Plant Ecology and Evolution 152 (2): 285–292, 2019 https://doi.org/10.5091/plecevo.2019.1605 New Amphora and Halamphora (Bacillariophyta) species from springs in the northern Apennines (Emilia-Romagna, Italy) Marco Cantonati 1,* , Nicola Angeli 1 , Horst Lange-Bertalot 2 & Zlatko Levkov 3 1 MUSE - Museo delle Scienze, Limnology & Phycology Section, Corso del Lavoro e della Scienza 3, I-38123 Trento, Italy 2 Goethe Universität Frankfurt, Biologicum, Max-von-Laue Straβe 13, 60438 Frankfurt, Germany 3 Institute of Biology, Faculty of Natural Sciences, SS Cyril and Methodius University, Arhimedova 3, 1000 Skopje, North Macedonia *Author for correspondence: marco.cantonati@muse.it REGULAR PAPER Background and aims – The detailed analysis of algae and cyanoprokaryotes in a heterogeneous group of spring habitats (including all the diferent typologies) of the northern Apennines (Emilia-Romagna Region, Italy) revealed a new Amphora species in a small mountain fowing spring with low conductivity, and a new Halamphora species in a large, inland-saline (Triassic gypsum), fast fowing spring (Poiano spring). The present study aims to describe in detail these two new species found in contrasting spring types. Methods – This study is based on light microscopy (both fresh –for plastids – and prepared materials) and scanning electron microscopy observations, as well as a thorough morphological, physical, chemical, and biological characterization of the habitats. Key results – Amphora eileencoxiae sp. nov. is most similar to A. vetula (and allied taxa), and is characterized by the outline with acutely rounded, moderately ventrally bent ends, by the dimensions, and by the well- defned, semi-elliptic dorsal area. Halamphora poianensis sp. nov. is most similar to H. gasseae but difers by the higher stria density, the clearly ventrally bent ends, and the strongly developed dorsal raphe ledge. Conclusions – This is a contribution to the knowledge of the genera Amphora and Halamphora in mountain springs in understudied geographic areas and inland-saline springs, the species communities of which are likely insufciently explored. Key words – Diatoms, springs, inland saline habitats, new species, Amphora eileencoxiae, Halamphora poianensis, northern Apennines. © 2019 The Authors. This article is published and distributed in Open Access under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits use, distribution, and reproduction in any medium, provided the original work (author and source) is properly cited. Plant Ecology and Evolution is published by Meise Botanic Garden and Royal Botanical Society of Belgium ISSN: 2032-3913 (print) – 2032-3921 (online) INTRODUCTION Amphora Ehrenb. ex Kütz. s. lat. is a large, widely distrib- uted, and diverse group of freshwater, brackish, and marine diatoms (e.g. Stepanek & Kociolek 2013). Recent important studies (e.g. Levkov 2009, Stepanek & Kociolek 2014, 2018, 2019) have advanced the understanding of this polyphyletic group, and of the evolution of amphoroid symmetry. Many species in Amphora s. lat. are marine (e.g. Round et al. 1990, Stepanek & Kociolek 2013) but an increasing number of species are being described from inland habitats (e.g. Levkov 2009, Stepanek & Kociolek 2018). However, in spite of recent revisions of Amphora s. lat. that included the elevation to the generic status of the subgenus Halamphora and the description of 63 new taxa from freshwater environ- ments (Levkov 2009), the genera Amphora and Halamphora still appear to be insufciently known in freshwater habitats (e.g. Stepanek & Kociolek 2013, 2015). Freshwater ecosystems which are insufciently stud- ied are springs, important habitats (Cantonati et al. 2012a, 2015), multiple ecotones, biodiversity hotspots (Cantonati et al. 2016a, Taxböck et al. 2017), and ideal sites for long-term ecological research (Cantonati & Ortler 1998). Their diatom communities have only been studied in a more detail in the