Search

Oreocharis hainanensis, a new species of Gesneriaceae is described and illustrated from low-altitudual karst areas in Hainan Island, South China. The new species is easily distinguished from its closely-related O. jasminina by campanulate floral tube, zygomorphic corolla and exserted stamens. It also shows different habitats from the four currently-recognized Oreocharis taxa on the island. Molecular phylogeny analysis based on plastid trnL-trnF and nuclear ITS1/2 sequences supported the delimitation of the new species, which forms a monophyletic clade with all the other Oreocharis taxa from Hainan Island. The roles of habitat and floral isolation in the evolution of the new species and its affinities are discussed. The species was assessed as Vulnerable (VU C1 and D2) according to IUCN Red List Categories and Criteria.

We summarize the knowledge on taxonomy and distribution of the genus Parnassia in Vietnam. Two species of the genus are found in Vietnam. We report additional records of P. wightiana, which appears to inhabit the provinces Ha Giang and Yen Bai. We provide detailed morphological description of the Vietnamese populations of this species, and discuss their deviation from the known variation range of P. wightiana. We report for the first time the second species of Parnassia from Vietnam, and provisionally identify it as P. procul. Our discovery of this species in Lam Dong Province in southern Vietnam is the first record of the genus outside the northern highlands within the country. We illustrate both Vietnamese species of Parnassia with analytical photographs, and show their distribution on a map. Additionally, we present an updated checklist of the family Celastraceae in Vietnam, which reflects the most recent views on taxonomic boundaries of the family and its genera, and includes discoveries of the last years as well as some earlier reports absent in the previous works. In total, 17 genera and 93 species are accepted in the checklist.

Oreocharis hainanensis S.J.Ling & M.X.Ren, sp. nov. (Figs 1, 2) Diagnosis:���The new species is easily distinguished from O. jasminina by campanulate (not narrowly tubular) floral tube, zygomorphic (not actinomorphic) corolla, exserted (not included) stamens (Fig. 1, 2, Table 1). Type: ��� CHINA. Hainan Island: Dongfang City, Baobaimiao Village, north to the Changhua River, 18��55���N, 109��02���E, elev. ca. 280 m a.s.l., on karst rocks, 17 September 2020, S. J . Ling 2020091701 (holotype HUTB!; isotypes HUTB!, KUN!, IBK!). Perennial herb, rhizomatous, acaulescent. Leaves basal, rosette; petiole 1.5���5 cm long, 2���3 mm in diameter, brown woolly; blade obovate, ovate to broadly ovate, rarely broadly ovate, 2.5���9 �� 2���7 cm, adaxially gray pubescent, abaxially brown pubescent, densely brown villous along veins, apex subrounded, rarely rounded, margin shallowly crenateserrate, base often cuneate, rarely subrounded, lateral veins 5���7 pairs, distinct, conspicuously prominent adaxially and conspicuously elevated abaxially. Inflorescence cymose, axillary, cymes 2���7, 3���8 - flowered; peduncle 5���17 cm long, brown, sparsely pale gray villous. Bracts 2, linear to narrowly triangular, 2���3 �� ca. 1 cm, abaxially pale gray villous, apex acuminate, margin entire; pedicel to 4 cm long, sparsely pale gray villous. Calyx green, 3���4 mm long, 5 - parted near to base, lobes narrowly lanceolate, 2.5���4 �� ca. 1 mm, apex acuminate, margin entire, adaxially pale gray pubescent, abaxially glabrous. Corolla yellow, 1���1.5 cm long, adaxially pubescent; tube campanulate, 1���1.7 cm �� 3���4.5 mm; limb 2 - lipped, adaxial lip shallowly 2 - lobed, lobes ca. 3.5 �� 5 mm, abaxial lip 3-lobed almost to base, lobes equal, subsemiorbicular, 5.5���8 �� 5���7 mm, apex acuminate. Stamens 4, didynamous, adnate to corolla 3���4 mm from base, exserted; filaments of adaxial pairs ca. 0.8 cm long, abaxial pairs ca. 1.4 cm long; anthers ovate, bithecous, dehiscing longitudinally, adaxial thecae 1���1.5 �� 0.7���1.1 mm, downward, abaxial thecae 1.8���2.8 �� 1���1.5 mm, upward; staminode 1, adnate to corolla 2���3 mm above base, ca. 2 mm long. Disc ca. 1 mm high, entire. Pistil ca. 1.6 cm long, glabrous; ovary narrowly oblong, ca. 8 mm long, glandular-puberulent; style cylindrical and glandular-puberulent, ca. 0.5 cm long; stigma 2, equal, suborbicular. Capsule linear, 2.5���4 cm long, glabrous to sparsely puberulent. Distribution and habitat: ��� Oreocharis hainanensis is currently only known on low-altitudual karst cliffs and rocks at the edge of evergreen broad-leaved forests near Changhua River, in the southwestern Hainan Island, South China. Phenology: ���Flowering from August to October and fruiting from September to November. Etymology: ���The specific epithet refers to the type location, Hainan Island, South China. Vernacular name:��������������ffă (Chinese, H��i N��n M�� L��ng J�� T��i). Conservation status: ���So far, Oreocharis hainanensis is only known from two locations (less than 5 locations) with about 3,000 ���4,000 individuals. The populations are under threat due to the limited and fragmented karst habitats, with a very restricted area of occupancy (typically less than 20 km 2). Therefore, we propose that O. hainanensis should be considered as Vulnerable (VU C1 and D2) according to the IUCN Red List Categories and Criteria (IUCN 2019)., Published as part of Ling, Shao-Jun, Wen, Fang & Ren, Ming-Xun, 2022, Oreocharis hainanensis (Gesneriaceae), a new species from karst regions in Hainan Island, South China, pp. 281-291 in Phytotaxa 538 (4) on page 288, DOI: 10.11646/phytotaxa.538.4.2, http://zenodo.org/record/6340385, {"references":["IUCN Standards and Petitions Subcommittee (2019) Guidelines for using the IUCN Red List Categories and criteria, version 14. Standards and Petitions Committee, 113 pp."]}

