A taxonomic revision of Monopteryx (Leguminosae): a florally divergent and ancient papilionoid genus of large Amazonian trees

Monopteryx is a florally divergent genus of Dipterygeae, an early-branching papilionoid legume clade largely marked by winged papilionate floral architecture, expanded upper calyx lobes often assuming a wing-shaped orientation and petals differentiated into standard, wings, and a keel enclosing the basally connate stamens. In contrast to the remaining Dipterygeae genera, Monopteryx has differentiated petals but the marginally coherent keel with interlaced trichomes exposes the free stamens and the expanded calyx upper lobes are nearly entirely fused with a standard-like dorsal orientation. Monopteryx species are restricted to the Amazonian rainforests, where they have diversified since the last ~15 Ma, but the divergence of the genus is estimated to be as old as ~39 Ma. They grow as large buttressed trees usually with a uniquely “flying” architecture, which are arched from the trunk to the ground and separated from one another, unlike that found in any other species of leguminaceous tre..., In order to assess the phylogenetic distinctiveness and relationships of all Monopteryx species, a new phylogenetic tree of the Dipterygeae was generated based on nuclear ribosomal ITS/5.8S and the plastid trnL intron and protein-coding matK DNA sequences. The new Dipterygeae phylogeny has greatly augmented the sampling of multiple accessions per species in Monopteryx after sequencing herbarium specimens and our newly collected samples preserved in silica gel. Comprehensive sampling across Monopteryx and related Dipterygeae genera was possible due to previously published taxonomically curated, vouchered sequences (Cardoso et al. 2012b, 2015b; Carvalho et al. 2023a) available in GenBank (http://www.ncbi.nlm.nih.gov/genbank/).
The DNA isolation, polymerase chain reaction (PCR), and amplifications follow the same protocols as described in our previous molecular phylogenetic studies (Cardoso et al. 2012b; Queiroz et al. 2015; Carvalho et al. 2023a). The products of the forward and reverse s...,