The genus (Lejeuneaceae, Marchantiophyta) in Thailand, with the description of .

A taxonomic study of the genus in Thailand is presented, based on herbarium specimens and new collections from field surveys. Three species are recognised including , and one new species, . The new species is distinguished by the strongly papillose lobules, the presence of 1-8 basal ocelli on the lateral leaf and male bracteoles occurring along nearly the whole of the androecial branch length. A key to species, descriptions and illustrations are provided; ecology and geographical distribution of the species are also described.