New Updates on the Distribution of Scapania umbrosa (Schrad.) Dumort. (Scapaniaceae, Marchantiophyta) in Pacific Asia

Abstract

The distribution of liverworts in the North Pacific is still poorly understood. Scapania umbrosa, which is rare in Asia, was first recorded during the study of the liverwort flora of the Commander Islands (the westernmost Aleutians). The results of the molecular genetic analysis not only confirmed that the specimen belonged to Scapania umbrosa but also demonstrated the genetic specificity of the discovered population in comparison with the European, Siberian, and Alaskan populations. The island population of Scapania umbrosa is likely a recently diverged isolate of the species. Previously reported data on the distribution of Scapania umbrosa in the Russian Far East from Kamchatka and Kunashir (VBGI Herbarium), as well as from Sakhalin and Southern Primorye (reported in GBIF), are based on misidentifications. Morphological descriptions, distinguishing characters, line drawings, and photographs of Scapania umbrosa based on the collected material are provided.