Conamomum vietnamense (Zingiberaceae), a new species from Tay Nguyen, Vietnam Author Ly, Ngoc-Sam 0000-0002-9925-5171 Institute of Tropical Biology, VAST, 85 Tran Quoc Toan Road, District 3, Ho Chi Minh City, Vietnam. & Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet, Cau Giay District, Ha Noi, Vietnam. & lysamitb @ gmail. com; https: // orcid. org / 0000 - 0002 - 9925 - 5171 lysamitb@gmail.com Author Hoang, Thanh-Son 0000-0003-0351-929X Silviculture Research Institute, Vietnamese Academy of Forest Sciences, Ha Noi 10000, Vietnam. & hoangsonfsiv @ gmail. com; https: // orcid. org / 0000 - 0003 - 0351 - 929 X hoangsonfsiv@gmail.com Author Insisiengmay, Oudomphone 0000-0001-5167-3174 Institut de Systématique Évolution Biodiversité (ISYEB), Muséum national d’histoire naturelle, Centre national de la recherche scientifique, École Pratique des Hautes Études, Université, des Antilles, Sorbonne Université, 45 rue Buffon, CP 50, 75005 Paris, France. & The Cabinet of the Lao Academy of Science and Technology, Ministry of Education and Sport, 100 Building, Na Haidiew Village, Chanthabouly District, Vientiane Capital, Lao PDR. & oudomphoneinsisiengmay @ gmail. com; https: // orcid. org / 0000 - 0001 - 5167 - 3174 oudomphoneinsisiengmay@gmail.com Author Haevermans, Thomas 0000-0001-8934-4544 Institut de Systématique Évolution Biodiversité (ISYEB), Muséum national d’histoire naturelle, Centre national de la recherche scientifique, École Pratique des Hautes Études, Université, des Antilles, Sorbonne Université, 45 rue Buffon, CP 50, 75005 Paris, France. & thomas. haevermans @ mnhn. fr; https: // orcid. org / 0000 - 0001 - 8934 - 4544 thomas.haevermans@mnhn.fr Author Newman, Mark F. 0000-0003-4851-015X Royal Botanic Garden Edinburgh, 20 A Inverleith Row, Edinburgh EH 3 5 LR, Scotland, UK. & MNewman @ rbge. org. uk; https: // orcid. org / 0000 - 0003 - 4851 - 015 X ewman@rbge.org.uk text Phytotaxa 2022 2022-01-18 531 2 129 135 journal article 2536 10.11646/phytotaxa.531.2.5 26cea477-ded7-4e5c-be11-7fd4ffa020ee 1179-3163 5869234 Key to the species of Conamomum in Cambodia and Vietnam 1. Stilt roots absent .................................................................................................................................................................................2 - Stilt roots present................................................................................................................................................................................3 2. Leaf blades 30–45 × 4.5–7 cm , ligules hairy, bracts rotting at early stage, calyx glabrous, corolla lobes reddish, labellum reniform, ovary glabrous ( Vietnam ) .................................................................................................................................................. C. rubidum - Leaf blades 25–30 × 3– 3.5 cm , ligules glabrous, bracts persistent, calyx pubescent, corolla lobes cream, labellum obovate, ovary hairy ( Vietnam ).................................................................................................................................................................... C. odorum 3. Stilt roots ≥ 20 cm long, petiole 5–8 mm long, calyx bilobed, 12–14 mm long, and sparsely pubescent, labellum obovate-orbicular, ovary hairy, fruit smooth and hairy ( Vietnam ) ............................................................................................................ C. vietnamense - Stilt roots < 20 cm long, petioles 20–30 mm long, calyx tridentate, 20–25 mm long and glabrous, labellum bowl-shaped, ovary glabrous, fruit finely ridged and glabrous ( Cambodia , Thailand ) ................................................................................ C. pierreanum