Encyonema oblonga (Bacillariophyta, Cymbellaceae), a new species from Shanxi Province, China Author Liu, Qi 0000-0002-8710-4560 Shanghai Normal University, Shanghai 200234, China. & School of Life science, Shanxi University, Taiyuan 030006, China. liuqi317@126.com Author Li, Jiajia 0000-0002-8609-900X School of Life science, Shanxi University, Taiyuan 030006, China. 1035730329@qq.com Author Wang, Quanxi 0000-0002-0317-6613 Shanghai Normal University, Shanghai 200234, China. wangqx@shnu.edu.cn Author Kociolek, John Patrick 0000-0001-9824-7164 Museum of Natural History and Department of Ecology and Evolutionary Biology, University of Colorado, UCB 218, Boulder, CO 80309, USA. patrick.kociolek@colorado.edu Author Xie, Shulian 0000-0003-2349-2071 School of Life science, Shanxi University, Taiyuan 030006, China. xiesl@sxu.edu.cn text Phytotaxa 2021 2021-01-22 480 3 284 290 http://dx.doi.org/10.11646/phytotaxa.480.3.8 journal article 305100 10.11646/phytotaxa.480.3.8 3d4e5f64-ca27-4276-a9c3-bd378a71c3be 1179-3163 5417478 Encyonema oblonga Qi Liu & Shulian Xie sp. nov. ( Figs 1–18 ). Description: Valves nearly symmetrical, linear-elliptical, dorsal and ventral margins almost parallel, ends broadly rounded. Length 21–30 μm, breadth 5.5–7.0 μm. Axial area narrow, linear. Central area asymmetric, formed by a distinctly-shortened stria on the ventral side and one- two slightly-shortened stria on dorsal side. Raphe filiform, proximal raphe ends are weakly expanded and deflected dorsally and distal raphe fissures are deflected ventrally. Striae parallel, becoming radiate at the ends, 10–11 in 10 μm. Areolae are distinct, 24–28 in 10μm. In the SEM, externally, striae extend from the axial area to the mantle and are composed of individual lineate areolae ( Figs 11 , 14). Areolae bordering the axial area are smaller than the others ( Figs 11 , 14). Raphe filiform, proximal raphe ends are dilated and distal raphe end are hooked ( Figs 11, 13 , 14). Internally, raphe slits are straight, the intermissio is not present ( Fig 15, 17 ). Distal raphe ends terminate as helictoglossae ( Figs 15, 16 ). Striae are separated by well-developed intercostal ribs. The areolae are rectangular to elliptic. Beam stubs project above the intercostal ribs ( Ohtsuka et al. 2004 ) ( Figs 15–18 ). Stigmata and apical pore fields are absent. Type :— CHINA . Shanxi Province , Manghe National Nature Reserve . N 35°17′20″ , E 112°31′35″ , altitude 826m , pH 8.6, temperature 15℃, Date: September 2017 , Collector: Qi Liu & Jiajia Li. (slide 201709046-1 , holotype illustrated in Fig 2 ! Isotype JPK Collection, COLO , slides201709046-2 ) . Etymology:—The species epithet refers to the oblong shape of the valve. Ecology and distribution: Encyonema oblonga was found in Manghe rivers and Yuntai Mountains. pH 8.6, temperature 15℃and conductivity 625μS/cm in Manghe river, Shanxi province in September 2017 . pH 8.5, temperature 19℃ and conductivity 475μS/cm of a small river at Yuntai Montains, Henan Province in May 2018 . These rivers are a part of Yellow River basin.