Betula pendula (as "B. oycoviensis") was previously listed on the Red List as vulnerable, though it is now considered a synonym of "Betula pendula" subsp. "pendula". "Betula szaferi" was previously considered extinct in the wild on the Red List, but is now considered a form of "B. pendula" with the presence of a mutant gene, causing it to grow weakly and fruit heavily. Silver birch is often planted in parks and gardens, grown for its white bark and gracefully drooping shoots, sometimes even in warmer-than-optimum places such as Los Angeles and Sydney. In Scandinavia and other regions of northern Europe, it is
Alnus cordata with a very long season in leaf, from April to December in the Northern Hemisphere; they are alternate, cordate (heart-shaped), rich glossy green, 5–12 cm long, with a finely serrated margin. The slender cylindrical male catkins are pendulous, reddish and up to 10 cm long; pollination is in early spring, before the leaves emerge. The female catkins are ovoid, when mature in autumn 2–3 cm long and 1.5–2 cm broad, dark green to brown, hard, woody, and superficially similar to some conifer cones. The small winged seeds disperse through the winter, leaving the old woody, blackish 'cones' on the tree