Saussurea is one of the largest and most rapidly evolving genera within the Asteraceae family, comprising approximately 520 species found in the Northern Hemisphere. These species display remarkable diversity in their morphologies and preferred habitats. Recently, researchers from the South China Botanical Garden of the Chinese Academy of Sciences, described and illustrated a new species named Saussurea degeensis.

In a molecular study focused on Saussurea subgenus Amphilaena, which is the most complex subgenus within Saussurea, five samples identified as S. nigrescens did not cluster with other samples of this species. The researchers examined the specimens and conducted botanical expeditions from the northern Qianlian Mountains to the southern Hengduan Mountains, investigating these five samples alongside S. nigrescens.

Phylogenetic reconstruction of 54 samples from four subgenera of Saussurea, based on 800 nuclear loci, revealed that the new species belongs to S. subg. Amphilaena. It is most closely related to S. acutisquama, S. iodostegia, S. nigrescens, S. superba, S. tatsienensis, S. veitchiana, and S. wenchengiae.

Morphologically, Saussurea degeensis is characterized by its distinctive purple bracts, uncolored phyllary apices, and simple inflorescence. It is similar to S. nigrescens in its prominent purple bracts but can be distinguished by its larger leaves with crisped margins, a greater number of bracts, and non-obtuse phyllary apices.

Geographically, S. nigrescens occurs in the southeastern Hengduan Mountains, while the new species is found in the border area between the Hengduan Mountains and the Qinghai-Tibet Plateau.

The researchers concluded that the five samples represent a previously undescribed species and named it "degeensis" in reference to its type locality, Dege County in Sichuan, China.

Additionally, five species of Saussurea sect. Saussurea (S. acutisquama, S. hieracioides, S. superba, S. tatsienensis, and S. wenchengiae) were transferred to S. sect. Amphilaena based on both molecular and morphological data.

This study has been published in Phytotaxa and was supported by the National Natural Science Foundation of China as well as the Guangzhou Science and Technology Project.

Figure 1. Morphology of Saussurea degeensis (Dege, Sichuan, China). A. Habitat. B. Phyllaries. C. Style. D. Floret. E. Anther. F. Capitula. G. Achene. H. Leaf. I. Outer pappus. J. Inner pappus. Photographed by Lian-Sheng Xu based on L.S. Xu & S.Y. Du XD2023289 (IBSC).（Imaged by XU et al)

Figure 2. Distribution of Saussurea degeensis and S. nigrescens.（Imaged by XU et al)