A team of researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences (CAS) and Kunming Institute of Botany (KIB) of CAS has identified a new species of flowering plant, Phlogacanthus xanthophyllus, in the limestone forests of southeastern Yunnan. The study is published in the Nordic Journal of Botany.

This new species was first discovered in Maguan County by Prof. Shui Yumin from KIB in 2005 during a botanical survey. However, it remained unidentified until two additional populations of the species were found in neighboring Hekou County in 2021 by XTBG researchers.

After comparison with similar species, specimen examination and literature review, the populations were confirmed to represent a new taxon belonging to P. sect. Cystacanthus.

Phlogacanthus xanthophyllus is a perennial herb to shrub reaching to about one meter tall. It is morphologically similar to P. pyramidalis in type of inflorescence as well as shape and size of flowers. However, its striking yellowish-green corolla with dark brown to yellow throat patches, creamy-white filaments marked by pink stripes, and leathery leaves adorned with grayish-white patches distinguish it from its closest relative, P. pyramidalis.

Phlogacanthus xanthophyllus thrives in limestone forests at elevations of 100–700 meters, and has been observed flowering in March–June, and fruiting in April–August. Its known populations are clustered near the China–Vietnam border, suggesting potential distribution in northern Vietnam.

With only three documented populations, the species has been provisionally classified as Data Deficient according to the IUCN red list categories and criteria, highlighting the need for further field studies to assess its conservation status.