This name is a synonym of Begonia modestiflora Kurz.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 363063) with original publication details: Bull. Misc. Inform. Kew 1911: 58 1911.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:105758-1.
This name was in version 1 of The Plant List, record kew-363063, and has not been changed.