Botanical Name : Quercus robur
Species: Q. rob
Synonym: Tanner’s Bark.
Habitat : Quercus robur is native to Europe, including Britain, from Scandanavia south and east to Spain, the Urals and Crimea. It grows often on the dominant woodland tree, especially on clay soils and in the eastern half of Britain, but avoiding acid peat and shallow limestone soils
Quercus robur is a large deciduous tree, with circumference of grand oaks from 4 m (13 ft) to exceptional 12 m (39 ft). Majesty Oak with the circumference of 12.2 m (40 ft) is the thickest tree in Great Britain, and Kaive Oak in Latvia with the circumference of 10.2 m (33 ft) is the thickest tree in Northern Europe. Q. 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 their 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.
It is a long-lived tree, with a large widespreading 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 Stelmuž? Oak in Lithuania and the Granit oak in Bulgaria, which are believed to be more than 1,500 years old, possibly making them the oldest oaks in Europe; another specimen, called the ‘Kongeegen’ (‘Kings Oak’), estimated to be about 1,200 years old, grows in Jaegerspris, Denmark. Yet another can be found in Kvilleken, Sweden, that is over 1,000 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 old. Also the Bowthorpe Oak in Lincolnshire, England is estimated to be 1,000 years old making it the oldest in the UK, although there is Knightwood Oak in the New Forest which is also said to be as old. Highest density of the Q. robur grand oaks with a circumference 4 metres (13 ft) and more is in Latvia.
Prefers a good deep fertile loam which can be on the stiff side. Young plants tolerate reasonable levels of side shade. Succeeds in heavy clay soils and in wet soils so long as the ground is not water-logged for long periods. Dislikes dry or shallow soils but is otherwise drought tolerant once it is established. Tolerant of exposed sites though it dislikes salt-laden winds. The oak is a very important timber tree in Britain, it is also a very important food plant for the caterpillars of many species of butterfly, there are 284 insect species associated with this tree. It has often been coppiced or pollarded for its wood in the past, though this should not be done too frequently, about once every 50 years is the average. The tree flowers on new growth produced in spring, the seed ripening in its first year. Older trees have a thick corky bark and this can protect them from forest fires, young trees will often regenerate from the base if cut down or killed back by a fire. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young. Hybridizes freely with other members of the genus. Immune to attacks by the tortix moth. This species is notably resistant to honey fungus.
Seed – it quickly loses viability if it is allowed to dry out. It can be stored moist and cool overwinter but is best sown as soon as it is ripe in an outdoor seed bed, though it must be protected from mice, squirrels etc. Small quantities of seed can be sown in deep pots in a cold frame. Plants produce a deep taproot and need to be planted out into their permanent positions as soon as possible, in fact seed sown in situ will produce the best trees. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.
Edible Uses: Coffee; Gum.
Seed – cooked. Nourishing but indigestible. Chopped and roasted, the seed is used as an almond substitute. It can be dried, ground into a powder and used as a thickening in stews etc or mixed with cereals for making bread. The seed contains bitter tannins, these can be leached out by thoroughly washing the seed in running water though many minerals will also be lost. Either the whole seed can be used or the seed can be dried and ground it into a powder. It can take several days or even weeks to properly leach whole seeds, one method was to wrap them in a cloth bag and place them in a stream. Leaching the powder is quicker. A simple taste test can tell when the tannin has been leached. The traditional method of preparing the seed was to bury it in boggy ground overwinter. The germinating seed was dug up in the spring when it would have lost most of its astringency. The roasted seed is a coffee substitute. An edible gum is obtained from the bark. Another report says that an edible manna is obtained from the plant and that it is used instead of butter in cooking. This report probably refers to the gum.
The astringent effects of the Oak were well known to the Ancients, by whom different parts of the tree were used, but it is the bark which is now employed in medicine. Its action is slightly tonic, strongly astringent and antiseptic. It has a strong astringent bitter taste, and its qualities are extracted both by water and spirit. The odour is slightly aromatic.
Like other astringents, it has been recommended in agues and haemorrhages, and is a good substitute for Quinine in intermittent fever, especially when given with Chamomile flowers.
It is useful in chronic diarrhoea and dysentery, either alone or in conjunction with aromatics. A decoction is made from 1 OZ. of bark in a quart of water, boiled down to a pint and taken in wineglassful doses. Externally, this decoction has been advantageously employed as a gargle in chronic sore throat with relaxed uvula, and also as a fomentation. It is also serviceable as an injection for leucorrhoea, and applied locally to bleeding gums and piles.
Quercus robur’ is planted for forestry, and produces a long-lasting and durable heartwood, much in demand for interior and furniture work. The wood of Q. robur is identified by a close examination of a cross-section perpendicular to fibres. The wood is characterised by its distinct (often wide) dark and light brown growth rings. The earlywood displays a vast number of large vessels (~0.5 mm (0.020 in) diameter). There are rays of thin (~0.1 mm (0.0039 in)) yellow or light brown lines running across the growth rings. The timber is around 720 kg (1,590 lb) per cubic meter in density.
Within its native range Quercus 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, because of their habit of taking acorns from the umbra of its parent tree and burying it undamaged elsewhere. Mammals, notably squirrels who tend to hoard acorns and other nuts most often leave them too abused to grow in the action of moving or storing them.
Quercus robur is cultivated as an ornamental tree in the temperate regions of most continents. A number of cultivars are grown in gardens and parks and in arboreta and botanical gardens. The most common cultivar is Quercus robur ‘Fastigiata’, and is the exception among Q. robur cultivars which are generally smaller than the standard tree, growing to between 10–15 m and exhibit unusual leaf or crown shape characteristics.
Known Hazards : Possible digestive complaints. May delay absorption of alkaloids and other alkaline drugs
The information presented herein is intended for educational purposes only. Individual results may vary, and before using any supplements, it is always advisable to consult with your own health care provider.