1. Department of Biology, University of Pisa, Pisa, Italy
2. Botanic Garden and Museum, University of Pisa, Pisa, Italy
3. Department for the Earth, Environment and Life Sciences (DISTAV), University of Genoa, Genoa, Italy
4. Department BABVE (Systematics and Evolution of Vascular Plants, Associate Unit to CSIC), Autonomous University of Barcelona, Bellaterra, Barcelona, Spain
5. Department of Botany, University of Santiago de Compostela, Santiago de Compostela, A Corunha, Spain
6. Department of Biology, University of Naples Federico II, Naples, Italy
7. Department of Life and Environmental Sciences, University of Cagliari, Cagliari, Italy