Vincetoxicum taiwanense (Hatus.) T.C. Hsu, comb. nov.

≡ Tylophora taiwanensis Hatusima (1963: 10); Lu et al. (1998: 243).

Type:— TAIWAN. Keelung City: Kiirun, 17 October 1925, S. Suzuki s.n. (holotype: KAG-006419!) .

Note:— Vincetoxicum taiwanense closely resembles V. koi (Merr. in Merrill & Chun 1934: 17) Meve & Liede in Liede-Schumann & Meve (2018: 153) distributed in southern China, Thailand and Vietnam and was considered as conspecific in some studies (e.g. Li et al. 1995; Liede-Schumann & Meve 2018). However, Lu et al. (1998) pointed out that the former differs from the later by the absence of colleters at the base of calyx lobes. After studying the materials collected from various localities of Taiwan as listed below, we agree with the observation of Lu et al. (1998) and thus keep V. taiwanense as a distinct species here.

Additional specimens examined:— TAIWAN. Nantou County: Lianhuachih Research Center, 3 September 2008, Jung 3343 (TAIF) ; New Taipei City: Shih-Tin, 11 May 1976, Lu 4290 (TAIF); Shuangshi, 7 September 2000, Ho 1183 (TAIF) ; Taoyuan Valley, 28 October 28, Lu 24794 (TAIF); Pingtung County: Lanjen Stream, 10 July 2010, Lin 164 (TAIF); Mt. Kaoshihfo, 12 November 2012, Chen 4302 (TAIF); Shouchia, 21 November 2002, Chung & Ho 6080 (TAIF) ; Taipei City: Neihu, 1 October 1993, Lu 24144 (TAIF) ; Taitung County: Hungshih Logging Trail, 2 November 2009, Wang 1155 (TAIF); Kueitien, 24 November 1994, Lu 24155 (TAIF); Lichia Logging Trail, 18 October 1985, Lu 17430 (TAIF) .