pimpernel n.

plant or herb of the primrose family, c. 1400, from Old French pimprenelle, earlier piprenelle (12c.) and directly from Medieval Latin pipinella name of a medicinal plant. This is perhaps from *piperinus "pepper-like" (so called because its fruits resemble peppercorns), a derivative of Latin piper "pepper" (see pepper (n.)); or else it is a corruption of bipinnella, from bipennis "two-winged;" thus etymologically "the two-winged little plant." The Scarlet Pimpernel was the code name of the hero in an adventure novel of that name, set in France during the Terror, written by Baroness Orczy and published in 1905.