The Madeiran laurel forest endemic Goodyera macrophylla (Orchidaceae) is related to American orchids

Abstract

Macaronesian laurel forests harbour many herbs and laurophyllous trees with Mediterranean/European or Macaronesian affinities. Traditionally, the origin of these taxa has been explained by the relict hypothesis interpreting these taxa as relics of formerly widespread laurel forests in the European continent and the Mediterranean. We analysed the phylogenetic relationships of the Madeiran laurel forest endemic Goodyera macrophylla (Orchidaceae) using sequences from the nuclear ribosomal DNA Internal Transcribed Spacers (ITS) and plastid DNA regions. The results were incongruent, either the two Central American G. brachyceras and G. striata (ITS) or the North American G. oblongifolia (plastid DNA) were sister group to G. macrophylla. Nonetheless, biogeographic analyses indicated an American origin of this nemoral laurel forest plant in the two data sets. Molecular clock analyses suggest a colonisation of Madeira in the span of the upper Miocene/lower Pliocene to the Pleistocene. Although the relict hypothesis cannot be ruled out by our data when assuming extinction events on the European and northern African mainland, dispersal from Central or North America to the archipelago of Madeira is a much more likely explanation of the data.

Molecular Phylogeny and Historical Biogeography of Goodyera R. Br. (Orchidaceae): A Case of the Vicariance Between East Asia and North America

“…Smidt et al ( 2021 ) conducted molecular dating and biogeographical analyses of Goodyerinae based on nuclear ribosomal ITS and plastid mat K sequences. Thiv et al ( 2021 ) identified the phylogenetic location of G. macrophylla , which is the sister group to North American species although it is endemic species of Madeira. However, both papers are less reliable in that they used a small number of genes or introns when analyzing them.…”

Goodyera medogensis (Orchidaceae), a new species from Tibet, China

“… Goodyera s.l. consists of about 99 species distributed in Africa (Mozambique), Western Indian Ocean Islands, Asia, Southwest Pacific islands, Northeast Australia, Europe, Macaronesia (Madeira), North and Central America and the Caribbean ( Chen et al 2009 ; Zhou et al 2020 ; Govaerts et al 2021 ; Thiv et al 2021 ). It is characterized by an elongate creeping rhizome, a cymbiform lip with a concave-saccate hypochile, sectile pollinia and one stigma.…”