| Polygonaceae Juss., 1789 |
| Polygonoideae Eaton, 1836 |
| Polygonum L., 1753 |
| Polygonum acre Lam., 1778 |
| Polygonum acuminatum Kunth, 1818 |
| Polygonum amphibium L., 1753 |
| Polygonum amphibium var. emersum Michx., 1803 |
| Polygonum amphibium var. stipulaceum N. Coleman, 1874 |
| Polygonum arenastrum Boreau, 1857 |
| Polygonum argyrocoleon Steud. ex Kunze, 1847 |
| Polygonum aubertii L. Henry, 1907 |
| Polygonum aviculare L., 1753 |
| Polygonum aviculare subsp. depressum (Meisn.) Arcang., 1882 |
| Polygonum aviculare subsp. neglectum (Besser) Arcang., 1882 |
| Polygonum barbatum Walter, 1788 |
| Polygonum beyrichianum Cham. & Schltdl., 1828 |
| Polygonum capitatum Buch.-Ham. ex D. Don, 1825 |
| Polygonum convolvulus L., 1753 |
| Polygonum douglasii Greene, 1885 |
| Polygonum ferrugineum Wedd., 1849 |