This name is a synonym of Youngia longiflora (Babc. & Stebbins) C.Shih.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 8DF95F72-A56F-4C6A-80E0-00E056287A13) with original publication details: 97 1937.
This name record (from TICA) 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 Youngia japonica in version 1 of The Plant List.