Betula celtiberica

About

Betula celtiberica, the Iberian white birch, is a species of flowering plant in the family Betulaceae, native to Great Britain, northwestern Spain and Portugal. In Spain is it often found on north-facing valley slopes, forming mixed mesic forests with the common beech Fagus sylvatica. Some authors, particularly in Britain, treat it as a subspecies of Betula pubescens, with the suggestion that it is a stabilised hybrid between that and Betula pendula.

Summary from Wikipedia