Phylogeny and generic delimitation of Asian Marantaceae

Abstract

Eight genera and approximately 55 species of Marantaceae occur in Asia. Until recently these were the most poorly understood members of the family, but over the last few years much progress have been made in understanding their alpha taxonomy and distribution. Generic delimitation and phylogenetic relationships between genera, however, remain unclear. We analysed phylogenetic relationships in Asian Marantaceae using maximum parsimony and Bayesian analysis of plastid (rps16 intron) and nuclear [internal transcribed spacer (ITS)1 and 5S-non-transcribed spacer (NTS)] DNA sequence data. The results show that two Asian genera, Halopegia and Stachyphrynium, are well-defined monophyletic entities that should be maintained in their current form. Schumannianthus virgatus is sister to Halopegia and should be transferred to a genus of its own. Phacelophrynium, Monophrynium and Cominsia are nested within a paraphyletic Phrynium. Within this large clade, a number of geographically focused monophyletic species groups can be identified, in some cases corroborated by flower and fruit characters not previously emphasized in taxonomic studies, but these do not provide a useful framework for a revised generic classification. A revised generic classification of Asian Marantaceae is supplied, including the description of a new genus Indianthus Suksathan & Borchs. to which S. virgatus is transferred.