One of the more popular members of the citrus family, the lemon boasts of its high vitamin C content -- one regular-sized lemon supplies about 30 percent of an average person's daily requirement. Lemon is essential not only in stimulating appetite and aiding digestion, but also in promoting the absorption of calcium and iron from natural foods.

With its essential oil called limonene, the lemon, especially its peel, is touted by natural healers as a therapy for cramps, inflammations, and gout and arthritis pains because it stimulates the healthy flow of lymph fluids. Lemon leaves, on the other hand, are prepared as infusions to reduce stress, relieve asthma symptoms, and cure insomnia.

In the kitchen, lemon adds a tangy flavor to soups, sauces, curds, sorbets and mousses. Much of its taste and aroma comes from the oils, called zest, that are abundant in the fruit's peel. This is why many culinary uses of lemon stress the importance of the lemon zest.

When buying lemons, choose the ones that are smallish, heavy for their size, shiny, lemon yellow in color, and have smooth or fine-grained skins. Lightweight, dry-looking, reddish (ripened), or coarse-skinned fruits are past their prime and may have lost much of their juices through evaporation; large lemons are often thick-skinned and contain less juice relative to the size.

If you plan to use the skin for cooking or for making marmalade and lemon zest sprinkles, choose lemons that are certified organic. If unsure of the fruit's origin, choose the un-waxed batch and remember to wash and scrub them before slicing or peeling.

When serving lemons for squeezing onto salads, fish, or seafood, slice them lengthwise into quarters or wedges (as against crosswise when squeezing for lemonade) so that the juices squirt directly onto the food.

Use lemon to substitute for vinegar in salad dressings, and squirt a few drops on poached egg to help it set. Remember to add lemon juice to dishes just before serving because its vitamin C components break down during the cooking process.

Fresh and firm lemons will last several weeks inside the refrigerator.