Definition of frostweed in English:

frostweed

noun

  • Either of two perennials of the eastern United States on which ice crystals tend to form from exuded sap under freezing conditions: Crocanthemum canadense (family Cistaceae), which has yellow flowers and is used medicinally as a tonic and an astringent, and a crown beard, Verbesina virginica, which has small white flowers.

Origin

Early 19th century.