Fragilaria pectinalis (O.F.Müll.) Lyngb.

De, Bart Van, Vijver, Mertens, Adrienne & Ector, Luc, 2020, Analysis of the type material of Synedra deformis W. Sm. and Synedra vaucheriae var. deformis Grunow (Fragilariaceae, Bacillariophyta), Cryptogamie, Algologie 20 (13), pp. 137-149 : 139

Fragilaria pectinalis (O.F.Müll.) Lyngb.

Tentamen Hydrophytologiae Danicae Continens omnia Hydrophyta Cryptogama Daniae, Holsatiae, Faeroae, Islandiae, Groenlandiae hucusque cognita, Systematice Disposita, Descripta et iconibus illustrata, Adjectis Simul Speciebus Norvegicis. Hafniae: 185 (1819).

MATERIAL. — Belgium. Poederlee, River Aa; coll. date 7. V.1994 (sample collected by B. Van de Vijver).

SAMPLE PREPARATION

Subsamples of all selected materials were prepared for light and scanning electron microscopy observations following the method described in van der Werff (1955). Small parts of the samples were cleaned by adding 37% H 2 O 2 and heating to 80°C for about 1 hour. The reaction was completed by addition of saturated KMnO 4. Following digestion and centrifugation (three times 10 minutes at 3700 × rpm), the resulting cleaned material was diluted with distilled water to avoid excessive concentrations of diatom valves on the slides. Cleaned diatom samples were mounted in Naphrax ®. All slides were analysed using an Olympus BX53 microscope, equipped with Differential Interference Contrast (Nomarski) optics and the Olympus UC 30 Imaging System. For each taxon, the number of specimens measured at random on the type slide is indicated (n = X). For scanning electron microscopy ( SEM), parts of the oxidized suspensions were filtered through a 2-µm Isopore̿ polycarbonate membrane filter (Merck Millipore). The stubs were sputter-coated with a platinum layer of 10 nm and studied using a JEOL-JSM-7100F field emission scanning electron microscope. Slides and stubs are stored at the BR-collection (Meise Botanic Garden, Belgium). Terminology used in the description of the structures of the siliceous cell wall is based on Anonymous (1975) and Round et al. (1990).