The olive, botanical name Olea europaea, meaning 'European olive', is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin, with wild subspecies found further afield in Africa and western Asia. When in shrub form, it is known as Olea europaea 'Montra', dwarf olive, or little olive. The species is cultivated in all the countries of the Mediterranean, as well as in Australia, New Zealand, North and South America and South Africa.[2][3] It is the type species for its genus, Olea. The tree and its fruit give their name to the Oleaceae plant family, which also includes species such as lilac, jasmine, forsythia, and the true ash tree.
The olive's fruit, also called an "olive", is of major agricultural importance in the Mediterranean region as the source of olive oil; it is one of the core ingredients in Middle Eastern and Mediterranean cuisines. Thousands of cultivars of the olive tree are known. Olive cultivars may be used primarily for oil, eating, or both. Olives cultivated for consumption are generally referred to as "table olives".[4] About 80% of all harvested olives are turned into oil, while about 20% are used as table olives.
The word olive derives from Latin ŏlīva 'olive fruit; olive tree',[5] possibly through Etruscan 𐌀𐌅𐌉𐌄𐌋𐌄 (eleiva) from the archaic Proto-Greek form *ἐλαίϝα (*elaíwa) (Classic Greek ἐλαία elaía 'olive fruit; olive tree'.[6][7] The word oil originally meant 'olive oil', from ŏlĕum,[8] ἔλαιον (élaion 'olive oil').[9][10] The word for 'oil' in multiple other languages also ultimately derives from the name of this tree and its fruit. The oldest attested forms of the Greek words are Mycenaean 𐀁𐀨𐀷, e-ra-wa, and 𐀁𐀨𐀺, e-ra-wo or 𐀁𐁉𐀺, e-rai-wo, written in the Linear B syllabic script.[11]
The olive tree, Olea europaea, is an evergreen tree or shrub native to Mediterranean Europe, Asia, and Africa. It is short and squat and rarely exceeds 8–15 m (25–50 ft) in height. 'Pisciottana', a unique variety comprising 40,000 trees found only in the area around Pisciotta in the Campania region of southern Italy, often exceeds this, with correspondingly large trunk diameters. The silvery green leaves are oblong, measuring 4–10 cm (1+1⁄2–4 in) long and 1–3 cm (3⁄8–1+3⁄16 in) wide. The trunk is typically gnarled and twisted.[12]
The small, white, feathery flowers, with ten-cleft calyx and corolla, two stamens, and bifid stigma, are borne generally on the previous year's wood, in racemes springing from the axils of the leaves.[citation needed]
The fruit is a small drupe 1–2.5 cm (3⁄8–1 in) long when ripe, thinner-fleshed and smaller in wild plants than in orchard cultivars. Olives are harvested in the green to purple stage.[13] O. europaea contains a pyrena commonly referred to in American English as a "pit", and in British English as a "stone".[14]
The six natural subspecies of Olea europaea are distributed over a wide range:[15][16][17]
The subspecies europaea is divided into two varieties, the europaea, which was formerly named Olea sativa, with the seedlings called "olivasters", and silvestris, which corresponds to the old wildly growing Mediterranean species O. oleaster, with the seedlings called "oleasters".[18] The sylvestris is characterized by a smaller, shrubby tree that produces smaller fruits and leaves.[19]
The subspecies O. e. cerasiformis is tetraploid, and O. e. maroccana is hexaploid.[20] Wild-growing forms of the olive are sometimes treated as the species Olea oleaster, or "oleaster." The trees referred to as "white" and "black" olives in Southeast Asia are not actually olives but species of Canarium.[21]
Hundreds of cultivars of the olive tree are known.[22][23] An olive's cultivar has a significant impact on its colour, size, shape, and growth characteristics, as well as the qualities of olive oil.[22] Olive cultivars may be used primarily for oil, eating, or both. Olives cultivated for consumption are generally referred to as "table olives".[4]
Since many olive cultivars are self-sterile or nearly so, they are generally planted in pairs with a single primary cultivar and a secondary cultivar selected for its ability to fertilize the primary one. In recent times, efforts have been directed at producing hybrid cultivars with qualities useful to farmers, such as resistance to disease,[24] quick growth, and larger or more consistent crops.[citation needed]
Fossil evidence indicates the olive tree had its origins 20–40 million years ago in the Oligocene, in what now corresponds to Italy and the eastern Mediterranean Basin.[25][26] Around 100,000 years ago, olives were used by humans in Africa, on the Atlantic coast of Morocco, for fuel and most probably for consumption.[27] Wild olive trees, or oleasters, have been collected in the Eastern Mediterranean since ~19,000 BP.[28] The genome of cultivated olives reflects their origin from oleaster populations in the Eastern Mediterranean.[29][30][31][32][33][34] The olive plant was first cultivated some 7,000 years ago in Mediterranean regions.[25][35]
For thousands of years olives were grown primarily for lamp oil, with little regard for culinary flavor.[36] Its origin can be traced to the Levant based on written tablets, olive pits, and wood fragments found in ancient tombs.[36][37] As far back as 3000 BC, olives were grown commercially in Crete and may have been the source of the wealth of the Minoan civilization.[38]
