he lichenized genus Syncesia is monographed. Seventeen species are recognized, all fructiferous. Imperfect tax.a are unknown. Two new species are described: Syncesia leprobola and S. rhizomorpha. Most Syncesia species are restricted to the neotropical region, with some species reaching southern United States and Hawaii. Four species are non-neotropical, with one restricted to southwestern Europe, two to Tanzania, and one to Australasia. Syncesia is bound mainly to dry areas of the tropics and subtropics. A key, descriptions, and distribution maps are supplied. A cladistic analysis based on morphological data and chemical data was performed, and a phylogenetic hypothesis of species relationships is proposed.
