Is the endemic species Fontinalis dichelymoides Lindb. not as rare as previously thought in Europe?

Abstract

Fontinalis dichelymoides is a species endemic to Europe. So far, it has only been reported from Finland, Sweden and the northwestern part of Russia. This species can be distinguished from other European taxa of this genus by the appearance of the turf, arrangement of leaves on the stem, the leaf shape, and cell dimensions. During the revision of European material of Fontinalis in the LOD herbarium, a specimen determined as F. dalecarlica was found. A detailed analysis of this material indicated that it represented the taxon currently understood as F. dichelymoides. This prompted the authors to analyze the largest possible European collection of F. dalecarlica. Further specimens of F. dichelymoides were found in other herbaria (BR-BRYO, JE, L, M, POZG-B, TAA, TALL). Our findings completely changed the known range of F. dichelymoides in Europe and indicate that it is not as rare in Europe as previously thought. New localities of this species have been documented in Denmark, Poland, Latvia and Estonia. The following article not only presents the new distribution of F. dichelymoides in Europe, and images of its main microscopic and macroscopic characters, but also provides a key to distinguish all European species of this genus.