This name is a synonym of Begonia polygonoides Hook.f..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 361223) with original publication details: Mitt. Deutsch. Schutzgeb. Ergänzungsh. 2: 155 1889.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:104384-1.
This name was in version 1 of The Plant List, record kew-361223, and has not been changed.