Polygonaceae - Knotweed family

Herbs (mostly, in ours), shrubs, climbers or rarely trees. Stems usually with sheathing stipules (ochreae). Leaves simple, alternate (rarely subopposite). Flowers actinomorphic, bisexual or unisexual. Petals 0. Perianth segments 3-6, sepaloid or petaloid, free or connate, persistent. Ovary superior, 1-locular, with a solitary ovule. Fruit a nut, indehiscent, hard, 3-angled or biconvex, usually enveloped in the perianth. Seeds with abundant endosperm.

Worldwide: 46 genera and 1100 species, ± cosmopolitan, but especially northern temperate.

Botswana: 6 genera and 22 taxa.