American tulip tree ( Liriodendron tulipifera ) , also called tulip poplar or yellow poplar is a type of tree . It is one of the two species in the genus Liriodendron . Liriodendron tulipifera , commonly known as the tulip tree , American tulip tree , tuliptree , tulip poplar or yellow poplar , is the Western Hemisphere representative of the two-species genus Liriodendron , and the tallest eastern hardwood .