bitterweed

[ bit-er-weed ]
/ ˈbɪt ərˌwid /

noun

any of various plants containing a bitter principle, as those of the genus Picris.
a sneezeweed, Helenium amarum.

Origin of bitterweed

An Americanism dating back to 1810–20; bitter + weed1

British Dictionary definitions for bitterweed

bitterweed
/ (ˈbɪtəˌwiːd) /

noun

any of various plants that contain a bitter-tasting substance