Leontopodium nyingchiense, a new species of Asteraceae from the Xizang (Tibet) Autonomous Region of China, is described and illustrated here. Morphologically, it is most similar to L. lingianum but can be distinguished by the combination of monoecious and dioecious individuals, involucral bracts arranged in 3–5 series (with outer series herbaceous and middle to inner series membranous), fimbriate apices on female florets, rough-edged lobes on male florets, and achenes lacking costae. Phylogenetic analyses further support the separation of this new species from related taxa. Finally, we characterize this new species through both morphological comparisons and molecular analyses.

Leontopodium, morphological analysis, new species, Nyingchi, phylogenetic analysis

Leontopodium R.Br. ex Cass. belongs to the Asteraceae, Gnaphalieae, Filagininae (Smissen et al. 2020). It comprises perennial herbs or subshrubs with approximately 60 species worldwide, primarily distributed in mountainous regions of Asia and Eurasia. In China, there are 37 species and 2 varieties of Leontopodium, with 16 species being endemic to China (Chen and Bayer 2011). This genus is a common component of alpine meadows and slopes in the western and southwestern regions of China, with the Tibetan Plateau being the center of its species diversity (Safer et al. 2011; Lee et al. 2016; Zhao 2021) and 21 species distributed in Xizang (Chen et al. 2023).

During the fourth national survey of traditional Chinese medicine resources conducted from 2013 to 2015, an unidentified species of Asteraceae was discovered in Lulang Town, Nyingchi City, Xizang (Tibet) Autonomous Region. In August 2024, this species was re-investigated, and additional specimens and molecular materials from leaves were collected. This species is morphologically very similar to L. lingianum (Y.L.Chen) Dickoré, but it differs from the latter in several characters. Its involucral bracts are arranged in 3–5 series, with the outer series being herbaceous and the inner and middle series having a membranous texture. The species can be either monoecious or dioecious. The achenes are without costa, puberulous, and papillose at the apex. The female floret corolla has fimbriate apices, and the male floret corolla has lobes that are rough and granulate at the edges. Based on morphological comparisons and phylogenetic analyses, we have identified this taxon as a new species.

According to the phylogenetic analysis, Leontopodium nyingchiense and L. calocephalum are very closely related, though they can be easily distinguished morphologically. The primary morphological distinction is that L. nyingchiense is a dwarf cushion plant and lacks involucral bracts. Morphologically, L. nyingchiense is most similar to L. lingianum, followed by L. haastioides. All three species are dwarf cushion plants and also lack involucral bracts, though L. nyingchiense differs from L. haastioides in that it does not produce rhizomes.

Sinoleontopodium was first described as a new genus by Chen (1985), but it was merged into the genus Leontopodium by Dickoré (Blöch et al. 2010), a classification accepted by POWO (Plants of the World Online https://powo.science.kew.org/). This classification was supported by our phylogenetic analysis using ITS and ETS sequences, which positioned this genus within Leontopodium. However, morphologically L. lingianum, L. nyingchiense and two species in the dense cushion group, L. haastioides and L. aurantiacum, are distinctly different from the other species in the genus due to the typical character of Leontopodium: prominent involucral bracts. This morphology suggests that L. lingianum, L. nyingchiense and the dense cushion group may warrant classification as a separate genus or subgenus. However, the phylogenetic results presented in this study indicate that, except for L. aurantiacum (for which molecular data is unavailable), the remaining three species are only distantly related. Therefore, with more molecular data, the classification of these species within the genus may need to be reassessed.

Field observations of L. nyingchiense revealed both monoecious and dioecious individuals. Typically, monoecious individuals have one male floret in the center of the female inflorescence, with the male floret being much smaller than the female florets. In dioecious individuals, male inflorescences are slightly larger than female ones, with the male florets being concealed among the leaves, while female inflorescences are located above the leaves. However, our dissection of samples in the laboratory revealed that in male plants, a small number of female florets occur within male inflorescences without any discernible pattern. These female florets are morphologically identical to those on female plants, possessing only a pistil with no stamens, and develop normally. In contrast, the male florets are functionally bisexual, with the pistil showing abnormal development, the ovary being sterile, and possessing five stamens. Therefore, in functional terms, this species lacks true male florets, possessing only bisexual and female florets. Under natural conditions, some fertile bisexual florets may occur, but the sample size in this study was insufficient, and further research is required.

We are very grateful to Meng Ran, Prof. Zhang Daigui, Jia Chenxue, and Li Guanfeng for their help and advice on morphological identification, phylogenetic analysis, and experimental assistance in this study.