Key to the species of Oreocharis in Hainan Island 1. Anthers horseshoe-shaped, 1-loculed, dehiscing transversely............................................................................................ O. flavida - Anthers broadly oblong, 2-loculed, dehiscing longitudinally............................................................................................................ 2 2. Stamens included, floral tube thin tubular...................................................................................................................... O. jasminina - Stamens exserted, floral tube conical or campanulate........................................................................................................................ 3 3. Corolla yellow............................................................................................................................................................. O. hainanensis - Corolla orange-red.............................................................................................................................................................................. 4 4. Leaf blade adaxially grey pubescent, base oblique, subrounded to cordate, margin serrulate; petiole to 14.5 cm, densely pale brown villous; cymes 1���3 (or 4)-flowered; corolla 1.7���2.4 cm, tube 1.1���2 cm....................................................................... O. dasyantha - Leaf blade adaxially grey to brown pubescent and villous, base sometimes oblique, cuneate to subcordate, margin crenate-serrate; petiole to 6 cm, densely pale brown woolly; cymes 3���8-flowered; corolla ca. 1.6 cm, tube 9���11 mm........................................................................................................................................................................................................... O. dasyantha var. ferruginosa, Published as part of Ling, Shao-Jun, Wen, Fang & Ren, Ming-Xun, 2022, Oreocharis hainanensis (Gesneriaceae), a new species from karst regions in Hainan Island, South China, pp. 281-291 in Phytotaxa 538 (4) on page 288, DOI: 10.11646/phytotaxa.538.4.2, http://zenodo.org/record/6340385

4. Elaeodendron Jacq. 1(14) Elaeodendron glaucum (Rottb.) Pers. (Pitard 1912a, Nguyen 2003a, Pham 2003), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 225, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

15. Salacia L. 1(77) Salacia chinensis L. (Pitard 1912b, Tardieu-Blot 1948b, Nguyen 2003a, Pham 2003) 2(78) Salacia cochinchinensis Lour. 3(79) Salacia dongnaiensis Pierre 4(80) Salacia gagnepainiana Tardieu 5(81) Salacia godefroyana Pierre 6(82) Salacia laotica Pit. (Tardieu-Blot 1948b, Nguyen 2003a) 7(83) Salacia macrophylla Blume (Nguyen 2003a) 8(84) Salacia noronhioides Pierre 9(85) Salacia pallens Pierre (Tardieu-Blot 1948b, Nguyen 2003a, Pham 2003) 10(86) Salacia phuquocensis Tardieu 11(87) Salacia rostrata Pierre 12(88) Salacia typhina Pierre 13(89) Salacia verrucosa Wight (Tardieu-Blot 1948b, Nguyen 2003a, Pham 2003) 14(90) Salacia viminea Wall. (Nguyen 2003a, Pham 2003) 15(91) Salacia viridis Craib (Tardieu-Blot 1948b, Nguyen 2003a, Pham 2003)

