This name is a synonym of Hieracium lachenalii subsp. argillaceoides (Litv. & Zahn) Greuter.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 520AB704-7EC4-43B6-917B-9DEE55FBF8C8) with original publication details: 239 1907.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:51023649-1.
This name was in version 1 of The Plant List, record gcc-60392, and has not been changed.