New and Interesting Diatoms from the Shiwan Wetwalls, Yunnan Province, China. III. Valve ultrastructure of four new species of Eunotia (Bacillariophyceae: Eunotiales) Author Liu, Qi 0000-0002-8710-4560 School of Life Science, Shanxi University, Taiyuan, People’s Republic of China liuqi317@126.com Author Liu, Enhui 0009-0008-0343-6981 School of Life Science, Shanxi University, Taiyuan, People’s Republic of China 18835572665leh@gmail.com Author You, Qingmin 0000-0002-5538-8503 College of Life Sciences, Shanghai Normal University, Shanghai, People’s Republic of China youqm1117@163.com Author Wang, Qinghua 0000-0002-1060-0822 Department of Biology, Taiyuan Normal University, Jinzhong 030619, People’s Republic of China wqinghua123@126.com Author Kociolek, John Patrick 0000-0001-9824-7164 Museum of Natural History and Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA patrick.kociolek@colorado.edu Author Xie, Shulian 0000-0003-2349-2071 School of Life Science, Shanxi University, Taiyuan, People’s Republic of China xiesl@sxu.edu.cn text Phytotaxa 2024 2024-04-03 642 4 242 254 http://dx.doi.org/10.11646/phytotaxa.642.4.2 journal article 300704 10.11646/phytotaxa.642.4.2 6c58cb6d-dbcb-4dc5-8d35-64b08d1e4072 1179-3163 13214365 Eunotia yunnanica Q. Liu, S.L.Xie & Kociolek sp. nov. ( LM: Figs 1–11, SEM: Figs 12–17 ) Description: LM: Valves asymmetrical to apical axis, dorsal margin convex outline appearing undulate, with produced, rounded ends; smaller valves with less produced apices. Ventral margin slightly concave to nearly straight; some specimens with slight degree of asymmetry about transapical axis. Valve length 21–52 µm; 6–8 µm; 5–6/10 µm. Striae not punctate (in LM), wider at dorsal margin, becoming narrow across valve face, parallel and widely spaced in valve center. Striae crossing valve face 5–6/10µm, denser at apices, 7–9/10 µm. Distal raphe ends barely extend onto valve face before valve terminus. Pseudoseptum present at each apex. In girdle view, dorsal portion of valve with multiseriate, punctate striae separated by hyaline areas. Striae appear in bundles of 3–5, distinctly punctate. Margin with spine-like projections. On ventral portion of valve mantle, raphe branches short, contained in narrow axial area. Raphe branches bent towards mantle, away from valve face. SEM: valve exterior with thickened ribs or ridges extending across valve face, dorsal margin also appears thickened, giving margin an undulate appearance (Figs 13, 14). Striae composed of 2–4 rows of round, unoccluded areolae at dorsal margin, except at apices (Figs 13–15). Striae uniseriate across valve face to ventral margin. Distal raphe end extending onto valve face (Fig. 15). Internally, areolae round, appear without occlusions (Figs 15, 16). Small pseudoseptum at apices. Raphe terminates in prominent helictoglossa (Figs 15, 17). PLATE 1. Eunotia yunnanica Q. Liu, S. L. Xie & Kociolek , sp. nov. Figures 1–11. Light microscope images showing size diminution series. Holotype population. Scale bar = 10 µm. Type: CHINA . Yunnan Province , Shiwan wet wall. Holotype preparation Slide No. YN201904033- 1 in the Freshwater Algal Herbarium of Shanxi University ( SXU ), Taiyuan, China. Isotype slide YN201904033-2 deposited in the Kociolek Collection at the University of Colorado ( COLO ) . Etymology: Named for its occurrence in Yunnan Province , China . Comments: This taxon was reported by Luo et al . (2019) , as Eunotia odebrechtiana Metzeltin & Lange-Bertalot (1998) , from streams and lakes in Sichuan Province. They noted that the Chinese specimens were narrower than the specimens described by Metzeltin and Lange-Bertalot (1998) from Brazil . Specimens from Yunnan are also narrower than the South American species and, like the specimens from Sichuan illustrated by Luo et al . (2019) , they have finer striae. Present in samples YN201904033, YN201904034, YN201904047, YN201904049 and YN201904055.