Phylogeny of the ingoid clade (Caesalpinioideae, Fabaceae), based on nuclear and plastid data

<p>We investigated generic relationships in the ingoid clade (Fabaceae) (sensu Koenen &amp; al. 2020a), with main focus on genera with a taxonomic history in <i>Calliandra</i> s.l. of the tribe Ingeae (i.e. <i>Afrocalliandra</i>, <i>Calliandra</i> s.s., <i>Sanjappa</i>,<i>Thailentadopsis</i>,<i> Viguieranthus,</i> <i>Zapoteca</i>), and three genera of the tribe Acacieae (i.e., <i>Acacia</i>, <i>Acaciella, Senegalia</i>). The nuclear ribosomal ETS and ITS, and the plastid <i>matK</i>, <i>trnL</i>-<i>trnF </i>and <i>ycf1 </i>DNA-regions were analysed for 246 representatives from 36 genera using maximum likelihood as implemented in IQ-tree. The results show an Ingeae–<i>Acacia </i>clade within the ingoid clade, resolved in three major clades. Clade 1 (<i>Calliandra</i> s.s. and <i>Afrocalliandra</i>) is sister to clades 2 and 3. Clade 2 comprises <i>Faidherbia</i>, <i>Sanjappa</i>, <i>Thailentadopsis</i>, <i>Viguieranthus</i> and <i>Zapoteca</i>. Clade 3 comprises the remaining genera of the Ingeae, plus <i>Acacia</i>. The ingoid genus <i>Senegalia</i> is excluded from the Ingeae–<i>Acacia </i>clade. <i>Acaciella </i>is sister to the remaining ingoid clade when nuclear ribosomal data is included in the analyses, but included in the Ingeae–<i>Acacia</i> clade based on plastid data. <i>Acacia </i>and perhaps also <i>Acaciella </i>are thus nested within Ingeae. Species traditionally referred to <i>Calliandra </i>(<i>Calliandra</i> s.l.) are resolved in two clades, and the "<i>Calliandra</i>-pod" has apparently evolved independently several times.</p>