Plants annual or perennial herbs with branched, terete, stems; ochreae brownish, entire or fringed but not torn. Leaves petiolate; petioles not jointed. Inflorescences terminal and spikelike or a panicle of 2-several, terminal, spikelike racemes, capitate panicles; bracts few and inconspicuous bracts. Tepals usually petalloid, without differentiation between tthe median and marginal areas; stamens 4-8; styles 2 or 3, united or free. Fruits lens-shaped (if styles2), trigonous if styles 3.
Persicaria includes about 150 species. It is almost comopolitan in its distribution but most widespread in the northern hemisphere.
The above description has been modified to more clearly include the variation described in the species descriptions.