pimpernel (PIM-per-nel) - n., any of about two dozen species of flowering plants of the genus Anagallis, esp. A. arvensis, the scarlet pimpernel.
Noted for keeping their star-shaped flowers open only under direct sunlight -- both at night and under sufficiently heavy cloud cover, sometimes used as a signal for approaching rain, and then reopening in morning or clearing. Not all species are red -- indeed, pimpernels can come in just about every flower color. The name is a bit of a tangle, but is definitely from Medieval French pimprenelle, earlier piprenelle, from Medieval Latin pipinella, name of a medicinal plant, possibly from *piperinus, pepper-like, because its fruits resemble peppercorns, from piper, pepper (from Greek, from Persian, from Sanskrit). The scarlet one:

Thanks, WikiMedia!
---L.
Noted for keeping their star-shaped flowers open only under direct sunlight -- both at night and under sufficiently heavy cloud cover, sometimes used as a signal for approaching rain, and then reopening in morning or clearing. Not all species are red -- indeed, pimpernels can come in just about every flower color. The name is a bit of a tangle, but is definitely from Medieval French pimprenelle, earlier piprenelle, from Medieval Latin pipinella, name of a medicinal plant, possibly from *piperinus, pepper-like, because its fruits resemble peppercorns, from piper, pepper (from Greek, from Persian, from Sanskrit). The scarlet one:

Thanks, WikiMedia!
---L.