The native subspecies of black poplar, Populus nigra betnifolia, is locally frequent in parts of lowland England and Wales, rarer in the north of England and Scotland, and rare in Ireland (9)(10), and also occurs in western Europe. At present the British population numbers just 2000 to 3000 trees (2). Elsewhere, black poplar is widely distributed but increasingly scarce throughout much of Europe reaching into central Asia and North Africa. It is generally absent from the far north of Europe (4).