Cynanchum longhushanense G.D.Tang & Miao Liao, nom. nov., non Cynanchum brevipedunculatum J.Y.Shen et al. (2019: 217).

Liao, Miao, Zeng, Si-Jin, Zeng, Lin-Ya, Yin, Hai-Jun, Yan, Mao-Lin, Zhang, Cai-Fei & Tang, Guang-Da, 2024, A new species and a replacement name in Cynanchum (Apocynaceae, Asclepiadeae) from China, PhytoKeys 241, pp. 49-63 : 49

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.

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) .

Figures

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 LM 78.