Noun: scarlet pimpernel
- Herb with scarlet, white or purple blossoms that close at approach of rainy weather
"The scarlet pimpernel's flowers closed, warning of approaching rain";
- red pimpernel, poor man's weatherglass, Anagallis arvensis
Derived forms: scarlet pimpernels
Type of: pimpernel
Encyclopedia: Scarlet pimpernel