⚠ Version 1 of The Plant List has been superseded.
This name record (from Tropicos) is not included in version 1.1 of The Plant List. It is possible the same name is included from a different data source, to check this you can search for Polygonum pennsylvanicum in version 1.1 of The Plant List.
This name is a synonym of Persicaria segetum .
The record derives from Tropicos which reports it as a synonym (record 26001119
) with original publication details: Rep. U.S. Mex. Bound., Botany 2(1): 178 178 1859.