8. Loeseneriella A.C.Sm. 1(52) Loeseneriella chesseana (Pierre) Tardieu 2(53) Loeseneriella dinhensis (Pierre) A.C.Sm. 3(54) Loeseneriella merrilliana A.C.Sm. (Tardieu-Blot 1948b, Nguyen 2003a) 4(55) Loeseneriella pauciflora (DC.) A.C.Sm. (Nguyen 2003a, Pham 2003)

2. Bhesa Buch. -Ham. ex Arn. 1(2) Bhesa robusta (Roxb.) Ding Hou (Pitard 1912a, Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 225, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

2. Parnassia aff. procul H. Turner & Veldkamp (2001: 601) (Fig. 5) Specimen examined: ��� VIETNAM. Lam Dong Province: Lac Duong District, Langbian Mountain, near summit, grassland area in evergreen forest, around point 12��01.879���N 108��24.759���E, at an elevation of 1847 m a.s.l., 5 September 2018, Pham Van The, Vo Duc Quang PVT1027 (photos LE: LE01093239 http://en.herbariumle.ru/?t=occ&id=99498). Phenology: ���Flowering and fruiting in August���September. Habitat and ecology: ���The species grows in an open place near the mountain summit. The area is covered with a pine forest; the forest floor is inhabited by various ferns, Poaceae and Melastomataceae. Brief description and notes: ���The population recently discovered in mountains of Lam Dong Province is insufficiently known, but quite distinct morphologically. It is characterized by broadly cordate basal leaves, floriferous stem with a single cauline leaf inserted approximately at its middle, almost entirely white petals (only very slightly greenish at base adaxially) divided into claw and blade, obovate-rhomboid petal blade, triangular petal apex, fimbriate petal margin with fimbriations of short to medium length, anther connective without apical projection, and conspicuously three-lobed staminodes with subequal slightly thickened lobes. The plants in question do not correspond to any of the species included in the treatment of Parnassia in ��Flora of China �� (Gu & Hultg��rd 2001). The keys provided by Gu & Hultg��rd (2001) lead to P. epunctulata J.T. Pan (1985: 220) endemic to NW Yunnan, from which the Lam Dong plants differ in several traits including broader basal leaves and uniformly subequal (vs. sometimes unequal) staminode lobes. Within the preliminary account of Parnassia in Thailand (Suksathan 2009), P. mysorensis B.Heyne ex Wight & Arnott (1834: 35) is described to have a broad variation, so that the Lam Dong plant appears to fit within the concept of this species. However, the concept proposed by Suksathan (2009) contradicts the description of P. mysorensis by Gu & Hultg��rd (2001): in the latter treatment, P. mysorensis is stated to possess entire, erose, or serrate (but not fimbriate) petal margin, which prevents assignment of the Lam Dong plant to this species. The record Pham Van The, Vu Dinh An PVT1027 is remarkably similar to P. procul in the majority of vegetative and floral traits, including leaf shape, shape of petal margin and staminode morphology (Turner & Veldkamp 2001, see also De Wilde & Duyfjes 1994). The Lam Dong plant differs from P. procul in obovate-rhomboid (vs. spathulate) petals with triangular and more or less acute (vs. obtuse to truncate) apex; however, this difference can possibly be a manifestation of an infraspecific variation. A significant variation of petal shape is already known, for example, in P. wightiana (Gu & Hultg��rd 2001). Taking all these arguments into account, we provisionally assign Pham Van The, Vu Dinh An PVT1027 to P. procul, a species hitherto known only from Mount Leuser in northern Sumatra (Turner & Veldkamp 2001). This finding represents a second species of Parnassia recorded in the flora of Vietnam. We argue that a comprehensive investigation of this population, including molecular phylogenetic studies, is needed for further clarification of its identity. In addition, a broad-scale morphological and phylogenetic revision of Asian tropical and subtropical Parnassia is required in order to better understand species boundaries in this genus, and make the species identification more straightforward., Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on pages 220-221, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842, {"references":["Turner, H. & Veldkamp, J. F. (2001) Parnassia (Parnassiaceae) in North Sumatra. Blumea 46 (3): 599 - 603.","Gu, C. Z. & Hultgard, U. M. (2001) Parnassia. In: Wu, Z. Y. & Raven, P. H. (Eds.) Flora of China, vol. 8. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, pp. 358 - 379.","Pan, J. T. (1985) New taxa of the genus Parnassia from China. Acta Phytotaxonomica Sinica 23 (3): 220 - 224.","Suksathan, P. (2009) Taxonomic notes on Thai Parnassia L. (Parnassiaceae) and threats to them. Thai Journal of Botany 1: 43 - 48.","Wight, R. & Arnott, G. A. W. (1834) Droseraceae. In: Wight, R. & Arnott, G. A. W. (Eds.) Prodromus florae peninsulae Indiae orientalis. Vol. 1. Parbury, Allen & Co., London, pp. 33 - 35. https: // doi. org / 10.5962 / bhl. title. 252","De Wilde, W. J. J. O. & Duyfjes, B. E. E. (1994) Brief history of the botanical exploration in the Gunung Leuser Natural Park and vicinity, North Sumatra with itineraries and reports of the exploration tours by Van Steenis (1937) and De Wilde & Duyfjes (1972 - 1991). Flora Malesiana Bulletin 11 (4): 253 - 291."]}

