Abstract
A new species endemic to rocky cliffs in southern Brazil, Hysterionica matzenbacherii, is described. This species is characterized by leaves that are distally irregularly incised to parted. It is morphologically similar to the Brazilian H. pinnatiloba and H. pinnatisecta in its habit, capitula and florets, but differs from them by its leaf features. A description of H. matzenbacherii, together with illustrations, a distribution map, habitat description, conservation assessment and diagnostic comparison with the other Brazilian species of Hysterionica is presented.