Aristolochia longeracemosa, a new synonym of A. chlamydophylla (Aristolochiaceae) Author Do, Truong Van Vietnam National Museum of Nature, Vietnam Academy of Science & Technology, 18 th Hoang Quoc Viet Road, Cau Giay, Ha Noi, Vietnam. & Chengdu Institute of Biology, Chinese Academy of Sciences, P. O. Box 416, Chengdu, Sichuan 610041, P. R. China Author Gao, Xin-Fen Chengdu Institute of Biology, Chinese Academy of Sciences, P. O. Box 416, Chengdu, Sichuan 610041, P. R. China text Phytotaxa 2017 2017-08-11 317 1 76 78 http://dx.doi.org/10.11646/phytotaxa.317.1.8 journal article 10.11646/phytotaxa.317.1.8 1179-3163 13696217 Aristolochia chlamydophylla C.Y. Wu ex S. M. Hwang, Acta Phytotax. Sin. 19(2): 223, pl. 2. 1981. Type :— CHINA . Yunnan : Ruili , elev. 1000 m , 27 April 1961 , S . Chow 610 ( holotype , KUN ; isotype , HITBC-057607!, PEM- 0001682!) Aristolochia longeracemosa B. Hansen & Leena Phuphathanaphong, Nord. J. Bot. 19(5): 577, fig. 2. 1999. Type:— THAILAND . Nan : Doi Phu Kha, elev. 1100 m , 5 April 1990 , H. Banziger 667 ( holotype , C-10006616!) syn. nov. Hwang (1981) originally described A. chlamydophylla on the basis of the specimens collected from southern China ( Yunnan & Guangxi ) and also indicated the specimen S. Chow 610 at KUN as the holotype of the species. However, the year in the type collection was wrongly written as “1916” in the protologue and is not matching the information provided on the field label, which is here corrected as “1961”. Nearly 20 year later, Hansen & Phuphathanaphong (1999) described A. longeracemosa , based on the type specimen only, H. Banziger 667 ( holotype C-10006616!), collected from Doi Phu Kha, Nan province , northern Thailand . The authors also compared this species with three similar species, i.e. A. pothieri Pierre ex Lec. (1909: 74) , A. kerrii Craib (1911: 450) (a synomym of A. cambodiana Pierre ex Lec. (1909: 74) ( Do et al. 2014 )), and A. tagala Cham. (1832: 207) (a synonym of A. acuminata Lam. (1783: 254) ( Bosser 1997 ). Aristolochia longeracemosa is morphologically clearly different from the abovementioned species by having a long petiole, up to 10 cm long, cymose inflorescences (it was described as “racemose” in the protologue, although this is a patent error as bracteoles are floweropposed) with a 8–10 flowered long axis, an amplexicaul, ovate to cordate bracteole, and a sessile utricle. These diagnostic characters, however, are mostly identical to those found in A. chlamydophylla , a previously described species endemic to southern China . Furthermore, we found very few differential characters between these two species related to the length of the inflorescences axis, the number of flower, and the size of the bracteole and the perianth, which are frequently variable during growth and the flower lifespan of Aristolochia species in general. Additionally, these two “species” grow at the same altitude ranging from 1000 to 1300 m , flower in April. Hence, A. longeracemosa is conspecific with A. chlamydophylla , and is treated here as a new synonym of the latter, based on the detailed comparison presented in Table 1 .