# Morphological and phylogenetic analyses of Weissia (Pottiaceae) in Türkiye

## TL;DR

This study explores the diversity of the moss genus Weissia in Türkiye using both physical traits and genetic data to better understand their relationships and distribution.

## Contribution

The paper provides the first phylogenetic and morphological analysis of Weissia in Türkiye, revealing marker-dependent relationships and a broader range for W. wilsonii.

## Key findings

- Phylogenetic relationships among Weissia species were found to be marker-dependent.
- W. wilsonii was found in Türkiye, expanding its known geographic range beyond England.
- Inconsistencies across genetic markers highlight the need for multi-locus approaches in future studies.

## Abstract

The genus Weissia is a highly diverse group of moss in the family Pottiaceae. Seven species of Weissia were included in this study to provide the first phylogenetic analysis along with a morphological assessment in Türkiye. The taxa studied include W. longifolia, W. brachycarpa, W. controversa, W. controversa var. crispata, W. condensa, W. rutilans, and W. wilsonii. We systematically evaluated morphological traits such as leaf length, seta length, capsule dimensions, and spore characteristics to distinguish closely related taxa. We used three genetic markers: rps4, psbA, and atpB-rbcL intergenic region to analyze their evolutionary relationship. The results showed that phylogenetic relationships among Weissia taxa were marker dependent. W. brachycarpa and W. controversa var. crispata were closely related in the rps4 tree, but this relationship was not consistent in either psbA or atpB-rbcL trees. Similarly, W. condensa and W. longifolia were in different clades in the psbA tree, while the former taxon was in its own clade and was somewhat related to W. brachycarpa in the atpB-rbcL tree. These inconsistencies across markers indicate the need for multi-locus approaches, and future studies using nuclear loci and broader geographic sampling may better resolve cryptic species boundaries in Weissia. Our finding of W. wilsonii in Bursa northwestern Türkiye a species once thought to be endemic England, supports a broader ecological and geographical range of this species than previously assumed. Together, these findings improve our knowledge of Weissia diversity in Türkiye and emphasize the value of integrating morphological and molecular methods in bryophyte systematics and conservation.