Clementines are small oranges that are seedless, easy to peel, and—when well-grown and ripe—perfectly sweet to eat, too.
Like a good stinky Muenster cheese or properly made crêpe, clementines used to be something I had to go to Europe to find. I first encountered them when living in Paris, where their arrival at the market across the street from my apartment was heralded with such high spirits and good cheer that it warmed the air on that gray, bone-chilling December morning. Since my parents did not raise a fool, I followed the example of the market regulars and bought a kilo of them. I had never seen such small oranges, but figured if everyone else was excited, I should at least try some. My roommate's eyes lit up with glee when I walked through the door with the small mass of gleaming orange treasures and I knew I'd made the right move. I dumped the sunny orbs onto the dining table in the cramped living room. We promptly sat down and ate the entire lot.
I pretty much repeat this ritual every winter when they and their like-minded tiny orange brethren (satsumas, Ojai pixies, etc.) show up at the markets in San Francisco. One day everyone comes home from work and school and—Wham!—there is a big bowl of clementines in the center of the dining room table. Their bright, sunny flavor and sweet, floral aroma fill the house and the onset of gloomy, rainy, dark winter doesn't seem so terribly bad.
That's the thing about clementines: not only are they are easy to eat, they are fundamentally cheery little fruits. The peel almost slips off—not as easily as a satsuma's peel, but easier than any other citrus I can think of, very little if any pith clings to the fruit, and the membrane surrounding each section is delicate enough to be almost unnoticeable.
In the U.S. clementines are often marketed as "Cuties" or "Sweeties" and sold in small crates or boxes, especially around Christmas time. Their association with the holiday season is a reasonable one since they are in season from late November into January. Spain still grows scads of clementines, but there are substantial groves in California, as well.
Store clementines in a cool place, but don't refrigerate them. As with all citrus, don't store clementines in plastic—it will make them sweat and spoil much quicker than they would just left out to breathe. Clementines last for several weeks after they're picked, if they are kept relatively cool and out of too much direct sunlight.