Phylogeny, morphology and circumscription of Myrcia sect. Sympodiomyrcia (Myrcia s.l., Myrtaceae)

Abstract

Myrcia s.l. comprises ca. 780 species distributed in nine numbered, informal monophyletic groups. The aims of this work are to improve the phylogenetic and morphological knowledge of one of these clades. The phylogenetic analyses included 24 of the 29 inferred species of "clade 7", plus 80 samples of other clades of Myrcia s.l. and outgroup taxa. Bayesian and maximum likelihood analyses were conducted using the markers ITS, ndhF, psbA‐trnH, trnL‐trnF and trnQ‐rps16. The morphological study employed a maximum‐parsimony algorithm to reconstruct the evolution of selected characters on the Bayesian topology. Myrcia sect. Sympodiomyrcia ("clade 7") is formally described and 28 species are assigned to the group. The new section is defined by the presence of cataphylls, an inflorescence with sympodial basal branching and opposite apical branching, a hypanthium elongated above the ovary and not tearing during anthesis, and calyx lobes free and deciduous. Statistical support for internal relationships is low and there is little congruence with morphology or geographical distribution. A clade corresponding to Calyptranthes appears to be the sister group of Myrcia sect. Sympodiomyrcia and sympodial branching (in vegetative and basal inflorescence branches), presence of cataphylls and deciduous calyx lobes are putative synapomorphies of this clade. Exclusive to Calyptranthes is the calyx with completely fused lobes. Results increase systematic understanding in the large genus Myrcia s.l. but highlight the need for further phylogenetic and morphological studies.

Phylogeny and biogeography of the hyper–diverse genus Eugenia (Myrtaceae: Myrteae), with emphasis on E. sect. Umbellatae, the most unmanageable clade

“…Evidence suggests that the areas in which most speciation occurred were the eastern forests now known as the Atlantic Forest, making this the cradle of Eugenia diversity. Elevated levels of Eugenia speciation in the Oligocene and Miocene correspond to rapid diversifications in other species-rich clades of fleshy fruited Myrtaceae (e.g., Myrcia; Santos & al., 2016) and of Neotropical mammals and birds (Hoorn & al., 2010). These vertebrate guilds favour fleshy Myrtaceae berries and likely acted as highly efficient dispersal vectors, driving new niche colonisation and accelerated speciation (Vasconcelos & al., 2017).…”

“…(2017) approach B. A second analysis is presented allowing comparison with other recent dated analyses of Neotropical Myrtaceae (e.g., Staggemeier & al., 2015;Santos & al., 2016) that use the macrofossil fruit of Paleomyrtinaea princetonensis Pigg & al. from the Paleocene to early Eocene of British Colombia (Crane & al., 1990;Pigg & al., 1993;Manchester, Version of Record 1999) for calibration. In this case the crown group of Myrteae was constrained, following the recommendations of Forest (2009), and a lognormal distribution applied with a median of 55.8 Ma (the lower bound of the Eocene), lower quartile (2.5%) of 54.94 Ma and upper quartile of (97.5%) 61.9 Ma, achieved using an offset value of 54.8 Ma.…”

Biogeographical patterns of Myrcia s.l. (Myrtaceae) and their correlation with geological and climatic history in the Neotropics

“…20 spp.) is distributed in montane areas of Atlantic Forest and Campo Rupestre vegetation with three disjunct species in the Guayana Region (Santos et al, 2016). Clade 9 (= Myrcia sect.…”

Floral uniformity through evolutionary time in a species‐rich tree lineage

“…10 cm to trees of 40 m, sometimes even in closely related species (e.g. Santos et al ., ; Silva Moraes et al ., ). Furthermore, there is evidence for high levels of diversity of chemical compounds in Myrcia leaves (e.g.…”

“…it is one of the richest pollen sources for pollinators (Wilms et al ., ) and fruit sources for vertebrates (Staggemeier et al ., ) in these biomes); (2) the availability of a series of recent systematic revisions that have significantly increased taxonomic stability (e.g. Lucas et al ., , ; Santos et al ., ); and (3) Myrcia has diversified into one of the most species‐rich areas on the globe, most probably after the establishment of the modern latitudinal gradient of species diversity (Mannion et al ., ; Santos et al ., ).…”