Two new species of Syncesia are described, which differ from all other species of the genus by having more than 3-septate ascospores. Syncesia afromontana is characterized by a byssoid thallus and 7-septate ascospores, and is known only from the type locality in the Nyungwe Forest in Rwanda where it might be endemic. Syncesia madagascariensis is characterized by a crustose thallus and 5-septate ascospores, and is known only from the type locality in a montane forest in central Madagascar.