Umbelopsis longicollis comb. nov. ined. and synonymization of U. versiformis, the type species of Umbelopsis (Mucorales) Ya-ning Wang, Xiao-yong Liu* Ru-yong Zheng* (State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101) Abstract: Speices of the genus Umbelopsis (Umbelopsidaceae) are saprobes, many of which are important oleaginous fungi. Typical characters of Umbelopsis are: 1) velvety and often colored colonies, 2) a low and dense layer of aerial hyphae; 3) sporangiophores which are often arising erectly from the vesicles; and 4) small columellae or not forming at all. In this study, based on morphological characters, maximum growth tempearature and molecular phylogentic analysis (SSU, ITS, LSU rDNA and actin genes), the relationship of allied species U. dimorpha, U. nana and U. versiformis are clarified. U. dimorpha is considered as a separate species because of unique morphology, though it is phylogenetically closely related to the other two. U. nana and U. versiformis are conspecific and U. nana has priority over the synonymous U. versiformis. A related species, Mortierella longicollis should be the new combination, U. longicollis ined. Lectotypes and epitypes for U. longicollis ined. and U. nana are also designated. Key word: Mucoromycotina, Taxonomy, Phylogenetics, synonym, typification Funds: this study is supported by the National Natural Science Foundation of China (No. 31370068) References: Meyer W, Gams W (2003) Delimitation of Umbelopsis (Mucorales, Umbelopsidaceae fam. nov.) based on ITS sequence and RFLP data.Mycol Res 107:339–350. Sugiyama M, Tokumasu S, Gams W (2003) Umbelopsis gibberispora sp. nov. from Japanese leaf litter and a clarification of Micromucor ramannianus var. angulisporus. Mycoscience 44:217–226. Wang YN, Liu XY, Zheng RY (2013) Umbelopsis changbaiensis sp. nov. from China and the typification of Mortierella vinacea. Mycol Progress, DOI 10.1007/s11557-013-0948-9. Wang YN, Liu XY, Zheng RY (2013) Four new species records of Umbelopsis (Mucoromycotina) from China. Journal of Mycology 2013, Article ID 970216, 6 pages. DOI: 10.1155/2013/970216. 196 .