Bitterweed

n.

1.

(Bot.) A species of Ambrosia (Ambrosia artemisiæfolia); Roman worm wood.

Noun	1.	bitterweed - widespread European weed with spiny tongue-shaped leaves and yellow flowers; naturalized in United States Synonyms: bristly oxtongue, oxtongue, Picris echioides, bugloss
	2.	bitterweed - 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: ambrosia, ragweed

bristly oxtongue, bugloss, genus Picris, oxtongue, Picris, Picris echioides, weed