Summary. Indonesia is one of the most important mangosteen producing countries whose the growing areas are scattered on almost all of the islands. Mangosteen variability was observed based on field expeditions from 1992 to 2005. The data were collected on morphological observations on mangosteen production centres in West Sumatra, Riau, Jambi, South Sumatra, Bengkulu, Bangka/Belitung, West Java, Central Java, and East Java based on a total number of 192 mangosteen trees. The objectives of the research were to find out the variability of Indonesian mangosteen based on the morphological characters and to determine the morphological characters that can be used to distinguish mangosteen accessions. Leaves and mature fruits were observed for morphological variations. The results show that mangosteens vary in their morphological appearances. Among the morphological variations obtained, there are 11 specific characters that can be used to distinguish the apomictic mangosteen. These characters are canopy shape, mature leaf colour, number of flowers and fruits per cluster, pedicel length, fruit shape, fruit-base shape, stigma lobe shape, size, and thickness, the number of fruit segments, and rind thickness. Based on the morphological characters the mangosteen in Sumatra and Java can be divided into seven kinds. This information will be useful for researchers and will make the task of the curators easier in the area of mangosteen germplasm evaluation.
Key words: morphology, variation, apomictic, Garcinia mangostana L.