Mapping the fern Blechnum heringeri (Blechnaceae, Polypodiopsida): recording the geographical distribution, ecological preferences and reporting a new record in northeastern Brazil

ABSTRACT Blechnum heringeri Brade is an endemic species from Brazil previously considered vulnerable. Until recently, there was a very limited number of records for this species, all from the Cerrado Phytogeographical Domain in central Brazil. Subsequent studies have reported its occurrence in the rupestrian grasslands (campos rupestres) on the “cangas”, within the Amazonian Domain. Here we present the first record of B. heringeri for northeastern Brazil, from an enclave of cerrado vegetation in the middle of the Caatinga Domain (Ceará State). This new record significantly extends the distributional range of the species, about 1,000 km from the known records in the Amazon and Cerrado Phytogeographical Domains. We also show that the species is associated with open vegetation or the transition between open vegetation and riverine forests, being recorded in cerrado vegetation, riverine forests associated with the cerrado, cerrado enclaves in the Caatinga and Amazonian Domains, and Amazonic campos rupestres on “canga”.