Four New Species of Solanum section Erythrotrichum (Solanaceae) from Brazil and Peru, and a Key to the Species of the Section

During a revision of Solanum section Erythrotrichum , four species, two from Brazil and two from Peru, were recognized as new and are described here. Solanum absconditum , from northeastern and northern Brazil, is similar to S. paludosum . It differs in its cordate to cordate-lanceolate, acuminate, and weakly bicolorous leaf blades that are yellowish to ferruginous above, the corolla tube 4–6 mm long, and the epicarp with stipitate-stellate trichomes. Solanum eitenii , from the “cerrado” of Maranhão, Brazil, resembles both S. decompositiflorum and S. rhytidoandrum , from which it can be distinguished by its long and pendent inflorescence and its calyx with a very short tube and oblanceolate lobes. Solanum megaspermum , from Peru, has similarities with S. mesopliarthrum , from which it differs by the triangular and very short calyx lobes (1.5–2 mm) and the scabrous and deciduous indumentum with somewhat stiff porrect-stellate trichomes. Solanum urubambaense from Cuzco, Peru, is similar to the Bolivian S. abutilifolium , but differs by its oblong-lanceolate anthers, strigose ovary, and trichomes with a reduced central ray. The species are described, illustrated and compared with similar species; commentaries on their affinities and distribution are also included. A key to the species of the section Erythrotrichum is provided.