Tree Of The Month – a majestic giant – oak tree number 1,200 in Knowle Park.

Sidmouth Herald: Knopper gall on Enlish oak acornKnopper gall on Enlish oak acorn (Image: Archant)

Continuing Sidmouth Arboretum's series Tree of the Month, we are focusing on tree 1,200 from the Arboretum's database, the large oak tree near the old bandstand in The Knowle.

This is the largest tree in The Knowle and just to stand underneath its huge canopy and look up is awe-inspiring.

It is definitely an oak because it has acorns, although they have furry cupules which are very different from English oaks.

The official East Devon District Council list for the park has it as the Devon speciality the Lucombe oak, but is it?

Sidmouth Herald: Oak 1,200 in the Knowle parklandOak 1,200 in the Knowle parkland (Image: Archant)

In the 18th century, the country was running out of mature English oak trees because they were being cut down in large numbers to maintain the Royal Navy - a single warship needed the timber from up to 4,000 mature Oaks and 35 ships were commissioned in the 1720s.

In 1735, Turkey oaks were imported as a possible replacement because they grow more quickly than English oaks.

Unfortunately, the timber was found to be unsuitable for building ships because it was prone to splitting, but the trees were planted on many estates as ornamental trees.

In Exeter, nurseryman William Lucombe was growing a range of imported oaks including Turkey oaks and Cork oaks.

Sidmouth Herald: Oak 1,200 in the Knowle parklandOak 1,200 in the Knowle parkland (Image: Archant)

In 1762, he noted that one of his Turkey oak saplings kept its leaves green through the winter, only shedding them when the new leaves emerged in spring.

It turned out to be a cross with a Cork oak.

It was such a novelty that William propagated many cuttings and sold them.

They were popular with the great estates in Devon and became known as Lucombe oaks.

Sidmouth Herald: Lucombe oak acorns.Lucombe oak acorns. (Image: Archant)

There are two huge Lucombe oaks at Killerton, and the largest known specimen stood in Phear Park, Exmouth until it blew down in 2009.

William Lucombe was so proud of his original tree, he decided to be buried with it.

When he thought he was a reasonable age, he had it felled and used the timber to make a coffin, which he stored under his bed ready for the inevitable.

He miscalculated, he didn't die until many years later, living until he was 102.

Sidmouth Herald: Oak 1,200 in the Knowle parklandOak 1,200 in the Knowle parkland (Image: Archant)

Meanwhile, the oak coffin had rotted, and another tree had to be felled to provide a new coffin.

Only cuttings from the original tree or cuttings from those grown-on cuttings can truly be called Lucombe oaks.

However, the original tree produced fertile acorns and many of these were germinated and sold.

They might be called 'nearly Lucombe oaks', they have leaves like the Lucombe oak and the characteristic furry acorn cupules that you find on Lucombe and Turkey oaks, but they do not keep their leaves for the whole winter.

Tree 1,200 in The Knowle is not a true Lucombe oak because it only holds its leaves until early December, but it is not a pure Turkey oak either, it has the furry acorn cupules, but the leaf shape is wrong.

At 25m (82ft) tall and with a girth of 5.6m (18ft), it is about 250 years old and so is possibly one of those early seedlings, the 'nearly Lucombe oaks', a double cross between the original Lucombe oak and a Turkey oak, bought in from the Lucombe Nursery as a young tree when the Knowle estate was being developed.

In late May to early June, our tree comes into flower.

Male catkins produce pollen which is wind dispersed.

The female flowers have fleshy red stigmas and develop into acorns in cupules like other oaks, but the cupules are covered in scales that give them the appearance of furry Russian hats.

Turkey Oaks and Lucombe Oaks are host to the gall wasp Andricus quercuscalicis, which has a two-stage life cycle.

One stage causes some of the male flowers of the Turkey oak to form into small galls.

The second stage migrates to young acorns of English oaks and causes them to turn into knopper galls rather than viable acorns.

It is not clear if this might pose a threat to future generations of English oaks.

Ed Dolphin is treasurer of Sidmouth Arboretum, visit the Arboretum website www.sidmoutharboretum.org.uk to find out more about the trees of Sidmouth.

To read more features from East Devon Resident, click here.