Australian Systematic Botany Australian Systematic Botany Society
Taxonomy, biogeography and evolution of plants

Just Accepted

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A revision of Cassinia (Asteraceae: Gnaphalieae) in Australia. 7. Cassinia subgen. Achromolaena

Anthony Orchard

Abstract

This paper completes a revision of the endemic Australian genus Cassinia R.Br.. Cassinia subgen. Achromolaena comprises two Sections: sect. Achromolaena of seven species (C. laevis, C. arcuata, C. uncata, C. tenuifolia, C. collina, C. subtropica, C. quinquefaria, and C. queenslandica), while Cassinia sect. Siftonia contains two species (C. sifton and C. theodorii). Cassinia laevis is divided into western (C. laevis subsp. laevis) and eastern (C. laevis subsp. rosmarinifolia (A.Cunn.) Orchard, comb. et stat. nov.) taxa. The formerly broadly circumscribed C. quinquefaria is shown to comprise two species, a southern C. quinquefaria s. str., and a northern C. queenslandica sp. nov. Examination of the type of C. arcuata revealed that this name is synonymous with C. paniculata, and applies to a relatively rare taxon with whitish capitula arranged in short erect compact panicles, and found in Western Australia, the northern midlands of South Australia, northwestern Victoria and (formerly) southwestern New South Wales. Furthermore it belongs in sect. Achromolaena. The taxon with red to brown capitula, widespread throughout southeastern Australia, which until now has been (incorrectly) known as C. arcuata (Sifton Bush) is distinct, but lacks a published name. The name Cassinia sifton Orchard, nom. nov. is here proposed for this taxon. An unfortunate outcome of this discovery is that the sectional name Cassinia sect. Arcuatae, with C. arcuata as type, becomes synonymous with sect. Achromolaena. The new name Cassinia sect. Siftonia is proposed to accommodate Sifton Bush (C. sifton) and its narrowly endemic sister species C. theodorii.

SB17033  Accepted 05 September 2017

© CSIRO 2017