Liverworts (Marchantiophyta) of Polylepis pauta forests from Ecuador with description of Leptoscyphus leoniae sp. nov. and Plagiochila pautaphila sp. nov

Forests dominated by Polylepis pauta occur in humid environments in the high Andes of Ecuador, Peru and Bolivia, at elevations between 3500-4500 m. Polylepis forests host a unique biodiversity of plants and animals and are an important supply of resources for local people. However, these forests are being destroyed by extensive burning practices, causing the replacement of the forest by grassland and favoring cattle grazing. As a consequence, Polylepis forests have become severely diminished and fragmented, and are considered as one of the most threatened ecosystems in South America. The vascular flora of Ecuadorian P. pauta forests has been documented in detail but little is known about bryophytes of these forests. This paper deals with the liverwort flora of remnant P. pauta forests in the páramo of Papallacta near Quito, Ecuador. The forest floor and trunk bases were almost completely covered by Lepidozia auriculata and four robust Plagiochila species (P. dependula, P. ensiformis, P. fuscolutea, P. ovata). Frullania paradoxa, Leptoscyphus hexagonus, Plagiochila bifaria and P. punctata were abundant on branches of Polylepis trees. In total 51 liverworts were recorded, being the highest number of liverwort species reported from Polylepis forest. Leptoscyphus leoniae Gradst. and Plagiochila pautaphila Gradst. & León-Yánez are new to science.