'Tree' in the Bible

Then you are to go on from there, and when you come to the oak-tree of Tabor, you will see three men going up to God to Beth-el, one having with him three young goats and another three cakes of bread and another a skin full of wine:

And Saul was still waiting in the farthest part of Geba, under the fruit-tree in Migron: there were about six hundred men with him;

And news was given to Saul that David had been seen, and the men who were with him: now Saul was in Gibeah, seated under the tree in the high place, with his spear in his hand, and all his servants were in their places before him.

And their bones they put in the earth under a tree in Jabesh; and for seven days they took no food.