This name is a synonym of Achillea distans subsp. alpina (Rochel) Soó.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 60882276-6494-48B4-BFD8-29270429F37D) with original publication details: Rochel. 1828. 23 1828.
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 Achillea magna in version 1 of The Plant List.