This name is a synonym of Wolffia arrhiza (L.) Horkel ex Wimm..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 109280) with original publication details: Mant. Pl. 2: 294 1771.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:303429-2.
This name was in version 1 of The Plant List, record kew-109280, and has not been changed.