Ophiorrhiza liuyanii (Rubiaceae), a new species from south-western China and northern Vietnam.

Ophiorrhiza liuyanii, a new species from south-western China and northern Vietnam, is described and illustrated. The new species is characterised by the glabrous surfaces on almost all plant parts, congested inflorescences and broad-ovate to ovate bracts 9–22 × 4–11 mm. It morphologically differs from the closest species, O. baviensis, mainly in most plant parts being glabrous, bracts broad-ovate to ovate, apex acute or sometimes obtuse, corollas inside with a ring of white hairs at the middle and anthers inserted near the middle in long-styled flowers. According to IUCN Categories and Criteria, O. liuyanii is assessed as Least Concern (LC). [ABSTRACT FROM AUTHOR]