Radish (Lat. radix, root), a cruciferous plant, raphanus sativus (Gr. , quickly, and , to appear, in allusion to its rapid germination), long cultivated for its edible root. The plant has rough and lyrately lobed leaves, the flowers purple or whitish and with the structure common to the family; but the pods differ from those of the other common cruciferce in being divided into cells by fleshy false partitions. The radish is a hardy annual of which the nativity is uncertain, but it was in cultivation in Egypt in very early times; being valued for its root only, all improvement has been directed toward that part, and it presents a great number of varieties, from the size of a small olive up to those weighing several pounds, and in shape from long and tapering to those much broader than long; some varieties are of very rapid growth, and must be eaten when very young, while others require as long to mature as turnips, and are kept all winter. The radish is to be regarded as a condiment rather than a nutritious food; in common with cresses, horseradish, and others of the family, it possesses a highly pungent principle which contains nitrogen and often sulphur; and with the others it is regarded as possessing antiscorbutic properties.
The summer varieties in ordinary culture are sown as early in spring as the soil can be prepared, but they may be had much earlier by sowing in a frame, or at any time during winter if a hot-bed is used. In market gardens, where the greatest economy in land is practised, it is customary to sow a bed with beets in regular drills, and then scatter radish seed over the bed broadcast and rake it in; the radishes are gathered before the slowly germinating beets need attention; they do best upon a light warm soil that has been heavily manured for some crop the previous year. In some localities a fly (antho-myia raphanum) makes their culture impossible; its larva, a small white maggot, is very destructive. The turnip-shaped and olive-shaped, the French breakfast, and long scarlet are the leading early sorts, and the catalogues give many others, including white and other colors. The winter varieties are sown late in July or early in August in the latitude of New York, and harvested before freezing weather; to keep them fresh, they should be packed in earth or sand.
The black and white Spanish are most common, but the rose-colored Chinese is by far the best. - The rat-tailed radish is probably a distinct species (R. caudatus); its root is not edible, but the pods, which are 2 ft. or more long, are used for pickles, and by some liked when dressed in the manner of asparagus. - The wild radish (R. raphanis-trum), also called jointed charlock, has yellow flowers and necklace-formed pods with a long beak; this is a common weed in European agriculture, and has firmly established itself in some of our older states; it has much the same general appearance as the true charlock (brassica sinapistrum, or sinapis arvensis of most authors), from which it is readily distinguished by its jointed pods, which when quite ripe often break up between the seeds. In 1860 M. Carrière, a French horticulturist, published an account of his experiments in improving the wild radish, and found that a careful selection gave him in four generations edible roots of as varied forms as are presented by the garden radish.
Varieties of Radish. 1. Chinese Winter. 2. Olive-shaped. 3. Long. 4. Turnip-shaped.