A taxonomic history of the British birch tree

Abstract

Most taxonomists now agree that there are three native birches in Britain but there is disagreement on their correct specific names. Linnaeus' Species Plantarum of 1753 introduced the binomial system to taxonomy and he described two birches that occurred in the cooler parts of Europe. One of these, the dwarf birch, which he called Betula nana has retained its original name but the other, the tree birch B. alba has undergone many changes of name and has been separated into several species by some taxonomists. This paper traces the changes that have occurred in the specific name of the British birch tree since 1753, and shows that if there are two species of birch tree then they should be called B. pendula Roth and B. pubescens ]Ehrh. The author concludes that until the status of the British birch tree has been satisfactorily examined B. pendula and B. pubescens should be regarded as subspecies of the Linnaean B. alba.

Betula mcallisteri sp. nov. (sect. Acuminatae, Betulaceae), a new diploid species overlooked in the wild and in cultivation, and its relation to the widespread B. luminifera

“…Aside from our case, a difference in ploidy has also been used to separate other closely related Betula species. For example, B. pendula and B. pubescens were once treated as a single species, B. alba ( Linnaeus, 1753 ), and were later acknowledged to be two species, as B. pendula is a diploid and B. pubescens is a tetraploid ( Tuley, 1973 ; Atkinson, 1992 ).…”