Santa-Maria feverfew, (Parthenium hysterophorus) Parthenium hysterophorus commonly known as Santa Maria, Broom, bitter broom, parthenium, carrot grass, white top or congress grass, is an annual, erect, herbaceous plant belonging to the family Asteracae (compositae). The origin of parthenium is considered to be from Mexico, America, Trinidad and Argentina. The Parthenium