Unio capillus Say, 1831
Say, 1831. Transylvania J. Med. Assoc. Sci. 4: 528.
(renamed Unio lapillus Say, 1831)

Micromya fabalis — Simpson (1900)
Micromya (Group of Micromya fabalis) fabalis — Simpson (1914)
Lemiox fabalis — Frierson (1927), Haas (1969)
Villosa fabalis — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), IUCN (2012)
Paetulunio fabalis — Watters (2018)

Unio fabalis Lea, 1831
Lea, 1831. Trans. Amer. Phil. Soc. 4 [O. 1]: 86, pl. 10, fig. 16.
Type(s): FIGURED SYNTYPE USNM_85270A, Ohio R.

Micromya fabalis — Simpson (1900), Ortmann (1909), Ortmann (1909), Ortmann (1910), Ortmann (1924), Ortmann (1925), Haas (1969)
Unio (s.s.) fabalis — Call (1900)
Eurynia (Micromya) fabalis — Ortmann (1912), Ortmann (1918)
Micromya (Group of Micromya fabalis) fabalis — Simpson (1914)
Lemiox fabalis — Frierson (1927), Haas (1969)
Ligumia (Micromya) fabalis — Thiele (1934)
Villosa fabalis — Burch (1975), R.I. Johnson (1980), Mackie et al. (1980), Turgeon et al. (1988), Cummings & Mayer (1992), ... Jones (2015), Lane et al. (2016), Williams et al. (2017), Klymus et al. (2020), Gasparini et al. (2020)
Paetulunio fabalis — Watters (2018), Graf & Cummings (2021), FMCS (2021), Hopper et al. (2023), FMCS (2025), Campbell & Lydeard (2026)

Unio lapillus Say, 1831
Say, 1831. Transylvania J. Med. Assoc. Sci. 4: 528.
Say, 1832. Amer. Conch. 5: pl. 41.
(new name for Unio capillus Say, 1831)

Micromya fabalis — Simpson (1900)
Unio (s.s.) fabalis — Call (1900)
Micromya (Group of Micromya fabalis) fabalis — Simpson (1914)
— de Gregorio (1914)
Lemiox fabalis — Frierson (1927), Haas (1969)
Villosa fabalis — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), IUCN (2012)
Paetulunio fabalis — Watters (2018)

Unio donacopsis de Gregorio, 1914
de Gregorio, 1914. Il Nat. Siciliano 2: 60, pl. 10 figs. 5a-d.

Unio donacopsis — de Gregorio (1914)
Villosa fabalis — Parmalee & Bogan (1998), Williams et al. (2008), Watters et al. (2009), IUCN (2012)
Paetulunio fabalis — Watters (2018)