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 55255) with original publication details: Monogr. Ikon. Orchid. 50 1976.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:887378-1.
This name was in version 1 of The Plant List, record kew-55255.