Luticola terrestris Kochman-Kedziora , M. Rybak & Peszek, 2021

Rybak, Mateusz, Kochman-Kedziora, Natalia & Peszek, Lukasz, 2021, Description of four new terrestrial diatom species from Luticola and Microcostatus genera from South Africa, PhytoKeys 182, pp. 1-26 : 1

Luticola terrestris Kochman-Kedziora, M. Rybak & Peszek sp. nov.

Holotype.

Slide no. 20-092 stored at the South African National Diatom Collection (SANDC) at North-West University, Potchefstroom South Africa.

Isotype 1.

Slide no. 27524 and unmounted material with same number at the Szczecin Diatom Collection (SZCZ) hosted by the University of Szczecin.

Isotype 2.

Slide no. 2018/424 and unmounted material with the same number at the University of Rzeszów, Poland.

Type locality.

Prince Alfreds’s Pass, Knysna, Western Cape, South Africa, 33°58.458'S, 23°08.811'E, leg. W. Morek and B. Surmacz, 20.09.2018.

Etymology.

The specific epithet refers to the terrestrial habitat from where the new species is described.

Description. LM (Fig. 3A-W ). Larger valves lanceolate with weakly-protracted apices; smaller valves rhombic-lanceolate, rectangular in girdle view. Apices usually rounded, in larger valves, slightly subcapitate. Valve dimensions (n = 25): length 8.0-28.5 μm, width 4.4-6.1 μm. Axial area linear, slightly widening towards both the central area and the apices. Central area bow-tie-shaped, often asymmetrical, bordered by shortened striae. One isolated pore present in the central area. Raphe branches straight. Proximal raphe endings unilaterally deflected away from the isolated pore; terminal raphe fissures elongated and hooked. Striae radiate throughout, 20-23 in 10 μm.

Description. SEM (Fig. 3X -AF). Striae composed of 2-4 transapically elongated areolae becoming larger towards the valve margins (Fig. 3X -AA). One elongated stigma present, positioned in between the proximal raphe endings and the valve face margin (Fig. 3X-Z ). Ghost areolae often present, mainly on a stigma-bearing site (Fig. 3X , AA). Raphe branches straight. Externally, proximal raphe endings deflected away from the isolated pore-bearing side with small drop-like endings (Fig. 3AB). Terminal raphe fissures clearly elongated, first curved to the same side as the proximal raphe fissures, then slightly bent to the isolated pore-bearing side. Terminal raphe fissures are towards the valve apices, terminating on the valve face/mantle junction, well after the final row of areolae (Fig. 3AC). Valve mantle bearing a single row of rounded areolae (Fig. 3Z , AA). Copulae with single row of areolae (Fig. 3AA). Internally, areolae occluded by hymenes, forming a continuous strip across each stria (Fig. 3AD-AF). Internal isolated pore opening rounded, covered by a lipped slit. Proximal and terminal raphe endings weakly deflected towards the pore (Fig. 3AE), the latter terminating on to small helictoglossae (Fig. 3AF). Longitudinal channel visible along valve edges (Fig. 3AE, AF).

Figures

Figure 3. Holotype population of Luticola terrestris Kochman-Kedziora, M. Rybak & Peszek, sp. nov. A-W LM images of valve views X-AF SEM images X-AA external view of an entire valve with several ghost areolae in the central area AB proximal raphe endings AC distal raphe endings AD internal view of an entire valve AE central area, internal view AF valve apex, internal view. Scale bars: 10 µm (A-W), 5 µm (X-AA, AD, AE), 4 µm (AF), 2 µm (AB, AC).