This large, majestic tree species is at home on floodplains and along watercourses, famously depicted in John Constable’s (1776–1837) . This is the rarest timber-producing tree native to Britain and Ireland. Sometimes known as Water Poplar.
Native to much of north-west Europe, western Asia, and a small area of Morocco in Africa. Locally native to England and Wales, preferring milder areas of Britain, also sparsely planted, with an uncertain status in Ireland, but considered likely native.
Dioecious, with male trees bearing red catkins and female trees green ones producing silky white-haired seeds carried on the lightest wind. Because females’ copious fluffy seed is seen as a nuisance, male trees have been preferentially propagated from cuttings, reducing females to under 10 per cent of the population, perhaps just 600-700 trees, giving low genetic diversity. Fertile seed is thus more likely from hybridising. The native subsp. betulifolia is one of several subspecies, another being Lombardy Poplar.
Black Poplar is not a woodland tree but grows on floodplains, wet meadows and ditch, stream and river banks, and field margins, where its shape once marked parish boundaries. To 30m, with a broad crown and lower branches arching down then up. The leaning trunk is deeply fissured and very gnarly with prominent burrs, 3-4m across, and is often pollarded. Twigs hairy; buds orange-brown, sticky, pointed. Leaves small (7cm), triangular, mildly balsam-scented, round-serrate. Male catkins red (March-April), female with white fluffy seed in June.
A pioneer well adapted to wet and waterlogged ground, but not shade-tolerant. Easily propagated from hardwood cuttings, ideally from female trees to tackle low genetic diversity. It needs moist ground, with young plants kept weed-free in full sun. In the landscape, the scarcity of both sexes nearby makes natural germination unlikely; even fertile seed needs moist summer soils, with drought or flooding likely to cause failure.
Pollen attracts insects in spring, while foliage favoured by many moths including Poplar Hawk-moth (Laothoe populi). Effective at stabilising riverbanks, its roots creating habitat for Otter and Common Kingfisher. Old trees provide nesting sites for owls and bats.
Loss of suitable wetland habitat. Limited genetic diversity in species is a serious threat. Trees can be infected by bacterial canker, leaf rusts and honey fungus.
Its pale timber was traditionally valued: large stems for barn and house beams, boards for flooring, cart brake-blocks, and fireplaces (being fire-resistant), with small pieces for kitchen utensils. Branches and leaves were fed to cattle. Today the species is most valued for biodiversity and conserving riparian habitats, and could help combat climate-change effects in the countryside.
