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BRITAIN’S RAREST TREE SPECIES
01/05/2025
People often ask which of all our native tree species is the rarest. The answer is the black popular, Populus nigra, specifically the subspecies betulifolia which is native to England, Wales and Ireland, not to be confused with hybrid black poplars which have often been planted.
In the native species, the young leaves are pubescent (veins finely downy) and are longer than wide, on twigs with spiral buds. The trees have trunks that are often dark brown, even blackish, with rugged bark and deep furrows, usually with many burrs and they tend to lean or twist. They like to grow near water, especially along rivers or streams, by ponds/wet ditches or in wet woods and can grow to a height of 30 metres. They don’t mind fluctuating water levels so play an important role in maintaining such mesic ecosystems in good health, with benefits to the wildlife of such places.
My photo here shows a rare female black poplar (the species is dioecious i.e trees are either male or female) with a picture of the female catkins of a twig shown inset at bottom left of the photo. The second photo below is of a very old male tree on a farm near Worcester, sprawling across an old pond.
Black poplars used to be common, valued for their beauty, their ability to stabilise river banks, their timber and contribution to biodiversity. Their decline, as so often, is due to changes in land use by humans, especially drainage of wetlands, the conversion of land to agriculture and poor regeneration driven by hybridisation with introduced alien trees and the lack of native female trees. There are thought to be about 6000 male trees in Britain and Ireland but only 300 female ones.
Awareness of the black poplar’s plight has grown recently and there are significant conservation efforts to reverse its decline through replanting, monitoring and caring for existing trees, and propagation programmes.
Betts Ecology would like to hear from you if you know of any mature native black poplars on or adjacent to any of our managed sites.
