Format: ORAL

Ashley Field1, Weston Testo2, Thais Almeida3, Lars Nauheimer1

1 Australian Tropical Herbarium, Cairns, Queensland, AU 2 Pringle Herbarium, The University of Vermont, Burlington, Vermont, USA 3 Universidade Federal de Pernambuco, Recife, Pernambuco, BR

Phlegmariurus (Huperzioideae, Lycopodiaceae) is a worldwide genus of 200 to 300 species comprised of a Neotropical radiation predominantly associated with mountain chains, and a Palaeotropical radiation predominantly associated with the canopies of rainforests. Our understanding of evolutionary radiation and species diversity in the Palaeotropical clade has remained a frontier due to the unresolved nature of species-level phylogenies, extreme homoplasy, and morphological intermediates between distant species. We present the first species-resolved phylogeny for Palaeotropical Phlegmariurus based on a comprehensive HybSeq dataset of 236 collections. We provide evidence that Palaeotropical Phlegmariurus comprises 13 major clades, each with morphological, ecological or geographic specialisation. Using the bioinformatics workflow HybPhaser, we present the first molecular evidence for hybrids in Phlegmariurus. Phlegmariurus of hybrid origin are common. We identify seventeen Phlegmariurus that are of hybrid origin, including five already described species and 12 that are newly identified, as well as evidence of hybrid species complexes. We postulate that, in addition to the long-distance dispersal, vicariance and habitat-driven diversification pathways previously identified, hybridisation has been an important species diversification pathway in Phlegmariurus.