The plant Bupleurum dracaenoides Huan C. Wang, Z. R. He & H. Sun, described in 2013, is distinct because of its long woody stem (up to 1.5 m) and clustered leaves. Of > 200 Bupleurum species only five have been recorded to have a woody stem with a shrub or sub-shrub habit, and all of these are endemic to the Mediterranean region. Bupleurum dracaenoides is the sole woody Bupleurum species in Asia. It grows in rocky cliff habitat in the dry, hot valley of Jinsha River, south-west China. Investigations prior to 2013 located only three populations of the species, and subsequent surveys located five more localities in an adjacent area.
In September 2018, sponsored by a grant of the National Key Research and Development Programme of China (2017YF0505200), we surveyed along the Jiansha River, revisiting the range of B. dracaenoides. We found a total of 10 populations, two of which were newly recorded. One of these is in Xueshan town, where B. dracaenoides had already been recorded, and the second is in Tangdan town, > 20 km from the other known locations of the species. Only seedlings were found in the Tangdan population, and the number of individuals in the 10 known populations is low (< 50 in each). Thus even though we located two previously unknown populations, the total number of known B. dracaenoides in the wild may be < 500. The known range of B. dracaenoides is < 10 km2, over altitudes of 2,300–2,700 m.
Road construction is a potential threat to B. dracaenoides. In the Huidong population, which is the only population known on the north bank of Jinsha River, the number of plants has decreased to only five individuals as a result of road building (22 individuals were known in 2015). The mountain cliffs around Xueshan town in Luquan county hold most of the extant B. dracaenoides individuals, possibly a result of the foggy, high-cliff habitat, which shelters the plants from human disturbance and is not under threat from road construction.
The seeds of B. dracaenoides have a high germination rate (L. Kong et al., 2017, Plant Science Journal, 3, 421–426), and we therefore believe that lack of germination is not restricting the species’ distribution. Kunming Institute of Botany is now carrying out comprehensive phylogeographical and tissue culture studies of B. dracaenoides to obtain genetic and physiological information to aid conservation and to recover the species in the wild.