5. Euonymus L. 1(15) Euonymus acanthoxanthus Pit. 2(16) Euonymus balansae Sprague 3(17) Euonymus cochinchinensis Pierre 4(18) Euonymus eberhardtii Tardieu 5(19) Euonymus fortunei (Turcz.) Hand. -Mazz. (Ma 2001) 6(20) Euonymus glaber Roxb. (Pitard 1912a, Tardieu-Blot 1948a, Ma 2001, Nguyen 2003a, Pham 2003) 7(21) Euonymus grandiflorus Wall. (Ma 2001) 8(22) Euonymus indicus B.Heyne ex Wall. (Pitard 1912a, Ma 2001, Nguyen 2003a, Pham 2003) 9(23) Euonymus japonicus Thunb. (Pitard 1912a, Ma 2001, Nguyen 2003a, Pham 2003) 10(24) Euonymus laxiflorus Champ. ex Benth. (Pitard 1912a, Tardieu-Blot 1948a, Ma 2001, Nguyen 2003a, Pham 2003) 11(25) Euonymus nitidus Benth. (Pitard 1912a, Ma 2001, Nguyen 2003a, Pham 2003) 12(26) Euonymus petelotii Merr. 13(27) Euonymus pittosporoides C.Y.Cheng ex J.S.Ma (Ma 2001) 14(28) Euonymus pseudovagans Pit. 15(29) Euonymus salicifolius Loes. (Ma 2001) 16(30) Euonymus tonkinensis (Loes.) Loes., Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 225, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

3. Celastrus L. 1(3) Celastrus annamensis Tardieu 2(4) Celastrus gemmatus Loes. (Merrill 1938, Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 3(5) Celastrus glaucophyllus Rehder & E.H.Wilson (Hou 1955) 4(6) Celastrus hindsii Benth. (Pitard 1912a, Tardieu-Blot 1948a, Hou 1955, Nguyen 2003a, Pham 2003) 5(7) Celastrus hirsutus Comber (Hou 1955) 6(8) Celastrus hookeri Prain (Merrill 1938, Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 7(9) Celastrus monospermus Roxb. (Merrill 1938, Tardieu-Blot 1948a, Hou 1955, Nguyen 2003a, Pham 2003) 8(10) Celastrus orbiculatus Thunb. (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 9(11) Celastrus paniculatus Willd. (Pitard 1912a, Tardieu-Blot 1948a, Hou 1955, Nguyen 2003a, Pham 2003) 10(12) Celastrus rosthornianus Loes. (Merrill 1938, Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 11(13) Celastrus stylosus Wall. (Hou 1955)

16. Siphonodon Griff. 1(92) Siphonodon celastrineus Griff. (Pitard 1912b, Tardieu-Blot 1948c, Nguyen 2003b, Pham 2003), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 227, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

6. Glyptopetalum Thwaites 1(31) Glyptopetalum annamense Tardieu 2(32) Glyptopetalum calyptratum Pierre 3(33) Glyptopetalum chaudocense Pierre 4(34) Glyptopetalum gracilipes Pierre (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 5(35) Glyptopetalum harmandianum Pierre (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 6(36) Glyptopetalum integrifolium Q.W.Lin, Z.X.Zhang & Q.R.Liu 7(37) Glyptopetalum longepedunculatum Tardieu 8(38) Glyptopetalum poilanei Tardieu 9(39) Glyptopetalum quadrangulare Prain ex King (Savinov 2014) 10(40) Glyptopetalum sclerocarpum (Kurz) M.A.Lawson (Hoang 2008, Pham 2003, Savinov et al. 2018) 11(41) Glyptopetalum thorelii Pit. (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 12(42) Glyptopetalum tonkinense Pit., Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on pages 225-226, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

