Polygonaceae (weeds) - (buckwheat family)
This family of flowering plants contains more than 1,000 species of herbs, as well as a few vines, shrubs and trees. They are mainly found in temperate regions. Some species are grown as crops, e.g. buckwheat and rhubarb. However, the family contains also various important agricultural and environmental weeds like Fallopia convolvulus or Polygonum aviculare.
The stems often have many swollen nodes (knots) and the family is also known as knotweeds. The alternately arranged leaves are simple with a pair of fused, sheathing stipules. The inflorescences are composed of many tiny flowers, each with 5 or 6 coloured sepals but without petals. The seeds are triangular or lens-shaped.
The following genera and individual species are currently entered under this family: