Tithonia diversifolia is a species of flowering plant in the family Asteraceae that is commonly known as the tree marigold, Mexican tournesol, Mexican sunflower, Japanese sunflower or Nitobe chrysanthemum. It is native to Mexico and Central America but has a nearly pantropical distribution as an introduced species. Depending on the area they may be either annual or perennial. It has shown great potential in raising the soil fertility in soils depleted in nutrients.

Tithonia is a genus of flowering plants in the tribe Heliantheae within the family Asteraceae.