A phylogeny of the genus Encyclia (Orchidaceae: Laeliinae), with emphasis on the species of the Northern Hemisphere

Abstract

Encyclia comprises over 150 species of orchids that occupy mainly seasonally dry habitats in tropical and subtropical America and are usually restricted to one or a few ecoregions. To determine whether species found in the same or neighboring ecoregions are closely related, we sampled more than 50 taxa, with an emphasis on species found in Mexico and Central America. We evaluated five DNA markers for their phylogenetic utility: the nuclear low copy gene PHYC, a plastid spacer region trnL‐F, a fragment of the plastid ycf1 gene, rpl32‐trnL, and the internal transcribed spacer (ITS) region of nuclear ribosomal DNA; we sampled only the last three markers for the main analyses based on an assessment of phylogenetic informativeness. We analyzed plastid regions and ITS separately in phylogenetic inference using a variety of methods, as we found strong incongruence between them, according to the ILD test. We also estimated clade ages using a relaxed molecular clock with indirect calibrations based on a larger taxonomic sampling. Encyclia is a monophyletic genus that originated ca. 12.43 Ma (10.55–14.25 Ma) ago, and has undergone several recent evolutionary radiations. We found a strong association between phylogenetic relationships and the geographic distribution of species and clades in the Caribbean, Central American, and the Pacific coast of Megamexico. Several groups of Encyclia occur in the latter region, the most species‐rich being the E. meliosma complex, which is restricted to the Pacific slope of Mexico from north of the Isthmus of Tehuantepec up to Sonora.

Target Nuclear and Off-Target Plastid Hybrid Enrichment Data Inform a Range of Evolutionary Depths in the Orchid Genus Epidendrum

“…As revisited by Pinheiro and Cozzolino (2013), hybridization likely is a key process shaping the diversification of some groups of Epidendrum. Similar patterns of strongly-supported incongruence between nuclear and plastid partitions at shallow phylogenetic levels have been observed within most of the genera of Laeliinae that have been investigated using Sanger sequencing, e.g., Cattleya (van den Berg et al, 2009;van den Berg, 2014), Encyclia (Leopardi-Verde et al, 2017), andLaelia (Peraza-Flores et al, 2016). This seems to be caused by the combination of few genetic incompatibility barriers and very low variation in chromosome numbers across the subtribe, including Epidendrum (Felix and Guerra, 2010;De Assis et al, 2013), and confirmed by the large number of natural hybrids (including intergenerics) reported in the subtribe (Adams and Anderson, 1958;van den Berg, 2014).…”

Spatial phylogenetics of the flora in the Sierra Madre del Sur, Mexico: Evolutionary puzzles in tropical mountains

“…The recent diversification of Mexican vascular flora and its main lineages has been previously pointed out to be developed during the Miocene, between 5 and 20 mya (Sosa et al, 2018). Several of their descendants are present in the SMS, including some endemic species of the subfamily Hechtioideae (Bromeliaceae; Rivera‐Martínez et al, 2022), the tribes Eupatorieae and Heliantheae (Asteraceae; Schmidt & Schilling, 2000), the genera Agave (Asparagaceae; Good‐Avila et al, 2006), Bursera (Burseraceae; De‐Nova et al, 2012), Dahlia and Hidalgoa (Asteraceae; Sánchez‐Chávez et al, 2019), Fouquieria (Fouquieriaceae; De‐Nova et al, 2018), Encyclia (Orchidaceae; Leopardi‐Verde et al, 2016), Salvia subg. Calosphace (Lamiaceae; Fragoso‐Martínez et al, 2018) and Stevia (Asteraceae; Soejima et al, 2017).…”

From Megamexico to the Amazon: Phylogeny, systematics and macroevolution of Clowesia (Orchidaceae: Catasetinae)

“…It is worth mentioning that C. glaucoglossa and C. thylaciochila are known to share the same pollinator ( Eufriesea caerulescens ) and appear to retain their identities by placing the pollinaria on different parts of the pollinator: C. glaucoglossa on the head, C. thylaciochila on the dorsal section of the thorax (Aguirre León, 1979). As in several studies of plants (e.g., Leopardi‐Verde, 2014; Leopardi‐Verde & al., 2016; Bastos, 2014; Ramírez‐Morillo & al., 2018; Calonje & al., 2019; Pelser & al., 2019; Carnevali & al., in press), it becomes evident that biogeography is a better predictor of relationships than morphology (particularly floral morphology), probably because of local radiations to invade different pollination niches. In this particular case, the two Clowesia species that grow in the Balsas basin are florally very different (see taxonomic treatment), with C. thylaciochila almost indistinguishable from the allopatric, more distantly related C. dodsoniana (with which it had been confused in the past), whereas C. glaucoglossa has a unique labellar morphology that renders a superficial assessment of relationships difficult.…”