Reassessment of generic boundaries in Neotropical Chrysophylloideae (Sapotaceae): Eleven reinstated genera and narrowed circumscriptions ofChrysophyllumandPouteria

Abstract

Classifications of the pantropical plant family Sapotaceae based solely on morphology have historically recognized between 125 and 53 genera. Phylogenetic analyses using molecular data have repeatedly demonstrated that broad concepts of two large genera belonging to subfamily Chrysophylloideae, Chrysophyllum and Pouteria, are untenable and their narrowed delimitations have restricted them to the Neotropics. A recent phylogenetic study proposed further amendments by resurrecting the genera Achrouteria, Cornuella, Lucuma, Martiusella, Nemaluma, Prieurella and Ragala, and questioned the status of three generally accepted genera, Chromolucuma, Pradosia and Sarcaulus. We test this suggested classification using expanded sampling that comprises 122 terminals, including material of 29 of the 34 name‐bringing species for generic names historically regarded as synonyms of Chrysophyllum and Pouteria. We used sequence data from ribosomal nrDNA (ETS, ITS), the nuclear gene RPB2, two cpDNA spacers (petN‐psbM, trnH‐psbA), and indel information to estimate phylogenetic relationships in a Bayesian framework using BEAST. All sequences were newly realigned to test reproducibility, and 26 morphological characters were mapped on the resulting tree. Our analyses recovered three African genera embedded within a large Neotropical clade of Chrysophylloideae. We found strong support for the reinstatement of the seven genera listed above as well as for four other genera, viz. Chloroluma, Englerella, Labatia, and Peteniodendron. This subsequently leads to further amendments of Chrysophyllum and Pouteria, which are now limited to include 25–30 and 7 species, respectively. However, one clade that includes many name‐bringing lineages largely corresponds to Pouteria s.l., a group that needs further phylogenetic research to unravel relationships and generic limits. The hypothesis that Chrysophyllum cuneifolium had an inter‐continental hybrid origin involving genomes from Africa and South America is rejected because it is shown to have been based on erroneous results obtained from a contaminated DNA aliquot. A total of 73 genera are currently recognised in Sapotaceae, 21 of which are Neotropical members of Chrysophylloideae. We update the nomenclature and synonymy of 75 species, make 36 new combinations, and designate lectotypes for 31 names.

Phylogenetic position and reinstatement ofGayella(Sapotaceae), a monotypic genus endemic to Chile with an Eocene origin in continental Australia

“…The tree was rooted on the African genus Aubregrinia Heine and the South American genus Ecclinusa Mart., following the latest results by Swenson & al. (2023).…”

“…Various systems based on morphology alone have adopted between 53 (Pennington, 1991) and 125 genera (Aubréville, 1964). However, molecular phylogenetics, often with support from morphology, have identified natural lineages in this family (Anderberg & Swenson, 2003;Bartish & al., 2005;Swenson & al., 2008aFaria & al., 2017;Borg & al., 2019), and 72 genera are currently accepted, of which 20 have been reinstated from Pennington's broad concepts (Swenson & al., 2023). This number will inevitably increase with further research.…”

“…Chrysophylloideae is one of three subfamilies of Sapotaceae, distributed in all tropical parts of the world, and including some 650-700 species in 43+ genera (Swenson & al., 2023). A recent phylogenetic study of New World Chrysophylloideae, including 123 terminals of which 40 have been (or still are) placed in Pouteria Aubl.…”

“…A recent phylogenetic study of New World Chrysophylloideae, including 123 terminals of which 40 have been (or still are) placed in Pouteria Aubl. (Pennington, 1990), was designed to test generic limits in the presumed monophyletic group of Neotropical species (Swenson & al., 2023). Sampling of Australasian taxa was therefore not an issue and instead limited to one species each of the recognized genera, i.e., eight type species and Magodendron mennyae Vink.…”

“…Two of these species were L. bifera Molina and L. valparadisaea Molina, of which the former was selected as the type of Lucuma (Britton & Millspaugh, 1920) and the generic name became attributed to Sapotaceae. These two and many other species originally described in Lucuma have for decades been included in Pouteria (Baehni, 1942(Baehni, , 1965Pennington, 1990Pennington, , 1991, but phylogenetic studies have identified a clade, including L. bifera, as distantly related to Pouteria, meriting resurrection of Lucuma with 17 species (Faria & al., 2017;Swenson & al., 2023).…”