leathery knotweed
- kingdom: Plantae
- phylum: Tracheophyta
- class: Magnoliopsida
- order: Caryophyllales
- family: Polygonaceae
- genus: Polygonum
- species: Polygonum achoreum
Calgary- Fort Saskatchewan
Alberta- Armstrong
- Cranbrook
- Creston
- Houston
- Prince George
- Vanderhoof
- Vernon
British Columbia- Fort Smith
Northwest Territories- Ottawa
Ontario
Canada
Challis
Idaho- Warren
Illinois- Cheboygan
Michigan- Fairmont
- Moorhead
- Saint Paul
Minnesota- Fargo
North Dakota- Hilliard
Ohio- Green Bay
- Saint Croix Falls
Wisconsin
United States