Scented geraniums. Leaf fragrances include nutmeg, peppermint, lemon, even coconut

Usually we lean down to smell a flower, not a leaf. But with scented geraniums -- or, properly, pelargoniums -- the reverse is the case. It's their greenery that gives off the heady fragrances, while the scent of the blossoms is insignificant. I had never seen a scented geranium before I went to work at a greenhouse a few years ago. There I was introduced to all sorts of geranium fragrances, including lemon, apple, peppermint, nutmeg, pine, and the better-known rose-scented geranium (a flavoring ingredient for rose geranium cake, recipes for which date back to the Civil War). Research informed me there are now at least 60 cultivars of geranium-scented hybrids. They are increasingly available at specialty greenhouses and from mail-order plant houses, particularly those that sell herbs.

These plants can be kept indoors all winter, adding green to the d'ecor, scent to the air, and flavor to culinary dishes. They also make unusual holiday gifts, especially when they're tagged with a card listing their uses and how to care for them during their indoor months.

The rose variety -- including Old-Fashioned Rose, Skeleton Rose, Attar of Roses, and Rober's Lemon Rose -- can flavor not only icings and cakes (wrap four leaves around each stick of butter to be used and chill them two days); it also goes well in applesauce and apple pie (add a leaf or two to cooking sauce or filling). Indeed, it was an important substitute flavoring in times of shortages.

The lemon group -- including the Kenya native, Mabel Gray -- was originally ``the finger-bowl geranium.'' A tiny ruffled leaf was floated in the water. These days, lemon can be used to make tea and drunk hot or cold, or made into an icy sorbet.

My favorite way to use these fragrant plants is to make potpourri. Place the leaves on newspapers on a bed or, better yet, on a framed screen where the air circulates and isn't too humid. Sometimes I tie them in bunches and hang them. They're not dry until they are crisp to the touch. Then crumble or crush the leaves to release the fragrances and put them in bowls or sew them into sachets.

It's not difficult to keep these potted plants indoors over the winter. Give them as much light as possible and keep them trimmed. (Use the trimmings for the potpourri and kitchen projects.) When the plants are tidily pruned, they're less likely to blossom, and that's good, because the plant can then give maximum energy to producing its fragrant leaves. If buds do appear, pinch them off. Let the plants dry out between thorough waterings; there's no need to feed them until February. Be sure to keep them indoors until the weather is extremely warm; the scented geraniums of African heritage won't tolerate the outdoors in a chilly spring.

The scented geranium's fragrance doesn't come from an injection; the perfume isn't added, like tint to a carnation. It's not a dip or a spray. The odor emanates from tiny glands scattered all over the leaves and stems. The glands produce complex mixtures of volatile oils which evaporate into the air, especially when you rub a leaf between your thumb and forefinger, as you might to feel a piece of cloth.

Dutch sailors discovered scented geraniums growing wild at the Cape of Good Hope (in South Africa) in the 1600s. They were first brought to England by sailors as early as 1632, and from England were dispersed to America and all parts of Europe. By the late 1700s, growing them had become a fad.

One reason for their popularity was that scented geraniums did not require special treatment, unlike other exotics being brought from newly explored regions at the time. When it was discovered that most species set seed freely and would hybridize spontaneously when kept in close proximity, business-minded people competed fiercely to breed the most astonishingly odoriferous varieties.

Business didn't stop there, especially when another discovery was made: that the rose geranium could be substituted for the costly attar of roses, out of which perfume is made. The result: Great, fragrant fields of rose geraniums were planted in southern France and Turkey.

In Kenya, the British cultivated scented geranium plantations. They hoped to introduce satisfactory substitutes for violet and lavender, among others. There they developed hundreds of cultivars, most of which, however, no longer exist.

Today, geranium oils are still used to replace the more expensive rose oils in perfumes. But at one point, the scenteds fell out of favor with home gardeners. The beauty of geraniums with showy flowers took precedence over fragrance. Certainly the scented geraniums' flowers are less than impressive. They are usually small, some even tiny, and only a few have exceptional colors. Now some public appreciation for the scented varieties is returning, albeit slowly.

Not only the flowers but sometimes the scents themselves are subtle. The rose is a rose, the lemon is a lemon, and the peppermint is downright arresting. But some of the others -- strawberry, orange, and coconut, for example -- have just a hint of the scent they're supposed to mimic. And some people may not agree that the so-named odor is the one they're smelling at all. But the names of the scented geraniums are meant as a reference, a suggestion, an imagination tickler. Their appreciation isn't a scie nce.

The look of the various plants determines their use in the outdoor garden. The uprights, like the speckled Snowflake rose or lemon-scented Prince Rupert, make dignified pot plants; the sprawlers, like the fuzzy-leaved peppermint, fill out hanging baskets well; some of the woodier-stemmed ones -- like the pungent oak leaf varieties (which to me smell like autumn's fallen leaves) -- can be nicely adapted to bonsai.

Of course, you will not want to spray any plants you plan to use in foods, drinks, or potpourris. Fortunately, the plants are not particularly susceptible to disease or pests.

For a culinary start, try using the rose-scented geranium in this pudding cake. Rose geranium sugar is made by layering rose geranium leaves with sugar in a tightly covered canister. Allow 8 to 12 leaves for good, strong flavor. Use the sugar for cooking or sprinkling over cookies. Rose Geranium Pudding-Cake 3 eggs, separated 2 teaspoons grated lemon peel 1/4 cup rose geranium sugar 1/2 cup granulated sugar 1 cup milk 3 tablespoons flour 1/4 cup lemon juice 1/8 teaspoon salt 4 small rose geranium leaves

Beat egg yolks with lemon peel and sugars until foamy. Combine flour and lemon juice and add alternately with milk to egg mixture. Beat egg whites with salt until stiff and fold into batter. Butter a 3- or 4-cup casserole; arrange geranium leaves in bottom and add batter.

Place in pan of hot water and bake 1 hour at 350 degrees F. Top with whipped cream and decorate with geranium leaves if desired. The bottom will be a thick, lemon-flavored, spongy sauce and the top will be like cake.