With bright reds and yellows -- and even the occasional white -- poppies are very bright and colorful. Their petals, however, are also very thin; they are made up of just three layers of cells.

If ever there was a flower that symbolises the fleeting, bittersweet beauty of the garden in summer, then it’s surely the poppy, with its gossamer-thin petals and delicate, slender stems. But do you ...