This name is a synonym of Geum sylvaticum Pourr..
The record derives from RJP
(data supplied on 2011-10-18)
which reports it as a synonym (record 32046) with original publication details: Flora lusitanica Flora lusitanica; 1804 353 1805.
This name record (from RJP) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Geum biflorum in version 1 of The Plant List.