Tithonia diversifolia is a species of flowering plant in the Asteraceae family that is commonly known as the tree marigold; Mexican tournesol; Mexican sunflower; Japanese sunflower or Nitobe chrysanthemum. It is native to eastern Mexico and Central America but has a nearly pantropical distribution as an introduced species.

Depending on the area Tithonia diversifolia may be either annual or perennial; 2-3 m (6.6-9.8 ft) in height with upright and sometimes ligneous stalks in the form of woody shrubs. The flowers are orange.

Once one of Thailand's remotest provinces; Mae Hong Son is now readily accessible by air from Chiang Mai; as well as by a wonderful loop drive through Mae Sariang and back via Pai and Soppong- or vice versa. Singularly isolated; Mae Hong Son is not yet very developed. The townsfolk may be citizens of Thailand; but most are Shan; Karen; Yunnanese Chinese or Hill Tribes. The temples are Burmese in style; and the pace of life amazingly tranquil.