Figures 4 from: Yu P, You Q, Pang W, Wang Q (2022) Two new freshwater species of the genus Achnanthidium (Bacillariophyta, Achnanthidiaceae) from Qingxi River, China. PhytoKeys 192: 11-28. https://doi.org/10.3897/phytokeys.191.78489

Figures 4 A–DAchnanthidium anhuense sp. nov., SEM external views of rapheless valve A, B external view of an entire rapheless valve C apices of the valve D central area of the valve. Scale bars: 5 µm (A, B); 1 µm (C, D).