About: The ‘true’ black poplar is one of the rarest trees in Britain. One of our most fascinating native trees, the black poplar has a deep historical connection with Britain. But with an ageing population of sparsely distributed trees, there are now very few truly wild black poplars left in the country. Black poplar can be seen at The Chase LWT Reserve in Barking & Dagenham.
Sparsely distributed trees - There are about 7,000 individuals left, and only 600 of these are known to be female; most of these females are over 100 years old. Black poplars have suffered as their natural habitat has been steadily removed over the years through woodland clearance and land drainage, while hotter and drier summers, as well as the tidying up of fallen trees and branches have all contributed to their decrease in numbers. The declining ratio of female to male trees is also significant. The majority of black poplars planted in parks and gardens are male trees, preferred to female trees which produce “unsightly” seed fluff. So now, in many cases the distance between male and female trees is too great for germination to occur.
Moreover, the introduction of fast-growing American and European poplars has meant that demand for the black poplar’s timber has rapidly declined. Indeed, the development of a variety of black poplar hybrids from the 18th century (to breed out some of their less popular features) has led to these now being far more numerous than the ‘true’ species. For example, the railway poplar (P. nigra X ‘Regenerata’) and Lombardy poplar (P. nigra X ‘Italica’) are examples now common throughout much of Britain. As a result of their decline in numbers, the true black poplar is now protected by the Wildlife and Countryside Act 1981, and is part of a London Biodiversity Action Plan (BAP).
How to spot: These broad-leaved deciduous trees are part of the willow family. Robust, with a wide trunk, they can grow up to 30m tall. Their triangular leaves are pale green when young, and turn darker as they mature. As a ‘dioecious’ plant, the species produces both male and female trees. The male catkins are crimson and female catkins are yellow-green. The tree’s natural habitat is wet woodland and forested floodplain.
Appearance and confusing species: Black poplar trees often lean at an angle and have dark grey bark, deeply furrowed, with large woody swellings or ‘bosses’. They can easily be confused with all the cultivated hybrid black poplars including the lombardy and railway poplars
Where and when to see them: Black poplars have been found in 21 London boroughs with a greater concentration along the Thames and the north-east of the City. The flowers (catkins) appear in spring.
Where - Hackney is the most populated borough and the majority of these can be found on Hackney Marshes and along the River Lea. This tree can also be seen at The Chase (in Barking & Dagenham), Tower of London and in Russell Square, Bloomsbury.
When - The male trees tend to flower earlier in the spring than the females. So look out for crimson catkins in early spring and yellow-green ones slightly later on.
Fascinating fact: In Greek mythology the black poplar was created when Phaeton’s sisters made such a nuisance of them mourning his death that the gods decided to turn them into black poplars.