DOI: 10.5061/dryad.tmpg4f51j
title: Phylogenetic position of Centroglossa and Dunstervillea (Ornithocephalus clade: Oncidiinae: Orchidaceae) based on molecular and morphological data

description: Even though the monophyly of the Ornithocephalus clade (Oncidiinae) is
 currently well defined, the systematic positioning of Centroglossa and
 Dunstervillea remains obscure in the clade due to the absence in previous
 phylogenetic studies. Centroglossa has a very similar habit and is
 indistinguishable from Zygostates, whereas Dunstervillea has as its main
 characteristic the calcarate labellum, also found in Centroglossa. We
 clarify the systematic and phylogenetic positioning of Centroglossa and
 Dunstervillea in the Ornithocephalus clade (OC) through analysis of
 maximum likelihood, Bayesian inference, and maximum parsimony from
 molecular data (nrITS and matK cpDNA) and morphology. Our results indicate
 that Dunstervillea is phylogenetically close to Eloyella; both genera have
 a psigmoid habit, single-sided and flattened leaves, floral perianth with
 the same coloring, petals with entire margins, and a short rostellum.
 Centroglossa appears as a subclade within Zygostates. In addition to
 several homoplastic features, these two genera have the dorsal position of
 viscidium as a synapomorphy. The calcarate labellum, common to
 Centroglossa and Dunstervillea, originated more than once in the OC. Based
 on the phylogenetic results, we propose the nomenclatural changes to
 include Dunstervillea in Eloyella and Centroglossa in Zygostates.
 Lectotypes are indicated to Centroglossa macroceras and C. glaziovii.
description: Leaf samples fresh or
 preserved in saturated NaCl-CTAB solution (Rogstad 1992) were obtained
 from collections in the regions of occurrence of the species and public
 and private collections. Unfortunately, some species were not found (such
 as <em>Dunstervillea mirabilis</em>), or we were not
 successful in amplifying and sequencing the studied regions. In these
 cases, we used data from GenBank (Appendix 1) or, if it is unavailable
 from this database, only its morphological data was used.
 For the morphological
 analysis, we included 54 species from <em>Zygostates
 </em>(23), <em>Centroglossa </em>(5),
 <em>Dunstervillea mirabilis</em>, and another 20 taxa of the
 OC. Five taxa of phylogenetically close clades inserted in the molecular
 analyses were used as the external group (Smidt et al. 2018).
 The morphological analysis was based on
 the protologues of the species, herbarium specimens deposited at the
 following herbaria: B, BR, BHCB, ESA, FUEL, FURB, GUA, HB, HEID, HUCP,
 HUEFS, HUPG, ICN, M, MBM, MBML, R, RB, SP, SPF, SPPS, UEC, UPCB, W
 (acronyms according to Thiers 2019, continuously updated), complemented
 with field-collected material data (Appendix 2), and the studies of
 Toscano de Brito (1994, 2001, 2007) and Royer et al. (2017a, b). We used
 characters found in vegetative (rhizome, stem, and leaf) and reproductive
 organs (inflorescence, flowers, sepals, petals, labellum, gynostemium, and
 pollinarium). The terminology used in the description of the characters
 and their respective states were extracted from Toscano de Brito (1994,
 2001), Harris and Harris (1999), and Stearn (2004) (Table 2).
 The matrix (Appendix 3 and
 4) was built with Mesquite program version 3.31 (Maddison and Maddison
 2017). We selected 72 qualitative characters, being ten vegetative
 characters (nine binaries and one multistate), and 62 reproductive
 characters (38 binaries and 24 multistate), according to the following
 cumulative criteria: (1) their potential to distinguish taxa through
 studied genera; (2) the stability of their states between individuals of
 the same taxon; (3) the viability of the associated observations; and (4)
 independence from each other (Emerson and Hastings 1998; Sereno 2007). All
 characters were treated with equal weight and unordered states
 (Fitch's parsimony; Fitch 1971).