Morphological and phylogenetic data confirm the identity of Prasiola fluviatilis (Prasiolales, Trebouxiophyceae) from glacier streams in the Tianshan Mountains, China

rbcL and tufA alignments used for the phylogenetic analyses. Genbank accession numbers of new sequences of Prasiola fluviatilis voucher XJ20170806: MT846163 (rbcL), MT846164 (<em>tuf</em>A). Samples deposited in the herbarium of the Laboratory of Algae and Environment, Biology Department, Shanghai Normal University (SHTU), Shanghai, China. Abstract of publication: The green alga <em>Prasiola fluviatilis</em> (Sommerfelt) Areschoug ex Lagerstedt occurs in cold lotic environments. The species has a mainly circumarctic distribution, but has also been reported from glacier areas in lower latitude regions in both hemispheres. It was reported from China on a single occasion in the first half of the 20^th century, but without description, illustrations or voucher specimens the identity of this record cannot be verified. Here we confirm the presence of <em>P. fluviatilis</em> in the Tianshan Mountains, Xinjiang Province, China based on morphological features, habitat characteristics, and plastid <em>rbc</em>L and <em>tuf</em>A gene sequences. The biogeographic distribution of <em>P. fluviatilis</em> and its phylogenetic relationship with other terrestrial and freshwater <em>Prasiola</em> species are discussed.