Morphological and amplified fragment length polymorphism (AFLP) data show that New Zealand endemic Myosotis petiolata (Boraginaceae) comprises three rare and threatened species

Species delimitation is of critical importance in systematics and biological and conservation research. The general-lineage species concept, which defines species as separately evolving metapopulation lineages, considers multiple lines of evidence to identify lineages and delimit species boundaries. Here, we apply the general-lineage concept to the New Zealand endemic Myosotis petiolata Hook.f. (Boraginaceae) species complex, to test its usefulness in the New Zealand Myosotis L. species radiation. We aimed to determine whether the complex contains separately evolving lineages to assess the criteria of monophyly, distinct genotypic clusters and fixed morphological differences by using amplified fragment length polymorphism (AFLP) and morphological data. The use of multiple criteria to identify separately evolving lineages within the M. petiolata complex was effective, but the different criteria were satisfied to varying degrees. Species rank is recommended for each of the currently recognised varieties as Myosotis pottsiana (L.B.Moore) Meudt, Prebble, R.J.Stanley & Thorsen (comb. & stat. nov.), M. pansa (L.B.Moore) Meudt, Prebble, R.J.Stanley & Thorsen (comb. & stat. nov.) and M. petiolata Hook.f. (North Island individuals only). A new allopatric subspecies, M. pansa subsp. praeceps Meudt, Prebble, R.J.Stanley & Thorsen (subsp. nov.), is also described. The distinguishing morphological characters and conservation status of each species are discussed. In addition, the low genetic diversity revealed in our population genetic analyses, coupled with few, fluctuating, disjunct populations, underscores the conservation priority of these three rare endemic New Zealand species.