New species of Iconella Jurilj (Bacillariophyta) from tropical areas of China

Abstract

Three distinctive species of the diatom genus Iconella Jurilj were described from tropical areas of China. These new species all have the canal raphe extending around valve margins, keel raised off the valve surface forming wings, fenestrae obvious and alar canals that are uniformly porous. Together these features suggest these species should be assigned to the newly re–established genus Iconella. Here we describe Iconella shiwana Yan Liu, Ziyi Jiang et Kociolek sp. nov., Iconella pseudoconstricta Yan Liu, Ziyi Jiang et Kociolek sp. nov. and Iconella uniformis Yan Liu, Ziyi Jiang et Kociolek sp. nov., all described on the basis of light and scanning electron microscope observations from material collected from Hainan and Southern Guangxi Provinces. Iconella shiwana differs from other taxa by its isopolar valves and broadly round apices, tri– to quadriseriate short striae and large elliptical hyaline area in the valve center. I. pseudoconstricta is also isopolar, but it has acute ends and a constricted valve center. I. uniformis has heteropolar valves with a broadly rounded head pole and acute foot pole, a large spine is present near the head pole, and hook–like helictoglossae present at the foot pole. Our previous studies in tropical areas in China showed the diatom flora includes endemic taxa, although additional investigations are needed to explore and describe the abundant biodiversity there.