Vegetative key to the families

OCHREA (sheath) Present around the stem and petiole, formed from fused stipules (Fig. 25). Leaves alternate. Herbs Polygonaceae

Perianth segments 5, ± equal

Flowers mostly bisexual. Calyx enlarged but not otherwise changed at fruiting stage

Nut much exceeding the perianth Fagopyrum

Nut enclosed by perianth