests to be done. Let cool 10 minutes in pan, then remove to rack and cool. agcrdt3 From "The Victory Garden Cookbook" by Marian Morash (Alfred A. Knopf, 1982) endcol VEGETABLE PARFAIT (6 servings)

1/2 pound fresh spinach leaves

2 large (or 4 to 5 small) sweet potatoes

1 large (or 2 to 3 small) white potatoes

1 teaspoon butter

1/4 cup milk

1/2 cup cream cheese

2 tablespoons sour cream

1/2 cup minced scallions

1/4 cup unseasoned bread crumbs

Dash salt

Oil to grease baking cups

Grated parmesan cheese for sprinkling

Rinse spinach thoroughly and trim off stems and bruised leaves. Trim ends of sweet potatoes, if necessary, and boil about 30 minutes, until soft. At the same time, cut potatoes into 2-inch chunks and boil in another pan about 30 minutes, until soft. Bring large pot of water to boil and blanch spinach briefly. Remove spinach from water and let drain.

Drain white potatoes. Add butter and milk and whip about 1 minute, unitl smooth and fluffy. Set aside.

Drain sweet potatoes; peel; trim any dark spots. Mash, then whip about 1 minute, until smooth and fluffy. Set aside.

Cut cream cheese into chunks. Blend with sour cream, scallions, bread crumbs and a dash of salt, then pure'e this mixture with spinach.

Oil 6 ovenproof custard cups lightly. Layer 3 vegetables in alternately: white potato, sweet potato, spinach pure'e; three layers repeated again; then an ornamental dollop of white and sweet potato side by side, topped with a dash of spinach pure'e for color. Sprinkle with grated parmesan cheese.

Place custard cups on baking sheet and bake at 375 degrees for 20 minutes.