ISSN 1346-7565 Acta Phytotax. Geobot. 71 (3): 201–229 (2020) doi: 10.18942/apg.202002 Fifteen New Species of Angiosperms from Bidoup-Nui Ba National Park, Southern Highlands of Vietnam 1,* 2 2 3 SHUICHIRO TAGANE , NGUYEN VAN NGOC , HOANG THI BINH , AI NAGAHAMA , 3 4 4 5 MENG ZHANG , TRUONG QUANG CUONG , LE VAN SON , VAN-SON DANG , 6 7 8 HIRONORI TOYAMA , NAtsUKI KOMADA , HIDETOSHI NAGAMASU AND 9 TEtsUKAZU YAHARA 1The Kagoshima University Museum, Kagoshima University, 1-21-30 Korimoto, Kagoshima 890-0065, Japan. *[email protected] (author for correspondence); 2Faculty of science, Dalat University, 01 Phu Dong Thien Vuong, Dalat City, Lam Dong, Vietnam; 3Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan; 4Bidoup-Nui Ba National Park, Lam Dong, Vietnam; 5The VNM Herbarium, Institute of Tropical Biology, Vast, 85 Tran Quoc Toan Street, District 3, Ho Chi Minh City, Vietnam; 6Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506, Japan; 7Laboratory of Forest Resources and Society, Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan; 8The Kyoto University Museum, Kyoto University, Yoshida Honmachi, Sakyo-ku, Kyoto 606-8501, Japan; 9Kyushu Open University, Fukuoka 819-0395, Japan Fifteen new species of angiosperms, Ilex bidoupensis, I. hongiaoensis (Aquifoliaceae), Mastixia hongiaoensis (Cornaceae), Daphniphyllum hongiaoense (Daphniphyllaceae), Platea hongiaoensis (Icacinaceae), Neolitsea bidoupensis, N. hongiaoensis (Lauraceae), Nyssa bidoupensis, N. hongiaoensis (Nyssaceae), Eriobotrya hongiaoensis, Prunus hongiaoensis (Rosaceae), Luvunga hongiaoensis (Ruta- ceae), Illicium viridiflorum (Schisandraceae), Symplocos hongiaoensis (Symplocaceae) and Alpinia hongiaoensis (Zingiberaceae), from the Hon Giao area in Bidoup-Nui Ba National Park, Lam Dong Province, in the southern highlands of Vietnam, are described and illustrated. Keywords: Angiosperms, flora, Indochina, new species, taxonomy, Vietnam Bidoup-Nui Ba National Park, established in located on a mountain ridge that suddenly de- 2004 and covering ca. 70,038 ha of Langbian Pla- scends towards South China Sea at the eastern teau, is located in Lam Dong Province, in the edge of Bidoup-Nui Ba National Park. The dis- central highlands of Vietnam (Fig. 1). The eleva- tance between Hon Giao and the sea is about 50 tion of the area varies from 800 m to 2,287 m at km. Warm moist air from the sea results in a high the peak of Mt. Bidoup. The area is thickly cov- amount of rainfall that supports thick, montane ered with subtropical evergreen rainforests and evergreen broad-leaved forests (Vu & Xia 2011) low montane subtropical forests and is famous for and primary broad-leaved, evergreen, humid its high species diversity (Bidoup-Nui Ba Nation- montane forests (Duy & Averyanov 2015) domi- al Park 2018). The flora is composed of a mixture nated by species of trees of Araliaceae, Clusia- of Himalayan, Chinese, Indochinese and Malay- ceae, Cornaceae, Fagaceae, Lauraceae, Magnoli- sian elements (Averyanov et al. 2003), including aceae, Myrtaceae, Nyssaceae and Symplocaceae. valuable and rare species and genetic resources The unique flora has attracted