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Issue: Vol. 780 No. 2: 15 Oct. 2026
Type: Article
Published: 2026-10-15
DOI: 10.11646/phytotaxa.780.2.5
Page range: 175-184
Abstract views: 14
PDF downloaded: 0

Placoneis montana sp. nov. (Bacillariophyta), a new diatom species from a small mountain stream

University of Rzeszów; Department of Ecology and Environmental Protection; Zelwerowicza 4; 35–601; Rzeszów; Poland
University of Rzeszów; Department of Ecology and Environmental Protection; Zelwerowicza 4; 35–601; Rzeszów; Poland
Luxembourg Institute of Science and Technology (LIST); Environmental Sensing and Modelling unit (ENVISION); Biodiversity Monitoring and Assessment group (BIODIV); 41 rue du Brill; L-4422 Belvaux; Luxembourg
Meise Botanic Garden; Research Department; Nieuwelaan 38; 1860 Meise; Belgium; University of Antwerp; Department of Biology; ECOSPHERE; Universiteitsplein 1; 2610 Wilrijk; Antwerpen; Belgium
Algae new species ecology freshwater morphology areolae

Abstract

During the survey on the diatom diversity in mountain streams of the Gorce Mountains National Park (southern Poland), several unidentified taxa were observed. Comparison with available literature and detailed morphological analyses using light microscopy (LM) and scanning electron microscopy (SEM) confirmed a set of distinct valve features in one of the taxa that could not be assigned to any known taxa. As a result, Placoneis montana sp. nov. is described as a new species. A detailed morphological comparison with similar taxa is provided, along with information on the associated diatom assemblage. This new Placoneis species expands knowledge of morphological and ecological variation in the genus, and its lack of visible areola occlusions raises questions about the reliability of that character for separating Placoneis from Witkowskia, pointing to the need for further SEM-based comparison across related taxa. Additionally, observations based on the type locality suggest that the new species is associated with high-altitude, well-oxygenated, low-nutrient environments, emphasising their potential value as indicators of mountain stream conditions.

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How to Cite

Kochman-Kędziora, N., Zarzycka, W., Wetzel, C.E. & Vijver, B.V.D. (2026) Placoneis montana sp. nov. (Bacillariophyta), a new diatom species from a small mountain stream. Phytotaxa 780 (2): 175–184. https://doi.org/10.11646/phytotaxa.780.2.5