Vincetoxicum (Apocynaceae: Asclepiadoideae) in Taiwan: Two new combinations and a new record Author Hsu, Tian-Chuan 0000-0002-2612-1885 Botanic Garden Division, Taiwan Forestry Research Institute, Taipei 100, Taiwan. lecanorchis@gmail.com Author Huang, Wei-Jie 0000-0001-7085-0586 Botanic Garden Division, Taiwan Forestry Research Institute, Taipei 100, Taiwan. wjhuang1991@gmail.com Author Chung, Shih-Wen 0000-0002-5669-4406 Botanic Garden Division, Taiwan Forestry Research Institute, Taipei 100, Taiwan. biflora@gmail.com text Phytotaxa 2021 2021-01-06 478 2 287 290 http://dx.doi.org/10.11646/phytotaxa.478.2.11 journal article 305314 10.11646/phytotaxa.478.2.11 e59eaca8-dfc7-41a3-a546-dfc9147469e2 1179-3163 5413120 A key to the species is also provided as below to aid their identification. 1. Stems erect; peduncles shorter than 1 cm .......................................................................................................... Vincetoxicum atratum - Stems twining or prostrate; peduncles longer than 2 cm ...................................................................................................................2. 2. Stems prostrate; leaves nearly orbicular.................................................................................................................... Vincetoxicum sui - Stems twining; leaves linear-lanceolate to ovate...............................................................................................................................3. 3. Corolla lobes oblong-lanceolate, 6–10 mm long...............................................................................................................................4. - Corolla lobes ovate, 2–4 mm long.....................................................................................................................................................5. 4. Stems puberulent along two lines; leaves sparsely puberulent on main veins and along margin, otherwise glabrous; corolla yellow-white ..................................................................................................................................................................... Vincetoxicum fordii - Stems and leaves uniformly pubescent; corolla purple or at least purplish at base ................................... Vincetoxicum mooreanum 5. Leaves obtuse to rounded at base, subtrinerved; calyx with 5 colleters inside ................................................ Vincetoxicum oshimae - Leaves rounded to subcorded at base, pinnately veined; calyx without colleters .............................................................................6. 6. Plant glabrous except for very young stems................................................................................................ Vincetoxicum taiwanense - Plants variously hairy ........................................................................................................................................................................7. 7. Leaves lanceolate, 0.8–2.1 cm wide, usually> 3× as long as broad.................................................................................................8. - Leaves ovate, 1.5–4.0 cm wide, usually <3× as long as broad.........................................................................................................9. 8. Peduncles and pedicels pubescent ................................................................................................................. Vincetoxicum insulicola - Peduncles and pedicels glabrous ............................................................................................................................... Vincetoxicum lui 9. Stems densely pubescent; leaves pubescent on both surfaces......................................................................... Vincetoxicum hirsutum - Stems sparsely pubescent; leaves glabrescent................................................................................................... Vincetoxicum brownii