bitterweed noun6 •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. formsbitterweeds
