Paronychia Mill., sec. Bittrich (1993c)
  • =Siphonychia Torr. & A.Gray, Fl. N. Amer. 1: 173. 1838 syn. sec. Hartman & al. (2005)
  • =Gibbesia Small in Bull. Torrey Bot. Club 25: 621. 1898 syn. sec. Hartman & al. (2005)
  • =Anychiastrum Small, Fl. S.E. U.S.: 400. 1903 syn. sec. Hartman & al. (2005)
  • =Odontonychia Small, Fl. S.E. U.S.: 401. 1903 syn. sec. Hartman & al. (2005)
  • =Gastronychia Small, Man. S.E. Fl.: 480, f. 1933 syn. sec. Hartman & al. (2005)



In a study mainly addressing Gymnocarpos, Oxelman & al. (2003) found Paronychia to be polyphyletic, with the subgenera Paronychia and Siphonychia forming a strongly supported sister group to Gymnocarpos, whereas species in subg. Anoplonychia were found to be more closely related to Herniaria and Philippiella. This was confirmed by Greenberg & Donoghue (2011). The group consists of 110 (Hartman & al. 2005) or more than 150 species (Bittrich 1993b). It is one of the large groups in the family that has not yet been extensively studied with DNA sequence data, especially in subg. Anoplonychia (only two of 48 species sampled).