Abstract
The work on the Isoetaceae account for the Critical Flora of Italy has resulted in a new, synonymic inventory of Italian Isoetes taxa, based on herbarium studies, observation by scanning electron microscopy and critical re-examination of the previously published works. Ten species are listed. The names I. longissima and I. gymnocarpa are restored as correct, to replace I. velata and I. subinermis, respectively. Eighteen lectotypes, one epitype and one neotype are designated. A dichotomous key to Italian taxa is provided.
Acknowledgements
We are grateful to the staff of the consulted herbaria (B, BORD, FI, PAD, PAL, RO, TO) for assistance in our search for original material, and especially to Brigitte Zimmer (B), Chiara Nepi (FI), Laura Guglielmone (TO). Thanks are due to the Herbarium, Dipartimento di Biologia Ambientale, Sapienza Università di Roma (RO), for the image of the lectotype of Isoetes malinverniana.