poor man's weatherglass

English

Etymology

Scarlet pimpernel flowers open only when the sun shines, and even close in overcast conditions.

Noun

poor man's weatherglass (countable and uncountable, plural poor man's weatherglasses)

1. A scarlet pimpernel (Anagallis arvensis).
   • 1940, Rosetta E. Clarkson, Green Enchantments: The Magic Spell of Gardens, The Macmillan Company, page 272:

     Pimpernel (poor man's weather glass) was also a protection, but as the gatherer collected the herbs, he must chant a certain incantation and continue to do so twice a day for 15 days[.]