7. Gymnosporia (Wight & Arn.) Benth. & Hook. f. 1(43) Gymnosporia bonii Pit. 2(44) Gymnosporia chevalieri Tardieu 3(45) Gymnosporia crassifolia Pit. 4(46) Gymnosporia diversifolia Maxim. (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 5(47) Gymnosporia marcanii Craib (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 6(48) Gymnosporia mekongensis Pierre 7(49) Gymnosporia stylosa Pierre 8(50) Gymnosporia tonkinensis Pit. 9(51) Gymnosporia wallichiana (Spreng.) M.A.Lawson (Pitard 1912a, Tardieu-Blot 1948a, Nguyen 2003a), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 226, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

10. Microtropis Wall. ex Meisn. 1(59) Microtropis apiculata Ding Hou 2(60) Microtropis cerocarpa Savinov & Nuraliev 3(61) Microtropis chlorocarpa Merr. & F.L.Freeman 4(62) Microtropis discolor (Wall.) Wall. ex Meisn. (Merrill & Freeman 1940, Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003) 5(63) Microtropis fallax Pit. 6(64) Microtropis osmanthoides (Hand.-Mazz.) Hand.-Mazz. (Nguyen 2003a, Pham 2003) 7(65) Microtropis pallens Pierre 8(66) Microtropis petelotii Merr. & F.L.Freeman 9(67) Microtropis rhynchocarpa Merr. 10(68) Microtropis tetragona Merr. & F.L.Freeman (Nguyen 2003a) 11(69) Microtropis triflora Merr. & F.L.Freeman (Nguyen 2003a), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 226, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

