The scientific name for miro: transfer it to Pectinopitys or keep it in Prumnopitys?
Some have advocated for changing the scientific name of miro, one of the podocarp conifers endemic to New Zealand from Prumnopitys ferruginea to Pectinopitys ferruginea. There are counterarguments to this proposal. The below is an extract from Perrie (2022) Are recently proposed genus changes for several New Zealand trees consistent with minimising change within a scientifically-based taxonomy? New Zealand Botanical Society Newsletter 149: 11-18.
Prumnopitys
Page (2019) proposed the transfer of six species, including New Zealand’s miro, Prumnopitys ferruginea (Fig. 2), from Prumnopitys to a genus he newly described, Pectinopitys. He retained three species within Prumnopitys, including New Zealand’s mātai, Prumnopitys taxifolia. He also maintained as a distinct genus the Malesian-Australian monotypic Sundacarpus that he had earlier described.
Page (2019) referenced earlier phylogenetic studies of DNA sequences, the more recent being Biffin et al. (2012), Knopf et al. (2012), and Little et al. (2013). There seems to be some conflict among the studied DNA loci, and relatively little data were studied given the deep divergences involved. Nevertheless, there seems to be overall agreement in recognising three lineages, with Sundacarpus sister to Prumnopitys s.s., and their clade sister to Pectinopitys. Having found the sole species of Sundacarpus to be nested within Prumnopitys s.l., the simplest course of action would be to return the former to the latter, as done explicitly by Knopf et al. (2012) and Little et al. (2013), and implicitly by Biffin et al. (2012). The alternative solution proffered by Page is perverse from the perspective of minimising taxonomic change (i.e., six additional name changes globally).
Page’s reasoning seems to have two parts. Firstly, Sundacarpus looks really different, and should therefore be a different genus, and that similar reasoning can be applied to Pectinopitys and Prumnopitys s.s. While these differences can be scientifically catalogued, the judgement as to how much difference is fit for recognition as a genus (or one of the other arbitrary categories of species groupings) is subjective, and not scientific. Such reasoning is a recipe for never-ending taxonomic change as taxonomists argue unscientifically about what a genus should be, and it has long been rejected by most modern taxonomists.
The second part is that the divergences within Prumnopitys s.l. are temporally deep and equivalent to those between genera elsewhere in the Podocarpaceae. But this is a parallel recipe for subjective-caused instability. Which genera within the Podocarpaceae should be the benchmarks? Further taxonomic name changes would inevitably be required as comparisons are variously made across conifers, gymnosperms, seed plants, land plants, and life. It is worth quoting Entwisle & Weston (2005, p.2) at length on this point: “The only criterion of absolute rank that we think is objective and logically defensible is Hennig’s (1966) idea of tying rank to geological age. However we believe this criterion is hopelessly impractical, for several reasons…”. Until this “hopelessly impractical” option is realised across the classification of life, taxonomists should refrain from trying to give equivalency to taxa of the same rank, as it is subjective and only induces instability.
Prumnopitys as broadly defined (i.e., including Pectinopitys and Sundacarpus) is monophyletic, and Prumnopitys ferruginea should be used for miro by those interested in minimising name changes while aiming for a scientific classification.
