For the Farmer S, the term oléastre indicates all olive-tree whose appearance moves away from that of the variety S of olive-tree known and productive (small sheets, stiff branches, buissonnant aspect).
For the botanist, this term indicates the olive-tree not cultivated, with small fruits or an aspect buissonnant.
For the biologist, this term indicates a tree pertaining to a true wild population, i.e. a line Olea europaea which used the favors of human forever to be propagated.

There exist three possible cases of olive-trees in a wild state:

• the wild olive-tree which does not have any relative domesticated in his ancestors: it is the “true oléastre”;
• the wild olive-tree which goes down from cultivated olive-trees: it is the olive-tree Féral;
• the cultivated olive-tree which was abandoned: only its aspect can evoke the oléastre. There exists however only thanks to the support of the human one. It is a olive-tree pertaining to a cultivated variety or having been cultivated.

However, the cultivated olive-trees and the wild olive-trees are interféconds. There is thus forms all the possible links of them.

Thus, we can have populations férales which were formed starting from cores resulting from cultivated olive-trees, which can be distinguished true populations of oléastres only by molecular biology.

The natural mode of propagation-perpetuation of the olive-tree rests on the interest of the birds for its fruit, the Olive. By swallowing olives, the birds allow seed Germer, possibly elsewhere than instead of ingestion. The characteristic resides in the fact that the current olive-tree plays on two tables, by simultaneously using the support of the nonhuman species, and in particular of the birds, on the one hand, and of human on the other hand, to be propagated. The capacity of the olive-tree to diffuse its pollen on long distances, by Anémogamie, as well as the difficulty that the human one meets to make germinate cores, make that until today the human ones do not have yet that very little been able to plan the selection of the species Olea europaea with their advantage, but on the contrary had to be satisfied to choose among the varieties which the chance placed at their disposal. The olive-tree thus preserves a share of independence with regard to the mankind, but benefits however from its sensitivities to colonize cultivated spaces, and, on the occasion, contiguous uncultivated spaces, by again using the birds or other animals. It thus constitutes populations férales, which in their turn can provide to human new varieties.