Polygonum

Prostrate to suberect annuals or perennials with a woody rootstock. Leaves subsessile, articulate on branches; ochreas glabrous, silvery or whitish-hyaline at least in upper part, soon becoming lacerated. Flowers bisexual, axillary, solitary or in small clusters; perianth segments usually 5, mainly sepaloid but often coloured toward margins, not or barely enlarging in fruit; stamens 3–8, widely dilated toward base; styles 3, rarely 2, stigmas capitate. Nut trigonous, or rarely biconvex.