Phylogenetic assessment of the monotypic genera Sundacarpus and Manoao (Coniferales: Podocarpaceae) utilising evidence from 18S rDNA sequences

Abstract

The Podocarpaceae are the most morphologically diverse of conifer families. A taxonomic trend has resulted in recognising this diversity via smaller generic groupings, including several monotypes. A phylogenetic assessment of the monotypic genera Sundacarpus and Manoao was conducted employing maximum parsimony the analysis of sequence data from 18S-ribosomal DNA from 34 gymnosperm taxa, including 29 Podocarpaceae. In resulting trees, there is high bootstrap support for Podocarpaceae, including Phyllocladus, but the order of deep branches within the family is equivocal. Prumnopitys (Sundacarpus) amara (Blume) de Laub. and four other Prumnopitys spp. comprise a clade with a bootstrap value of 100%, supporting the retention of Sundacarpus as a section of Prumnopitys. Lagarostrobos franklinii (Hook.f.) Quinn and L. (Manoao) colensoi (Hook.) Quinn comprise a clade with equivocal bootstrap support, echoing previous results from parsimony analysis of morphological data. A conservative approach (i.e. one avoiding unnecessary monotypes) favours the retention of L. colensoi in Lagarostrobos, pending further evidence of relationships within the group.