Synonyms: Common Oak, English Oak, Pedunculate Oak
Scientific Name: Quercus robur L.
Family: Fagaceae (beech family)
Catechin tannins, gallic acid
It is the epitome of steadfastness: the good old oak tree, which was already revered by the Celts. The oak can reach an age of 500 or even 1000 years and a height of up to 50 metres. The furrows on its mighty grey-green trunk form a diamond-shaped pattern. Most people are probably familiar with the characteristically lobed oak leaves. The rather more inconspicuous flowers – male and female separately – may be seen at the tips of the shoots from mid-April to the end of May. The acorns that ripen in the autumn are collected not only by deer and squirrels but also by children, who use them to make little figures.
The medicinally used part is the smooth bark (silver bark) of 10- to 15-year-old oaks. Its high tannin content is responsible for the astringent, drying, anti-diarrhoeal, antiviral, anti-inflammatory and bowel-strengthening action. Decoctions of oak bark are used externally as bath additives or gargles for diseases of the skin and mucous membranes or as poultices for itching and weeping eczemas, for sweaty feet, chilblains, burns, haemorrhoids, anal eczema and fissures, for inflammatory conditions of the mouth and throat as well as the eyes. Oak bark is used internally in tea mixtures for heartburn or acute diarrhoea.
The name Quercus goes back to Roman times. Robur means strength and refers amongst other things to the hard wood of this old tree but also to its inner strength which it passes on to human beings. The origin of the German name Eiche is not known. In almost treeless Iceland the word eik is used to refer to any kind of tree.
The imposing oak tree has been greatly respected by all peoples throughout the ages. The deep-rooted oak, with its connection to water, was the tree most often struck by lightening. This was probably the reason why it was almost always dedicated to the god of lightening, the highest god: by the Greeks to Zeus, by the Romans to Jupiter, by the Teutons to Donar and by the Celts to Tanaris. Its attraction of lightening has given rise to a German saying that goes: „Eichen sollst du weichen, Buchen sollst du suchen, kannst die Linden grad nicht finden“ – telling you that in a thunderstorm you should keep away from oak trees and look for a beech, or a lime if you can find one. Female godheads were also associated with the oak, the nurturer. Ana or Dana, the Celtic mother goddess, revealed herself in the oak tree which is the home and source of food for many animals.
The sacred oak was an assembly place where courts of justice were held or the gods were asked for their advice. If lies were spoken beneath this oak tree ill-fortune would befall the community or the oak would no longer bear acorns which were very valuable as flour substitute and pig feed. Vows were made under the oak, Socrates already swore by the oak. And the English king planted this sturdy tree on the occasion of his coronation. The Celts regarded the oak tree as the gate from the old to the new year which, incidentally, began at the summer solstice.
The tall and deep-rooted oak connects the upper and the lower worlds and was therefore an oracle tree for many peoples. Priestesses and druids heard the oracle in the rustling of the leaves. As 'world tree' the mighty oak supported the sky and prevented it from falling on to the earth. This explains why early tribes were so horrified when conquerors like Caesar or missionaries felled their sacred oaks.
The healing powers of the oak were also known in very early times. Doctors such as Dioskorides already described its medicinal actions. And the oak also had a firm place in folk medicine. For example, shepherds are said to have used rain water collected from holes in oak trunks to treat bloody urine.
The Teutons used oak leaves stored over the winter to tan the skins of sacrificial animals. Oak bark with its high tannin content was until very recently the most important raw material used for preparing tanning solutions. It was only supplanted by chemical agents.
Oak wood is a much sought-after building material because of its hardness and resistance. It is used to make furniture, windows, barrels, parquet flooring, organs and railway sleepers. The wood is even resistant to wetness and is therefore used for shipbuilding or for underwater piles.
The leaf galls produced by gall wasps can be used together with iron salts to make a very durable ink.
The plant from another perspective
The oak is mighty and composed. It takes its time to reach its imposing height. It is 60 to 80 years before the oak flowers for the first time and forms acorns. This slowness reveals the play of two polar forces: in the oak the exuberant vitality and growth is suppressed, kept in check, by a forming, contracting component which appears to have materialised in the tannin. The oak leaf with its partial indentations appears to be a symbol of this process. Likewise the tree's gnarled and twisted growth. Forming is important in all inflammatory and allergic processes. The tannin suppresses the exuberant metabolic process and directs it back into calmer channels. Inflammation, allergic reactions and itching subside.
The plant in our products
Oak bark extract is contained in: