This name is a synonym of Begonia grandis subsp. sinensis (A.DC.) Irmsch..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 363031) with original publication details: Ann. Sci. Nat., Bot. IV, 11: 125 1859.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:105741-1.
This name was in version 1 of The Plant List, record kew-363031, and has not been changed.