Morphological variability of Thelotrema lepadinum in the southern Russian Far East and notes on the genus

The purpose of our study was to test whether any significant morphological differences exist among specimens of Thelotrema lepadinum from the mainland of the southern Russian Far East, Sakhalin I., and the Kuril Is. The study found statistically significant differences among regional for eight of the nine studied morphological characters (seven continuous and two discrete) after Holm correction. For these eight characters, model estimates were consistently lower in specimens from Sakhalin and the Kuril Is. than in mainland specimens, although not all pairwise differences were statistically significant and the patterns varied between the two island groups. This predominant reduction in morphological character values in island specimens is consistent with a possible manifestation of the island effect. Additionally, some specimens previously identified as T. lepadinum and all specimens of T. bicinctulum were re-identified as T. suecicum. This article reports T. suecicum for the first time in Primorye Territory and Shikotan I. Specimens of T. foveolare from Sakhalin I. and the Primorye Territory were also re-evaluated and re-identified as Phlyctis agelaea. Phlyctis agelaea is reported for the Primorye Territory for the first time. Thelotrema foveolare and T. bicinctulum should be considered excluded from the list of lichens of Russia.