This name is a synonym of Alternanthera aquatica (Parodi) Chodat.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50296315) with original publication details: Anales Soc. Ci. Argent. 5: 316 1877.
This name was in version 1 of The Plant List, record tro-50296315, and has not been changed.