Contrary to what most of us think, this fruit was not named for its color. Instead, the word orange comes from a transliteration of the sanskrit naranga . . . which comes from the Tamil naru . . . which means "fragrant. " It's thought that the reason oranges have long been associated with fertility (and therefore, weddings) is because this lush evergreen tree can simultaneously produce flowers, fruit and foliage. Though oranges originated in Southeast Asia, they now also thrive around the world in warm-climate areas including Portugal, Spain, North Africa and, in the United States (the world's largest producer), Arizona, California, Florida and Texas. There are three basic types of orange — sweet, loose-skinned and bitter. Sweet oranges are prized both for eating and for their juice. They're generally large and have skins that are more difficult to remove than their loose-skinned relatives. They may have seeds or be seedless. Among the more popular sweet oranges are the seedless navel, the juicy, coarse-grained valencia and the thin-skinned, red-fleshed blood orange. Sweet oranges are better eaten fresh than cooked. Loose-skinned oranges are so named because their skins easily slip off the fruit. Their segments are also loose and divide with ease. Members of the mandarin orange family are all loose skinned; they vary in flavor from sweet to tart-sweet. Bitter oranges, the most well-known of which are the seville and the bergamot, are — as their name implies — too sour and astringent to eat raw. Instead, they're cooked in preparations such as marmalade and bigarade sauce. Bitter oranges are also greatly valued for their peel, which is candied, and their essential oils, which are used to flavor foods as well as some liqueurs, such as curaçao. Most of the bitter orange supply comes from Spain. USDA grading of oranges is voluntary and not considered necessary by most growers. The two grades used are U. S. Fancy (best) and U. S. No. 1. Fresh oranges are available year-round at different times, depending on the variety. Choose fruit that is firm and heavy for its size, with no mold or spongy spots. Unfortunately, because oranges are sometimes dyed with food coloring, a bright color isn't necessarily an indicator of quality. Regreening sometimes occurs in fully ripe oranges, particularly with Valencias. A rough, brownish area (russeting) on the skin doesn't affect flavor or quality either. Oranges can be stored at cool room temperature for a day or so, but should then be refrigerated and can be kept there for up to 2 weeks. Oranges are an excellent source of vitamin C and contain some vitamin A. Once cut or squeezed, however, the vitamin C quickly begins to dissipate. After only 8 hours at room temperature or 24 hours in the refrigerator, there's a 20 percent vitamin C loss. Canned, bottled and frozen-concentrate orange juices have a greatly decreased vitamin C content. See also king orange; temple orange.