An updated checklist reveals strong incongruities with previous studies: insights after revisiting a regional orchid list

Abstract

An updated checklist of the Orchidaceae from the state of Maranhão is provided. We confirmed 51 genera and 119 species, of which the most representative genera are Habenaria (17 spp.), Catasetum (14 spp.) and Epidendrum (10 spp.). Our checklist includes 30 species that are not listed in the Flora do Brasil for the state, many of which, however, have been recorded in previous publications. Thus, excluding these, six species are cited here for the first time to Maranhão, all of which are also new records for the Brazilian Northeast region. Comparing such data with previous lists, with 103 and 105 species, we detected a strong incongruity among the data. Of the former list, 25 species lack vouchers from the state and were not collected in our expeditions, thus these taxa are not confirmed, while of the latter we found 20 species that are also not confirmed for the same reasons. A list with the 34 excluded taxa is provided. Most of the collection effort in the state coincides with university campuses, and the northwestern region is the most species rich, but unfortunately it is also the most threatened area.

Acanthaceae from Cuiabá lowlands, Mato Grosso, Brazil: a vegetational mosaic extending from Chapada dos Guimarães to Pantanal

“…This indicates that, even with our own collection effort, field work is still needed in these areas, which is impaired by scarce funding, difficult access and the lack of research infrastructure. Similarly, biased results were reported by Siqueira et al (2014) and Pessoa et al (2022) for orchids.…”