Published online by Cambridge University Press: 28 March 2007
The genus Polythelis Clem, has been almost entirely ignored since its description in 1909. It belongs to the Pyrenulaceae and is close to Pyrenula Massal. from which it is distinguished in having a true septum (euseptum) near the base of the ascospores as well as locules (distosepta) identical to those of Pyrenula. The genus includes a single doubtfully lichenized species, Polythelis sexlocularis (Müll. Arg.) Clem. (syn. Microthelia sexlocularis Müll. Arg.), known only from the type material collected on the bark of a species of Croton, probably C. linearis Jacq., in the West Indies or southern Florida prior to 1824.