Ecología: Bosques Amazónico, Chiquitano, premontano a montano (Yungas, Tucumano-Boliviano); suelo, suelo rocoso, troncos. Altitud: 278-3585 m. Distribución: Beni, Chuquisaca, Cochabamba, La Paz, Pando, Santa Cruz.
Lejeunea laetevirens is characterized by plants 450-550 µm wide (so about 0.5 mm or less wide), with caduceus branches or fragmenting stems, leaves obliquely spreading, apices generally obtuse, leaf cell cuticle papillose, underleaves distant, < 3x stem width, margins generally angular with a ± well developed tooth.