winter cress or upland cress, species of Barbarea, herbs of the family Cruciferae (mustard family). The pungent leaves of several species have been used for salads or garnishes, and the plants are sometimes cultivated as ornamentals, e.g., the common winter cress, or yellow rocket (B. vulgaris), in garden varieties with variegated leaves and double flowers. Widely naturalized in North America, it is a common weed (called spring mustard) of croplands. A medicinal substance, Herba Barbaraea, was formerly made from it and used in Europe for healing wounds. Another species, B. uverna, is often sold as cress in Europe. Winter cress is classified in the division Magnoliophyta, class Magnoliopsida, order Capparales, family Cruciferae.