many botanists. (Ban et al. 2007, Bidoup-Nui Ba National Park Recent botanical inventories of the area have re- 2018). sulted in the discovery eight new species of vas- Hon Giao area (elevation 1,630–2,050 m) is cular plants endemic to Hon Giao and adjacent 202 Acta Phytotax. Geobot. Vol. 71 Materials and methods To verify that the species were distinct, we consulted herbarium specimens at BKF, FOF, FU, HNL, KAG, KYO, RAF, TI, TNS and VNM, specimen images on the web (e.g. JSTOR Global Plant, https://plants.jstor.org/), taxonomic litera- ture on particular groups and regional floras, in- cluding the Illustrated Flora of Vietnam (Hô 1999–2003), the Flore du Cambodge, du Laos et du Vietnam (Aubréville et al. 1960–present), the Flora of China (Wu et al. 1994–2013) and the Flora of Thailand (Smitinand & Larsen et al. 1970–present). Voucher specimens have been de- posited in the herbaria of Dalat University, Dalat (DLU), Kyushu University, Fukuoka (FU), some in the Forest Herbarium, Bangkok (BKF), some in the Kagoshima University Museum, Kagoshi- ma (KAG) and in the Kyoto University Museum (KYO). Taxonomic treatments FIG. 1. Location of Bidoup-Nui Ba National Park. Aquifoliaceae areas: Adinandra hongiaoensis Son & L. V. Dung Ilex bidoupensis Yahara & Tagane, sp. nov. — (Pentaphylacaceae, Son & Dung 2014), Billolivia Fig. 2A–D. kyi Luu & G. Tran (Gesneriaceae, Luu et al. Ilex bidopuensis resembles Ilex chevalieri Merr. but dif- 2015), Bulbophyllum bidoupense Aver. & N. V. fers in having fewer secondary veins (3–5 pairs vs. 6–7 Duy (Orchidaceae, Duy & Averyanov 2015), pairs), longer petioles [(0.8–)1–1.6 cm long vs. 0.5–0.9 cm Dendrobium trankimianum T. Yukawa (Orchida- long)] and glabrous calyx lobes (vs. puberulent). Typus. VIETNAM. Lam Dong Province. Bidoup-Nui ceae, Yukawa 2004), Garcinia hopii H. Toyama Ba National Park: Hon Giao, in wet evergreen forest, & V. S. Dang (Clusiaceae, Toyama et al. 2017), 1,620 m elev., 12°11′14.83″N, 108°42′52.20″E, 22 Apr. Magnolia bidoupensis Q. N. Vu (Magnoliaceae, 2019, T. Yahara, S. Tagane, A. Nagahama, N. Komada, H. Vu & Xia 2011), Nianhochloa bidoupensis H. N. V. Thanh V9851 [fl.] (holo- KYO!, iso- DLU!, FU!, KAG!). Nguyen & V. T. Tran (Poaceae, Nguyen & Tran Trees, evergreen, to 10 m tall with GBH (girth at 2012) and Siliquamomum oreodoxa N. S. Lý & breast height) 23.5 cm. Young twigs greenish in Škorničk. (Zingiberaceae, Lý et al. 2010). vivo, dark reddish brown when dry, glabrous, old Since 2011, we conducted field surveys to as- twigs grayish brown, with minute lenticels. Stip- sess the plant diversity in Bidoup-Nui Ba Nation- ules triangular, 0.5–0.7 mm long, glabrous. al Park (Tagane et al. 2017, Toyama et al. 2017, Leaves alternate; blade 2.4–6.8 × 1.2–2.9 cm, Binh et al. 2018, Nagahama et al. 2019) and col- thinly leathery, greenish, drying dark reddish lected 3,468 specimens. In this study, we describe brown adaxially, dull grayish yellow abaxially, 15 new species in 11 families based on collections glabrous on both surfaces, punctate abaxially, from Hon Giao. apex acuminate to caudate, acumen to 1.3 cm long, base broadly cuneate, acute, or