California knotweed
- kingdom: Plantae
- phylum: Tracheophyta
- class: Magnoliopsida
- order: Caryophyllales
- family: Polygonaceae
- genus: Polygonum
- species: Polygonum californicum
Chico- Napa
- Sacramento
- Sheridan
- Yreka
California- Fruitdale
- Grants Pass
- The Dalles
Oregon- Dallesport
- White Salmon
Washington
United States