Staurosirella binodiformis Van de Vijver & Peeters & Hansen & Ballings & de Haan 2024, sp. nov.

• Main Authors: Van de Vijver, Bart, Peeters, Valérie, Hansen, Iris, Ballings, Petra, de Haan, Myriam
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2024
• Subjects: Biodiversity; Taxonomy; Chromista; Ochrophyta; Bacillariophyceae; Fragilariales; Fragilariaceae; Staurosirella; Staurosirella binodiformis; Iceland
• Online Access: https://doi.org/10.5281/zenodo.11404250; http://treatment.plazi.org/id/6A343AFD5CFB5BA7A5CFE58BBD943C9A

Staurosirella binodiformis Van de Vijver sp. nov. Fig. 2 Holotype. BR- 4841 (Meise Botanic Garden, Belgium). Fig. 2 E represents the holotype. Isotype. Slide 443 (University of Antwerp, Belgium). Registration. http://phycobank.org/104534. Type locality. outflow from a small lake near Þingvellir, Iceland, sample 29, coll. date 15 Jul. 1954, leg. Niels Foged. Description. LM (Fig. 2 A – AP). Valves isopolar, linear, slightly constricted near the valve center in longer specimens (Fig. 2 A – G), becoming linear, linear-lanceolate to even almost elliptical in smallest specimens (Fig. 2 AM – AP). Apices in longer specimens protracted, rostrate to subcapitate, to not protracted, broadly rounded in smaller valves. Valve dimensions (n = 50): length 6–21 µm, width 3.0–3.5 µm. Sternum narrow, linear. Striae almost parallel weakly radiate in the valve center, becoming more radiate towards the apices, long, almost reaching the sternum, 14–15 in 10 µm. Areolae not discernible in LM. SEM (Fig. 2 AQ – AV). Valve face surface weakly undulating with raised virgae extending almost up to the valve middle (Fig. 2 AR – AT). Virgae almost double as broad as the striae. Striae long, extending without interruption from the valve face onto the mantle (Fig. 2 AQ). Very large hyaline zone present at the abvalvar mantle edge (Fig. 2 AQ). Mantle plaques absent (Fig. 2 AQ). Striae uniseriate, composed of slit-like, linear areolae, running parallel to the apical axis (Fig. 2 AQ – AU). Areolae diminishing in size towards the sternum (Fig. 2 AT), becoming almost rounded at the sternum. Mantle striae often very short, reduced to only one areola (Fig. 2 AU), occasionally also longer (Fig. 2 AS). Vimines very narrow, not raised. Irregular but dense series of short, marginal spines located on the virgae, usually bordering immediately the striae (Fig. 2 AR – AS). Spines occasionally bifurcated (Fig. 2 AQ, AS). Apical pore fields present at both apices, usually similar in size and shape (Fig. 2 AR – AT), located at the valve face / mantle ...