frost-weed n 1: perennial of the eastern United States having early solitary yellow flowers followed by late petalless flowers; so-called because ice crystals form on it during first frosts [syn: {frostweed}, {frostwort}, {Helianthemum canadense}, {Crocanthemum canadensei}] 2: tall perennial herb having clusters of white flowers; the eastern United States [syn: {Virginia crownbeard}, {frostweed}, {Verbesina virginica}]