Petalophyllum ralfsii (Wilson) Nees et Gottsche in Calabria: distribution, ecology and conservation

This paper reports data on distribution of Petalophyllum ralfsii in Calabria (S Italy). Investigations conducted from 2016 to 2019 permitted to outline an updated and accurate overview on the number and size of the populations of the species in the region. New findings were recorded, while some known locations were not confirmed. The size of each population was measured by direct counting of thalli or by sampling with plots, enabling to have a reliable estimate of the species density. Analysis of data gives also important information on the ecology and dynamism of the species.