New Plant Species Discovered in Yunnan’s Gaoligong Mountains
Scientists have identified a new species of alpine rhubarb in the Gaoligong Mountains of Yunnan Province, China — a discovery that overturns a 170-year-old botanical classification. Named Rheum lushuiense (Lushui Rheum nobile), the new species was formally announced on May 22, 2026, by the city of Lushui in Nujiang Prefecture, following research published in the journal Plant Diversity on May 19.
A 170-Year Taxonomic Revision
For more than 170 years, botanists believed that Rheum nobile — commonly known as tower rhubarb or noble rhubarb — was a single species distributed across the Himalayas and the Hengduan Mountains. However, a research team from the Kunming Institute of Botany, Chinese Academy of Sciences, has now demonstrated that this iconic alpine plant actually comprises four distinct evolutionary lineages.
According to CCTV News, the research team conducted systematic sampling of 18 natural populations across the entire Himalayas-Hengduan Mountains range, including nearly all known distribution points in China and two populations in Nepal. Using morphological comparison, multi-gene molecular phylogenetic analysis, and Bayesian species delimitation methods, the scientists resolved the single species into four well-supported lineages.
The New Species: Rheum lushuiense
The newly identified species, Rheum lushuiense, is named after its type locality in Lushui. It is found exclusively in the Lushui section of the Gaoligong Mountains, an area recognized as a UNESCO World Heritage site and one of China’s most important biodiversity hotspots.
As reported by Sina News, the research team noted that Lushui Rheum nobile is the smallest of the four species, reaching a flowering height of only 45 to 80 centimeters — a stark contrast to other lineages that can grow up to two meters tall. It also occupies the southernmost and lowest-elevation distribution among the four.
An Alpine Greenhouse Plant
Rheum nobile is known as an “alpine greenhouse plant” for its remarkable adaptation to extreme environments. Growing at elevations of 4,000 to 4,800 meters, the plant features large, translucent bracts that create a greenhouse-like microclimate, protecting its flowers from intense cold and ultraviolet radiation. It is a monocarpic perennial, growing vegetatively for five to seven years before flowering once and then dying.
The four lineages identified in the study correspond to distinct geographic regions: the Gaoligong Mountains lineage (GLG) — now classified as Rheum lushuiense — the Central Himalayas lineage (CHM), the Eastern Himalayas lineage (EHM), and the Hengduan Mountains lineage (HDM).
Discovery and Research Journey
The unique Rheum population in the Lushui section was first observed in 2018, when local staff noticed its unusual morphology. In September 2019, a team from the Kunming Institute of Botany began systematic field sampling. The multi-year research effort integrated chloroplast genome data, ribosomal ITS sequences, and low-copy nuclear gene markers to confirm that the Lushui population was genetically and morphologically distinct.
Conservation Significance
The extremely limited distribution of Rheum lushuiense raises important conservation concerns. As the smallest and lowest-elevation species among the four lineages, it may be particularly vulnerable to climate change and habitat disruption. The species also holds value in traditional Tibetan medicine, which could make it a target for harvesting.
The Gaoligong Mountains continue to yield new species discoveries, underscoring the importance of continued botanical exploration in this biodiversity-rich region. Yunnan Province, known as China’s “Kingdom of Plants,” is home to more than 17,000 species of higher plants.
What’s Next
The discovery highlights the power of modern molecular phylogenetic methods to uncover hidden biodiversity, even in well-studied plant groups. The research team’s findings raise several important questions: What conservation status will Rheum lushuiense receive? Will the other three lineages be formally described as new species in subsequent publications? And what other cryptic species might still be waiting to be discovered in the world’s most biodiverse mountain ranges?
For now, the discovery of Rheum lushuiense stands as a testament to the remarkable botanical wealth of the Gaoligong Mountains and the ongoing contributions of Chinese botanical science to global biodiversity knowledge.