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Lasiosiphon Fresen. (Thymelaeaceae: Thymelaeoideae) is now understood to be a morphologically diverse genus distributed across southern and tropical Africa, Madagascar, and India. It is diagnosed morphologically by ± involucrate, mostly pedunculate heads of pentamerous or tetramerous flowers, with or without petaloid scales, and a bright yellow, orange, or red corolla. The taxonomic history of Lasiosiphon has been marked by several revisions in its circumscription and status, particularly regarding its relationship with Gnidia L. Our phylogenetic analysis of nuclear (ITS) and plastid (matK, rbcL, rps16 and trnL-F) regions of an expanded sampling of the tropical African species of Gnidia provides compelling supporting evidence for existing morphological evidence to include all the tropical African species of Gnidia in Lasiosiphon. We accordingly provide 31 new combinations in Lasiosiphon for species of Gnidia that currently lack combinations in that genus. We also provide a comprehensive nomenclator of all currently recognized Lasiosiphon species at the regional level encompassing their distribution across different geographic regions globally. This will serve as the framework for future taxonomic revisions in the genus. [ABSTRACT FROM AUTHOR]

One of the biggest challenges for conservation biology is to provide conservation planners with ways to prioritize effort. Much attention has been focused on biodiversity hotspots. However, the conservation of evolutionary process is now also acknowledged as a priority in the face of global change. Phylogenetic diversity (PD) is a biodiversity index that measures the length of evolutionary pathways that connect a given set of taxa. PD therefore identifies sets of taxa that maximize the accumulation of ‘feature diversity’. Recent studies, however, concluded that taxon richness is a good surrogate for PD. Here we show taxon richness to be decoupled from PD, using a biome-wide phylogenetic analysis of the flora of an undisputed biodiversity hotspot—the Cape of South Africa. We demonstrate that this decoupling has real-world importance for conservation planning. Finally, using a database of medicinal and economic plant use, we demonstrate that PD protection is the best strategy for preserving feature diversity in the Cape. We should be able to use PD to identify those key regions that maximize future options, both for the continuing evolution of life on Earth and for the benefit of society. [ABSTRACT FROM AUTHOR]