What does "scarlet pimpernel" mean?

A flowering plant, of species Lysimachia arvensis (syn. Anagallis arvensis), of the Primulaceae family, having small orange flowers.

Scarlet pimpernel

Common synonyms include: anagallis arvensis, pimpernel, pimpernels, poor man's weatherglass, red pimpernel.

noun

noun ·Rare ·Advanced level

Noun

1
A flowering plant, of species Lysimachia arvensis (syn. Anagallis arvensis), of the Primulaceae family, having small orange flowers.
"[T]ogether they went north and were at Silloth in August, where James picked a scarlet pimpernel to press for her album[.]"
2
herb with scarlet or white or purple blossoms that close at approach of rainy weather wordnet

"[T]ogether they went north and were at Silloth in August, where James picked a scarlet pimpernel to press for her album[.]"