Diatoms of soils and pyroclastic deposits from South Kamchatka volcanoes

Twenty-four species of diatoms belonging to 14 genera, 12 families and 5 orders were identified from soils and pyroclastic deposits of the Gorely, Mutnovsky, Avachinsky, Koryaksky and Vilyuchinsky volcanoes (Kamchatka Peninsula, Russia). Two species of these (Nupela tenuicephala, Pinnularia bullacostae) are new to the flora of the Kamchatka Peninsula, three ones (Eunotia palatina, Neidium bergii, Stauroneis borrichii) to the Russian Far East, and another three (Psammothidium lacustre, Humidophila sceppacuerciae, Gomphonema reichardtii) to the flora of Russia. Three revealed taxa (Navicula sp., Chamaepinnularia sp., and Pinnularia sp.) are probably new to science, as their morphological and morphometric characteristics differ from those of previously described species.