This name is a synonym of Hieracium lachenalii subsp. subhastulatum (Zahn) Greuter.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record AB2761FB-FB87-4662-8F94-313F292E347E) with original publication details: 28 1912.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:51024169-1.
This name was in version 1 of The Plant List, record gcc-26657, and has not been changed.