Reinstatement and generic reassignment of Phyllanthus asteranthos Croizat (Phyllanthaceae) based on living plant observations and specimen analysis

Phyllanthus asteranthos Croizat has been treated as a synonym of P. pulcher Wall. ex Müll. Arg. (syn. Nymphanthus glaucescens (Miq.) R.W.Bouman) since 1987. Through detailed morphological observations of living plants and critical examinations of type materials and additional specimens, this study revealed that the two taxa are morphologically very distinct from each other, thus warranting recognition as two distinct species. We therefore reinstate the specific status of P. asteranthos and reassign it to the genus Nymphanthus Lour. as Nymphanthus asteranthos (Croizat) Huan C. Wang et Feng Yang. All previous Chinese ‘wild' records of N. glaucescens actually represent N. asteranthos , as N. glaucescens is only cultivated in China (Xishuangbanna Tropical Botanical Garden) and absent from the natural habitats. This study highlights the importance of integrating fresh material observations to resolve taxonomic issues in Phyllanthaceae.