[Watercresses and Yellow Cresses: The Genera Nasturtium and Rorippa East of the Cascade Mountains of Oregon and Washington]

Western Yellow Cress

Rorippa curvisiliqua

Synonyms: Nasturtium curvisiliqua, Nasturtium lyratum, Radicula curvisiliqua, Rorippa curvisiliqua var. curvisiliqua, Rorippa curvisiliqua var. lyrata, Rorippa curvisiliqua var. orientalis, Rorippa curvisiliqua var. spatulata, Rorippa lyrata, Sisymbrium curvisiliqua

Curvepod Yellowcress, Lyrateleaf Yellowcress, Western Yellowcress, Western Yellow Cress: Rorippa curvisiliqua (Synonyms: Nasturtium curvisiliqua, Nasturtium lyratum, Radicula curvisiliqua, Rorippa curvisiliqua var. curvisiliqua, Rorippa curvisiliqua var. lyrata, Rorippa curvisiliqua var. orientalis, Rorippa curvisiliqua var. spatulata, Rorippa lyrata, Sisymbrium curvisiliqua)

Western yellow cress from vernal pond (impoundment for watering cows) atop the Columbia Hills, Columbia River Gorge........June 1, 1997.
Inflorescence of Curvepod Yellowcress, Lyrateleaf Yellowcress, Western Yellowcress, Western Yellow Cress: Rorippa curvisiliqua (Synonyms: Nasturtium curvisiliqua, Nasturtium lyratum, Radicula curvisiliqua, Rorippa curvisiliqua var. curvisiliqua, Rorippa curvisiliqua var. lyrata, Rorippa curvisiliqua var. orientalis, Rorippa curvisiliqua var. spatulata, Rorippa lyrata, Sisymbrium curvisiliqua) Photo at right of western yellow cress from the Fisher Hill Rd, Major Creek Plateau, Columbia River Gorge.......June 30, 1991. Note the numerous curved seed capsules (siliques).
Characteristics:

Western yellow cress is an annual or biennial with a single stem branched above or a widespread cluster of branches from near the base. The plant ranges from 10-40 cm tall. The variable leaves range from 2-7 cm long. They are oblong and entire to pinnatifid. The lobes are entire to toothed and linear to ovate in shape.

The flowers are small and yellow and measure from 1-2 mm in length. The sepals are 1-2 mm long while the spreading pedicels are 2-4 mm in length. The siliques range from 6-15 mm long and are 1-1.5 mm wide. They are curved to straight and are round in cross-section.

Habitat:

Western yellow cress is found in moist soil or shallow water at varied elevations, and may be found in ponds, ditches, and along river shores.

Range:

Western yellow cress is found from British Columbia east to Montana and Colorado, and south to Baja California.

Paul Slichter