1. Parnassia wightiana Wallich ex Wight & Arnott (1834: 35) (Figs. 2���4) References: Grierson (1987: 517), Gu (1987: 46), Gu & Hultg��rd (2001: 114), Suksathan (2009: 46), Bhaskar & Shinobu (2012: 1), Shu et al. (2017: 6), Wang et al. (2018: 133), Averyanov et al. (2020: 282). TYPE: ��� INDIA. Sine loc., R. Wight 116 (lectotype, designated by Shu et al. [2017: 6]: K: 000739468 photo!; isolectotypes: E: E00174108 photo!, E00174109 photo!, E00174110 photo!; GZU: 000100142; K: 000739466 photo!; P: P00709377 photo!). Description (based on Vietnamese specimens):���Herbs perennial, forming dense clumps, generally glabrous. Rhizome 2���4 cm long, 1.0��� 1.5 cm in diam., with numerous roots. Basal leaves 8���10, 11��� 15 cm long; petiole 8���13 cm long, 1.5���2 mm in diam., adaxially grooved, winged at base, wings sheath-like, 2 cm long and 1 mm wide; blade adaxially dark green, abaxially light green, broadly cordate to reniform, 2.5���4.5 �� 3.0��� 6.5 cm, base cordate, apex rounded to obtuse with short mucro, margin entire, with 9���11 veins pedately originating at base. Floriferous stem subterminal (arising near the rhizome apex), usually 1, stout, angled, to 20 cm long, 2.0 mm in diam. Cauline leaf 1, at middle of floriferous stem, nearly sessile; blade similar to that of basal leaf in shape but smaller, with several dark brown hairs at margin near base. Inflorescence 1-flowered. Flower 4 cm in diam.; hypanthium short, 6 mm wide. Sepals 5, light green to yellowish, broadly oblong, 10���12 �� 4.5���6.0 mm, slightly narrowed towards base, apex obtuse, with margins decurrent onto inferior part of ovary, with some inconspicuous parallel veins. Petals 5, white with bright green base on adaxial side (especially so at vein bases), broadly obovate, 15���19 �� 13���15 mm, with a claw 2.0���3.0 mm long; apex rounded and slightly lobed, blade margin at its basal 2/3 with long branched fimbriations or more rarely erose. Stamens 5; filament 6���9 mm long, 1 mm in diam.; anther 2.5���3.0 mm long, 1.5 mm in diam., longitudinally dehiscent. Staminodes 5, flat, 5���6 mm long, 2.0��� 2.5 mm wide at base, up to 4.5 mm wide distally, 5���7-lobed for up to almost 2/3 of their length; lobes spreading laterally, unequal in size, 2���3 mm long, 0.3���0.5 mm in diam., with distinct glands at apex (resembling toes of tree frog). Gynoecium of 3 united carpels; ovary semi-inferior; inferior part 5.5 mm high; superior part conical, obtusely three-angled, 3.5 mm high, 3.5 mm in diam. at base; style 1.5 mm long, 1 mm wide, bearing 3 short stigmatic lobes. Capsule triangular pyramidal, dehiscing into 3 valves; mature fruit 6 mm high, 6.5 mm wide at base. Seeds numerous, oblong, 1 mm long, 0.5 mm in diam. Specimens examined: ��� VIETNAM. Ha Giang Province: Quan Ba District, Tung Vai commune, disturbed primary evergreen forest on limestone mountain, around point 23��04���03.1������N 104��50���23.9������E, at elevation of 1297 m, 17 March 2018, Pham Van The, Trinh Ngoc Bon TB 069 (VAFS); Ha Giang Province: Quan Ba District, Tung Vai commune, Thang village, around point 23��03���13.4������N 104��51���48.8������E, steep rocky slopes of stream valley composed with eroded stratified highly eroded limestone at elevation 1000���1200 m a.s.l., primary evergreen broad-leaved very humid forest, open wet mossy river rocks, 23 April 2018, L. Averyanov, Nguyen Sinh Khang, Nguyen Tien Hiep, Nguyen Quang Hieu, Chuong Quang Ngan, T. Maisak VR 760 (LE: LE01050109 http://en.herbariumle.ru/?t=occ&id=3978); Ha Giang Province: Quan Ba District, Tung Vai commune, Thang village, around point 23��03���00.4������N 104��52���02.2������E, steep rocky slopes of river valley composed with eroded limestone at elevation 1000���1060 m a.s.l., remnants of primary evergreen broad-leaved very humid forest, wet grassy places along river and on mossy open wet stream rocks, 19 October 2018, L. Averyanov, Nguyen Sinh Khang, T. Maisak, Truong Quang Ngan VR 1045 (LE: LE01048857 http://en.herbariumle.ru/?t=occ&id=576, LE01049038 http://en.herbariumle.ru/?t=occ&id=4903, LE01049078 http:// en.herbariumle.ru/?t=occ&id=4918); Ha Giang Province: Quan Ba district, Ta Van commune, Can Ho village, around point 23.03513��N 104.87016��E, steep rocky mountain slopes composed of eroded limestone at elevation 1100��� 1250 m a.s.l., secondary evergreen broad-leaved humid forest along rocky stream, open wet mossy stream rocks, 9 October 2019, L. Averyanov, Nguyen Sinh Khang, T. Maisak VR 1494 (LE: LE01066941 http://en.herbariumle. ru/?t=occ&id=12724, photos LE01061037 http://en.herbariumle.ru/?t=occ&id=13091); Yen Bai Province: Mu Cang Chai District, Nam Co commune, Lung Cung village, secondary evergreen broad-leaved woodland and scrub, around point 21��54���23.5������N 104��16���59.4������E, at elevation of 1762 m, 22 September 2011, Pham Van The, Nguyen Tien Vinh, Hoang Van Than CPC 4488 (CPC ��� Herbarium of the Center for Plant Conservation, Vietnam Union of Science and Technology Associations, Hanoi, Vietnam; photos LE: LE01087319 http://en.herbariumle.ru/?t=occ&id=27233). Distribution: ��� Afghanistan, N India, Nepal, Bhutan, China, N Thailand, N Vietnam (Ha Giang and Yen Bai provinces). Phenology: ���In Vietnam, flowering was observed from March to October, fruiting was observed from April to October. Habitat and ecology: ���In Vietnam, Parnassia wightiana was found in wet places along streams in disturbed primary evergreen forest on limestone, and also in secondary evergreen broad-leaved woodland and scrub on nonlimestone mountains at elevations of 1000���1760 m, as a lithophyte or a terrestrial herb (see Fig. 1). Parnassia wightiana is known from several populations within Vietnam, some of which contain numerous individuals (Averyanov et al. 2020; this study). In the secondary forests with Taiwania cryptomerioides in Yen Bai Province, P. wightiana (the specimen Pham et al. CPC 4488) grows together with Dicranopteris linearis (Gleicheniaceae), Asplenium sp. (Aspleniaceae), Amorphophallus sp. (Araceae), Carex sp. (Cyperaceae), Rubus sp. (Rosaceae), Melastoma sp. (Melastomataceae), Ageratina adenophora (Asteraceae). In the limestone landscape of Ha Giang Province, P. wightiana (the specimen Pham Van The, Trinh Ngoc Bon TB 069) was recorded to grow together with the following herbs and small understorey woody plants: Equisetum diffusum (Equisetaceae), Dryopteris stenolepis (Dryopteridaceae), Pyrrosia bonii (Polypodiaceae), Acorus calamus (Acoraceae), Tacca integrifolia (Taccaceae), Nervilia fordii (Orchidaceae), Caryota urens (Arecaceae), Anemone sumatrana (Ranunculaceae), Ficus abelii (Moraceae), Elatostema dissectum (Urticaceae), Begonia lecomtei (Begoniaceae), Micromelum minutum (Rutaceae), Maesa montana (Primulaceae), Ophiorrhiza baviensis, O. japonica (Rubiaceae). The primary forest at high elevations in that area comprises tree species including Fokienia hodginsii (Cupressaceae), Amentotaxus yunnanensis, Taxus chinensis (Taxaceae), Magnolia coriacea, M. grandis (Magnoliaceae), Actinodaphne ellipticibacca, Cinnamomum parthenoxylon, Phoebe macrocarpa (Lauraceae), Mahonia nepalensis (Berberidaceae), Castanopsis cerebrina, Lithocarpus balansae, Quercus platycalyx (Fagaceae), Aucuba japonica (Garryaceae); understorey woody plants include Gomphandra mollis (Stemonuraceae); herbs include Paris polyphylla (Melanthiaceae), Paphiopedilum hirsutissimum, P. micranthum (Orchidaceae), Dysosma difformis (Berberidaceae); vines include Stephania tetrandra, Tinospora sagittata (Menispermaceae), Jasminum elongatum (Oleaceae); epiphytes include Rhaphidophora decursiva (Araceae), Coelogyne lockii, Dendrobium chrysanthum, Eria scabrilinguis (Orchidaceae). Notes: ��� Gu & Hultg��rd (2001) indicated considerable morphological variability of Parnassia wightiana manifested, in particular, in differences in leaf shape and flower size between populations from different regions of China. The recently proposed ample synonymy of P. wightiana (Shu et al. 2017, Wang et al. 2018) should also contribute to the variation ranges of its characters. Our study extends further the known morphological diversity of the species, as compared with its earlier published descriptions (Grierson 1987, Gu & Hultg��rd 2001, Bhaskar & Shinobu 2012). The Vietnamese specimens are remarkable in their numerous (8���10 vs. 2���5) basal leaves with larger number of veins (9���11 vs. 7���9), and larger flower parts, including sepals 10���12 mm (vs. 5���10 mm) long, petals 15���19 mm (vs. 8���15 mm) long, anthers 2.5���3 mm (vs. 1.5���2.5 mm) long. A detailed comparison is presented in Table 1., Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on pages 215-217, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842, {"references":["Wight, R. & Arnott, G. A. W. (1834) Droseraceae. In: Wight, R. & Arnott, G. A. W. (Eds.) Prodromus florae peninsulae Indiae orientalis. Vol. 1. Parbury, Allen & Co., London, pp. 33 - 35. https: // doi. org / 10.5962 / bhl. title. 252","Grierson, A. J. C. (1987) Parnassiaceae. In: Grierson, A. J. C. & Long, D. G. (Eds.) Flora of Bhutan. Vol. 1, part 3. Royal Botanic Garden, Edinburgh, pp. 515 - 517.","Gu, C. Z. [Ku, T. C.] (1987) A revision of the genus Parnassia (Saxifragaceae) in China. Bulletin of Botanical Research Harbin 7: 1 - 61. [in Chinese]","Gu, C. Z. & Hultgard, U. M. (2001) Parnassia. In: Wu, Z. Y. & Raven, P. H. (Eds.) Flora of China, vol. 8. Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, pp. 358 - 379.","Suksathan, P. (2009) Taxonomic notes on Thai Parnassia L. (Parnassiaceae) and threats to them. Thai Journal of Botany 1: 43 - 48.","Bhaskar, A. & Shinobu, A. (2012) Parnassiaceae. In: Watson, M. F., Akiyama, S., Ikeda, H., Pendry, C. A., Rajbhandari, K. R. & Shrestha, K. K. (Eds.) Flora of Nepal. Royal Botanic Garden Edinburgh, Edinburgh. Available from: http: // data. rbge. org. uk / publications / FloraofNepal / library / Parnassiaceae / 1 (accessed 13 July 2021)","Shu, Y. M., Yu, H. Y., Mu, X. Y. & Zhang, Z. X. (2017) Checklist and typification of Parnassia (Celastraceae). Phytotaxa 309 (1): 1 - 22. https: // doi. org / 10.11646 / phytotaxa. 309.1.1","Wang, Y. P., Chen, S., Shu, Y. M., Li, B. & Wu, D. (2018) Taxonomic note of Parnassia (Celastraceae) in China: the identity of P. wightiana. Phytotaxa 375 (1): 130 - 134. https: // doi. org / 10.11646 / phytotaxa. 375.1.10","Averyanov, L. V., Nguyen, K. S., Tran, T. H., Averyanova, A. L., Maisak, T. V. & Nguyen, H. T. (2020) Plant diversity, flora and vegetation of Bat Dai Son Mountain area, northern Vietnam. Strata, Saint-Petersburg, 561 pp."]}

