This name is a synonym of Dactylorhiza elata subsp. sesquipedalis (Willd.) Soó.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 55268) with original publication details: Wilde Orchid. Eur. 1: 204 1977.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:887381-1.
This name was in version 1 of The Plant List, record kew-55268.