Breynia enchengensis, a new species with a narrowly geographic distribution in limestone areas of southwestern Guangxi, China, is described and illustrated. The new species is morphologically similar to B. poomae (Welzen & Chayam.) Welzen & Pruesapan in having creeping stems, ovate to oblong leaf blade and reddish brown to dark purple flowers, but can be easily distinguished from the latter by the size of leaf blade and flowers, the number of lateral veins, the growing way of inflorescence and the shape of ovary. A table to distinguish the new species from B. poomae, as well as color plates and type specimens of the new species are also provided.

Isotrema jinquanii, a new species of Aristolochiaceae from limestone areas in Guangxi, China is described and illustrated now. This new species is most similar to I. sinoburmanicum in the shape of perianth. The morphological differences from the latter by the stem densely golden-tomentose at young twigs and densely brown-tomentose when aged, the petiole 1.5–3.1 cm long, densely golden (brown)-tomentose, the leaf blade 5.2–10.8 × 2.3–4.4 cm, densely golden (brown)-tomentose abaxially, the bracteole triangular, ca. 1.5 × 1 mm, the perianth outside densely brown-villous, the throat constricted, densely warty inside.