Three new Achnanthidium (Bacillariophyceae) species from Lake Salda (Anatolia, Turkey), a deep soda lake Author Solak, Cueneyt Nadir https://orcid.org/0000-0003-2334-4271 Dumlupinar University, Kuetahya, Turkey cnsolak@gmail.com Author Wojtal, Agata Zofia https://orcid.org/0000-0002-5233-2205 Institute of Nature Conservation, Polish Academy of Sciences, Krakow, Poland Author Peszek, Lukasz https://orcid.org/0000-0001-8661-5118 University of Rzeszow, Rzeszow, Poland Author Rybak, Mateusz https://orcid.org/0000-0001-8998-9537 University of Rzeszow, Rzeszow, Poland Author Yilmaz, Elif https://orcid.org/0000-0001-7939-1814 Dumlupinar University, Kuetahya, Turkey Author Gastineau, Romain https://orcid.org/0000-0001-8661-5118 University of Szczecin, Szczecin, Poland Author Blanco, Saul https://orcid.org/0000-0002-9015-2512 Universidad de Leon, Leon, Spain text Plant Ecology and Evolution 2022 2022-06-24 155 2 221 235 http://dx.doi.org/10.5091/plecevo.89304 journal article http://dx.doi.org/10.5091/plecevo.89304 2032-3921-2-221 8795D71D7AD7535FAB23D5ED86B54244 6746706 Achnanthidium dumlupinarii C.N.Solak, Wojtal, S.Blanco, Peszek & M.Rybak sp. nov. Figs 5 , 6 , 7 Type . TURKEY • Lake Salda ; 37°30 '41.43" N , 29°42 '41.78" E ; 1316 m a.s.l. ; 4 Nov. 2016 ; Cueneyt Nadir Solak ; holotype : slide n° 27293 illustrated here in Fig. 5F & V : deposited in the collection of Andrzej Witkowski at the University of Szczecin , Poland; isotype: slide n° TR _ BRD_ Salda Lake _ Nov2016 _EPL_1; deposited at Kuetahya Dumlupinar University, Turkey . Description. Valves linear-lanceolate to linear-rhombic, clearly inflated in the central portion. Apices subcapitate to capitate, larger specimens slightly undulate (Fig. 5B ). Valve dimensions (n = 60): valve length 15-26 µm , valve width 2.5-3.5 µm (Table 1 ). Raphe valve (Figs 5A, C-Q & 6A-H ): small central area, bordered by 1-3 widely spaced striae on one or both sides (Fig. 6B, F ). Striae visible in LM. Externally, raphe straight, filiform, with slightly expanded central endings and short terminal raphe fissures (Fig. 6A-D ). Internally, central raphe endings slightly deflected in opposite directions and terminal endings terminating onto small helictoglossae (Fig. 6E-H ). Transapical striae strongly radiate throughout entire valve, more dense towards apices, 27-28 per 10 µm . Striae composed of 3-4 rounded to rectangular areolae, sometimes slit-like near the valve margin (Fig. 6B-D, F-H ). Rapheless valve (Fig. 7C-H ): central area bordered by 1-2 more widely spaced striae on one or both sides (Figs 5B, R -AC & 7C-H). Transapical striae strongly radiate throughout entire the entire valve, more densely spaced towards the apices, 28-29 per 10 µm at central area. Striae composed of 3-5 rounded areolae (Fig. 7D-H ). On both valves, a single row of elongated areolae present on the mantle, separated from the striae on the valve face by a hyaline area (Fig. 7A, B ). In girdle view, valves C-shaped at the apices (Figs 5AD, AE & 7A, B). Figure 5. Achnanthidium dumlupinarii sp. nov., LM micrographs. A , C - Q . views of raphe valves. B , R - AC . Views of rapheless valves. AD , AE . Views of raphe valves in girdle view. Scale bar = 10 µm (A, B: 2500 x ; C-AE: 1000 x magnification). Figure 6. Achnanthidium dumlupinarii sp. nov., SEM micrographs. A . General external valve view of a raphe valve. B . Detail of the central area of a raphe valve showing the slit-like areolae in the margins. C , D . Details of apices. E . General internal valve view of a raphe valve. F . Details of central area. G , H . Details of apices. Scale bars 10 µm (A, E), 3 µm (D), 2 µm (B, C, F, G), 1 µm (H). Figure 7. Achnanthidium dumlupinarii sp. nov., SEM micrographs. A , B . External girdle view of a raphe valve showing the row of areolae in the mantle. C . General external valve view of a rapheless valve. D . General internal valve view of a rapheless valve. E , F . Details of central area. G , H . Details of apices. Scale bars 10 µm (A, C, D), 2 µm (B, E-H). Etymology. The species is named after Dumlupinar University, which supports diatom research in Turkey. According to art. 60.4 of the International Code of Botanical Nomenclature, the spelling of the name Dumlupinar is changed to Dumlupinar ( Turland et al. 2018 ).