Reconciling morphological and molecular approaches: The integrative taxonomy of Leucobryum (Leucobryaceae) in the Malagasy region

Leucobryum (Leucobryaceae) is a genus of moss (Bryophyta) that has been poorly investigated in Africa, particularly in the western Indian Ocean region. This study integrates morphological and molecular data to revise the taxonomy of the genus in this area. A morphological analysis was conducted on type specimens housed at the Herbier de Cryptogamie (PC, MNHN, Paris) and on field collections gathered between 1994 and 2019, resulting in the recognition of 10 distinct morphological clusters. Sequence data were obtained for three barcode markers, and multiple species delimitation methods were employed. Distance‐based approaches (ASAP) and tree‐based coalescent models (bPTP, GMYC) were implemented to infer species boundaries. Within an integrative taxonomy framework, the Conspecificity Matrices (CoMa) decision tool supported the recognition of 10 species in total: nine well‐delimited species ( L. acutifolium , L. boivinianum , L. boryanum , L. cambouei , L. cucullatum , L. galinonii , L. madagassum , L. parvulum , L. perrotii ), and L. comorense , which, together with L. isleanum , L. mayottense , and L. sanctae‐mariae showed little morphological and molecular differentiation, supporting their synonymization. The genus Leucobryum remains taxonomically challenging and highlights the need for a similar integrative approach to be conducted across continental Africa.