Knorringia in Novosti Sist. Vyssh. Rast. 24: 76. 1987 sec. ???
- ≡Polygonum sect. Knorringia in Novosti Sist. Vyssh. Rast. 3: 92-93. 1966 syn. sec. ???
- ≡Aconogonon sect. Knorringia in Preslia 46: 151. 1974 syn. sec. ???
- Type: Knorringia sibirica
The genus was segregated from Polygonum s.l. (or from Aconogonum) and placed in the Coccolobeae by Hong (1989). Later on it was included within Persicaria (Persicarieae) by Brandbyge (1993) and after that considered as incertae sedis within Polygoneae by Galasso & al. (2009). Its isolated position from Persicaria was statistically well supported by molecular data in Sanchez & al. (2011). The taxon is sister to the remaining members of the Polygoneae, with which it shares characters such as tepal nervature, structure of the exocarp and pollen morphology (Galasso & al. 2009).