BITTERWEED

ragweed, ambrosia, bitterweed

(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

oxtongue, bristly oxtongue, bitterweed, bugloss, Picris echioides

(noun) widespread European weed with spiny tongue-shaped leaves and yellow flowers; naturalized in United States

Source: WordNet® 3.1

Etymology

Noun

bitterweed (plural bitterweeds)

Any plant in the genus Ambrosia, especially Ambrosia artemisiifolia (common ragweed).

The plant Helenium amarum (yellow sneezeweed).

Parthenium hysterophorus (false ragweed)

Artemisia tripartita subsp. tripartita (syn. Artemisia trifida; threetip sagebrush)

Picris rhagadioloides (syn. Picris sprengeriana; tall oxtongue)

Tetraneuris spp.

Source: Wiktionary

Bit"ter*weed`, n. (Bot.)

Definition: A species of Ambrosia (A. artemisiæfolia); Roman worm wood. Gray.

Source: Webster’s Unabridged Dictionary 1913 Edition