Pinnularia wuyiensis W. Zhang, A.C. Pereira & J.P. Kociolek, 2016

Zahng, Wei, Pereira, Andreia Cavalcante, Kociolek, J. Patrick, Liu, Caihong, Xu, Xiaoying & Wang, Liqing, 2016, Pinnularia wuyiensis sp. nov., a new diatom (Bacillariophyceae, Naviculales) from the north region of Wuyi Mountains, Jiangxi Province, China, Phytotaxa 267 (2), pp. 121-128 : 124-125

Pinnularia wuyiensis W. Zhang, A.C. Pereira & J.P. Kociolek sp. nov. ( Figs 2–30 )

Valves narrowly linear-lanceolate, with slightly undulate margins and a gibbous center and rounded, capitate and broadly rounded apices ( Figs 2–21 ), valve length 46–59 μm (average 52.9 μm), breadth 6.5–7.9 μm (average 7.15 μm), length-to-breadth ratio about6.3–8.6 (average 7.3) (n=105 valves). Axial area narrow, 1/7–1/4 of the valve breadth, linear, widening towards the central area ( Figs 2–21 ). Central area present, generally forming asymmetric, rhombic fascia ( Figs 2–18 , 20 ). Fascia wider at the ventral portion( Fig. 24 ). Raphe lateral with outer fissures weakly curved. Proximal raphe ends weakly expanded deflected in same direction ( Figs 2 –20,24). Terminal raphe fissures curved towards secondary side of valves strongly sickle-like, approximately hooked ( Figs 22, 23 ). Striae 13–15/10 μm (n=45), radiate in the middle, strongly convergent towards the ends ( Figs 2–21 ). Alveoli pattern with 2–6 rows of rounded areolae, each row with 15–17 areolae in 2 μm ( Figs 22, 23, 25 , 30 ). Internally, the central nodule is present but only weakly developed and not covering the proximal raphe ends. The internal raphe fissures run next to the central nodule and are interrupted by the intermissio ( Figs 26, 29 ). The internal proximal raphe ends are hooked backwards in the same direction ( Fig. 29 ). The distal fissures slightly deflected ending in prominent helictoglossae distant 1.9–2.2 μm from apices ( Figs 27, 28 ).

Type:— CHINA. North region of Wuyi Mountains: Yingtan City, River Xinjiang, 28° 12’ 37” N, 118° 18’ 02” E, 290 m a.s.l., X. J. Song, s. n. (holotype: SHOU!, slide Wuyishan 004FZ, illustrated in Fig.3 ).

Etymology:— Pinnularia wuyiensis is named after the type locality.

Figures

FIGURES 2–18. Pinnularia wuyiensis, LM, DIC. General valve view. Scale bar = 10 μm.

FIGURES 19–25. Pinnularia wuyiensis, SEM. External view of morphological features. 19–21. General view of valve. 22, 23. Detail of the sickle-shaped raphe fissure at pole, and alveolus with rows of rounded areolae. 24. Central area showing proximal raphe fissures bent in the same direction. 25. Detail of an alveolus with rows of rounded areolae. Scale bars: Figs19–21 = 10 μm, Figs 22–25 = 2 μm.

FIGURES 26–30. Pinnularia wuyiensis, SEM. Internal view of morphological features. 26. Internal view of an entire valve. 27, 28. Internal view of the valve apex showing typical helictoglossa. 29. Internal view of the central area. 30. Internal view of alveoli pattern. Scale bars: Fig. 26 = 10 μm, Figs 27–29 = 3 μm, Fig. 30 = 1 μm.