Ophiorrhiza xishuiensis (Rubiaceae), a new species endemic to Guizhou, Sichuan, and Chongqing, China Author He, Xuan-Ze https://orcid.org/0009-0002-6432-1834 Gesneriad Conservation Center of China (Guizhou), National Forestry and Grassland Administration Key Laboratory for Biodiversity Conservation in Karst Terrain of Southwestern China, Guizhou Botanical Garden, Guiyang 550000, China Author Dai, Zheng-Xian https://orcid.org/0009-0003-7938-7243 Guizhou Xishui National Nature Reserve Management Bureau, Xishui 564600, China Author Xu, Jian 0000-0002-0714-0917 Gesneriad Conservation Center of China (Guizhou), National Forestry and Grassland Administration Key Laboratory for Biodiversity Conservation in Karst Terrain of Southwestern China, Guizhou Botanical Garden, Guiyang 550000, China Author Yang, Jia-Wen 0000-0003-3427-714X Gesneriad Conservation Center of China (Guizhou), National Forestry and Grassland Administration Key Laboratory for Biodiversity Conservation in Karst Terrain of Southwestern China, Guizhou Botanical Garden, Guiyang 550000, China Author Tang, Sheng-Hu 0000-0002-2168-8559 Gesneriad Conservation Center of China (Guizhou), National Forestry and Grassland Administration Key Laboratory for Biodiversity Conservation in Karst Terrain of Southwestern China, Guizhou Botanical Garden, Guiyang 550000, China text PhytoKeys 2026 2026-05-29 275 163 176 journal article 315298 10.3897/phytokeys.275.189435 e4064f1f-ca4e-4c19-a7a3-b0fc0b950630

Table 1. Detailed comparisons among Ophiorrhiza xishuiensis, O. japonica, O. guizhouensis, O. chinensis, O. cantonensis, O. umbricola, O. grandibracteolata and O. liuyanii.

Characters	O. xishuiensis	O. japonica	O. guizhouensis	O. chinensis	O. cantonensis	O. umbricola	O. grandibracteolata	O. liuyanii
Rooting stem	1–7 cm long	10–30 cm, or longer	10–30 cm, or longer	1–7 cm long, rarely longer	unknown	usually 15 cm, or longer	unknown	unknown
Stems	glabrous	glabrous or with 2 hirtellous or pilosulous lines	densely hirtellous	subglabrous to pilosulous	glabrous to densely puberulent or villosulous	glabrous or subglabrous	densely villous with trichomes multicellular or sometimes also unicellular	glabrous
Leaves	mostly arranged in markedly unequal pairs, base somewhat inequilateral, rarely subequilateral	arranged in subequal pairs, base subequilateral	arranged in subequal pairs, base subequilateral	arranged in subequal pairs, base subequilateral	arranged in subequal pairs, base subequilateral	mostly arranged in unequal pairs, base subequilateral	mostly arranged in markedly unequal pairs, base somewhat inequilateral	mostly arranged in equal pairs, base subequilateral
Bracteoles	persistent, ovate, broadly ovate, or oblong, 4.7–12 mm long	persistent, lanceolate-linear, spatulate, or linear, 1–6 mm long	persistent, lanceolate-linear, spatulate, or linear, 1–6 mm long	absent or reduced (caducous, linear, 1–1.5 mm long)	persistent, linear, 1–6 mm long	persistent, elliptic or oblong, 4–7 mm long	persistent, ovate, 10–15 mm long	persistent, ovate or broadly ovate, 9–22 mm long
Inflorescence	congested-cymose	congested-cymose to cymose	congested-cymose to cymose	paniculiform to cymose	paniculiform to corymbose	congested-cymose	congested-cymose	congested-cymose
Inflorescence axes	congested-cymose	congested-cymose or helicoid	congested-cymose or helicoid	helicoid	helicoid	congested-cymose	congested-cymose	congested-cymose
Peduncle	5–8 cm long, rarely shorter	0.5–6 cm long	1–2 cm long	1.5–3.5 cm long	1.5–7 cm long	1.5–3 cm long	0.6–1.7 cm long	1–2 cm long
Style in short-styled flowers	reaching above the middle of the tube	reaching below the middle of the tube	reaching below the middle of the tube	reaching below the middle of the tube	reaching below the middle of the tube	unknown	unknown	reaching below the middle of the tube
Style in long-styled flowers	glabrous	pubescent	pubescent	pubescent	unknown	unknown	unknown	pubescent