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

A–M’ LM images of little known and new “araphid” diatoms from the Bolivian Altiplano A–E Nanofrustulum cataractarum F–L N. rarissimum M–S Pseudostaurosira sajamaensis T–Z P. pulchra sp. nov. (Fig. 1U is the holotype) A’–G’ P. aedes sp. nov. (Fig. 1A’ is the holotype). H’–M’ P. heteropolaris sp. nov. (Fig. 1I’ is the holotype). Scale bar: 10 µm.