This name is a synonym of Hygrophila costata Nees.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 103812) with original publication details: Notas Mus. La Plata, Bot. 13: 79 1948.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:125349-2.
This name was in version 1 of The Plant List, record tro-103812.