This name is a synonym of Carduus schimperi subsp. platyphyllus (R.E.Fr.) C.Jeffrey.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 5B4B968B-3004-48B6-BC37-07C91C474CB0) with original publication details: 20 1925.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:188954-1.
This name was in version 1 of The Plant List, record gcc-4184, and has not been changed.