This name is a synonym of Betula pendula var. fontqueri (Rothm.) G.Moreno & Peinado.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 21580) with original publication details: Willdenowia 13: 350 1983 publ. 1984.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:903692-1.
This name was in version 1 of The Plant List, record kew-21580, and has not been changed.