This name is a synonym of Begonia mucronistipula C.DC..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 361394) with original publication details: J. Wash. Acad. Sci. 40: 242 1950.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:30501-2.
This name was in version 1 of The Plant List, record kew-361394.