Parnassia Linnaeus (1753: 273) TYPE:��� Parnassia palustris Linnaeus (1753: 273) Description:���Herbs perennial, rosulate, glabrous. Rhizome sympodial, robust. Floriferous stems (scapes) 1 to several, bearing 1 to several cauline leaves or rarely leafless. Basal leaves 2 or several, forming a rosette; stipules membranous; petiole usually long; leaf blade entire. Cauline leaves 1 to several or absent, often sessile and semiamplexicaul. Flower solitary, terminal; hypanthium sometimes present. Sepals 5, usually imbricate. Petals 5, imbricate, white or yellowish or rarely greenish; margin fimbriate, erose or entire. Stamens 5, inserted opposite sepals; anthers longitudinally dehiscent, usually inappendaged but in some species connective projected into a lanceolate appendage. Staminodes 5, inserted opposite petals, terete and entire or flat and divided into lobes or filiform rays, apically somewhat glandular or with distinct globose glands. Gynoecium syncarpous, 3���4-carpellate; ovary superior to semi-inferior, 1-loculed; placentation parietal; ovules numerous; style terminal, short or almost absent; stigmatic lobes distinct, commissural. Fruit a capsule, superior to semi-inferior, sometimes longitudinally angled, loculicidally dehiscent into 3 or 4 valves, with persistent sepals. Seeds numerous, brown, obovoid or oblong, minute, 1���2 mm long; testa thin, membranous, reticulate, smooth; endosperm thin or absent. The genus Parnassia comprises ca. 60 species distributed predominantly in extratropical regions of the Northern Hemisphere, with several species in northern tropics, including the southernmost known population in northern Sumatra. Two species are recorded in Vietnam (Fig. 1)., Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on pages 214-215, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842, {"references":["Linnaeus, C. (1753) Species Plantarum 1. Imprensis Laurentii Salvii, Stockholm, 560 pp. https: // doi. org / 10.5962 / bhl. title. 669"]}

