frostweed

[ frawst-weed, frost- ]
/ ˈfrɔstˌwid, ˈfrɒst- /

noun

a plant, Helianthemum canadense, of the rockrose family, native to eastern North America, having narrow leaves and a solitary yellow flower.

Origin of frostweed

1830–40, Americanism; frost + weed1; so called from the ice crystals which form on it during the first frosts