Olive tree means in the bible: Olea Europea is a well-known species. For the purpose of oil, it is widely cultivated in Palestine. It must be grafted. Paul makes reference to Rom. 11:17-24. But he describes the opposite of an ordinary gardening operation, verse 24, and it is referred to as “contrary nature”. Jacob 5 cites Zenos as saying that Zenos also uses the olive tree to show Israel and the Gentiles in an allegorical way. Isaiah used the illustration of a grapevine to illustrate the same thing Isa. 5:1-7.
(in Bible Dictionary)