The demise of Monechma: new combinations and a new classification in the resurrected genera Meiosperma and Pogonospermum (Acanthaceae).

Recent molecular phylogenetic results have demonstrated that s.l., a group of plants with ecological importance in the savanna and succulent biomes of sub-Saharan Africa, is polyphyletic with two discrete lineages recognisable. In the present work, we recognise Groups I and II at the generic rank, which can be distinguished by differences in inflorescence characteristics and seed morphology. The nomenclatural implications of these findings are investigated. The lectotype of , Hochst., is a part of a small lineage of plants closely allied to L. sect. (Solms) Benth. for which the earliest valid name is found to be Raf. Hence, is synonymised within , which comprises six accepted species and two undescribed taxa. The majority of species of former s.l. are resolved within the second lineage for which the only validly published generic name is Hochst. This resurrected genus comprises 34 accepted species plus two undescribed taxa. displays considerable morphological variation and is here subdivided into six sections based primarily on differences in plant habit, inflorescence form, calyx, bract and bracteole venation, and seed indumentum. The new combinations and new sections are validated, and seven accepted species names are lectotypified.