Dillenia is a genus of about 100 species of flowering plants in the family Dilleniaceae, native to tropical and subtropical regions of southern Asia, Australasia, and the Indian Ocean islands. The genus is named after the German botanist Johann Jacob Dillenius, and consists of evergreen or semi-evergreen trees and shrubs. The leaves are simple and spirally arranged. The flowers are solitary, or in terminal racemes, with five sepals and five petals, numerous stamens, and a cluster of five to 20 carpels; they are superficially similar in appearance to Magnolia flowers.