Biogeographical investigations on the schismatoglottis nervosa complex (Araceae : schismatoglottideae) in Borneo

This study presents a biogeography hypotheses for the Schismaloglottis nervosa complex (Araceae: Schismatoglottideae) based on plastid (MatK) DNA sequence data. The aim is to provide insight into the floristic evolution and taxagenesis of the localized endemics in ever-wet and per-humid tropical forests. The Schismalogloltis nervosa complex comprises fourteen species endemic to several localities in Borneo and West Malaysia: Kuching (Bau, Matang, Padawan, and Lundu), Serian, Bintulu, Sarikei, Kapit, Miri, Tawau and Perak. Each species is endemic to specific substrate: shales, limestone, sandstone and granite. Maximum parsimony and maximum likel ihood analyses were performed with PAUP* 4.0b lOusing PaupUp graphicaf interface. Results from these analyses revealed that there are three major clades: the North East Borneo (above Lupar Line) clade, the Rejang clade, and the West Borneo clade (below Lupar Line). The results suggested that evolution was estimated to have occurred during Tertiary period. The results also indicated that the species have adapted to their own heterogeological and homogeologicallocalities