The ancestry of the cultivated olive is unknown. Fossil olea pollen has been found in Macedonia and other places around the Mediterranean, indicating that this genus is an original element of the Mediterranean flora. Fossilized leaves of olea were found in the palaeosols of the volcanic Greek island of Santorini and dated to about 37,000 BP. Imprints of larvae of olive whitefly Aleurobus olivinus were found on the leaves. The same insect is commonly found today on olive leaves, showing that the plant-animal co-evolutionary relations have not changed since that time.[39] Other leaves found on the same island are dated back to 60,000 BP, making them the oldest known olives from the Mediterranean.[40]
Olives are not native to the Americas. Spanish colonists brought the olive to the New World, where its cultivation prospered in present-day Peru, Chile, Uruguay and Argentina. The first seedlings from Spain were planted in Lima by Antonio de Rivera in 1560. Olive tree cultivation quickly spread along the valleys of South America's dry Pacific coast where the climate was similar to the Mediterranean.[41] Spanish missionaries established the tree in the 18th century in California. It was first cultivated at Mission San Diego de Alcalá in 1769 or later around 1795. Orchards were started at other missions, but in 1838, an inspection found only two olive orchards in California. Cultivation for oil gradually became a highly successful commercial venture from the 1860s onward.[42][43]
In Japan, the first successful planting of olive trees happened in 1908 on Shodo Island, which became the cradle of olive cultivation in Japan.[44]
In 2016, olive oil production started in India, with olive saplings planted in Rajasthan's Thar Desert.[45]
Favoured by climate warming, several small-scale olive production farms have also been established at fairly high latitudes in Europe and North America since the early 21st century.[46][47][48][49]
There were an estimated 865 million olive trees in the world as of 2005, and the vast majority of these were found in Mediterranean countries, with traditionally marginal areas accounting for no more than 25% of olive-planted area and 10% of oil production.[50]
Olives are thought to have been domesticated in the third millennium BC at the latest, at which point they, along with grain and grapes, became part of Colin Renfrew's Mediterranean triad of staple crops that fueled the emergence of more complex societies.[51] Olives, and especially (perfumed) olive oil, became a major export product during the Minoan and Mycenaean periods. Dutch archaeologist Jorrit Kelder proposed that the Mycenaeans sent shipments of olive oil, probably alongside live olive branches, to the court of the Egyptian pharaoh Akhenaten as a diplomatic gift.[52] In Egypt, these imported olive branches may have acquired ritual meanings, as they are depicted as offerings on the wall of the Aten temple and were used in wreaths for the burial of Tutankhamun. It is likely that, as well as being used for culinary purposes, olive oil was also used to various other ends, including as a perfume. [citation needed]
The ancient Greeks smeared olive oil on their bodies and hair as a matter of grooming and good health. Olive oil was used to anoint kings and athletes in ancient Greece. It was burnt in the sacred lamps of temples and was the "eternal flame" of the original Olympic games. Victors in these games were crowned with its leaves. In Homer's Odyssey, Odysseus crawls beneath two shoots of olive that grow from a single stock,[53] and in the Iliad, (XVII.53ff) there is a metaphoric description of a lone olive tree in the mountains, by a spring; the Greeks observed that the olive rarely thrives at a distance from the sea, which in Greece invariably means up mountain slopes. Greek myth attributed to the primordial culture-hero Aristaeus the understanding of olive husbandry, along with cheese-making and bee-keeping.[54] Olive was one of the woods used to fashion the most primitive Greek cult figures, called xoana, referring to their wooden material; they were reverently preserved for centuries.[55]
It was purely a matter of local pride that the Athenians claimed that the olive grew first in Athens.[56] In an archaic Athenian foundation myth, Athena won the patronage of Attica from Poseidon with the gift of the olive. According to the fourth-century BC father of botany, Theophrastus, olive trees ordinarily attained an age around 200 years,[57] he mentions that the very olive tree of Athena still grew on the Acropolis; it was still to be seen there in the second century AD;[58] and when Pausanias was shown it c. 170 AD, he reported "Legend also says that when the Persians fired Athens the olive was burnt down, but on the very day it was burnt it grew again to the height of two cubits."[59] Indeed, olive suckers sprout readily from the stump, and the great age of some existing olive trees shows that it was possible that the olive tree of the Acropolis dated to the Bronze Age. The olive was sacred to Athena and appeared on the Athenian coinage. According to another myth, Elaea was an accomplished athlete killed by her fellow athletes who had grown envious of her; but