I lifted the metal lid of our circa-1958 shamrock-green letterbox. Small daughter handed me with a wodge of envelopes, clamped with a fat elastic band. “Bills!” I groaned.

Four-year-old was now scrabbling behind the rickety mailbox post. “Something fell out!” she shouted and flapped her discovery above her head.

It was a postcard. A striking botanical drawing stood out against an inky background. It pictured the life cycle of a sunflower, drawn in exquisite detail in every incarnation, from bud to bloom to seed.