Orchids of the central region of eastern Maranhão, Brazil

Abstract

The eastern portion of the state of Maranhão is a transitional area between Amazon Rainforest, Cerrado and Caatinga. Knowledge about the flora of this region is very poor, especially regarding Orchidaceae. The aim of this study was to provide a survey of the species of this family in the central area of this region. Fieldwork was performed monthly between December 2015 and April 2019 in the municipalities of Aldeias Altas, Caxias, Codó and São João do Sóter. An identification key, morphological descriptions and illustrations of the species are presented. Orchidaceae is represented in the area by seven genera and 17 species. The richest genera were Catasetum (five species), and Habenaria (four species). Habenaria schenckii is a new record for the state. The majority of the species are epiphytes (eight species, 47%) or terrestrial (seven species, 41%). The municipality of Caxias was the richest, with 13 species (76%), of which six were collected in the conservation units (CU’s) existing in the municipality (Área de Proteção Ambiental Municipal (APAM) Buriti do Meio Municipal and APAM Inhamum). Our data highlight the importance of the CU’s for the conservation of Orchidaceae, and the potential of ecotonal regions for discovering new records for the region.

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

“…Our checklist includes 30 species that are not listed in Flora do Brasil 2020 (2020) to the state, however many of them have been recorded in previous publications (Silva et al 1999;Ferreira et al 2017;Rodrigues et al 2019;Saraiva et al 2020;Oliveira et al 2021;Gomes et al 2021;Silva et al in press). Thus, excluding these, a total of six species are cited here for the first time to Maranhão, all also being new records for northeastern Brazil (Tab.…”

“…Our initial database was constructed based on the lists provided by Silva et al (1999) andBFG (2015; and new records published more recently (Ferreira et al 2017;Rodrigues et al 2019;Saraiva et al 2020;Oliveira et al 2021;Gomes et al 2021;Silva et al in press). Subsequently, the main Brazilian herbaria and local herbaria were visited (CEN, HABIT, HB, HUEFS, INPA, IAN, MAR, MG, RB, SLUI, SP, SPF, UB, acronyms according to Thiers 2021, continuous adapted) in order to find specimens collected in the state to serve as vouchers of the taxa reported in the literature.…”

Expansion of the geographic distribution of a Brazilian endemic, Encyclia gonzalezii L.C. Menezes (Orchidaceae, Epidendroideae), to the Cerrado of Maranhão and the Northeast Region of Brazil

“…Encyclia gonzalezii bloomed under cultivation between October and November, a time similar to the flowering period mentioned by Meneguzzo et al (2012), i.e., between September and October. Despite the botanical potential of Maranhão, not much research is available about surveying species. Recent studies in Maranhão have shown that, with increasing sampling effort, new records of Orchidaceae (Ferreira et al 2017(Ferreira et al , 2019aGomes et al 2021;Oliveira et al 2021;Pessoa et al in press) and other plant families (Ferreira et al , 2019bGuarçoni et al 2020b;Silva Júnior et al 2020) are discoverable. Even new species are found in Maranhão, as attested by Scatigna et al (2019), Guarçoni et al (2020a), andSantos et al (2020).…”

Anatomia foliar e radicular comparativa de sete espécies de Catasetum Rich. ex Kunth (Orchidaceae: Catasetinae)

“…Parte do material utilizado neste estudo (Figura 1) foi coletado por Oliveira et al (2021) [23], em áreas do Domínio da Amazônia e do Cerrado, em quatro municípios da região central do Leste do estado do Maranhão: Aldeias Altas (04º37'12" S e 43º28'12" O); Caxias (04º 51' 32" S e 43º 21' 22" O); Codó (04°27'12,8" S e 43°53'01,7" O) e São João do Sóter (05º06'36" S e 43º48'36" O) [24][25][26][27][28].…”