14. Reissantia N.Hall�� 1(75) Reissantia indica (Willd.) N.Hall�� (Pitard 1912b, Tardieu-Blot 1948b, Nguyen 2003a, Pham 2003) 2(76) Reissantia setulosa (A.C.Sm.) N.Hall�� (Tardieu-Blot 1948b, Nguyen 2003a), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 227, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

12. Plagiopteron Griff. 1(72) Plagiopteron suaveolens Griff. (Chinh et al. 2016, Nghiem et al. 2017), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 226, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

1. Arnicratea N.Hall�� 1(1) Arnicratea cambodiana (Pierre) N.Hall��, Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 225, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

17. Tripterygium Hook. f. 1(93) Tripterygium wilfordii Hook. f. (Hai et al. 2021) Note added in proof: Bhesa was transferred to the family Centroplacaceae (Malpighiales) based on molecular phylogenetic data (Stevens 2001 onwards, etc). SUPPLEMENTARY MATERIAL ONLINE SUPPLEMENTARY FILE S1. An updated checklist of Celastraceae in Vietnam: an extended version with references to protologues, synonymy, reference(s) for occurrence in Vietnam, links to species profiles in the taxonomic databases, and brief notes on taxonomy and distribution. Available at: https://doi.org/10.5281/zenodo.6125317, Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on page 227, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842

13. Pleurostylia Wight & Arn. 1(73) Pleurostylia cochinchinensis Pierre 2(74) Pleurostylia opposita (Wall.) Alston (Tardieu-Blot 1948a, Nguyen 2003a, Pham 2003), Published as part of Pham, Ngoc Hoai, Ren, Ming-Xun, Nuraliev, Maxim S., Trinh, Ngoc Bon, Nguyen, Tien Dat, Ragupathi, Gopi & Pham, Van The, 2022, The genus Parnassia in Vietnam, and a checklist of Vietnamese Celastraceae, pp. 213-227 in Phytotaxa 536 (3) on pages 226-227, DOI: 10.11646/phytotaxa.536.3.2, http://zenodo.org/record/6331842