*Landoltia punctata (G.F.W. Meyer) Les & D.J. Crawford. Hab: Still to slowly moving waters of ponds, lakes, beaver ponds, and swamps. Dist: Native of the Southern Hemisphere. Widespread worldwide.
Origin/Endemic status: Pantropics
Taxonomy Comments: Les & Crawford (1999) make a good case for recognition of this species in the monotypic genus Landoltia, very possibly more closely related to Lemna than to Spirodela.
Other Comments: An introduced aquarium plant.
Synonymy: = Ar, ETx1, FNA22, K3, NE, Ok, Pa, Tn, Va, WH3, Les & Crawford (1999), Spaulding et al (2019); = Spirodela oligorhiza – Tx, orthographic variant; = Spirodela oligorrhiza (Kurz) Hegelm. – F, G, K4, RAB; = Spirodela punctata (G.Mey.) C.H.Thomps. – C, GW1, Il, K1, NcTx, Landolt (1980), Landolt (1986)