Biogeography of Stigmaphyllon (Malpighiaceae) and a Meta-Analysis of Vascular Plant Lineages Diversified in the Brazilian Atlantic Rainforests Point to the Late Eocene Origins of This Megadiverse Biome

Abstract

We investigated the biogeography of Stigmaphyllon, the second-largest lianescent genus of Malpighiaceae, as a model genus to reconstruct the age and biogeographic history of the Brazilian Atlantic Rainforest (BAF). Few studies to date have focused on the tertiary diversification of plant lineages in the BAFs, especially on Stigmaphyllon. Phylogenetic relationships for 24 species of Stigmaphyllon (18 ssp. From the Atlantic forest (out of 31 spp.), three spp. from the Amazon Rainforest, two spp. from the Caatinga biome, and a single species from the Cerrado biome) were inferred based on one nuclear DNA (PHYC) and two ribosomal DNA (ETS, ITS) regions using parsimony and Bayesian methods. A time-calibrated phylogenetic tree for ancestral area reconstructions was additionally generated, coupled with a meta-analysis of vascular plant lineages diversified in the BAFs. Our results show that: (1) Stigmaphyllon is monophyletic, but its subgenera are paraphyletic; (2) the most recent common ancestor of Stigmaphyllon originated in the Brazilian Atlantic Rainforest/Caatinga region in Northeastern Brazil ca. 26.0 Mya; (3) the genus colonized the Amazon Rainforest at two different times (ca. 22.0 and 6.0 Mya), the Caatinga biome at least four other times (ca. 14.0, 9.0, 7.0, and 1.0 Mya), the Cerrado biome a single time (ca. 15.0 Mya), and the Southern Atlantic Rainforests five times (from 26.0 to 9.0 Mya); (4) a history of at least seven expansion events connecting the Brazilian Atlantic Rainforest to other biomes from 26.0 to 9.0 Mya, and (5) a single dispersion event from South America to Southeastern Asia and Oceania at 22.0 Mya via Antarctica was proposed. Compared to a meta-analysis of time-calibrated phylogenies for 64 lineages of vascular plants diversified in the Brazilian Atlantic Rainforests, our results point to a late Eocene origin for this megadiverse biome.

A new classification system and taxonomic synopsis for Malpighiaceae (Malpighiales, Rosids) based on molecular phylogenetics, morphology, palynology, and chemistry

“…Eight of these studies focused on the family as a whole, trying to sample its main morphological or phylogenetic groups ( Cameron et al 2001 ; Davis et al 2001 ; Davis and Chase 2004 ; Davis and Anderson 2010 ; Davis et al 2014 ; Willis et al 2014 ; Cai et al 2016 ; Almeida et al 2023a , b , c; Do et al 2024 ). Nine of these studies focused on phylogenetic clades (i.e., Tetrapteroid clade ≡ tribe Hiptageae ) or specific genera (i.e., Acridocarpus , Amorimia , Chlorohiptage , Hiptage , Lasiocarpus , Mionandra , and Stigmaphyllon ; Davis 2002 ; Almeida et al 2018 ; 2023a , b , c; Tan et al 2019 ; Almeida and van den Berg 2020 , 2021 , 2022 ; Cardona-Cruz et al 2021 ; Do et al 2024 ). All ten phylogenetic clades recognised by us here in the new classification system proposed for Malpighiaceae have consistently been recovered in almost all previous molecular phylogenetic studies ( Cameron et al 2001 ; Davis et al 2001 ; Davis and Chase 2004 ; Davis and Anderson 2010 ; Davis et al 2014 ; Willis et al 2014 ; Almeida et al 2023a , b , c; Do et al 2024 ).…”

Untargeted Metabolomics Sheds Light on the Diversity of Major Classes of Secondary Metabolites in the Malpighiaceae Botanical Family

“…Most plant samples were collected by R.F. Almeida on field expeditions throughout Brazil from 2013 to 2017, or were retrieved from discarded fragmented samples used for DNA extraction in molecular studies ( de Almeida et al, 2017 , 2018 ; de Almeida and van den Berg, 2020 , 2021 ). For information regarding all sampled specimens, see Supplementary Table 1 .…”

The two South American dry diagonals

“…Even more recent exchanges have been suggested for vertebrates through coastal region of the Caatinga on the eastern portion of both rainforests, possibly associated with Pleistocene climatic cycles (Ledo and Colli 2017). These studies, however, underscore the importance of the eSADD as a barrier between Amazon and Atlantic Forest, which may explain early vicariant events in both vascular plants and vertebrates (e.g., Fouquet et al 2012, Batalha-Filho et al 2013, Thode et al 2019, Almeida and van den Berg 2020Masa-Iranzo et al 2021) as a consequence of the formation of these dry environments during the Miocene (see above).…”