In Thailand, Craib (1934) listed Ixora in the Florae Siamensis Enumeratio and
enumerated about 38 species and seven varieties. Boonbundral (1978) carried out a
preliminary study of the genus Ixora in Thailand with 23 species and 3 varieties. In peninsular
Malaysia only 20 species of Ixora were recorded from the lowlands and mountains (Corner,
1941).