Gene flow between Impatiens radicans and I. javensis (Balsaminaceae) in Gunung Pangrango, central Java, Indonesia

This study reports the natural hybridization of two species of Impatiens in the mountain forests of Gunung Gede-Pangrango, in central Java, Indonesia. Impatiens radicans, which inhabits the highest altitude zone in the mountains of this park, and I. javensis, which inhabits a zone of lower altitude, can be easily distinguished by their morphological features. However, some populations that inhabit regions between the two zones have characteristics that appear to be combinations of traits of I. radicans and I. javensis. Sequence analysis of the 800-bp nuclear ITS region and 449-bp plastid trnL-F locus demonstrated that hybridization between the two species has occurred, and suggests gene flow between the species.