Abstract: A new species from Fiji, Lejeunea heinrichsii is described and illustrated herein based on morphological characters and molecular phylogenetic analyses. The taxonomic descriptions of L. heinrichsii and the comparison with their allies are presented, together with the Maximum Likelihood (ML) and Bayesian phylogenetic analyses based on sequences of two chloroplast regions (trnL‐trnF, rbcL) and the nuclear ribosomal ITS region. This delicate and rather minute species is characterized by its autoicy, eplicate perianths, the oblong‐rectangular leaf lobes, the distantly arranged underleaves with lobes to 1/2‐2/3 underleaf length, and the leaf cells without well‐developed trigones and intermediate thickenings. In the molecular phylogeny, L. heinrichsii is placed sister to the Asian L. compressiuscula from Indonesia and forms an independent lineage including accessions of Neotropical L. adpressa from the Dominican Republic and the widespread Palaeotropical L. anisophylla from São Tomé and Príncipe. Morphologically, L. heinrichsii is very similar to L. capensis, however the result based on the molecular phylogenetic analyses revealed that the two species are very distinct.

Key words: Asia, eplicate perianth, Fiji, Lejeunea, Lejeuneaceae, liverworts, new species