Phylogeny of Podocarpaceae: comparison of evidence from morphology and 18S rDNA.

Maximum parsimony analyses of the genera of Podocarpaceae were conducted using sequence data from 18S ribosomal DNA. Trees from sequence, morphological, and combined data differ in taxon arrangement, but are similar in that Podocarpus sensu lato and Dacrydium s.l. are unnatural, while Podocarpaceae (including Phyllocladus) are monophyletic. The clade Microcachrys + Microstrobos is recognized in all analyses, but its placement differs, i.e., nested among other scale-leaved taxa in the morphological analysis, but associated with Nageia and other tropical genera in the sequence analyses. Trees from combined data reflect this ambiguity. Podocarpus sensu stricto is paraphyletic according to most trees. Inferences of plesiomorphic character states within the family are largely consistent between analyses and support the view that prototypical podocarps had bifacial leaves, cones with several fertile cone scales, and large epimatia (cone scales) that covered the inverted ovules.