| Family | Scientific Name | Common Name | Habitat | Distribution | Image |
|---|---|---|---|---|---|
| Polygonaceae | Polygonum aviculare ssp. aviculare | Knotweed | Disturbed areas. | Native of Eurasia. |  |
| Polygonaceae | Polygonum aviculare ssp. buxiforme | Small's Knotweed | Bottomlands, swamps, marshes, also disturbed areas, roadsides. | NL (Newfoundland), NL (Labrador), NU, and NT, variously reported south to SC, AL, MS, LA, TX, and CA. |  |
| Polygonaceae | Polygonum aviculare ssp. depressum | Dooryard Knotweed | Bottomlands, marshes, disturbed areas. | Native of Europe. |  |
| Polygonaceae | Polygonum aviculare ssp. neglectum | Needle-leaf Knotweed | Fields, disturbed areas. | Native of Europe. Documented from scattered locations in s. PA (Rhoads & Klein 1993); DE, NJ, and MD (Kartesz 1999); and WV (as P. aviculare ssp. rurivagum) (Costea & Tardif 2003). |  |
| Polygonaceae | Polygonum aviculare ssp. rurivagum | Disturbed areas. |