Water cress as seen blooming in a stream running under a cattle guard along Washington Highway 14 about a mile west of Murdock, WA in the central Columbia River Gorge.........June 3, 2009.
An aquatic perennial, the plants are often found standing or floating in water, with both erect and lax stems. Stems which contact the soil may root at the nodes. The flexible stems range from 10-60 cm long. The leaves are smooth and waxy, from 4-12 cm long. The leaves are simple to compound, with 3-11 oval or lance-shaped leaflets. The terminal leaflet is the largest.
The 4 petals are white to purplish with purple veins. They are 3-4 mm long and spoon-shaped. The 4 sepals are white too. The flowers are borne on stalks from 8-20 mm long that arch or bend slightly backwards. The seed capsules are long siliques from 10-30 mm long and up to 2 mm wide.
Water cress may be used as a salad green with a peppery flavor. Because of possible fecal pollution, the greens should be thoroughly rinsed before preparation in salads.
Water cress is found in slow-moving, shallow water (small streams and ditches).
A native of Europe, water cress has become established in much of North America.
In the Columbia River Gorge, it may be found throughout the length of the gorge between 0-800'.