Format: ORAL

Lucas L. Miller1, Maria Cristina Duarte2, Mnica Moura3, Maria M. Romeiras2,4, Christian Braeuchler5, Mathieu Chambouleyron6, Hanno Schaefer1

1 Technical University of Munich, Freising, Germany 2 University of Lisbon, Campo Grande, Portugal 3 Universidade dos Açores, Ponta Delgada, Portugal. 4 Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon, Portugal. 5 Oberösterreichische Landeskultur GmbH, Linz, Austria 6 Reneco International Wildlife Consultants LLC, Rabat, Morocco

Umbilicus is a small genus of Crassulaceae with a distribution ranging from the Mediterranean region to Macaronesia, sub-Saharan Africa, and West Asia. The number of species is unclear due to the controversial taxonomy with multiple unresolved taxa and characters traditionally used for species delimitation being rather ambiguous. So far, only genetic analyses at the family level with a very limited number of Umbilicus species have been available. Here, we sequenced six plastid genes and spacers (matK, psbA-trnH, rps16, trnQ, trnS and trnL) plus the nuclear ribosomal ITS region of 235 specimens covering most of the distribution range of the genus and most described taxa. We inferred phylogenies with maximum likelihood and Bayesian methods and studied the morphology of herbarium material and photos of observations on iNaturalist. Using Bayesian molecular clock dating with secondary calibration we estimated a stem age of 14 (+/- 6) Million years for the genus. We inferred West Asia as the geographic origin with Chiastophyllum as sister lineage. The first diverging clades including U. albido-opacus and U. luteus as well as species with a paniculate inflorescence are restricted to West Asia, northeast Africa, and southeastern Europe. The remaining species, which all exhibit a racemose inflorescence and mostly greenish tubular flowers, diverged 9 (+/- 6) Ma ago and repeatedly colonized Africa, Europe, and Asia. Within this clade we inferred several cases of long-distance dispersal, most notably the colonization of Cameroon, Angola, and India as well as several independent colonization events of the Macaronesian islands. More data on the pollination biology of the genus, including pollinator shifts and transitions to selfing, will help us understand the discovered phylogenetic patterns.