Elachanthus, Isoetopsis and Kippistia are nested in the genus Minuria (Asteraceae: Astereae)

Abstract

While conducting phylogenetic analyses of sequence-capture data of Australian members of Asteraceae tribe Astereae, we found that Elachanthus pusillus F.Muell., Isoetopsis graminifolia Turcz. and Kippistia suaedifolia F.Muell. formed a clade with Minuria. We, therefore, conducted an analysis focused on this clade, but with replicate samples of the three smaller genera, and confirmed our results. Kippistia had been synonymised under Minuria between 1876 and 1980, when it was reinstated. Elachanthus and Isoetopsis had not previously been suggested to be part of Minuria, and, indeed, Isoetopsis had been considered so morphologically divergent that even its tribal affiliations were long controversial. However, on closer examination, Elachanthus and Isoetopsis are strikingly similar to Minuria, especially in cypsela and pappus morphology. The evolution of both genera from a common ancestor in Minuria appears plausible in the light of their overall similarity to annual species of that genus such as M. annua, their multiple uniform rows of herbaceous phyllaries with scarious margins, a pappus of scales v. the tendency of Minuria to form pappi with scale-like bases, female outer and male inner florets, and a cypsela indumentum shared with some species of Minuria. We propose the following three new combinations under Minuria: M. pusilla, M. glabra and M. graminifolia.