This is a distinctive species. It creeps along the ground with leaves in pairs at intervals. It grows inland, often in arable fields, hence the name arvensis, but also on the dunes and the flower is usually bright red but it can vary with pink and even bright blue forms.Along with many other species the flower only opens when the sun is out. It is when the sun is out that pollinating insects are about, and when there is no sun it might rain and damage the flower. This characteristic which is very pronounced with this species gives rise to some of its other common names such as poor man’s barometer, poor man’s weather-glass and shepherd’s weather glass.
I have sometimes seen the blue form but only inland a not by the coast. That is not to say it does not occur somewhere in this form.
There is of course a novel by Baroness Emmuska Orczy written in 1905 about a fictional character Sir Percy Blakeney who rescued French noblemen from the guillotine during the French revolution. It was made into a television series in 1982 and the Scarlet Pimpernel was played by Anthony Andrews. The Scarlet Pimpernel, Blakeney’s character used a drawing of a small, red, star-shaped flower known in England as a “scarlet pimpernel” as a signature of his involvement in an escape.
Coastal Wild flowers 