The genus Lagerstroemia comprises about 50 species of small to middle-sized trees, occurring from India to Japan and Australia. Its center of species richness is found in the Indo-China region. In Cambodia, Laos and Vietnam 20 species occur of which four, Lagerstroemia densiflora (W.J.de Wilde & Duyfjes, sp. nov., in sched.), L. kratiensis W.J.de Wilde & Duyfjes, L. lecomtei Gagnep., and L. petiolaris Laness. are endemic. In Thailand 18 species are known of which two, L. huamotensis W.J.de Wilde & Duyfjes, and L. subangulata (Craib) Furtado & Srisuko, are endemic.

Lagerstroemia is easily recognizable by its showy mostly pinkish purple flowers. Some have been successfully cultivated and serve as ornamentals in gardens and along roads. In this presentation useful characters to identify the species will be explained through the help of images.