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 21311) with original publication details: Bol. Soc. Brot. II, 14: 149 1940.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:107774-1.
This name was in version 1 of The Plant List, record kew-21311, and has not been changed.