BITTERWEED

Definition

1. noun widespread European weed with spiny tongue-shaped leaves and yellow flowers. — synonyms: oxtongue, bristly_oxtongue, bugloss, Picris_echioides
2. noun any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma. — synonyms: ragweed, ambrosia