This name is a synonym of Achillea millefolium subsp. sudetica (Opiz) Oborny.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record D6B26B00-6F09-485B-A680-21581670CDF2) with original publication details: 623 1813.
This name was in version 1 of The Plant List, record gcc-18052, and has not been changed.