A 638‐gene phylogeny supports the recognition of twice as many species in the Malagasy endemic genusCapurodendron(Sapotaceae)

Abstract

The Malagasy genus Capurodendron currently accommodates 26 described species and is the largest genus of the family Sapotaceae in Madagascar. These species are frequently logged because of their valued hardwood, which potentially puts them at risk of extinction. Species‐level identifications are often problematic, and this hinders both an accurate assessment of their conservation status and the development of effective protection measures. We sorted all the material (ca. 860 collections) available in the herbaria with significant collections for Madagascar into 47 putative species based on morphology. On 41 of these, for which we were able to retrieve suitable DNA, we conducted a phylogenetic reconstruction based on molecular sequences of 638 loci from 108 Capurodendron specimens, performing a target capture approach combined with next‐generation sequencing. Maximum likelihood (RAxML), pseudocoalescence (ASTRAL), and coalescence (STACEY) analyses showed that Capurodendron comprises two deeply divergent lineages. One, which includes a single species, is here newly described as C. subg. Reflexisepala based on its distinctive morphology. The second lineage contains all remaining species, which seem to have resulted from a rapid radiation event. The phylogenetic tree provides good support for most of the species hypothesized based on morphology, with the exception of two species‐groups that we have named the Arid Complex and the Eastern Complex. As many as 20 species‐level lineages genetically distinct from any of the currently recognized species were identified, 17 of which were morphologically well‐characterized, representing strong candidates for new species. This would suggest that Capurodendron is the most species‐rich endemic genus of plants in Madagascar. While 14 of these 20 clades are still under study, we here describe six species new to science: Capurodendron andrafiamenae (provisionally assessed as CR), C. aubrevillei (VU), C. birkinshawii (CR), C. naciriae (EN), C. randrianaivoi (CR), and C. sakarivorum (EN). Capurodendron oblongifolium comb. nov. (EN), previously regarded as a variety of C. perrieri, represents a distinct lineage that is here recognized at the species level. The newly described species are illustrated by line drawings and photographs from the field, and a preliminary threat assessment is provided. We discuss the evolutionary history of Capurodendron and also explore the question of node age estimates and their methodological limitations.

One in, one out: Generic circumscription within subtribe Manilkarinae (Sapotaceae)

“…On the contrary, changes in corolla and androecium merism are frequently observed between (and sometimes even within) individuals of the same species (e.g., Capurodendron madagascariensis and C . oblongifolium – Boluda & al., 2022) and are interpreted by Kümpers & al. (2016) as having a much lower taxonomic significance.…”

“…Both clades have a radiation‐like topology (Glor, 2010) which is known to result in unresolved polytomies (Naciri & Linder, 2020). Recent studies suggest that this type of rapid radiation might be common in Malagasy Sapotaceae (Boluda & al., 2021, 2022; Christe & al., 2021) as well as in other Malagasy tree genera (e.g., Canarium – Federman & al., 2018; Dalbergia – Crameri, 2020). Weak support for species relationships was expected, considering that the current sampling was designed to resolve generic issues and not interspecific relationships within each genus, which will require further sampling and more analyses.…”

Two further new species in the highly-diverse Malagasy endemic genus Capurodendron (Sapotaceae)

“…These species candidates were then sampled for molecular study, including adequate geographic representation of widespread and disjunct morphospecies. The analysis of 638 genes (Christe et al, 2021;Boluda et al, 2022) confirmed the placement of the genus in the tribe Tseboneae (Gautier et al, 2013) and showed a massive radiation with numerous new species, upgrading Capurodendron as the richest endemic Malagasy genus with 33 described species so far. Boluda et al (2021) characterized the so-called "Arid Complex", comprising Capurodendron androyense Aubrév., C. mandrarense Aubrév., and some specimens collected north of the city of Toliara which were morphologically hypothesised to be hybrids between C. mandrarense and C. greveanum Aubrév.…”

“…It is however closely related to C. mandrarense. Together with the very distinctive C. androyense, these three species form the core of what has been referred as the "Arid Complex" (Boluda et al, 2021(Boluda et al, , 2022. 130 m, 17.II.2017, old fl.…”

A Taxonomic Revision of the Madagascar-Endemic Genus Bemangidia (Sapotaceae), With Description of a Second Species

“…Two collections of Bemangidia lowryi, including the type, and the three Bemangidia sp., were selected for molecular analysis. As outgroups, we added the 131 specimens analysed by Boluda et al (2022), comprising all described tribes of Sapotaceae and 35 species of Capurodendron Aubrév., a genus related to Bemangidia and Tsebona. Additionally, we included a recent Malagasy accession (Andriamiarisoa 2582) of a disjunct collection of Tsebona situated at a latitude of 23°S (all the remaining known collections were growing between 14°S and 19°S), as well as a specimen (Bernardi 14641) of Northia seychellana Hook.f., from the Seychelles, a genus of uncertain position (Gautier et al, 2013) but hypothesised as being the closest relative to the tribe Tseboneae.…”