In the courtyard of Jerusalem's elegant, Turkish-style American Colony Hotel an exquisite lemon tree stands as a centerpiece. Throughout the day visitors sit beneath the yellow fruits, surrounded by seasonal flowers, sometimes sipping fresh lemonade.

The lemon is revered in Jerusalem and throughout the Middle East. Just as the lemon tree blends into the setting of this courtyard, so, yoo, does the fruit add subtle taste and balance to countless recipes.

Although it grew first in India or northern Burma, the lemon has been cultivated in the Mediaterranean for over a thousand years. The Crusaders later brought this citrus fruit to northern Europe and the Spanish brought it to the Americans where it prospered. Today, California grows over half the world's production.

But to guide our use of lemons, we might well look back to the legacy of Mediterranean cuisines. There it is often used instead of vinegar in salad dressing with oil, salt, pepper, herbs and garlic. A squeeze of lemon on fish, chicken and beef not only enlivens the natural flavor but also acts as as tenderizer. With vegetables it can serve as a low calorie seasoning in place of salt and it prevents avocadeos and artichokes from discoloring.

It is a main ingredient in Greek avgolemono soup and for egg-lemon sauces in general.Moroccans pickle lemons and use them for many recipes, including the tart chicken with lemons and olives. Lemon juice is an essential ingredient in hummus, stuffed grapeleaves and most eggplant and zucchini recipes. Freshly squeezed lemonade with mint is still the non-alcoholic Middle Eastern equivalent to gin and tonic, and hot tea with lemon and mint is a year-round favorite.

French culinary masters inherited and expanded upon this legacy of lemon cuisine. As late as the 17th century the lemon was still a luxury food in northern Europe, although La Varenne recommended using lemon with meat drippings as a sauce. It later became an essential ingredient in hollandaise sauce and mayonnaise. The juice and zest of fresh lemon found their way into pies, souffles, mousses, cakes, ice cream and sherbet. Fish was served garnished with lemon slices or wedges and parsley.

Meanwhile the English learned from the Orientals that lemons and other citrus fruits could prevent scurvy. An ounce of lemon juice a day was given to sailors in the British navy. In old merchant ships huge vats labeled "Grog" were filled with rum, water and the daily requirements of lemon juice. Even now many people religiously drink hot water with lemon as a daily "constitutional."

When purchasing lemons select small, smooth thick-skinned ones with a bright yellow color. THese have the fewest seeds. Avoid greenish fruits with coarse rough skin. If using lemons within a few days do not refrigerate. If refrigerated, return to room temperature before extracting the juice. The fruit will keep for weks in the bottom of the refrigerator.

To obtain the maximum amount of juice from the lemon roll it with the palm of your hand before dividing in half. When extracting the juice use a fork to keep the seeds from escaping or, in Middle East-style, cup on hand with the fingers separated enough to act as a sieve and collect the seeds while the juices pass through to a bowl. In cooking, one medium lemon equals approximately three tablespoons of juice.

The following are some easily prepared warm weather recipes that are enhanced by the tangy flavor of fresh lemon. LEMON SALAD DESSING 2 tablespoons lemon juice 1/4 cup olive oil 1 to 2 cloves crushed garlic (optional) Salt and pepper to taste

Combine the above adding more or less lemon juice to taste. Freshly chopped parsley, mint, dill or coriander can be added to the basic dressing. CITRON PRESSE (Makes 1 quart of lemonade) 4 lemons 1/2 cup sugar, or taste 1/2 cup boiling water Water and ice cubes

Fresh mint leaves (optional)

Squeeze 3 of the lemons (optional) pitcher. Add the sugar and boiling water. Stir to combine and dissolve sugar. Fill pitcher with ice cubes and cold water. Thinely slice the remaining lemon and add. Do not leave the lemon rinds in the lemondade for more than 1 day as they will turn bitter. Serve with a sprig of fresh mint leaves in each glass.

Note: A concentrate can also be made by combining 1 cup of fresh lemon juice with 1/4 cups sugar. When the sugar is dissolved, the concentrate can be stored in covered glass jars or bottles. For one glass of lemonade mix 1/4 cup concentrate with 3/4 cup iced water, or to taste. BAKED CHICKEN WITH AVGOLEMONO SAUCE (4 to 6 servings)

1 chicken (3 pounds) Salted water 5 eggs 1 lemon Salt and pepper to taste 1/4 cup butter or margarine

Place the chicken in a heavy casserole, cover with salted water and bring to a boil. Cover and simmer 40 minutes or until chicken is cooked. Remove to a separate plate and cool the chicken.

Bone the chicken and place all the meat and skin in an ovenproof low caserole.

Pour off all but 2/3 cup liquid from the original casserole. Then gradually beat in the eggs, lemon, salt, pepper and butter or margarine. Pour this sauce over the chicken.

Bake in a 350 degree oven for about 25 minutes, or until golden brown. LEMON SQUARES (Makes 32 squares) 1 cup softened butter or margarine 1/2 cup confectioners' sugar 2 cups plus 5 tablespoons unbleached flour 4 eggs, well beaten 2 cups granulated sugar Juice of 2 large lemons

Combine the butter, confectioners' sugar and 2 cups of the flour. Pat into a 1/2-inch-by-13 1/2-inch pan. Bake in a preheated, 350-degree oven for 20 minures. Mix the eggs, granulated sugar, the remaining 5 tablespoons flour and the lemon juice. Pour this mixture over the top of the baked crust.Bake acrust. Bake an additional 25 minutes.

Remove from the oven and sift more confectioners' sugar over the top. Cool and cut into squares before removing from pan. COLD LEMON SOUFFLE (6 servings) 3 eggs, separated 1 cup sugar 2 1/2 lemons 10 ounces heavy cream 2 packages unflavored gelatin 1/4 cup hot water Pinch of salt

Combine the egg yolks, grated rind and juice of the lemons in the top of a double boiler. Using a whisk, beat over hot water until the mixture is thick and creamy. Cool. Whip the cream and fold in . Soften the gelatin in the hot water and, using a metal sppon, combine well to dissolve all particles and add to the mixture. Whip the egg whites until foamy, then add salt and beat until stiff peaks form. Fold in. Pour into a souffle dish, using for several hours before serving. Remove collar and decorate sides and top with slivered almonds or raspberry jam. Or top with whipped cream, fresh raspberries or strawberries.