Distribution: Introduced weed found in much of North America and throughout the Pacific Northwest.
Habitat: Swamps, ditches, and other wet places, mostly at low elevations.
Flowers: July - September
Conservation Status: Not of concern
Mostly glabrous annual, the stems rooting at the nodes, the upright stems simple to freely branched, peppery to the taste, the herbage with glands in small pits.
Leaves alternate, numerous, all cauline, only slightly reduced upward, the blades lanceolate to elliptic-lanceolate, 5-7 cm. long, the stipules up to 15 mm. long, oblique.
Inflorescence a terminal raceme and several lateral, spike-like, interrupted, lateral racemes 2-7 cm. long; pedicles 1-2 mm. long; perianth 3-4 mm. long, glandular, attached to about mid-length, the 4 segments greenish with white or pink margins, oblong; stamens 4 or 6; styles 2 or 3, distinct.
Achenes brown, 3 mm. long.