POPULOUS NIGRA LINN - A RARE ESSEX TREE 155
Populus nigra Linn—a rare Essex tree
By Edgar Milne-Redhead
43 Bear Street, Nayland, Colchester, C06 4HX
The native Black Poplar (Populus nigra Linn) is Britain's rarest timber
tree. Since 1973 I have been conducting a survey of its natural distribution
in Britain (organised by the Botanical Society of the British Isles), because
the distribution-map published in Walters & Perring (1962) gives a com-
pletely misleading picture, as, in addition to records for P. nigra, it includes
records for the man-made hybrids, known collectively as P. x canadensis,
which have been planted widely throughout the British Isles.
I will describe P. nigra for the benefit of those who may be unfamiliar
with the tree. When mature it is a massive tree, up to 30 or even 35 m high,
with the upper branches ascending or spreading irregularly to form a
broken but roundish crown, and at least some of the lower branches arch-
ing strongly and descending almost to the ground, with the tips of the
twigs upturned. The dark greyish-brown bark is deeply and coarsely
fissured, and is often beset with large swollen bosses. The leaves are
variable in shape, smaller than those of most of the hybrids, and they lack
the hooked teeth and the pair of glands where the petiole joins the blade,
characters of P. x canadensis.
The Black Poplar is a tree of the flood-plains of rivers and streams in
England south of a line from the Mersey to the Humber, and in eastern
and northern Wales. It is unknown as a native tree in northern England,
Scotland and Ireland, in west Wales and in Cornwall. It is relatively un-
common in Essex, yet Suffolk is one of its better-populated counties.
I was hoping to obtain some additional Essex records when Jermyn
(1974) reached me last year. But I was sadly disappointed as the Author
gave no detailed records whilst the map showed it in 45 of the 57 part or
whole 10 km grid-squares in the county, far more records than my survey
has yet produced. Jermyn (1974) states 'uncommon but well distributed'
and 'mostly as a planted tree' and goes on to say 'by rivers and streams,
in damp hedgerows and parklands, possibly native in some woods'. My
experience of P. nigra in Britain is that it is never native in woods, and that
its native habitat is by rivers and streams or at least within their flood-
plains. It has been planted by countrymen over the ages by ponds, wells
and ditches, probably by planting cuttings taken from local 'wild' trees.
It has even been planted on village greens! I would describe it as rare in
Essex except in the northern part of the county, where it is local, but no-
where well-distributed. I fear that Jermyn has, as so many reputable
botanists before him, failed to separate P. nigra from P. x canadensis.
This being so, I list here my records to date, presented in the
format used in Jermyn (1974), except that I have divided the records
into vice-counties and added six-figure map-references. All records relate