Fig. 115.—A Silique. roots of the Horse-Radish, and the common Radish, and in the leaves and seeds of Mustard, and the different kinds of Cress, &c. This acridity, however, is never so great as to be injurious; and Cruciferous plants, particularly if their texture be succulent and watery, may always be eaten with perfect safety. Even those which, in a wild state, are tough and stringy, such as the wild Cabbage and the root of the wild Turnip, become excellent by cultivation; and all Cruciferous plants are so extremely nourishing as to be considered next in this quality to animal food.
Among the many garden flowers which belong to this order, few are more popular than the common Wallflower (Cheiranthus Cheiri). Its hardiness, and the facility with which it is raised and cultivated—the gaiety of its flowers, their profusion, and their delightful fragrance, combine to make it a general favourite; and I think I cannot take a flower to illustrate the order which is more generally known and liked. The flowers of the Wallflower (see fig. 116, a) consist of four petals, each of which is furnished with a long tapering point, called the claw (b), and a broad flat part called the limb (c). The claws of the petals are buried in a calyx of four sepals, placed alternately to the petals, and somewhat swelled out at the base, (see d). The stigma (e) is two-lobed, and forms a kind of notched head. There are six stamens, which appear at first to be all nearly of the same height, but on examination it will be found that two are somewhat shorter than the others. The seed-vessel is of course the lower part of the pistil; which, after the petals drop, becomes elongated into a somewhat cylindrical silique, which contains several flattish seeds.
Fig. 116.—Flowers of the Wallflower.
The Brompton Stock (Mathiola incana), and the Ten-week Stock (M. annua), differ from the
Fig. 117.—Flower of the Brompton Stock. Wallflower principally in the shape of the stigma (see fig. 117, a). The petals have also rather longer claws, and hang looser, as shown at b. The Virginian Stock (Malcomia maritima) has a roundish silique, and only one stigma, which ends in a long tapering point. The Candytuft (Iberis umbellata) has a short pod or sillicle, which has the appearance of being cut off at the point, and which contains only one seed in each cell; and the outer two petals of the flower are somewhat larger than the inner ones. Many other Cruciferous plants might be described, but I think my readers will have pleasure in seeking them out themselves, and examining them, to discover their points of agreement and of difference; particularly as, though the order is such a very large one, the flowers of all the plants are so much alike, that no one can be in doubt respecting their alliance.