It is considered to be native throughout most of the world, from arctic to tropical realms, except South America and Southern Africa.

Other common names for the plant include pale smartweed, curlytop knotweed, and willow weed.

Persicaria lapathifolia is an annual herb with erect reddish stems with swollen joints, growing to a height of 20 to 80 cm (8 to 31 in).

The leaf blades often have a dark-coloured blotch in the centre and are lanceolate or narrowly elliptical and have entire margins.

Each leaf base has stipules which are fused into a stem-enclosing sheath that is loose and fringed with few if any hairs at the upper end.