The Mustard Family is one of the easiest of all plant families to recognize because of the 4 distinct petals arranged to form a cross. This family is also known as Cruciferae because of this feature. There are 4 sepals and 6 stamens, two of which are shorter than the other four. The stem leaves are alternate and many species have basal rosettes. The mature seed pods (capsules) take several distinct shapes, but are always noticeable. They are usually needed if uncertain about which species is being examined.
This very large family contains a number of our common food plants-cabbage, turnip, radish, etc. There are 27 genera locally, a great many of them introduced weeds. Watercress and Sweet Alyssum have crept in from elsewhere. Even the abundant Wild Radish (Raphanus sativus) frequent in waste places and the Sea Rocket (Cakile maritima) on the sandy beaches are immigrants. (Dale 79).