It’s complicated: A brief overview of the taxonomy of the New Zealand Brachyglottis rotundifolia
 species complex (Senecioneae)

Robb Eastman-Densem

School of Biological Sciences, University of Canterbury, Christchurch, New Zealand

https://orcid.org/0000-0002-2287-7677

Pieter Pelser

School of Biological Sciences, University of Canterbury, Christchurch, New Zealand

https://orcid.org/0000-0002-6990-1419

DOI: http://dx.doi.org/10.53875/capitulum.01.2.07

ABSTRACT: Brachyglottis J.R.Forst. & G.Forst. (Senecioneae Cass.; Asteraceae) is a mostly woody genus of ca. 24 species. It is endemic to New Zealand in classifications where B. brunonis (Hook.f.) B.Nord. from Tasmania is segregated as Centropappus brunonis Hook.f. As part of his undergraduate research project at University of Canterbury, Eastman-Densem performed an unpublished pilot study into patterns of morphological variation in a group of four discoid Brachyglottis species with unclear taxonomic boundaries (i.e., the B. rotundifolia species complex): B. buchananii (J.B.Armstr.) B.Nord., B. cockaynei (G.Simpson & J.S.Thomson) B.Nord., B. elaeagnifolia (Hook.f.) B.Nord., and B. rotundifolia J.R.Forst. & G.Forst. With the aim of supporting future studies focused on resolving this species complex, we here provide a brief overview of its current taxonomic treatment and synonymy (summarized in Table 1), with notes about its complicated taxonomic history. We conclude that although Senecio bennettii G.Simpson & J.S.Thomson is listed as a synonym of B. buchananii in recent publications and other works and treatments, this name should instead be considered as a synonym of B. rotundifolia if the current taxonomic delimitation of the complex is followed.  

Keywords: Asteraceae, Compositae, nomenclature, Senecio bennettii, species delimitation