Yellowcresses are annual to perennial herbs, mostly hairless to stiff-hairy with unbranched hairs and simple to pinnate leaves, usually growing in aquatic, marshy, or at least damp habitats.
The flowers are rather small, borne in clusters without bracts at bases. The 4 sepals are only slightly or not at all pouch-shaped at the base, from promptly dropped to persistent for some time after flowering. The 4 petals are white or purplish-tinged to yellow. There are 6 stamens. The fruit pods are cylindrical to slightly compressed, oval to linear, readily opening when ripe, the valves 1-nerved. The style is prominent to almost lacking, the stigma from enlarged and disc-shaped to smaller than the style tip. There are several to many seeds, arranged in 2 rows to occasionally more or less irregularly in 1 row, the shape from ovoid to somewhat flattened and slightly wing-edged, the surface with honey-combed patterns to more or less covered with minute bumps, not slimy when wet.
The genus has about 40 species, on all continents, but mostly of the N. Temperate Zone, especially in the Old World. The name is said to be derived from rorippen, the Saxon common name for the plant.