Figure 2 from: Morales EA, Wetzel CE, Ector L (2021) New and poorly known araphid diatom species (Bacillariophyta) from regions near Lake Titicaca, South America and a discussion on the continued use of morphological characters in araphid diatom taxonomy. PhytoKeys 187: 23-70. https://doi.org/10.3897/phytokeys.187.73338

Figure 2 A–F SEM images of little known "araphid" diatoms from the Bolivian Altiplano A, BNanofrustulum cataractarumA specimen from the Desaguadero River, showing quasifract girdle elements with prominent ligulae (white arrows) B specimen from the Sajama River showing common internal depression into which the areolae open (dotted arrows) and the blister-like depositions of silica at the abvalvar edge of the mantle C, DN. rarissimum from the Desaguadero River C small, spineless valve D internal view showing apical and foot pole pore fields (black arrows) and internal depressions containing all areolae within a stria (dotted arrow) E, FPseudostaurosira sajamaensis from the Desaguadero River E top view showing gradual transition of valve face to mantle and the reduced apical pore fields (black arrow) F side view of two half cells still attached by heavily silicified spines. Notice open girdle elements (white arrows). Scale bars: 1 µm (B); 3 µm (C, E); 4 µm (A, D); 5 µm (F).