A new species and a replacement name in Cynanchum (Apocynaceae, Asclepiadeae) from China Author Liao, Miao https://orcid.org/0000-0003-2545-9419 College of Forestry and Landscape Architecture, South China Limestone Plants Research Center, South China Agricultural University, Guangzhou, China & CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China & Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, China & University of Chinese Academy of Sciences, Beijing, China Author Zeng, Si-Jin https://orcid.org/0000-0002-3256-0286 State Key Laboratory of Plant Diversity and Specialty Crops / Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China kaileqixia@gmail.com Author Zeng, Lin-Ya https://orcid.org/0000-0002-4788-1867 State Key Laboratory of Plant Diversity and Specialty Crops / Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China Author Yin, Hai-Jun https://orcid.org/0009-0004-9804-1958 Tongbiguan Provincial Nature Reserve, Ruli, Yunnan, China Author Yan, Mao-Lin https://orcid.org/0009-0003-5188-6796 Tongbiguan Provincial Nature Reserve, Ruli, Yunnan, China Author Zhang, Cai-Fei https://orcid.org/0000-0002-2818-5751 CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, China & Sino-Africa Joint Research Center, Chinese Academy of Sciences, Wuhan, China Author Tang, Guang-Da https://orcid.org/0000-0001-5623-3928 College of Forestry and Landscape Architecture, South China Limestone Plants Research Center, South China Agricultural University, Guangzhou, China & Henry Fok College of Biology and Agriculture, Shaoguan University, Shaoguan, China text PhytoKeys 2024 2024-04-08 241 49 63 http://dx.doi.org/10.3897/phytokeys.241.111499 journal article http://dx.doi.org/10.3897/phytokeys.241.111499 1314-2003-241-49 922ED8D5FD2A56DFBAB78CC334E2E096 Cynanchum longhushanense G.D.Tang & Miao Liao, nom. nov., non Cynanchum brevipedunculatum J.Y.Shen et al. (2019: 217). Fig. 2 Raphistemma brevipedunculatum ≡ Raphistemma brevipedunculatum Y.Wan, in Guihaia 3(3): 197 (1983). Type . China . Guangxi : Longan County , Longhushan Nature Reserve , open woods, 2 Jul. 1981 , D.H. Tan 81329 ( holotype : GXSP[GXSP0000038!]; isotype : CANT[CANT00002128!]) . Chinese name. Guangxi Dahuateng (广西大花藤). Notes. Raphistemma brevipedunculatum was considered a synonym of R. hooperianum ( Li et al. 1995 ), which was transferred to Cynanchum as C. hooperianum ( Khanum et al. 2016 ). Although C. hooperianum is not included in our molecular study, morphological differences between specimens of C. hooperianum and R. brevipedunculatum are significant. We therefore reinstate R. brevipedunculatum as a distinct species of Cynanchum . We renamed Raphistemma brevipedunculatum as Cynanchum longhushanense because the specific epithet ' Cynanchum brevipedunculatum ' is occupied in Cynanchum ( C. brevipedunculatum J.Y.Shen). C. longhushanense differs from C. hooperianum by the longer calyx lobes (5-6 mm vs. 3-4 mm), the longer corolla-tubes (12-16 mm vs. 8-9 mm), the oblong corolla lobes (vs. ovate), and the corona lobes with connivent corona-scales apex, not exceeding the throat of the corolla (vs. corona-scales apex separate, reaching the middle of the corolla-segments or further). It should be noticed that in the protologue of Cynanchum longhushanense (≡ R. brevipedunculatum ) ( Wan 1983 ), the number of glands at the base of the calyx was described as five, but we observed 10-15 glands per calyx in our Guangxi collection (Fig. 2j ). More specimens are expected to be collected to determine the morphological variation. Figure 2. Cynanchum longhushanense G.D.Tang & Miao Liao a flowering branch b cross-section of hollow stem c node with small glands d petiole with glands at the top e inflorescence f bracteoles at the base of the pedicel g flower bud (above: top view; below: side view) h flower (1) top view, (2) lateral view, showing the connivent corona-scales apex, not exceeding the throat of the corolla, (3) side view, showing corolla lobes overlapping to the right and corolla tube i opened corolla, adaxial (above) and abaxial (below) view j ovary with calyx (above: top view, showing glands at the base of the calyx, below: side view of ovary, calyx and pedicel) k ovary l calyx lobes m gynostegium with corona lobes n gynostegium o corona lobes p pollinarium. All photos based on Miao Liao LM78 . Other specimens examined. China . Guangxi : Longan County , Pingshan Village , 10 Oct. 1977 , Longan Investigation Team 2-040 (GXMI[GXMI031735!]); Longan County , Longhushan Nature Reserve , 14 Nov. 1982 , Y. Wan & Rui-Ju Liu 82430 ( paratype : GXSP[GXSP0000039!]); Longan County , Longhushan Nature Reserve , 25 Jun. 2021 , Miao Liao LM 78 (IBSC) .