1.  frost-weed(n = noun.plant) crocanthemum canadense, frostweed, frostwort, helianthemum canadense - 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; Array
is a kind of helianthemum, sun rose, sunrose

2.  frost-weed(n = noun.plant) frostweed, verbesina virginica, virginia crownbeard - tall perennial herb having clusters of white flowers; the eastern United States; Array
is a kind of crown-beard, crown beard, crownbeard