Polygonum pensylvanicum
（重定向自Pinkweed）
Polygonum pensylvanicum (syn. Persicaria pensylvanica) is a species of flowering plant in the buckwheat family, Polygonaceae. It is native to parts of North America, where it is widespread in Canada and the United States. It has also been noted as an introduced species in parts of Europe and South America. Common names include Pennsylvania smartweed and pinkweed.