This name is a synonym of Betula pubescens var. glabrata Wahlenb..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 341947) with original publication details: Consp. Fl. Eur. Suppl. 2: 282 1890.
This name was in version 1 of The Plant List, record kew-341947.