Unio decisus Lea, 1831
Lea, 1831. Trans. Amer. Phil. Soc. 4 [O. 1]: 92 [102], pl. 12, fig. 23.
Type(s): HOLOTYPE USNM_84723, Claiborne, Ala.

Pleurobema (s.s.) decisa — Simpson (1900)
Unio (s.s.) clavus — Call (1900)
Pleurobema decisum — Ortmann (1912), Burch (1975), Turgeon et al. (1988), Williams et al. (1993), Turgeon et al. (1998), ... Graf & Cummings (2021), FMCS (2021), Morrison et al. (2021), Hopper et al. (2023), Hauck et al. (2023)
Pleurobema (s.s.) decisum — Simpson (1914)
— de Gregorio (1914)
Pleurobema (s.s.) decisus — Frierson (1927)
Pleurobema decisum decisum — Haas (1969)
Pleurobema decisus — Jones et al. (2005)

Unio scalenius Say, 1834
Say, 1834. Amer. Conch. 6: ??.
(misidentified reference to Obliquaria (Scalenaria) scalenia Rafinesque, 1820)

Pleurobema (s.s.) decisa — Simpson (1900)
Pleurobema (s.s.) decisum — Simpson (1914)
Pleurobema (s.s.) decisus — Frierson (1927)

Unio chattanoogaensis Lea, 1858
Lea, 1858. Proc. Acad. Nat. Sci. 10: 166.
Lea, 1859. Jour. Acad. Nat. Sci. 4 [O. 7]: 209 [27], pl. 25, fig. 90.
Type(s): HOLOTYPE USNM_84729, Chattanooga, Tenn.

Pleurobema (s.s.) chattanoogaensis — Simpson (1900)
Unio (s.s.) clavus — Call (1900)
Pleurobema (s.s.) chattanoogaense — Simpson (1914)
Pleurobema (s.s.) decisus-chattanoogaensis — Frierson (1927)
Pleurobema decisum chattanoogaensis — Haas (1969)
Pleurobema chattanogaense [sic] — Burch (1975)
Pleurobema chattanoogaense — Turgeon et al. (1988), Williams et al. (1993), Parmalee & Bogan (1998), Turgeon et al. (1998), Lydeard et al. (1999), ... Campbell et al. (2008), Cummings & Graf (2010), ITIS (2012), Inoue et al. (2018), Morrison et al. (2021)
Pleurobema decisum — Williams et al. (2008), Williams et al. (2017), Graf & Cummings (2021)
Pleurobema chattanoogaensis — Hauck et al. (2023)

Unio anaticulus Lea, 1861
Lea, 1861. Proc. Acad. Nat. Sci. 13: 40.
Lea, 1862. Jour. Acad. Nat. Sci. 5 [O. 8]: 92 [96], pl. 13, fig. 240.
Type(s): HOLOTYPE USNM_84735, Columbus, Miss.

Pleurobema (s.s.) decisa — Simpson (1900)
Unio (s.s.) clavus — Call (1900)
Pleurobema (s.s.) decisum — Simpson (1914)
Unio anaticulus — de Gregorio (1914)
Pleurobema (s.s.) decisus — Frierson (1927)
Pleurobema decisum decisum — Haas (1969)
Pleurobema curtum — Williams et al. (2008)

Unio consanguineus Lea, 1861
Lea, 1861. Proc. Acad. Nat. Sci. 13: 60.
Lea, 1862. Jour. Acad. Nat. Sci. 5 [O. 8]: 67 [71], pl. 7, fig. 217.
Type(s): HOLOTYPE USNM_84726, Cahawba R., Ala.

Pleurobema (s.s.) decisa — Simpson (1900)
Unio (s.s.) clavus — Call (1900)
Pleurobema (s.s.) decisum — Simpson (1914)
Unio consanguineus — de Gregorio (1914)
Pleurobema (s.s.) decisus — Frierson (1927)
Pleurobema decisum decisum — Haas (1969)
Pleurobema decisum — Williams et al. (2008)

Unio crebrivittatus Lea, 1861
Lea, 1861. Proc. Acad. Nat. Sci. 13: 60.
Lea, 1866. Jour. Acad. Nat. Sci. 6 [O. 11]: 43 [47], pl. 15, fig. 41.
Type(s): HOLOTYPE USNM_84725, Coosawattee R., Ga.

Pleurobema (s.s.) decisa — Simpson (1900)
Unio (s.s.) clavus — Call (1900)
Pleurobema (s.s.) decisum — Simpson (1914)
Pleurobema (s.s.) decisus — Frierson (1927)
Pleurobema decisum decisum — Haas (1969)
Pleurobema decisum — Williams et al. (2008)

Unio medius Reeve, 1864
‘Lea’ Reeve, 1864. Conch. Icon. 16: pl. 17, sp. 77.
(misidentified reference to Unio medius Lea, 1861)

Pleurobema (s.s.) decisa — Simpson (1900)
Pleurobema (s.s.) decisum — Simpson (1914)
Pleurobema (s.s.) decisus — Frierson (1927)
Pleurobema decisum decisum — Haas (1969)

Unio decisus Küster, 1852
‘Lea’ Küster, 1852. Conchyl. Cab. 9(2): 41, pl. 7, fig. 3. [in part]
(reference to Unio decisus Lea, 1831)

Pleurobema (s.s.) decisa — Simpson (1900)
Pleurobema (s.s.) decisum — Simpson (1914)

Pleurobema chattanogaense Burch, 1975
‘Lea’ Burch, 1975. Freshw. Unio. North Amer.: 12.
(error for Unio chattanoogaensis Lea, 1858)