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
source: WordNet 3.0
tall perennial herb having clusters of white flowers; the eastern United States
source: WordNet 3.0
An American species of rockrose (Helianthemum Canadense), sometimes used in medicine as an astringent or aromatic tonic.