A new species of Lejeunea Lib. (Lejeuneaceae) from Low Varzea forest in lower Amazon (Para, Brazil)

An unknown species of Lejeunea was identified among the liverworts collected in the framework of a study of the bryophyte flora from the Varzea forest in Combu Island (Belem municipality, Para) in lower Amazon. The species, characterized by autoicous plants, ovate leaves with crenulate to crenate margins, sometimes with 1-2 obtuse subapical teeth on the dorsal margin, leaf apex obtuse to acute, sometimes acuminate (1-2 cells in a row), rarely rounded, perianths smooth cylindrical, without keels, only weakly pentagonal at the apex, without beak and apex slightly recessed, is considered to be new to science and here described as Lejeunea combuensis. In the present paper, the new species is described, illustrated, its ecology as well as the differences to the morphologically similar Lejeunea bermudiana, L. caulicalyx and Taxilejeunea isocalycina are discussed; a key to Lejeunea species with eplicate perianths is presented.