Flora of New Zealand Series

Erect annual andromonoecious herbs with hollow stems. Lvs cauline, triangular to sagittate or hastate, cordate; ochreae short, truncate. Fls in terminal or axillary racemose to corymbose panicles, heterostylous. Pedicels not jointed. Perianth segments 5, free, not keeled, equal or nearly so, not or scarcely accrescent. Stamens 8, alternating with nectaries. Styles 3; stigmas capitate. Fr. a trigonous nut, long-exserted from perianth; surrounding perianth segments spineless.

c. 6 spp., temperate Eurasia. Naturalised sp. 1.

Fagopyrum has been included in Polygonum but differs from it by the combination of lf shape, hollow stems and long-exserted nut.