Rorippa

Rorippa is a genus of flowering plants in the Brassicaceae family, commonly known as yellowcresses. The genus comprises numerous species of annual and perennial herbs that are adapted to moist environments. Rorippa is distributed across cool temperate regions of the Northern Hemisphere, with some species extending into temperate regions of the Southern Hemisphere.

Most species have slender, creeping or upright stems with leaves that are variable, often pinnate or deeply lobed. Leaves are generally stalked, with serrated margins. The flowers are small, cross-shaped, and typically white or pale yellow, arranged in racemes. Each flower has four petals and six stamens. The fruits are slender pods called siliques or silicles that release seeds when mature.

Habitats range from marshes, stream banks, and wet meadows to aquatic or semi-aquatic environments along ponds and ditches. Several species tolerate standing water and can form dense mats along waterways. Some species are weedy in disturbed habitats, while others are valued for ecological restoration and as forage in appropriate settings.

Notable species include Rorippa palustris, known as marsh yellowcress, and forms historically treated as watercress in older classifications. The taxonomy of the group has varied, with some authorities placing many species in Nasturtium or related genera within Brassicaceae. Overall, Rorippa represents a diverse group of moisture-loving plants with ecological and, in some cases, culinary significance.