The genus Lejeunea Lib. (Lejeuneaceae, Marchantiophyta) in Brazil

Lejeunea is one of the largest genera of liverworts in the Neotropics and probably the largest liverwort genus in Brazil. We present the first treatment of Lejeunea for Brazil, and for any major part of the Neotropics. Fifty-eight species and three varieties are recognized. A key to the Brazilian species of Lejeunea is provided and each species is briefly described with data on geographical distribution, habitat, differentiating characters and affinities, and reference to published illustrations. Illustrations of a few selected species are also provided. Almost half of the species (24) are widely distributed in tropical America and four of them occur also in Africa; one species, L. flava, is pantropical. About 40% of the species (23) have more restricted ranges and are limited to tropical South America. Ten of them (L. atlantica, L. beyrichiana, L. combuensis, L. flagellifera, L. juruana, L. longidentata, L. oligoclada, L. perpapillosa, L. pulchra, L. subplana) are only known from Brazil. Within Brazil 19 species are widespread, the remaining ones have restricted distributions in the country. Twenty-three species are newly reduced to synonymy (see list in text), fourteen new lectotypifications are designated, two species are newly described, L. atlantica sp. nov. and L. pulchra sp. nov., and four new combinations are proposed: L. acanthogona var. cristulata comb. nov., L. acanthogona var. diversicuspis comb. nov., L. acanthogona var. grossiretis comb. nov. and L. beyrichiana comb. nov. Lejeunea cochleata is reported new to Brazil and L. rionegrensis is new to Ecuador.