Phylogenetic relationships among all of the 47 recognised species and 10 putative new taxa of Utricularia subgenus Polypompholyx, were assessed using maximum parsimony and Bayesian inference analyses of DNA sequences representing the plastid rps16 intron, trnL–F intron and spacer regions and the trnD–T intron. We found strong jackknife and posterior-probability support for a monophyletic subgenus Polypompholyx and a sister relationship between the sections Polypompholyx+Tridentaria and Pleiochasia. Within the section Pleiochasia, are two well-supported major clades, each containing three supported clades. Our S-DIVA biogeographic analysis, using five major Australian drainage basins and New Zealand as geographic areas, estimated two early vicariance events between south-western and north-western mainland regions, corresponding with known periods of increased aridity at 15 and 6million years ago. Subsequent dispersal events were estimated between northern and south-eastern Australia, with recent dispersal of species from south-western regions to the south-east and New Zealand occurring between 4million and 1million years ago. There were 28 speciation events inferred within the north-western region, followed by 9 for the south-western and south-eastern regions, indicating that the north-western monsoonal savanna habitats are a biodiversity hotspot for the lineage. We also show the evolutionary shifts in growth habit, and show that lifecycle corresponds strongly with shifts in seasonality between temperate and monsoonal regions. On the basis of our molecular phylogenetic results and morphology, we here designate a new sectional ranking for subgenus Polypompholyx.

Utricularia is a morphologically and ecologically diverse genus currently comprising more than 230 species divided into three subgenera—Polypompholyx, Utricularia, and Bivalvaria—and 35 sections. The genus is distributed worldwide except on the poles and most oceanic islands. The Neotropics has the highest species diversity, followed by Australia. Compared to its sister genera, Utricularia has undergone greater rates of speciation, which are linked to its extreme morphological flexibility that has resulted in the evolution of habitat-specific forms: terrestrial, rheophytic, aquatic, lithophytic, and epiphytic. Molecular phylogenetic studies have resolved relationships for 44% of the species across 80% of the sections. Scant data are available for phylogeography or population-level processes such as gene flow, hybridization, or pollination. Because nearly 90% of the species are endemics, data are urgently needed to determine how to protect vulnerable species and their habitats.

Abstract—Uncovering phylogenetic diversity is important, but not simple. A species complex is defined by different taxa with close evolutionary relationships harbouring limited morphological and/or genetic gaps. One such example exists within neotropical Utricularia sect. Foliosa, which is a taxonomically problematic assemblage composed of three currently recognized species: Utricularia amethystina, U. tricolor, and U. tridentata. The section type, Utricularia amethystina, contains 27 synonymized names. Morphological variation across the three species and associated synonyms suggests that previous taxonomic studies had underestimated taxonomic diversity. To examine taxonomic limits we sampled multiple accessions representing the three currently recognized species and many of the synonymized taxa classified under U. amethystina. We reconstructed a molecular phylogeny using three plastid regions (rps16, trnL-F, trnD-T) and nuclear ribosomal ITS. The three plastid markers produced similar phylogenetic topologies, and the combined plastid and nuclear phylogenies were congruent. The combined analysis provided strong support for most taxa previously identified through morphological analysis, also containing distinct groupings that likely represent both putative new species, and synonyms that are not monophyletic under the type accessions to which they had previously been relegated. The current analysis also shows a sister relationship between U. amethystina s. s. and U. tricolor, with U. tridentata found to be nested within the sister clade. Our results uncovered previously underestimated phylogenetic diversity within Utricularia sect. Foliosa, possibly driven by isolation factors such as specific phytophysiognomy across the varied habitats of the broad distribution across Central and South America.

Utricularia sect. Foliosa Kami enski comprises three recognized species, U. amethystina Salzm. ex A.St.-Hil. & Girard, U. tricolor A.St.-Hil., and U. tridentata Sylv en, delimited based mainly on shape and structure of the corolla. In comparison with the two latter members of the section, U. amethystina forms a complex of morphological variants, reflected taxonomically by the previous recognition of 31 synonyms. In his monograph of the genus, Taylor synonymized these taxa based primarily on his observation of continuous morphological variation of the flowers. In the same treatment he also suggested a future taxonomic re-evaluation could re-establish two, three or more taxa. Here we examine this question utilizing morphometric analyses of floral variation across most of the synonyms mentioned above, within populations from across their Neotropical distribution. Based on both morphological and geographic characters we identify strongly differentiated morphotypes. Our data provide support for both the maintenance of taxa previously recognised as synonyms under U. amethystina, and the resurrection of taxa to species status, namely U. bicolor, U. damazioi, U. lindmanii and U. hirtella, and four other putative new taxa.