Lycopus is a genus of perennial herbs, 0.1-1 m tall, stems 4-sided, colonial from rhizomes or stolons, stems 4-sided, barely aromatic.
Leaves opposite, simple, margins prominently toothed to pinnately lobed.
Flowers white, small, tubular, petal lobes 5, nearly radially symmetrical, calyx tube sharply 5-toothed; stamens 2; ovary superior, 4-parted, stigma 2-lobed; inflorescence of numerous, dense clusters in leaf axils; most, if not all are pollinated by bees (Lovell 1918).
Fruit dry, of four 1-seeded nutlets.
Habitat: Wet soil.