Lectotypifications in Nephelium L. and Xerospermum Blume (Sapindaceae) Boonchuang Boonsuk 1 & Pranom Chantaranothai 1 Summary. Eleven synonyms for five Nephelium species: N. cuspidatum Blume, N. hypoleucum Kurz, N. juglandifolium Blume, N. lappaceum L. and N. melanomiscum Radlk. and 11 synonyms of Xerospermum noronhianum (Blume) Blume are discussed and typified. Key Words. Nephelieae, nomenclature, Southeast Asia, synonym, taxonomy, Thailand. Introduction The genera Nephelium L. and Xerospermum Blume have generally been placed in Sapindaceae tribe Nephelieae (Radlkofer 1931), although Acevedo- Rodriguez et al. (2011) treated them as genera of uncertain position. The former genus comprises 22 species distributed from Assam, Yunnan, Hainan to Southeast Asia (Leenhouts 1986), whereas only two species were recognised for the latter, occurring from Bangladesh, Assam, Myanmar, Indo-China and the Malay Peninsula, to Sumatra, Java and Borneo (Leenhouts 1983). Nephelium is extremely difficult to identify based on sterile parts or flowers. Fruits and vegetative parts are important for species delimitation (Welzen 1999) but it rather resembles Mischocarpus Blume and Xerospermum in overall morphology, which can easily cause mis-identification (Leenhouts 1983). Revisions of Nephelium, Xerospermum and the wider Sapindaceae in Malesia have been undertaken (Leenhouts 1983, 1986; Adema et al. 1994) but the typification of several accepted names and synonyms remained unclear. Therefore, the present study aims to lectotypify names as required by the International Code for Nomenclature (ICN), especially Articles 9.5, 9.11, 9.12 and 9.17 (McNeill et al. 2012). Materials and methods Type specimens of Nephelium cuspidatum Blume, N. hypoleucum Kurz, N. juglandifolium Blume, N. lappaceum L., N. melanomiscum Radlk., Xerospermum noronhianum (Blume) Blume and associated synonyms, deposited in herbaria at A, BM, C, CAL, FI, G, K, L, M, NY, P, SING, U and US, were examined. Nearly all type specimens housed at BM, K and SING and specimen images from A, BM, FI, G, K, L, M, NY, P, U and US were seen. Those not seen are indicated by ‘n.v.’. For taxa from Myanmar and the Malay Peninsu- la, many collections were deposited in CAL, especially those made by King, Kurz, etc. We requested all appropriate material, namely of N. dasyneurum Radlk., N. longana (Lam.) Cambess. var. hypoleuca (Kurz) King, Cupania glabrata Kurz, Xerospermum echinulatum Radlk., X. intermedium Radlk. and X. wallichii King. However, only the type of X. echinulatum was located. Typifications Nephelium cuspidatum Blume (1847: 110). Type: Indonesia, Borneo, Korthals s.n. (lectotype L! [L0014463], selected here; isolectotype L! – 3 sheets [L0014464, L0014465, L0014466]). Nephelium beccarianum Radlk. (Radlkofer 1879a: 97). Type: Malaysia, Sarawak, Gunon Mattan, July 1866, fl., Beccari 2279 (lectotype FI! [FI008668], selected by Leenhouts (1986)). N. multinerve Radlk. (Radlkofer 1879a: 97). Type: Malaysia, Sarawak, cult., Beccari 2820 (holotype FI! [FI008667]). N. ophiodes Radlk. (Radlkofer 1879b: 116). Type: Malay Peninsula, Maingay 543 (lectotype K! [K000701872], selected here). N. bassacense Pierre (1894: pl. 319B). Type: Laos, ad Bassac, Harmand 1427 (lectotype P! [P02297355], selected by Leenhouts (1986); isolectotypes K! [K000701756], M! [M0224992], P! – 3 sheets [P02297356, P02297359, P02297366]). N. dasyneurum Radlk. (Radlkofer 1907: 353). Type: Indonesia, Sumatra, Forbes 2842 (lectotype FI! [FI008670], selected here; isolectotypes L!-3 sheets [L0014468, L0014469, L0014470], P!-2 sheets [P02297374, P02297375], SING! [SING0045632]). N. obliquinerve Radlk. (Radlkofer 1907: 354). Type: Malay Peninsula, Malacca, Kesang Tua, Goodenough 1304 (lectotype SING! [SING0045630], selected here). Accepted for publication 31 January 2018. 1 Department of Biology and Centre of Excellence on Biodiversity (BDC), Faculty of Science, Khon Kaen University, Khon Kaen, 40002, Thailand. e-mail: chantaranothai@gmail.com KEW BULLETIN (2018) 73:15 DOI 10.1007/S12225-018-9735-8 ISSN: 0075-5974 (print) ISSN: 1874-933X (electronic) © The Board of Trustees of the Royal Botanic Gardens, Kew, 2018