It's funny how some American plants have to leave home to become famous. We have a wealth of native treasures, but such beauties as goldenrod and black-eyed Susan didn't make their mark until they were improved or merely approved by growers in Europe. Even some of our native foods have been more widely embraced abroad. Take claytonia, a salad green you might not recognize, even by the more descriptive name of miner's lettuce. It's not a lettuce but a small plant found throughout the West Coast in areas that are damp in winter. Miners foraged for it during the Gold Rush in order to avoid scurvy, because it provided a rare winter source of vitamin C. Meanwhile, Europeans were growing it on a commercial scale, calling it winter purslane. It's not a purslane, either, even though both are members of the portulaca family, a group of plants known for their juicy, succulent leaves.

Winter hardy claytonia or miner's lettuce. (Corbis)

When you finally meet claytonia (or if you already know it) you'll agree that it's a plant with everything going for it. In the ever-widening field of intriguing salads, this one looks like no other. From a hard, little base at soil level sprout dozens of thin stems, topped with tiny, heart-shaped leaves. As these mature, each encircles its stem, clasping it, so that the leaf appears as a flat-topped parasol, or one blown into a slightly cupped shape by a gust of wind. In botany this is called a perfoliate leaf, the trait that gives the plant its Latin name Montia perfoliata (or Claytonia perfoliata, depending on which taxonomist you consult). From the center of the parasol, a tiny white or pink flower appears, then a cluster, then a little sprig. Finally, the sprig elongates as a continuation of the stem. The flowers turn into brown capsules that scatter multitudes of tiny black seeds, as the rest of the plant turns pale and dies. Harvested before then, the leaves are nutritious and wonderfully fresh-tasting, a great background for more assertive flavors in a mixed salad, such as arugula, beet leaf, tat soi and mustard. Though not quite as pillowy as purslane, claytonia leaves contain so much air that they float on the water in your sink, like a raft of baby lily pads. I rarely wash them, though. Unless spattered by mud, they are held so erect by the stems that you can grasp them like a bouquet of violets. I cut them with just an inch or two of stem. The leaves are also beautiful, even before the flowers appear -- brilliant green, sometimes tinged with red, or with pale green streaks. They're the perfect edible garnish. Sometimes I make a nest of them on which to set a fish filet, a pork medallion, an egg. But I'll also toss a whole salad with claytonia alone. Cooking it seems beside the point, although a few handfuls dropped into a soup at the last minute will lend just a bit of thickness, the way sorrel would. This is one way to use the leaves if they have grown larger and firmer, as they may in mild-climate gardens. At my place they stay very tender, rarely more than an inch across. Claytonia is a low-growing winter annual, happy to grow even when the temperature falls below freezing. Its seeds drop in spring, but they don't germinate and grow until the days begin to shorten at the end of summer. In the wild, this strategy ensures that taller plants will shade them and keep them moist during their early growth, then die down just as the small plants need more sun. For a gardener, this means that a spring-planted crop of claytonia can be successful, but a fall and winter one, planted in September, will be better still, because it won't quickly bolt to seed. If you have some in your garden now, you might protect it with straw, or transplant it into a cold frame or cool greenhouse. You should be able to cut it and re-cut it until spring, being careful to leave that little nubbin at the base intact. Growing claytonia is ridiculously easy. It is not fussy about soil, asking only consistent moisture. You might even plant it in the shade of a deciduous tree where other garden crops might languish. It will receive the sun it needs after the tree's leaves fall. Though the seeds are tiny, try to sow them sparsely so you don't have to thin them later. Rip out the plants promptly when they start to set seed (they're easy to pull up). Otherwise, you will have a galaxy of claytonia plants the following year, and not necessarily where you want them. On the other hand, letting a few plants self-sow in the bed may prove a handy way to ensure a yearly supply of this elfin crop for your winter table.