Relationships, gene flow and species boundaries among New Zealand <i>Fuscospora</i> (Nothofagaceae: southern beech)

We analysed DNA profiles at eight simple sequence repeat (SSR) loci for 449 individuals of <i>Fuscospora</i> species from New Zealand. The two species with serrated leaves (<i>F. fusca</i> and <i>F. truncata</i>) are clearly distinct genetically despite the occurrence of wild hybrids. Further, from our results, we infer that they are no more closely related to each other than they are to either of the entire-leaved species (<i>F. cliffortioides</i> and <i>F. solandri</i>). Although genetic groups corresponding with <i>F. cliffortioides</i> and <i>F. solandri</i> can be distinguished, our data suggest that considerable admixture may occur between them in some areas. Nonetheless, the broadly sympatric distribution of these two genetic groups, and their consistency with morphological and ecological groups, support their recognition at species rank rather than their treatment as varieties of one variable species.