Mussaenda saxatilis (Rubiaceae), a new limestone species from Guangxi, China

A new species of Mussaenda (Rubiaceae), M. saxatilis , is described from the limestone karst regions of Guangxi, southern China. Morphologically, the new species most closely resembles M. hainanensis but differs from that species in having shallowly or moderately 2-lobed stipules, subsessile inflorescences, rotundate-ovate corolla lobes, smaller berries, and a pericarp that lacks lenticels. A detailed description, habitat information, phenology, distribution, and comparisons with morphologically similar species are provided.