Gyrothyraceae (Marchantiophyta) — a new family for the Russian liverwort flora

Abstract

Gyrothyra underwoodiana is the only species of a peculiar monotypic family, a remarkable western North American endemic. Recent exploration has revealed Gyrothyra at the western end of the Commander-Aleutian Island Chain (Bering Island), and this is the first record of the taxon in Russia. The species was collected in four localities in various parts of the island and these findings formally emphasizes the West-North American connections of the flora of the Commander Islands. However, the distribution patterns of Gyrothyra in other Aleutians may suggest the adventive character of occurrence of the species on Bering Island. The morphological description and illustrations of G. underwoodiana based on specimens from Bering Island, as well as discussion on its ecology, morphology and distribution are provided.

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

“…Admittedly, the bryoflora of the Commander Islands is very specific [9,10]; therefore, a finding such as Scapania umbrosa is not the only finding. For example, the abovementioned representative of the monotypic family, Gyrothyra underwoodiana [69] is located on Bering Island, which is the westernmost locality of the species worldwide. Similar examples are known among mosses, including North American Claopodium bolanderi Best, Pseudoleskea baileyi Best et Grout, Brachythecium frigidum (Müll.…”

“…Additionally, birds could be considered possible agents for reaching the island. Indeed, it is logical to expect that Scapania umbrosa may be introduced from other Aleutians, as we considered this way of migration for the Pacific North American Gyrothyra underwoodiana, which we unexpectedly discovered on Bering Island earlier [69]. However, this mechanism does not explain the absence of this species in the Aleutian Islands.…”