This name is a synonym of Echinopsis quadratiumbonata (F.Ritter) D.R.Hunt.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50136328) with original publication details: Kakteen Südamer. 2: 566 1980.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:257124-2.
This name was in version 1 of The Plant List, record tro-50136328, and has not been changed.