Facts about the olive tree
The olive tree (Olea europaea; Heb. zayith, Gk, elaia) is an evergreen tree usually about 5 meters (about 16 ft) high when pruned, but it can get much taller when unpruned.
Young trees have a smooth silver grey bark, but with age the slender trunks become fluted, knobby and stout. Many old trees develop holes in the sides of the trunks which themselves are hollow; the holes result from old side branches rotting away. Besides the great olives, the numerous branches form a dense and shady tree that shelters a lot of animals in the heat of the day.
Olive leaves are narrow and sharply pointed, grey-green on the upper surface and white on the underside owing to a complete covering of minute white scales - that helps to keep down water loss from the tree. Flowers open on May, they bud develop among the leaves on the previous year's wood. There are between 10 and 40 flowers carried on each short inflorescence, the white flowers are divided in 4 parts but they have only two stamens. The young olive trees start flowering when they are at least 5 or 6 years old, their best olive production is between 40 and 50 years old, but it is said there are a lot ancient trees that bear regular crops.
The root system is enormously and it's spreading around each tree to absorb sufficient moisture, it's just one of the side effects of the dry condition the olive trees are normally growing (besided the color, shape and density of the leaves). Wide spacing in the groves allows plenty of light to reach the crown for best fruit ripening.
The olive seeds are the only type of seeds that are fully digested by the humans.
Myths about the olive tree
The most relevant stories about the olive trees come from the Greek mythology. The basic story tells that Poseidon and Athena were in a competition for the love of the people of the area around the Acropolis, it was decided that the divinity who created the most useful object would win the right to have the city named for them. So that Poseidon created horses and the Athena created the useful olive tree - it gives shade, oil and olives. So the most important city, that later became the capital of Greece, was called Athens. The Parthenon was built on the Acropolis, where Athena is believed to have produced the first olive tree.