Studies on Lejeuneaceae subfam. Ptychanthoideae (Hepaticae) IV. Verdoornianthus, a new Genus from Amazonas, Brazil

The new Amazonian liverwort genus Verdoornianthus is considered to be a specialized derivative of the widespread tropical genus Archilejeunea. Differences are the absence of innovations, the dull, suberect leaves, the tristratose rhizoid pad and the larger size of the lobule of the female bracts in Verdoornianthus. There are two species, V. marsupiifolius (Spruce) comb. nov. (Lejeunea marsupiifolia Spruce) from the upstream part of the Rio Negro and V. griffinii sp. nov. from Manaus.