This name is a synonym of Centaurea argentea subsp. chionantha (Turland & L.Chilton) Greuter.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record BF8ECB66-7BF9-4E65-AE4E-26B892E04156) with original publication details: 77 2000.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:1015323-1.
This name was in version 1 of The Plant List, record gcc-20942, and has not been changed.