bitterweed

Noun bitterweed has 2 senses

• bitterweed(n = noun.plant) bristly oxtongue, bugloss, oxtongue, picris echioides - widespread European weed with spiny tongue-shaped leaves and yellow flowers; naturalized in United States;
is a member of genus picris, picris
is a kind of weed

• bitterweed(n = noun.plant) ambrosia, ragweed - any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma;
is a member of genus ambrosia
has particulars: ambrosia artemisiifolia, common ragweed, ambrosia trifida, great ragweed, ambrosia psilostachya, perennial ragweed, western ragweed
is a kind of weed