Evolution of Leaf Morphoanatomical Characters in the Catolesia Clade (Asteraceae, Eupatorieae, Gyptidinae) Reveals the New Monotypic Genus Nadia

The Catolesia clade (Asteraceae, Eupatorieae, Gyptidinae) comprises four genera (Bahianthus, Catolesia, Lapidia, and Morithamnus), mostly confined to the Espinhaço mountain range of Eastern Brazil. Although this lineage is statistically well supported in molecular phylogenetic studies, recent findings point to Disynaphia praeficta being currently placed in the Catolesia clade, making Disynaphia paraphyletic. We analysed, scored, and mapped 102 leaf anatomical characters from all species of the Catolesia clade and selected outgroups to test the placement of D. praeficta into this clade, proposing a new monotypic genus and a taxonomic synopsis for the Catolesia clade, besides standardising descriptive anatomical terminology. We recovered several homoplasies and synapomorphies circumscribing all lineages sampled in our study, including Disynaphia s.s. and the remaining sampled outgroups. Our results also corroborated the placement of D. praeficta within the Catolesia clade with high statistical support. The cuneate to truncate lamina base was recovered as a synapomorphy supporting the Catolesia clade, whereas a petiole with three vascular bundles, ducts distributed throughout the lamina, and collenchyma sheath cell extensions were recovered as synapomorphies supporting Nadia praeficta (B.L. Rob.) A.V.F. Guterres and R.F. Almeida as a new monospecific genus. We demonstrated how highly informative leaf morphoanatomical characters are for the systematics of Eupatorieae and Asteraceae, besides demonstrating that leaf morphoanatomical characters provide a robust phylogenetic signal for generic delimitation within Eupatorieae, even if characterised as homoplasies.