Quassia occurs as genus in the family Simaroubaceae. Its size is disputed; a select few botanists treat it as consisting of single 1 mintage, Quassia amara from tropical South America, while others handle it around the wide circumscription as a pantropical genus containing up to Forty coinage of trees & bush.

Wide treatments of a genus include the as a result & more mintage: Quassia africana Quassia amara Quassia bidwillii Quassia indica Quassia undulata