taxonID	type	description	language	source
C0727E167D6DF126FF01F984063BFBD9.taxon	materials_examined	Type: — BELGIUM. Flanders, Province of Limburg, Maaseik, Bosbeek, sample APM 21 - 91, 51 ° 5.6348 ’ N, 5 ° 45.894 ’ E, coll. date 25 Jun. 2021, leg. Vlaamse Milieu maatschappij (VMM) (holotype slide BR- 4850, Fig. 5 represents the holotype, isotype slide 448 in Collection University of Antwerp, Belgium). PhycoBank registration: — http: // phycobank. org / 104825.	en	Vijver, Bart Van De, Wetzel, Carlos E. (2024): A new Pseudostaurosira species (Bacillariophyta, Staurosiraceae) from lowland rivers and lakes in Europe (Atlantic Biogeographic Region). Phytotaxa 663 (1): 49-54, DOI: 10.11646/phytotaxa.663.1.6, URL: https://doi.org/10.11646/phytotaxa.663.1.6
C0727E167D6DF126FF01F984063BFBD9.taxon	etymology	Etymology: — The new species is named after Katharina Wilfert, oldest stepdaughter of the first author.	en	Vijver, Bart Van De, Wetzel, Carlos E. (2024): A new Pseudostaurosira species (Bacillariophyta, Staurosiraceae) from lowland rivers and lakes in Europe (Atlantic Biogeographic Region). Phytotaxa 663 (1): 49-54, DOI: 10.11646/phytotaxa.663.1.6, URL: https://doi.org/10.11646/phytotaxa.663.1.6
C0727E167D6DF126FF01F984063BFBD9.taxon	biology_ecology	Ecology and distribution: — Pseudostaurosira katharinae was described from a small river near Maaseik, in the northeastern part of Belgium. The type locality had an almost circumneutral pH (6.9 – 7.3), a moderate conductivity (> 200 µS / cm), and higher sulphate (12 – 30 mg / l) and nitrate levels (1.4 – 3.3 mg / l). The associated flora was dominated by several small-celled araphid species such as, apart from P. katharinae, also larger populations of Staurosirella marginostriata Van de Vijver & V. Peeters (in Van de Vijver et al. 2024: 142), S. stoksiana, Pseudostaurosira alvareziae and P. brevistriata. Other dominant species in the sample included Aulacoseira ambigua (Grunow in Van Heurck 1882: pl. 88, figs 12 – 15) Simonsen (1979: 56), A. granulata (Ehrenberg 1843 b: 415) Simonsen (1979: 58) and Navicula cryptocephala Kützing (1844: 95), pointing to more meso-eutrophic, alkaline conditions (Lange-Bertalot et al. 2017). The species has also been found in a French lake (“ Mare à Goriaux ”) (Figs 26 & 27). The Mare à Goriaux, an intraforest pond, is located within the perimeter of the Regional Natural Park of the Scarpe and Escaut Plains, at the southern edge of the Raismes, St-Amand, and Wallers state forest (Marchyllie, 1992). The pond, formed from mining subsidence caused by the exploitation of the Vicoigne and Arenberg pits, was originally a wetland due to groundwater outcrops. The exploitation of the Arenberg pit caused the most significant collapses, initially creating three ponds that merged around the 1930 s to form the current Mare à Goriaux (Marchyllie, 1992). The high mineral content of the pond’s water is largely due to SO 4 - ions (6 to 700 mg / l), Cl- ions (145 mg / l), as well as Na + ions (560 mg / l) and Ca + ions (110 mg / l). It is likely that the species is more widespread than currently known due to confusion with similar taxa.	en	Vijver, Bart Van De, Wetzel, Carlos E. (2024): A new Pseudostaurosira species (Bacillariophyta, Staurosiraceae) from lowland rivers and lakes in Europe (Atlantic Biogeographic Region). Phytotaxa 663 (1): 49-54, DOI: 10.11646/phytotaxa.663.1.6, URL: https://doi.org/10.11646/phytotaxa.663.1.6
