<P> Quercus robur is a large deciduous tree, with circumference of grand oaks from 4 m (13 ft) to exceptional 12 m (39 ft). The Majesty Oak with a circumference of 12.2 m (40 ft) is the thickest tree in Great Britain, and the Kaive Oak in Latvia with a circumference of 10.2 m (33 ft) is the thickest tree in Northern Europe . Quercus robur has lobed and nearly sessile (very short - stalked) leaves 7--14 cm (2.8--5.5 in) long . Flowering takes place in mid spring, and the fruit, called acorns, ripen by the following autumn . The acorns are 2--2.5 cm (0.79--0.98 in) long, pedunculate (having a peduncle or acorn - stalk, 3--7 cm (1.2--2.8 in) long) with one to four acorns on each peduncle . </P> <P> Q. robur is very tolerant to soil conditions and the continental climate but it prefers fertile and well - watered soils . Mature trees tolerate flooding . </P> <P> It is a long - lived tree, with a large wide spreading crown of rugged branches . While it may naturally live to an age of a few centuries, many of the oldest trees are pollarded or coppiced, both pruning techniques that extend the tree's potential lifespan, if not its health . Two individuals of notable longevity are the Stelmužė Oak in Lithuania and the Granit Oak in Bulgaria, which are believed to be more than 1500 years old, possibly making them the oldest oaks in Europe; another specimen, called the' Kongeegen' (' Kings Oak'), estimated to be about 1200 years old, grows in Jaegerspris, Denmark . Yet another can be found in Kvilleken, Sweden, that is over 1000 years old and 14 metres (46 ft) around . Of maiden (not pollarded) specimens, one of the oldest is the great oak of Ivenack, Germany . Tree - ring research of this tree and other oaks nearby gives an estimated age of 700 to 800 years . Also the Bowthorpe Oak in Lincolnshire, England is estimated to be 1000 years old, making it the oldest in the UK, although there is Knightwood Oak in the New Forest that is also said to be as old . Highest density of the grand oak trees Q. robur with a circumference 4 metres (13 ft) and more is in Latvia . </P> <P> Within its native range Q. robur is valued for its importance to insects and other wildlife . Numerous insects live on the leaves, buds, and in the acorns . Q. robur supports the highest biodiversity of insect herbivores of any British plant (> 400 spp). The acorns form a valuable food resource for several small mammals and some birds, notably Eurasian jays Garrulus glandarius . Jays were overwhelmingly the primary propagators of oaks before humans began planting them commercially (and still remain the principal propagators for wild oaks), because of their habit of taking acorns from the umbra of its parent tree and burying them undamaged elsewhere . Mammals, notably squirrels who tend to hoard acorns and other nuts usually leave them too abused to grow in the action of moving or storing them . </P>

How long does an english oak tree live