Morphological and molecular features were analyzed for a species of Phacus to better understand the phylogenetic relationships among them and establish the taxonomy. Phylogenetic analyses were based on nSSU rDNA and the research resulted in 55 new sequences. The study included species available in algal collections and those isolated directly from the environment in Poland and the Czech Republic. As a result, the obtained phylogenetic tree of Phacus includes 50 species, out of which 7 are represented on a tree for the first time (Phacus anacoelus, P. anomalus, P. curvicauda, P. elegans, P. lismorensis, P. minutus and P. stokesii) and many have been taxonomically verified. For all verified species, diagnostic descriptions were amended, the naming was reordered and epitypes were designated.

中文翻译：

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基于形态和分子数据的Phacus（Euglenida）属的富含分类群的系统发生学和分类学。

分析了一个Phacus种类的形态和分子特征，以更好地了解它们之间的系统发生关系并建立分类学。系统发育分析是基于nSSU rDNA的，该研究产生了55个新序列。该研究包括藻类收集中可用的物种以及直接从波兰和捷克共和国环境中分离出来的物种。其结果是，所获得的系统发生树Phacus包括50种，其中有7上的第一次（一个树来表示Phacus anacoelus，P. anomalus，P.实蝇，P.线虫，P. lismorensis，P.蝽和P. stokesii），并且其中许多已通过分类学验证。对于所有经过验证的物种，修改了诊断说明，重新命名并指定了表型。