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  1. Abstract— Acanthaceae is a family of tropical flowering plants with approximately 4900 species. Despite remarkable variation in morphological traits, research on patterns of character evolution has been limited by uncertain relationships among some of the major lineages. We sampled 16 taxa from these major lineages to estimate a phylogenomic framework using a combination of five newly sequenced shotgun genome skims plus seven new and four publicly available transcriptomes. We used OrthoFinder2 to infer a species tree with strong branch support. Except for the placement of Crabbea , our results corroborate the most recent chloroplast and nrITS sequence-based topology. Of 587 single copy loci, 10 were recovered for all 16 species; a RAxML tree estimated from these 10 loci resulted in the same topology as other datasets assembled in this study, with the exception of relationships among three sampled species of Barleria ; however, branch support was lower compared to the tree reconstructed using more data. ABBA-BABA tests were conducted to investigate patterns of introgression involving Crabbea ; few nucleotides supported alternative topologies. SplitsTree networks of the 587 loci and 6136 orthogroup trees revealed conflict among the branches leading to Andrographideae, Whitfieldieae, and Neuracanthus . A principal components analysis in treespace found no distinct clusters of trees. Our results based on combined genome skim and transcriptome sequences strongly corroborate the previously published chloroplast and nr-ITS-based phylogeny of Acanthaceae with increased resolution among Barlerieae, Andrographideae, Whitfieldieae, and Neuracanthus . This advance in our knowledge of Acanthaceae relationships will allow us to investigate character evolution and other phenomena within this diverse group of plants in studies with increased taxon sampling. 
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  2. Summary Recent molecular phylogenetic results have demonstrated that Monechma 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 Monechma 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 Monechma , M. bracteatum Hochst., is a part of a small lineage of plants closely allied to Justicia L. sect. Harnieria (Solms) Benth. for which the earliest valid name is found to be Meiosperma Raf. Hence, Monechma is synonymised within Meiosperma , which comprises six accepted species and two undescribed taxa. The majority of species of former Monechma s.l. are resolved within the second lineage for which the only validly published generic name is Pogonospermum Hochst. This resurrected genus comprises 34 accepted species plus two undescribed taxa. Pogonospermum 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. 
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  3. null (Ed.)
    Monechma Hochst. s.l. (Acanthaceae) is a diverse and ecologically important plant group in sub-Saharan Africa, well represented in the fire-prone savanna biome and with a striking radiation into the non-fire-prone succulent biome in the Namib Desert. We used RADseq to reconstruct evolutionary relationships within Monechma s.l. and found it to be non-monophyletic and composed of two distinct clades: Group I comprises eight species resolved within the Harnieria clade, whilst Group II comprises 35 species related to the Diclipterinae clade. Our analyses suggest the common ancestors of both clades of Monechma occupied savannas, but both of these radiations (~13 mya crown ages) pre-date the currently accepted origin of the savanna biome in Africa, 5–10 mya. Diversification in the succulent biome of the Namib Desert is dated as beginning only ~1.9 mya. Inflorescence and seed morphology are found to distinguish Groups I and II and related taxa in the Justicioid lineage. Monechma Group II is morphologically diverse, with variation in some traits related to ecological diversification including plant habit. The present work enables future research on these important lineages and provides evidence towards understanding the biogeographical history of continental Africa. 
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