Olives are the small fruits of Olea europaea, a remarkably hardy, drought-tolerant tree that’s native to the eastern Mediterranean region, and that can live and bear for a thousand years. In addition to sustenance, the olive has given us an everyday word: its ancient Greek name elaia is the source of the English oil (and Italian olio, French huile). The pulp layer surrounding the large central seed can be as much as 30% oil, which prehistoric peoples could extract by simple grinding and draining, and used in cooking and lamps, and for cosmetic purposes. Olives are also unusual among our commonly eaten fruits for being extremely unpalatable! They are richly endowed with bitter phenolic compounds, which offer some protection from both microbes and mammals. (Wild olives are eaten and their seeds dispersed mainly by birds, which swallow them whole; mammals chew and damage seeds.) Their bitterness has long been moderated or removed by various curing techniques. The dark color of ripe olives comes from purplish anthocyanin pigments in the outer layer of the fruit.