A Blue Scarlet Pimpernel

Nearly forty years ago, when I worked in the Agricultural Research Service, I visited a farm in Shropshire where I noticed the blue form of scarlet pimpernel Anagallis arvensis ssp. foemina growing in a field of onions, alongside the typical scarlet form. This beautiful blue variant is rather uncommon and restricted to central and southern England, so I never encountered it again when I moved to north-east England - until now. Last year I was given some seeds of A. arvensis ssp. foemina and this year they've flowered in our garden. The gentian-blue flowers are as exquisite as I remember them from that first encounter.

The scarlet form already grows in our garden. The plant is also known as poor-man's-weather-glass as the flowers close quickly when the sun is obscured by cloud - so they've been closed rather a lot this summer. They also close entirely in mid-afternoon every day, as regular as clockwork.

The other curious feature of these plants is their spherical seed capsule, known botanically as a pixidium, that opens by splitting around its circumference - click here to see one in action.