Alstonia scholaris (Apocynaceae), is widely distributed in the tropical regions of Africa and Asia [1]. It has also been planted as shade tree in Pu'er, Nanning, Guangzhou, Shenzhen and some other tropical and subtropical regions, P. R. China. Kunming located at temperate zone, is known as the “City of Eternal Spring”, the monthly 24-hour average temperature ranges from 8.1 °C (46.6 °F) in January to 19.9 °C (67.8 °F) in June, and temperature has seldom exceeded 30 °C (86 °F) [2]. Interestingly, A. scholaris has been cultivated successfully in Kunming Botanic Garden in recent years. Th