This cabbage-family root vegetable resembles a large (3 to 5 inches in diameter) turnip and, in fact, is thought to be a cross between cabbage and turnip. The name comes from the Swedish rotabagge, which is why this vegetable is also called a Swede or Swedish turnip. Rutabagas have a thin, pale yellow skin and a slightly sweet, firm flesh of the same color. There is also a white variety but it is not generally commercially available. This root vegetable is available year-round with a peak season of July through April. Choose those that are smooth, firm and heavy for their size. Rutabagas can be refrigerated in a plastic bag for up to 2 weeks. They may be prepared in any way suitable for turnips. Rutabagas, which are a cruciferous vegetable, contain small amounts of vitamins A and C.