Note: Information is dated. Do not rely on it.Primrose. A genus of beautiful low plants of the order Primulaceae. Some are among the earliest flowers in spring, as the common primrose, the oxlip, and cowslip; several Japanese and other varieties are cultivated in gardens as ornamental plants. Their roots are perennial, the leaves almost always radical, and the flowers are supported on a naked stem, usually disposed in a sort of umbel. The varieties of the common primrose which have arisen from cultivation are very numerous.