The review of Bulbophyllum section Tripudianthes (Orchidaceae) in the flora of Vietnam with the description of new species, B. viridipallidum Author Nguyen, Van Canh 0000-0001-9578-0342 Institute of Applied Technology, Thu Dau Mot University No. 06, Tran Van On Street, Phu Hoa Ward, The Dau Mot City, Binh Duong Province, Vietnam. & nguyenvancanh @ gmail. com; https: // orcid. org / 0000 - 0001 - 9578 - 0342 nguyenvancanh@gmail.com Author Averyanov, Leonid V. 0000-0001-8031-2925 Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Street 2, 197376, St. Petersburg, Russia. & av _ leonid @ mail. ru; https: // orcid. org / 0000 - 0001 - 8031 - 2925 av_leonid@mail.ru Author Maisak, Tatiana V. 0000-0001-5919-6755 Komarov Botanical Institute of the Russian Academy of Sciences, Prof. Popov Street 2, 197376, St. Petersburg, Russia. & tmaisak @ mail. ru; https: // orcid. org / 0000 - 0001 - 5919 - 6755 tmaisak@mail.ru Author Nguyen, Thi Lien Thuong 0000-0001-8219-0431 Institute of Applied Technology, Thu Dau Mot University No. 06, Tran Van On Street, Phu Hoa Ward, The Dau Mot City, Binh Duong Province, Vietnam. & thuongntl @ tdmu. edu. vn; https: // orcid. org / 0000 - 0001 - 8219 - 0431 thuongntl@tdmu.edu.vn Author Nguyen, Van Khuong 0000-0002-1264-5178 Institute of Applied Technology, Thu Dau Mot University No. 06, Tran Van On Street, Phu Hoa Ward, The Dau Mot City, Binh Duong Province, Vietnam. & nguyenkhuongbanme @ gmail. com; https: // orcid. org / 0000 - 0002 - 1264 - 5178 nguyenkhuongbanme@gmail.com Author Pham, Thi Thanh Dat 0000-0003-0585-1050 Institute of Applied Technology, Thu Dau Mot University No. 06, Tran Van On Street, Phu Hoa Ward, The Dau Mot City, Binh Duong Province, Vietnam. & phamthithanhdat @ gmail. com; https: // orcid. org / 0000 - 0003 - 0585 - 1050 phamthithanhdat@gmail.com Author Nguyen, Danh Duc 0000-0002-3331-8571 Institute of Applied Technology, Thu Dau Mot University No. 06, Tran Van On Street, Phu Hoa Ward, The Dau Mot City, Binh Duong Province, Vietnam. & nguyendanhduc @ tdmu. edu. vn; https: // orcid. org / 0000 - 0002 - 3331 - 8571 nguyendanhduc@tdmu.edu.vn Author Dang, Van Son 0000-0001-8681-4141 Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay District, Hanoi, Vietnam. & Institute of Tropical Biology Vietnam Academy of Science and Technology, 85 Tran Quoc Toan, District 3, Ho Chi Minh City, Vietnam. Number 199 / 128 the connect 9 Kaset-Navamin rd. Klong Kum, Bueng Kum, Bangkok 10240. & dvsonitb @ gmail. com; https: // orcid. org / 0000 - 0001 - 8681 - 4141 dvsonitb@gmail.com Author Aromyen, Warapong 0009-0004-8510-8981 warapongnoom @ gmail. com; https: // orcid. org / 0009 - 0004 - 8510 - 8981 warapongnoom@gmail.com Author Truong, Ba Vuong 0000-0003-3452-8455 Graduate University of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay District, Hanoi, Vietnam. & Institute of Tropical Biology Vietnam Academy of Science and Technology, 85 Tran Quoc Toan, District 3, Ho Chi Minh City, Vietnam. Number 199 / 128 the connect 9 Kaset-Navamin rd. Klong Kum, Bueng Kum, Bangkok 10240. & bavuong 2019 @ yahoo. com; https: // orcid. org / 0000 - 0003 - 3452 - 8455 bavuong2019@yahoo.com text Phytotaxa 2023 2023-05-19 598 1 59 68 http://dx.doi.org/10.11646/phytotaxa.598.1.4 journal article 263159 10.11646/phytotaxa.598.1.4 7ebba404-44c5-4981-aa61-fb8e307b4042 1179-3163 7958804 4. B. refractum ( Zollinger 1847: 456 ) Reichenbach (1861: 259) , Seidenfaden (1970: 347) , Averyanov (1994: 284) , Seidenfaden (1992: 263) . ( Fig. 4 ). ≡ Cirrhopetalum refractum Zollinger 1847: 456 . Type :— INDONESIA . Java , Zollinger, 2261 (G00165064 photo!). ≡ Phyllorkis refracta ( Zollinger 1847: 456 ) Kuntze (1891: 677) . ≡ Tripudianthes refracta ( Zollinger 1847: 456 ) Szlachetko & Kras (2007: 96) . Habitat and phenology: —Epiphyte on tall trees in primary evergreen broad-leaved forests. Flowering observed in December–February. Distribution: — Vietnam ( Lam Dong , Gia Lai , Dak Nong , Binh Phuoc , Dien Bien provinces), Bhutan , India , Myanmar , Thailand , Java and Sumatra. Proposed conservation status :—According to currently available data, B. refractum seems quite common in Vietnam . Due to attractive nature of flowers, the species is widely collected for trade. Based on the national EOO 148,826.741 km 2 and AOO 28.000 km 2 , and in accordance with IUCN criteria ( IUCN, 2022 ), the species should be assessed in Vietnam as VU B2ab(v). The verifiable data for this species’ conservation status outside Vietnam is not available. Note :—Common in Vietnam , with relatively large flowers having a large dorsal sepal. The species is sometime misidentified as B. kanburiense ; the main differences is indicated under the note for B. kanburiense . The drawing of Pham Hoang Ho (1992: 844) named as B. refractum possibly based on specimens of Tixier 15 (P00348218) having a very small dorsal sepal typical for B. wallichii . Studied specimens: — VIETNAM , Lam Dong Province , Annam : piste de Fyan, 1957, Tixier, 15 (P00348218 photo!). VIETNAM , Gia Lai Province , 1987, Averyanov, LX-VN 2143a/190a (photos LE01057662!, LE01087253!). VIETNAM , Binh Phuoc Province , 2005, Averyanov et al., HLF 4932a (photos LE01087116!). VIETNAM , Lam Dong Province , 2011, NPT 006 (photos LE0105766!, LE01070245!). VIETNAM , Lam Dong Province , 2018, Truong Ba Vuong, Ngo Quang Dang, BV 1035 (VNM00043084!). VIETNAM , Gia Lai Province , Truong Ba Vuong, BV 1083 (VNM00043085!). VIETNAM , Dak Nong Province , 2019, Averyanov, Nguyen Van Canh, T. Maisak, AL 1183.4 (photos LE01067185!). VIETNAM , Dak Lak , 2019, Truong Ba Vuong, BV 532 (VNM00043069!). VIETNAM , Lam Dong Province , 2021, Truong Ba Vuong, Ngo Quang Dang, BV 1046 (photos LE01089814!, VNM00043072!). VIETNAM , Dien Bien Province , 2023, Nguyen Sinh Khang, AL 2191 (photos LE01123884!). INDONESIA , Java , 1844, Zollinger, 2261 (isotype P00347107 photo!).