For a very long time now, confusion reigns as to the classification of turnip, swede, and rutabaga since they are very closely related and their names interchangeably used.
The white turnip is a creamy globe tinged with rose at the top. The rutabaga is a large globe with bumpy tan skin and a yellow interior. The outside is usually waxed to keep the vegetable from drying out. Both the turnip and rutabaga are moderately good sources of food fiber, calcium, and vitamins A and C; but, nutritionally, rutabagas are superior, having almost twice the amount of nutrients as the white turnip.
The turnip is one of the oldest cultivated vegetable and thought to have originated in northern Europe about 2000 BC. Not officially a root, the turnip is rather a swollen base of the stem of the plant, and selection and breeding have produced many different larger varieties. Before the spread of potatoes, the highly nutritive turnip, was among the most important staple food for man and beast. Turnips are usually white or creamy white, but there are now golden yellow and red-skinned varieties. Turnip tops, like other brassica greens, are edible and nutritious. The leafy parts of the turnip are obtained from all May or fall varieties of turnip roots. All turnip greens are excellent chopped in salads or cooked briefly as a side dish.
Rutabagas (or swedes) are taproots of plants belonging to the cabbage family and very closely related to the turnip. It is thought to be a cross between the fall turnip and kohlrabi.
For the most part, rutabagas grow above ground, looking much like giant turnips, except their flesh is yellow compared to turnip's white or opaque colored flesh. The flavor tends to be sweeter, but more assertive. Rutabagas are tan or yellow, with a dark purple or reddish band at the top of their lumpy, irregular, roundish shape. They range in size from half a pound to almost three pounds, and are usually coated with a layer of wax. The leaves are always a blue-green in contrast to the grass-green leaves of the turnip. The white-fleshed varieties are generally grown for animal fodder, while the orange-fleshed ones are more nutritious.
Rutabagas contain more nutrients and calories than turnips. They are an excellent source of Vitamin C, folate, potassium, dietary fiber, calcium, iron, niacin, and Vitamin A. Turnips do not contain any Vitamin A. Being a member of the cabbage family, these vegetables also contain valuable phytochemicals. Raw rutabaga contains an exceptionally high amount of the cancer-fighting glucosinolates, even more than other cabbage members.