Two species of lichen-forming fungi with pyrenocarpous ascomata are described as new to science: Aspidothelium silverstonei and Astrothelium fuscosporum. The epiphytic lichens were found in Chocó Biogeographic region of Colombia. Aspidothelium silverstonei is characterized by the largest muriform ascospores known in the genus, while Astrothelium fuscosporum is the first species of Astrothelium known to produce pigmented ascospores.