Milkmaids are dicot angiosperms in the mustard family (Brassicaceae), a family of major economic importance that has very broad distribution. There are many well-known species and cultivars in the family including common vegetable crops such as cabbage, cauliflower, broccoli, turnips, watercress and radish, and ornamentals such as sweet alyssum and stock; there are also invasive weeds such as black mustard, wild radish, and sea rocket. Interestingly, six of our common vegetables–cabbage, cauliflower, kohlrabi, Brussels sprouts, broccoli, and kale–were all bred from a single species of mustard, Brassica oleracea.143
Members of the mustard family are characterized by four petals in a cross shape (from which came the former family name Cruciferae, or cross-bearing); and by six stamens, four long and two short. Mustard seedpods come in a variety of shapes. When mature, they split open from both sides, exposing the seeds on a central membrane. Seedpods occur radially around the flower stalk, “like a spiral staircase for the little people.”143
Sixteen species in the mustard family have been reported from the Reserve.48 Eight of these are non-native weeds, including black mustard and field mustard (Brassica nigra and B. rapa), wild radish (Raphanus sativus), sea rocket (Cakile maritima) and stock (Matthiola incana). Others include lovely spring natives such as milkmaids and wallflowers (Erysimum capitatum).
The species was previously divided into several varieties on the basis of leaf morphology. These are no longer accepted as valid.
Jepson eFlora Taxon Page