Phylogenetic analysis of Andinia (Pleurothallidinae; Orchidaceae) and a systematic re-circumscription of the genus

Abstract

Most of the species studied in this paper have previously been placed in either Pleurothallis or Lepanthes. However, at one time or another, members of the group have also been placed in the genera Andinia, Brachycladium, Lueranthos, Masdevalliantha, Neooreophilus, Oreophilus, Penducella, Salpistele and Xenosia. Phylogenetic analyses of nuclear ITS and plastid matK sequences indicate that these species form a strongly supported clade that is only distantly related to Lepanthes and is distinct from Pleurothallis and Salpistele. Since this clade includes the type species of Andinia, A. dielsii, and it has taxonomic precedence over all other generic names belonging to this group, Andinia is re-circumscribed and expanded to include 72 species segregated into five subgenera: Aenigma, Andinia, Brachycladium, Masdevalliantha and Minuscula. The required taxonomic transfers are made herein. We hypothesize that convergent evolution towards a similar pollinator syndrome involving deceit pollination via pseudocopulation by Diptera resulted in a similar floral morphology between species of subgenus Brachycladium and species of Lepanthes; hence the prior placement of the species of subgenus Brachycladium in Lepanthes. Species of the re-circumscribed Andinia are confined exclusively to the Andes, ranging from about 1,200 to 3,800 m, from Colombia south to Bolivia, making the generic name very apt. Elevational distributions of the individual clades are discussed in relation to the possible evolutionary diversification of the most species-rich clade, subgenus Brachycladium.

A clarification of the distinctions between Pleurothallis talpinaria and Pleurothallis trimeroglossa (Orchidaceae: Pleurothallidinae) and an allied new species from Ecuador

“…The nrITS region was sequenced for P. trimeroglossa and the new species using methods described previously (Wilson et al 2017). …”

To be, or not to be a Stelis

“…There is no doubt that all typical species of Crocodeilanthe belong here. They consistently group together into a well supported clade that is very closely related to Stelis in the strict sense , Solano-Gómez 2005, Wilson et al 2017, Ponert et al 2019. This is consistent with the Stelis-like morphology of their flower, especially in an overall reduction in the column and lip, and pollinaria with a viscidium.…”

“…1). , Solano-Gómez 2005, Chiron et al 2012, Wilson et al 2017, Chumová et al 2018, Ponert et al 2019, showing the proposed subgenera and sections.…”

“…For the sake of consistency with previous works in related genera, including Acianthera Scheidw. , Andinia (Luer) Luer (Wilson et al 2017) and Specklinia Lindl. , and in the interest of aiding the reader, an infrageneric classification of Stelis s.l.…”

A new species of Andinia subgen. Brachycladium (Orchidaceae: Pleurothallidinae) from Colombia

“…Brachycladium (Wilson et al 2017), and among the species of that subgenus it can be recognized by the glabrous leaves, yellow flowers with broadly ovate sepals, the minute lip and especially the large, cucullate, orbicular, plump column with ventral anther. Within A. sect.…”