621 Betula humilis Schrank

This variable, Eurasiatic species is mapped together with the closely related B. fruticosa Pall., B. extremiorientalis Kuzen. & Vassil., both in E. Asia, and B. pumila L. in N. America. Hybrids with geographically adjacent taxa are recorded. Cf. also Meusel et al. 1965, map p. 119.