A new species of Gomesa (Oncidiinae, Orchidaceae) from inselbergs in Brazilian caatinga: morphological and karyological evidence

Abstract

We describe a new species of Gomesa (Oncidiinae, Orchidaceae), Gomesa caatingana, with restricted distribution on caatinga inselbergs in Paraíba and Pernambuco States, Brazil. Morphological and karyological characters of the new species were compared with those of Gomesa flexuosa, which is morphologically the most closely related species. Differences in geographical distribution, habit, flower morphology and chromosome number support description of this new species.

An overview of the Brazilian inselberg genus Ameroglossum (Linderniaceae, Lamiales), with the description of seven new species

“…In addition to these two new genera, many new populations of Ameroglossum have been discovered, which exhibit a greater morphological diversity than previously known. A number of populations represent undescribed species, which follows the trend of recent taxonomic discoveries from the inselbergs in north-eastern Brazil (e.g., Pontes 2012;Cordeiro et al 2018;Cardoso et al 2019aCardoso et al , 2019bde Lima et al 2019;Santos et al 2019;Morales & Morais 2020;Morales & Kollmann 2020), showing that this often taxonomically neglected region of Brazil has a greater diversity than previously assumed.…”

Chromosomal variability in Brazilian species of Anthurium Schott (Araceae): Heterochromatin, polyploidy, and B chromosomes

“…Polyploidy and disploidy are among the most important karyotype phenomena associated with the evolution of plant groups (Stebbins, 1971; Soltis et al , 2014). Species showing disploidy and polyploidy tend to be morphologically distinct from their parental diploids, and can present adaptations to different habitats and ecological niches (Madlung, 2013; Ramsey and Ramsey, 2014; Cordeiro et al , 2018; Scholthof et al , 2018). However, the occurrence of disploidy or polyploidy in Anthurium does not appear to have any apparent ecological correlation or link to their geographic distributions, although they may have considerable effects on speciation within the genus, especially in the species A. scandens (Aubl.)…”

Chromosome number, heterochromatin, and genome size support recent polyploid origin of the Epidendrum nocturnum group and reveal a new species (Laeliinae, Orchidaceae)

“…purpureocaulis, E. micronocturnum and E. tumuc-humaciense, reported here for the first time, represent three ploidies. Whole genome duplication was previously recorded for E. subgenus Amphyglottium (Assis et al 2013) Soltis et al 2016;Cordeiro et al 2018;Ren et al 2018;Song et al 2020;Wu et al 2020;Zhang et al 2020).…”

“…In orchids, especially in Catasetum Rich. ex Kunth, Epidendrum and Gomesa R.Br., which are mostly epiphytes, high ploidy is typically associated with saxicolous or terrestrial species (Felix and Guerra 2000;Assis et al 2013;Cordeiro et al 2018). Polyploidy has been linked to speciation and diversification and is hypothesized to provide raw material for adaptation to different kinds of environments (Jiao et al 2011;Madlung 2013;Cordeiro et al 2018; D r a f t Han et al 2020).…”

“…ex Kunth, Epidendrum and Gomesa R.Br., which are mostly epiphytes, high ploidy is typically associated with saxicolous or terrestrial species (Felix and Guerra 2000;Assis et al 2013;Cordeiro et al 2018). Polyploidy has been linked to speciation and diversification and is hypothesized to provide raw material for adaptation to different kinds of environments (Jiao et al 2011;Madlung 2013;Cordeiro et al 2018; D r a f t Han et al 2020). In fact, Epidendrum tumuc-humaciense is a robust terrestrial species up to 2 m tall and grows in sunny habitats on sandstone outcrops in mats of organic matter, whereas the species with 2n = 40 and 80 are epiphytes up to 30 cm tall in humid forests (Carnevali and Romero 1996).…”