As our most ancient native tree, the story of the European Black Poplar (Populus nigra subsp. betulifolia) is one of decline and fall from a once common timber species with a substantial economic and cultural significance to a near vanishing point from the British landscape. Calls for a nationwide recording project in the 1990s1 has ferreted out a scattered population of about 7,000 ageing trees. London has a fair smattering across 21 boroughs, though most are confined to the rural edges of the Hackney Marshes and along the rivers Lea and Thames.2 There are a few urban loners too such as the sentinel by the Tower of London but closer to home I went in search of the solitary Black Poplar in Russell Square.
Planted on the East side facing on to the congested one-way system and nudged out by an adjacent London Plane, this Black Poplar ekes out a rather precarious existence as a mono-trunked specimen with stumped limbs. I confess to being rather dismayed at first sighting as, unlike its streamlined Italian and Lombardy cousins, the native species is a ruggedly robust character. Somewhat ungainly and having a typical leaning stance, the grey-brown bark is deeply crevassed with blackened furrows lending it a gloomy appearance. The linearity of the trunk is regularly interrupted by large woody swellings or ‘bosses’ which are a main feature in distinguishing the native Black Poplar from its hybrids.
Identifying a tree in mid December is perhaps not ideal as much also depends on flower and leaf. This tree is almost certain to be a male clone (see Summary) and only Spring will confirm this when handsome crimson catkins should appear. Commonly known as ‘ Devils Fingers’, the long male flowers are quite distinct from the slightly later, yellow-green female flowers.3
Despite the lateness of the year, the Black Poplar still held to its top canopy and the fallen serrated leaves displayed some of the usual mid-green mature colouration with variable triangular size and shape. There was no sign however of the spiral leaf galls that are typically present and caused by a parasitic aphid.
Otherwise known as the Water Poplar, its natural environs are riverside woodland and floodplains. This backdrop not only aesthetically sets off the true Salicaceaen character but more importantly is the requisite (and declined) habitat for their stringent seed-germinating requirements. Although Water Poplars exist in a wide variety of urban locations, they have a somewhat stark, high-and-dry appearance compared to their riverine relatives. Here in Bloomsbury the Black Poplar can only look on rather nostalgically at the distant fountain where children and pigeons play and bathe with equal enthusiasm.
In Greek Mythology, Black Poplars represent the Heliades, the grief-stricken sisters of Phaeton, who were petrified through perpetually mourning his death. Gazing up at the dark, skeletal structure in January, I can clearly see an association although the tall, angular specimen of Russell Square bears the distinct look of a Sagittarian with hand-held bow. A case of the hunted becoming the hunter perhaps.
February Festival of the Trees: Now live at Treeblog. Next month’s festival will be hosted by Rebecca in the Woods
Summary: UK’s Black Poplar Facts.
The European Black Poplar (Populus nigra subsp. betulifolia) is a ‘dioecious’ species but with only 500 recorded females in the UK and with few located in ideal habitats and close enough to male trees, virtually none can reproduce by seed. They have however readily crossed with imported Poplar species to produce fertile hybrids which can also back cross with either parent leading to a dilution of the native species. The majority of Black Poplars are actually cloned males, grown from truncheoned cuttings, resulting in such a small genetic variation that they are vulnerable to the threat of disease, such as Poplar Scab currently decimating trees in the North-East. Males were planted in preference to the females with their copious cottonwool seeds.
Most of the UKs trees are veterans of the 19th and early 20th Century, having been grown when demand for the springy, impact and fire resistant timber was at its industrial peak. A targeted planting conservation scheme across most counties is regenerating the Black Poplar population, co-incident with some life-extending coppicing and pollarding of the geriatric trees.4
Related Post: For the Love of Poplar