Abstract
In this paper three new species of Plectocarpon, P. dimorphosporum (on Ricasolia patinifera), P. parmotrematis (on Parmotrema reticulatum) and P. ramalinae (on Ramalina celastri), are described from tropical montane forests in the Bolivian Andes. Plectocarpon dimorphosporum is characterized by strongly convex ascomata covered by the host cortex when young, presence of Atra-brown pigment and 1–3-septate ascospores developing a brown-pigmented granular perispore, P. parmotrematis by rounded and slightly superficial ascomata, presence of pigments reacting K+ aeruginose to turquoise and colorless 3-septate ascospores, and P. ramalinae by ellipsoid, black ascomata, Atra-brown pigment, and short, colorless, 3-septate ascospores. In addition, the rare Protounguicularia fasciculata is reported here for the first time from Bolivia.