Polygonum arenarium

Polygonum arenarium, the lesser red-knotgrass or European knotweed, is a species of flowering plant in the family Polygonaceae. It is native to Morocco, France, the former Czechoslovakia, Hungary, southeastern and eastern Europe, the Caucasus, Turkey, the Levant, Iraq, Iran, and Central Asia, and it has been introduced to Argentina, the British Isles, Germany, the Baltic States, and central European Russia. A scrambling or procumbent annual, it is often found in disturbed habitats. In more natural situations it is a psammophyte.

Subtaxa

The following subspecies are accepted:

• Polygonum arenarium subsp. arenarium – Southeastern Europe, the former Czechoslovakia, Hungary, Ukraine, Crimea, southern and eastern European Russia, the Caucasus, Turkey, the Levant, Iraq, and Central Asia, and introduced to southern Argentina, Germany, and central European Russia.
• Polygonum arenarium subsp. pulchellum – Morocco, France, Italy, Ukraine, Bulgaria, Greece, Turkey (including European Turkey), the Levant, North Caucasus, and Iran, and introduced to Ireland, Great Britain, and the Baltic States.

References