This name is a synonym of Rosa majalis Herrm..
The record derives from RJP
(data supplied on 2011-10-18)
which reports it as a synonym (record 34854) with original publication details: Systema vegetabilium Systema vegetabilium; 1824 547 1825.
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 Rosa microphylla in version 1 of The Plant List.