Identity of Ophiopogon tonkinensis and O. ogisui, with a new species O. tiandengensis from Guangxi, China

An examination of herbarium specimens (type material) and living plants in the wild, we demonstrate that Ophiopogon ogisui, described from Longzhou county in Guangxi, China, is conspecific with O. tonkinensis, a species distributed in Southwestern Guangxi of China and Northern Vietnam. We therefore reduce O. ogisui to the synonymy of O. tonkinensis herein and present a comprehensive description of O. tonkinensis. O. tiandengensis from Guangxi of China is described here as new to science. This species is morphologically similar to O. tonkinensis, but can be readily distinguished from the latter by its blades size and shape, and pedicel articulated in the middle, inflorescences with fewer flowers, flower campanulate, lobes somewhat divergent distally and flowering in May–July. In addition, the inflorescence of the new species is similar to that of O. sinensis, but the leaves of the latter narrowing at the base, petiolate indistinctly, anthers ca. 4.5 mm, initially connate, later free.