Polygonaceae

Mostly terrestrial, sometimes aquatic or wetland loving, non-woody (herbaceous), sometimes viny, perennials, biennials and annuals that typically have a papery sheath called an ochrea wrapped around the stem just above where each leaf is attached; the ochrea is thought to be an outgrowth of the sheathing base of the leaf stalk, or from expansion or fusion of stipules from the axils. The top of the ochrea sometimes has a fringe of hairs.

Stem erect, sprawlng along the ground, or climbing, solid or hollow, usually with swollen nodes, smooth or hairy, sometimes glandular, rarely with downward curved spines.

Leaves usually both basal and on stem, usually alternate, rarely opposite or whorled, stalked at base or not; if stalked, the stalk sometimes jointed. Leaf blades simple, the edges mostly without teeth, occasionally wavy or with blunt teeth.

Flowers in cymes, racemes, spikes or umbels at top of stem and its branches, or in leaf axils; flower arrays sometimes supported by multiple bracts at base. Each flower usually producing both pollen and seeds, but in some plants also sometimes with some flowers producing one or the other; each flower radially symmetrical. Sepals and petals almost indistinguishable from one another (tepals), a total of 2-6, in 1 or 2 whorls, all sepal-like or petal-like, separate or fused at base to form a bell-shaped or urn-shaped tube, persistent, often increasing in size after flowering; often greenish, white, pink, yellow, red, or purple, rarely winged or keeled; smooth or hairy, sometimes with glands. Stamens 6-9, the stalks separate, fused at base, or sometimes fused into a tube, attached to the tepals or not. Carpels usually 3 (sometimes 2 or 4), fused to form 1 pistil; ovary located above point of attachment of other flower parts (radially) with only 1 chamber; styles 1-3, separate or fused at base; stigmas 1 per style. Nectar produced by a disk at base of ovary, glands associated with bases of filaments, and/or leaf stalks. Fruit achenes, triangular or with 2 sides curving outward in cross section; with 1 seed.