Achnanthes kohleriana Kopalova, Zidarova & Van de Vijver 2016, sp. nov.

• Main Authors: Kopalová, Kateřina, Zidarova, Ralitsa, Vijver, Bart Van De
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2016
• Subjects: Biodiversity; Taxonomy; Chromista; Bacillariophyta; Bacillariophyceae; Achnanthales; Achnanthaceae; Achnanthes; Achnanthes kohleriana; Antarc*; Antarctic; Antarctica; Deception Island; South Shetland Islands
• Online Access: https://doi.org/10.5281/zenodo.3853084; http://treatment.plazi.org/id/03873C46FFCEFFEFFEFE4831A7EFFCE7

Achnanthes kohleriana Kopalová, Zidarova & Van de Vijver sp. nov. Figs 1–24 Etymology The species is named after our friend and colleague Dr. Tyler Kohler (Charles University in Prague and University of Boulder, Colorado, USA) in recognition of his diatom ecology work in the Dry Valleys of the Antarctic Continent. Type Deception Island, South Shetland Islands, Antarctica, sample D13 (62°58′24.5″ S 60°43′03.2″W) (leg. R. Zidarova), coll. date: 21 Jan. 2013 (holo-: slide no. BR–4436; iso-: slide PLP–292, University of Antwerp, Belgium). Description Light microscopy (Figs 1–13) Frustules in girdle view bent, with concave raphe valve and convex rapheless valve (Fig. 13). Valves linear to linear-elliptic, with almost straight to weakly concave in the middle valve margins. Valve apices broadly rounded, not protracted. Valve dimensions (n = 24): length 38–45 µm, width 9.0– 10.5 µm. Raphe valve (Figs 1–6): raphe distinctly lateral, curved. Proximal raphe endings deflected to one side terminating in drop-like expanded pores. Distal raphe fissures elongated and hooked. Axial area 1/4–1/5 of the valve width, almost linear, following the curvature of the raphe, not or only slightly widening toward the central area. Central area forming a rectangular to bow-tie-shaped fascia, lacking any striae near the margins. Transapical striae weakly to moderately radiate in the middle, becoming more radiate toward the apices, 11–12 in 10 µm. Areolae well discernible in LM, rounded, c. 14–18 in 10 µm. Rapheless valve (Figs 7–12): rapheless sternum narrow, located close to the valve margin. Striae parallel at the valve middle, becoming radiate toward the apices, 10–11 in 10 µm. Areolae well discernible in LM, rounded, c. 14–18 in 10 µm. Scanning electron microscopy (Figs 14–24) Raphe valve (Figs 14–19): valve face weakly concave in the middle. Apices presenting a rather larger hyaline zone (Figs 14, 16). Raphe slightly curved with tear-drop-shaped, weakly deflected proximal raphe endings, not extending in the central area (Figs 14, ...