Contribution to the floristic knowledge of Mount Pennino massif (Umbria-Marche Apennines, central Italy)

The inventory of the taxa collected in 2021 during the annual field trip of the Working Group for Floristics, Systematics, and Evolution of the Italian Botanical Society is reported. The field trip was held in the Mount Pennino massif, between Umbria and Marche administrative regions (central Italy). The flora documented for the study area amounts to 413 specific and subspecific taxa (including one hybrid), belonging to 234 genera and 64 families. Thirty-seven taxa are endemic to Italy; 42 are included in the IUCN Red List of the Italian Flora. Only three alien taxa were found. Ten taxa and one hybrid are considered floristic novelties because either new or confirmed for the regional flora of Umbria and/or Marche. Particularly, 6 taxa are new and 4 are confirmed for Umbria; one taxon and one hybrid are new for Marche.