Orthomnion elimbatum (Mniaceae, Bryophyta), a Malesian and Australian species new to China and Vietnam based on molecular data

Orthomnion elimbatum (Mniaceae) is herein reported new to China and Vietnam, representing the first record of the species northwards outside the Malesian and Australian regions. The species differs from the closely related species O. dilatatum by having undulate leaf margin, almost isodiametric laminal cells, and unbordered apical leaf margins. Confirmation of the species identity is validated by a molecular analysis based on rps4 and trnL-F sequences.