Discovery of cryptic plant diversity on the rooftops of the Alps

Florian C Boucher (1) , Cédric Dentant (2, 3) , Sébastien Ibanez (1) , Thibaut Capblancq (1, 4) , Martí Boleda (1) , Louise Boulangeat (1) , Jan Smyčka (5, 1) , Cristina Roquet (1, 6) , Sébastien Lavergne (1)

1 LECA - Laboratoire d'Ecologie Alpine
2 Parc national des Ecrins
3 PACTE - Pacte, Laboratoire de sciences sociales
4 University of Vermont [Burlington]
5 UK - Univerzita Karlova [Praha, Česká republika] = Charles University [Prague, Czech Republic]
6 UAB - Universitat Autònoma de Barcelona = Autonomous University of Barcelona = Universidad Autónoma de Barcelona

High elevation temperate mountains have long been considered species poor owing to high extinction or low speciation rates during the Pleistocene. We performed a phylogenetic and population genomic investigation of an emblematic high-elevation plant clade (Androsace sect. Aretia, 31 currently recognized species), based on plant surveys conducted during alpinism expeditions. We inferred that this clade originated in the Miocene and continued diversifying through Pleistocene glaciations, and discovered three novel species of Androsace dwelling on different bedrock types on the rooftops of the Alps. This highlights that temperate high mountains have been cradles of plant diversity even during the Pleistocene, with in-situ speciation driven by the combined action of geography and geology. Our findings have an unexpected historical relevance: H.-B. de Saussure likely observed one of these species during his 1788 expedition to the Mont Blanc and we describe it here, over two hundred years after its first sighting.

Domaines: Systématique, phylogénie et taxonomie

Florian C Boucher, Cédric Dentant, Sébastien Ibanez, Thibaut Capblancq, Martí Boleda, et al.. Discovery of cryptic plant diversity on the rooftops of the Alps. Scientific Reports, 2021, 11, ⟨10.1038/s41598-021-90612-w⟩. ⟨hal-03246552⟩