This name is a synonym of Begonia tenuifolia Dryand..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 362907) with original publication details: Pl. Jungh. 418 1855.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:105640-1.
This name was in version 1 of The Plant List, record kew-362907, and has not been changed.