Polygonaceae

Polygonaceae, commonly known as the knotweed family, or in the United States as the smartweed buckwheat family, is a family of flowering plants in the order Caryophyllales comprising approximately 1,200 species across roughly 48 genera. Its members are marked by swollen stem nodes and by an ochrea, a papery sheath formed from fused stipules at the base of each leaf, with small bisexual flowers bearing three to six sepals and no petals. The family includes buckwheat, rhubarb, common sorrel, and sea grape, as well as the invasive Japanese knotweed.