Achnanthes sinaensis (Hustedt) Levkov, Tofilovska et C.E. Wetzel 2014

Lee, Sang Deuk, Yun, Suk Min, Cho, Pyo Yun, Yang, Hye-Won & Kim, Oe Jung, 2019, Newly Recorded Species of Diatoms in the Source of Han and Nakdong Rivers, South Korea, Phytotaxa 403 (3), pp. 143-170 : 150-152

Achnanthes sinaensis (Hustedt) Levkov, Tofilovska et C.E. Wetzel 2014 * Figures 2–5

Basionym: Achnanthes coarctata var. sinaensis Hustedt 1949, p. 43 , Figs 6, 7 .

Original description: Tofilovska et al. (2014), p. 19.

Key literature: Tofilovska et al. (2014), p. 19.

Specimen examined: Tables 1, 2.

Dimension: Length 48.2–55.1 μm, width 12.3–14.4 μm; nine striae in 10 μm on the raphe valve and 10 in 10 μm on the rapheless valve.

FIGURES 51–65. LM (51, 54, 58) and SEM (52, 53, 55–57, 59–65) microphotographs. 51–53. Eunotia circumborealis . 54–57. Fragilaria crotonensis . 58–62. Fragilaria recapitellata . 63–65. Gomphonema tergestinum . (Scale bars: 51, 52, 54, 58 = 10 μm; 53, 55, 64 = 2 μm; 56, 57, 62, 65 = 1 μm; 59–61, 63 = 5 μm).

Description: The valves are linear to linear-lanceolate with broadly round to trunctate valve apices. The raphe valve is concave with narrow and slightly curved axial area. The central area is rectangular with broad stauros extending to the valve margin. The raphe is weakly lateral with slightly curved raphe branches. The proximal raphe fissures expanded into large central pores, terminal raphe fissures unilaterally extending onto the valve mantle with polar hyaline areas. The transapical striae radiate with uniseriate, coarsely punctate throughout the valve. The rapheless valve convex with narrow and slightly curved axial area. The transapical striae parallel to the mid-valve, becoming strongly radiate near the apices. The frustule weakly flexed with a concave raphe valve and convex rapheless valve.

Distribution and ecology: Achnanthes sinaensis is freshwater, aerophytic species, and it usually occurs as epiphyte on wet mosses or rocks (Toflilovska et al. 2014).

Figures

FIGURES 2–7. LM (4) and SEM (2, 3, 5–7) microphotographs. 2–5. Achnanthes sinaensis. 6, 7. Achnanthidium atomus. (Scale bars: 2–5 = 10 μm; 6, 7 = 1 μm).