Redescription of the suspended aquatic Utricularia aurea Lour. (sect. Utricularia) and a new species U. adamsii for northern Australia

Abstract

Australia has seven species in Utricularia L. section Utricularia, with the habit for all members of either affixed or suspended aquatic. Of the six recognised Australian species, one is endemic, one is pantropical, three are also distributed across Asia or Papua New Guinea - with U. australis R.Br. extending into Europe, and one other, U. stellaris L.f. into Africa. We present a molecular phylogeny based on two plastid and the nuclear ITS sequences for members of the subgenus Utricularia representing U. aurea Lour. and closely allied species from across each of their distributions. The molecular phylogeny provides strong support for recognition of a new species Utricularia adamsii R.W.Jobson & Davies-Colley (Lentibulariaceae), here described as new member of section Utricularia. This taxon was previously included within U. aurea, however, our molecular phylogeny and morphology supports a sister relationship with U. muelleri Kamienski. We provide a revised concept of U. aurea, and a description of the new species. The morphological differences between U. adamsii, U. muelleri, U. aurea and closely related species are here discussed, and an identification key provided. Distributions and habitat preferences of these taxa are discussed.