Symphynota compressa Lea, 1829
Lea, 1829. Trans. Amer. Phil. Soc. 3 [O. 1]: 450, pl. 12, fig. 22.
(renamed Margaron (Unio) pressus Lea, 1852)
Type(s): LECTOTYPE USNM_83961, Yellow Cr., Cincinnati, Ohio.

Symphynota (s.s.) compressa — Simpson (1900), Simpson (1914)
Symphynota compressa — Ortmann (1909), Ortmann (1909), Ortmann (1910), Ortmann (1912)
Unio compressa — de Gregorio (1914)
Lasmigona (Platynaias) compressa — Ortmann & Walker (1922), F.C. Baker (1928), Clarke (1985), Graf & Cummings (2007)
Lasmigona (Platynaias) viridis — Frierson (1927), Haas (1969)
Lasmigona (sec. Platynaias) compressa — Thiele (1934)
Lasmigona (Platynaias) viridis viridis — Haas (1969)
Lasmigona compressa — Clarke (1973), Burch (1975), Heard (1975), Mathiak (1979), R.I. Johnson (1980), ... Dai et al. (2024), Dai et al. (2025), Perkins et al. (2025), Chen et al. (2025), Chen et al. (2025)
Platynaias compressa — Wu et al. (2023), Wu et al. (2024), Wu et al. (2024), Hou et al. (2024), FMCS (2025), Hou et al. (2025), Wang et al. (2025), Campbell & Lydeard (2026), Wu et al. (2026)

Unio compressus var. plebius C.B. Adams, 1842
C.B. Adams, 1842. [in] Thompson, History of Vermont (1): 16.
(intro'd as intra-sp. of Symphynota compressa Lea, 1829)
Type(s): LECTOTYPE MCZ_154361 (by R.I. Johnson, 1956: 130), small brook in Middlebury, Vermont.

Symphynota (s.s.) compressa var. plebius — Simpson (1900)
Symphynota (s.s.) compressa var. plebia — Simpson (1914)
Lasmigona (Platynaias) viridis-plebia — Frierson (1927)
Lasmigona (Platynaias) viridis plebia — Haas (1969)
Lasmigona compressa — Clarke (1973), Burch (1975), Strayer & Jirka (1997), Watters et al. (2009)
Lasmigona (Platynaias) compressa — Clarke (1985)

Margaron (Unio) pressus Lea, 1852
Lea, 1852. Synopsis Fam. Naiades: 19.
Lea, 1870. Synopsis Fam. Naiades: 29.
(new name for Symphynota compressa Lea, 1829)
Type(s): HOLOTYPE USNM_83961, Yellow Cr., Cincinnati, Ohio.

Symphynota (s.s.) compressa — Simpson (1900), Simpson (1914)
Unio (s.s.) pressus — Call (1900)
Lasmigona (Platynaias) viridis — Frierson (1927)
Lasmigona (Platynaias) compressa — F.C. Baker (1928), Clarke (1985)
Lasmigona (Platynaias) viridis viridis — Haas (1969)
Lasmigona compressa — Strayer & Jirka (1997), Watters et al. (2009)

Unio compressa var. lindus de Gregorio, 1914
de Gregorio, 1914. Il Nat. Siciliano 2: 14, pl. 6, figs. 1a-d.
(intro'd as intra-sp. of Symphynota compressa Lea, 1829)

Unio compressa var. lindus — de Gregorio (1914)
Lasmigona (Platynaias) viridis viridis — Haas (1969)
Lasmigona compressa — Watters et al. (2009)

Unio alasmodontina Lea, 1829
‘Barnes’ Lea, 1829. Trans. Amer. Phil. Soc. 3 [O. 1]: 451.
(intro'd as syn of Symphynota compressa Lea, 1829)

Lasmigona (Platynaias) viridis — Frierson (1927)
Lasmigona (Platynaias) compressa — Clarke (1985)
Lasmigona compressa — Watters et al. (2009)

Complanaria alasmodontina Stimpson, 1851
‘Barnes’ Stimpson, 1851. Shells of New England: 14.
(reference to Unio alasmodontina Lea, 1829)

Symphynota (s.s.) compressa — Simpson (1900), Simpson (1914)
Lasmigona (Platynaias) viridis viridis — Haas (1969)
Lasmigona compressa — Watters et al. (2009)

Unio compressus var. plebeius Lea, 1852
‘Adams’ Lea, 1852. Synopsis Fam. Naiades: 19.
(error for Unio compressus var. plebius C.B. Adams, 1842)