The genus Rosenvingea (Phaeophyceae: Scytosiphonaceae) in south-west Australia, with the description of Rosenvingea australis sp. nov.

Two species of the brown algal genus Rosenvingea are reported from south-west (SW) Australia, including the widely distributed R. orientalis and the new species R. australis Huisman, G.H. Boo et S.M. Boo, sp. nov. Molecular phylogenies of mitochondrial cox3 and plastid psaA unequivocally align the SW Australian R. orientalis with specimens from Vietnam and the species is morphologically consistent throughout its Australian range. Australian specimens of the new species R. australis join with a specimen from New Caledonia and these resolve as a sister species to R. intricata, with levels of pairwise divergence (4.2-4.9% in cox3 and 3.9-4.0% in psaA) comparable to those between other scytosiphonacean species. The new species can be distinguished morphologically by its branch dimensions and the arrangement and size of plurangia, but further studies including molecular analyses of a full range of species and possible morphological variants are needed. [ABSTRACT FROM AUTHOR]