In Southeast Asia (excluding India) 44 taxa are recognized, 39 species, of which four are newly described ( I. kerrii, I. luzoniensis, I. emmae, and one unnamed species A, which will be treated by Nguyen Van Thuan, Paris), four subspecies, one of which is new (I. sootepensis subsp. acutifolia) and three are new combinations ( (I. suffruticosa subsp. guatemalensis, I. trifoliata subsp. unifoliata, I. trita subsp. scabra) ), and one variety which is a new combination I. spicata var. siamensis). A key, descriptions and full synonymy are given as well as 4 distribution maps and 5 figures.