Which of these is botanically a berry?

A banana. The botanical definition of a berry is a fruit with seeds inside a fleshy wall, grown from a single ovary - which admits bananas, grapes, tomatoes, peppers, cucumbers, aubergines and avocados, and excludes strawberries, raspberries and blackberries.

The banana is odd in other ways too. The plant is not a tree; it is a giant herb, with no woody trunk at all - what looks like one is tightly packed leaf bases. And the cultivated banana has no viable seeds, because it is a sterile triploid propagated entirely from cuttings, which means every Cavendish banana in every shop in the world is a clone of the same plant.

That monoculture has already been destroyed once. The Gros Michel, the variety exported before the 1950s, was wiped out commercially by Panama disease, and the industry switched to the Cavendish because it resisted that strain. A new strain now attacks the Cavendish, it has spread across Asia, Africa, the Middle East and into Latin America, and there is no resistant replacement ready. The joke that artificial banana flavouring tastes wrong because it was matched to the Gros Michel is, unusually for such stories, broadly true.