Gymnanthemum extensum

Gymnanthemum extensum, also known as bitterleaf tree, "zhan zhi ban jiu ju", "nan chao woei", is a species of flowering shrub of the family Asteraceae. It is an up to 8 m shrub or small tree found naturally growing at to above sea level in open forests or thickets in slopes, valleys and by the roadside.
Distribution.
Southern China (Guizhou, Yunnan), the Himalayas (Sikkim, Nepal, Bhutan) and the Shan Hills (Myanmar, Thailand). It has been cultivated in Thailand as a garden tree for the medicinal properties of its leaves and the fragrance of its flowers.