Olives (Olea europaea).
The fruit and the tree are the basis not only of Greek cuisine but Greek life, the symbol of peace and prosperity (although in Greek history the latter two have often proved elusive).
In myth, the sea good Poseidon tried to lay claim to Attica by smashing his trident into the Acropolis and bringing forth a spring. Athena then peacefully planted the first olive tree next to the spring. The gods judged hers the better gift, and hence 'Athens'.
No one knows when people in the Mediterranean began to cultivate olives. The oldest-known fossils of the trees, dating back to 38,000 BC were found on Santoríni. By the early Bronze Age (c.3000 BC) the Minoans were selling their olive oil around the Mediterranean.
It’s a mystery who realized that olives, which are naturally very bitter, were edible if cured (when archaeologist Nikolaos Platon excavated the ancient Minoan palace of Zákros on Crete's east coast, he found olives at the bottom of a well, and they tasted pretty good).
Images by Dana Facaros, ΣΤΡΑΤΗΣ ΣΤΑΜΑΤΑΚΟΣ, Creative Commons License