Plants Belonging To Polygonaceae
Polygonaceae is a family of flowering plants also known as the knotweed or buckwheat family.The Buckwheat family has many familiar members including sorrel and rhubarb. The leaves are simple and the stems have swollen joints or "knee" which the latin Polygonum refers to. Worldwide there are about 40 genera and 800 species, with 15 genera here in North America. Many plants in this family contain oxalic acid in the fresh juice. The Rheum genus is known for tannins and anthraquinones which are used in laxatives. Elpel, Thomas J.