The scarlet pimpernel (Anagallis arvensis; also known as the red pimpernel, red chickweed, poorman's barometer, shepherd's weather glass, or shepherd's clock) is a low-growing, annual plant in the family Myrsinaceae, growing in Europe, Asia and North America. The barometer (weather glass) common names have their origin in the fact that the flowers close when atmospheric pressure decreases and bad weather is approaching.
This common European plant is generally considered a weed and is an indicator of light soils.
It is most well known for being the emblem of the fictional hero The Scarlet Pimpernel.
are about 45 cm
long and generally prostrate. The bright green ovate sessile leaves
grow opposite. The small orange flowers
grow in the leaf axils from spring till autumn. The petal
margin is somewhat crenate.
The subspecies Anagallis arvensis
has bright, deep blue flowers. Many botanist consider it a species on its own, namely Anagallis foemina