Duabanga grandiflora is native to Cambodia, Eastern India, Laos,
Malaysia, Myanmar, Thailand, and Vietnam where it is found in
evergreen rain forests between 900-1500 m in elevation. It is
found in open forests including vegetation adjacent to
riverbanks and in valleys. The genus Duabanga contains only two
other species including Duabanga moluccana, and a cultivated,
proposed hybrid species Duabanga x taylorii. Duabanga x taylorii
is unusual as it is known only in cultivation at the Royal
Botanic Gardens in Peradeniya, Sri Lanka. It was grown from seed
obtained from an unknown source and is thought to have come from
Indonesia, however, its geographic origin and its proposed
hybrid origin cannot be confirmed. (Haining, Q. S. Graham, and
M.G. Gilbert. Lythraceae. In Flora of China 13: 274-276)