Peperomia dryadica (Piperaceae), a new karstic species from the Brazilian Atlantic Forest

Peperomia is known for its remarkable diversity, the Atlantic Forest in Brazil being particularly noteworthy for its high levels of richness and endemism. Floristic research in the Atlantic Forest karst ecosystems has revealed new discoveries in the genus, based on fieldwork and thorough study of herbaria collections. Peperomia dryadica Marcusso is here described and characterised as entirely glabrous except for the distal third of the leaf margins which is ciliolate, light green stems when fresh, alate distal internodes, leaves decussate, opposite or alternate basally and opposite or 3-whorled distally, lamina oblanceolate, obovate or rarely elliptic and nerves sunken adaxially and raised abaxially. Peperomia dryadica is found solely in the Vale do Ribeira region of São Paulo state, in Southeast Brazil, which holds the largest limestone outcrops in the Atlantic Forest.