This name is a synonym of Begonia plumieri var. barahonensis O.E.Schulz.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 361044) with original publication details: Repert. Spec. Nov. Regni Veg. 18: 193 1922.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:30402-2.
This name was in version 1 of The Plant List, record kew-361044, and has not been changed.