rounded, October 2020 TAGANE & AL. — Fifteen New Species from Southern Vietnam 203 FIG. 2. Ilex bidoupensis Yahara & Tagane (A–D). A: Flowering branch. B: Lower leaf surface. C: Leafy twig. D: Staminate inflorescence.Ilex hongiaoensis Tagane (E–I). E: Fruiting twig. F: Lower leaf surface. G: Fruit. H: Transverse section of fruit. I: Fruit pericarp removed showing pyrenes. Photographs A, B & D from Yahara et al. V9851 taken on 22 Apr. 2019; C from Yahara et al. V8650 taken on 18 June 2018; E–I from Tagane et al. V9412 taken on 1 Oct. 2019; all taken by Shu- ichiro Tagane. 204 Acta Phytotax. Geobot. Vol. 71 margin entire, slightly recurved when dry, midrib Additional specimens examined. VIETNAM. Lam sunken or prominent only in basal ca. 1/3 adaxi- Dong Province. Bidoup-Nui Ba National Park: Hon Giao, in montane evergreen forest, 1,533 m elev., 12°10′34.7″N, ally, prominent abaxially, secondary veins 3–5 108°41′08.4″E, 21 Feb. 2016, S. Tagane et al. V3999 [ster.] pairs, invisible adaxially, faintly visible abaxial- (DLU, FU); same locality, 1,666 m elev., 12°11′12.0″N, ly, tertiary veins invisible on both surfaces; peti- 108°42′51.0″E, 18 June 2018, T. Yahara et al. V8650 [ster.] ole (0.8–)1–1.6 cm long, glabrous. Staminate in- (DLU, FU); —Khanh Hoa Province: Mt. Hon Ba, 1,498 m florescences 2–5-flowered in simple cymes or elev., 12°07′08.64″N, 108°56′51.99″E, 18 July 2013, S. Tagane et al. V308 [ster.] (FU, VNM, the herbarium of sometimes in compound cymes; peduncle 3–6 Hon Ba Nature Reserve); same locality, 17 July 2014, S. mm long, glabrous; bracts narrowly triangular, Tagane et al. V1732 [young fr.] (FU, VNM, herbarium of ca. 0.5 mm long. Staminate flowers whitish, Hon Ba Nature Reserve). 4-merous; calyx lobes 4 or rarely 5, broadly trian- gular to transversely triangular, ca. 0.3 mm long, glabrous, margin ciliolate; petals 4, ovate-oblong, Ilex hongiaoensis Tagane, sp. nov. —Fig. 2E–I. ca. 1.5 mm long, white, glabrous on both surfac- Ilex hongiaoensis is most similar to I. chapaensis Merr. es, connate at base; stamens 4, ca. 1.8 mm long; of northern Vietnam and China but differs in having few- filaments ca. 1 mm long, glabrous; anthers ca. 0.8 er secondary veins (5–8 pairs in I. hongiaoensis vs. 8–10 mm long; rudimentary ovary conical, ca. 0.4 mm pairs in I. chapaensis), prominent and distinct tertiary in height; pedicel 3–4 mm long, glabrous; bracte- veins on the lower leaf surface (vs. not prominent) and shorter petioles (0.5–1.2 cm long vs. 1.2–3 cm long). oles triangular, ca. 0.2 mm long, glabrous. Pistil- Typus. VIETNAM. Lam Dong Province: Bidoup-Nui late inflorescences not seen. Infructescence Ba National Park, Hon Giao, in wet evergreen forest, (young), simple cymes, with 1–3-fruits; peduncle 1,666 m elev., 12°11′12.0″N, 108°42′51.0″E, 1 Oct. 2018, 2–4 mm long, glabrous. Young fruits subglobose, S. Tagane, A. Nagahama, M. Zhang, K. Tsuchiya, T. ca. 2.5 mm in diam., glabrous, green in vivo, red- Nguyen, C.T. Nguyen V9412 [fr.] (holo- KYO!, iso- DLU!, FU!, KAG!). dish brown when dry, calyx persistent, shallowly lobed, stigma columnar, persistent, ca. 1 mm Trees, to 12 m tall, GBH 32.6 cm.