This name is a synonym of Centaurea ambigua Guss..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 30DAEE1B-EB57-46B7-B579-D8515C2A0C3D).
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 Centaurea ambigua in version 1 of The Plant List.