The genus Heterostemma comprises 45 species and is widely distributed from India, China to Australia and the Western Pacific Islands. To date, 11 species of Heterostemma have been recorded in China.

During extensive botanical surveys in Dehong Prefecture in Yunnan, researchers from Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences and their collaborators collected specimens of Heterostemma in Yingjiang County. After a thorough review of the literature, specimens, and photographs of the genus across Asia, as well as comprehensive morphological examination, they confirmed that the materials represented a species new to science.

The new species has been named Heterostemma tongbiguanense and published in Phytotaxa.

Heterostemma tongbiguanense is a climbing plant that can reach up to 10 meters in length. It resembles Heterostemma cucphuongense and Heterostemma tanjorense, but can be distinguished from them by several unique morphological features.The floral structure is distinctive, with corona lobes that are serrated at the tips and feature papillae (small, nipple-like projections) on both sides below the middle. The striking flowers are rotate (wheel-shaped), with a yellow inner surface adorned with deep purple spots and a pale greenish-yellow outer surface bearing similar purple markings.

Heterostemma tongbiguanense was found growing in montane moist evergreen broad-leaved forests at elevations between 1,600 and 1,800 meters. It has only been found in Yunnan Tongbiguan provincial Nature Reserve and its surrounding areas.

Due to the limited scope of the initial surveys and the possibility that the species may also occur across the border in Myanmar’s Kachin State, its full distribution and population status remain unclear. Therefore, the researchers assessed the conservation status of Heterostemma tongbiguanense as Data Deficient (DD) according to the IUCN Red List Categories and Criteria.

Heterostemma tongbiguanense (Image by SHEN Jianyong)

Published:05 February 2026