IN a corner of Cockerton stands a curious tree which has just revealed its true colours – although its real history can only, at this stage, be guessed at.

The tree is a native of China. It bears the name of a Russian princess who became the queen of the Netherlands, and is the only known mature specimen of its species in County Durham.

It is known as the Empress Tree, the Princess Tree or the Foxglove Tree because its lilac blossoms, which are remarkably on display for the second time this year, look like those of a foxglove.

Even more remarkably, for the last 60 or 70 years, it has been tucked away in a line of greenery beside a roundabout with no one remarking upon it.

About ten years ago, members of the Darlington & Teesdale Naturalists’ Field Club spied it. Council records suggested it was an Indian bean tree – a fairly unusual tree from the southern states of the US – but when the botanists studied its leaves, that identification didn’t ring true with them.

But what was it?

“We thought we knew but we couldn’t prove it until it flowered, but it didn’t flower for ten years and then last year, when we were all in lockdown, it was covered in purple flowers,” says Fal Sarker of the field club. “Then we could prove it was Paulownia tomentosa, the foxglove tree.

“It only flowers from the middle of April to early May, but this year it appears to be flowering for a second time, into June.”

The tree only flowers on its uppermost branches, and its leaves only appear once its flowering is over.

The foxglove tree was discovered by Philipp Franz Balthasar von Siebold, a Germany physician who worked for the Dutch navy in the Far East in the 1820s. He was a botanical enthusiast, and he collected 1,000 Chinese and Japanese plants in his hot-houses.

He is the man who sent back the first hostas and hydrangeas to Europe, and he has everything from an acer to a viburnum named after him.

Not that we should be entirely grateful to him: every invasive Japanese knotweed in all of Europe is said to be descended from a single female specimen that he sent back because he thought its leaves would look dramatic in a stately garden.

Another of Siebold’s finds was the foxglove tree, which, according to Japanese legend, is the only tree that a returning phoenix will land in. Apparently, it is traditional in Japan to plant a foxglove tree on the birth of a girl. It is quick growing so it will mature as she grows, and it is customary to cut it down when she marries so that its wood can be carved into items for her dowry.

Siebold dedicated to Anna Pavlovna and so its name is Paulownia tomentosa – “Paulownia” for Pavlovna and “tomentosa” which is Latin for “covered in hairs”.

Anna was the grand-daughter of Catherine the Great and the daughter of the Russian tsar who, in 1816, married the Prince of Orange who became King William II of the Netherlands in 1840.

The first of the trees arrived in this country in 1838 but, according to the Botanical Society of Britain and Ireland, the Cockerton specimen is the only mature one in England north of the Humber – there is one in Scotland, on the southern bank of the Forth.

So how did it come to be in Cockerton?

It grows where once there was a line of cottages leading to a hump-backed bridge over the Cocker Beck. The bridge was removed in 1904 so that trams could get into the village, and the cottages were taken down in 1925 to widen the road.

Just over the beck was Cockerton Hall, a 17th Century mansion that was enlarged by William Wrightson – “the squire of Cockerton” – after 1745. Its last inhabitant left in 1946 and it was demolished in 1963 when Strike’s garden centre took over the site. Now flats cover its gardens.

So could the tree be a descendant of a specimen that once grew in the grounds of the hall, or is it an escapee from the garden centre?

Any theories would be most welcome.