This name is a synonym of Ludwigia longifolia (DC.) H.Hara.
The record derives from WCSP (in review)
(data supplied on 2012-03-23)
which reports it as a synonym with original publication details: Mém. Soc. Phys. Genève 2(2): 141 1824.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:613087-1.
This name was in version 1 of The Plant List, record kew-2332304, and has not been changed.