The lamduan is both the official flower and official tree of Sisaket Province, which is situated on the Khorat Plateau in Thailand's northeast, an area the Thais call "Isaan." Sisaket, the capital city of the province, holds a festival annually to coincide with the blossoming of the lamduan trees, usually in early March, and to celebrate the heritage of the four tribes that originally settled in the region: the Yer, Suay, and Lao, all originally from nearby Laos; and the Khmer, from nearby Cambodia.