Discussion
Cylindrolobus gaoligongensis shares the same habitat with the other two Cylindrolobus species, C. motuoensis andC. glabriflorus , in the northern Gaoligong Mountain, the two later species were newly described from Motuo, southeastern Xizang and the border region between China and Myanmar in 2019 (Ya et al. 2019). All three species have similar slender and terete stems that are difficult to identify without floral traits. To date, the genusCylindrolobus consists of 9 species in the tropical and subtropical regions of southwest China (Rao 1997, Chen et al. 2009, Hu et al. 2010, Liu et al. 2013, Ya et al. 2019). The key to the Chinese species of Cylindrolobus is provided here.
Key to the Chinese species of Cylindrolobus
1 Stems stout, clavate………………………………………………………………………….2
– Stems slender, terete…………………………………………………………………………4
2 Lip yellow………………………………………………………………………………C. cristatus
– Lip lateral lobes with purple edges, mid-lobe with lighter purple edges
and patch …………………………………………………………………………………………………3
3 Inflorescence glabrous, the lateral lobes bigger than mid-lobe…..C. clavicaulis
– Inflorescence pubescent, the lateral lobes smaller than mid-lobe………………..
…………………………………………………………………………………………….C. marginatus
4 Inflorescence glabrous…………………………………………………………………………….5
– Inflorescence pubescent ………………………………………………………………………….6
5 lip mid-lobe thickened and papillate on margin………………………...C. tenuicaulis
– lip mid-lobe not thickened and smoothly on margin …………………C. glabriflorus
6 Flowers yellow …………………………………………………………………………C. foetidus
– Flowers white………………………………………………………………………………………….7
7 Lip oblong and front margin papillate………………………….…C. motuoensis
– Lip obovate and front margin with long hairs or long glandular hairs…………..8
8 lip mid-lobe triangular-ovate and apex mucronate……………C. gaoligongensis
– lip mid-lobe reniform and apex emarginated………….……..C.