Wiesnerella denudata (Mitt.) Steph., a complex thalloid liverwort in the family Wiesnerellaceae (Marchantiales), is reported as a new species to Peninsular India from the Anamudi Shola National park in the Western Ghats of Kerala. This species is easily confused with another thalloid liverwort, Dumortiera hirsuta (Sw.) Nees, due to similar morphological characters, especially size of thallus, colour and habit. Wiesnerella denudata is characterised by the presence of elevated air pores which can be seen with the help of a hand lens or even with naked eye, subsessile rotund male receptacle, raised female receptacle with deeply dissected carpocephalum and absence of pseudoperianth. A detailed account of the species along with photographs and SEM images of spores is provided here.