Camellia flosculora: a new species of Camellia section Thea series Sinenses (Theaceae) from Vietnam VAN SON LE1, ANTHONY S CURRY2, QUANG CUONG TRUONG1, VAN DUNG LUONG3, THI LIEU NGUYEN4 AND Vườn Quốc Gia Bidoup Núi Bà, Trụ sở chính: Tiểu khu 97, Đạ Nhim, Lạc Dương, Lâm Đồng; Văn phòng ĐD: 5E Trần Hưng Đạo, Phường 10, Tp Đà Lạt, Lâm Đồng, Vietnam; e-mail: leson1502@gmail.com; email: quangcuongvqg@gmail.com ACurry|hortbot, Ferguson Road, Springwood, NSW 2777, Australia; e-mail: anthonycurry55@gmail.com Đại học Đà Lạt, Phù Đổng Thiên Vương, Phường 8, Thành phố Đà Lạt, Lâm Đồng, Vietnam; e-mail: luongvandungdl@gmail.com Graduate School of Science, Botanical Gardens of Osaka City University, Osaka 558-8585, Japan; Faculty of Biology, VNU University of Science, Hanoi, 100000, Vietnam; e-mail: lieunt_sh@dlu.edu.vn Abstract A new species of Camellia is described from material collected from Hon Giao Mountain, Bidoup-Nui Ba National Park, southern Vietnam The analysis and figures demonstrate how Camellia flosculora differs from other known Camellia species and illustrate the new species, which is characterized by relatively small leaf blades, short pedicels, and very small flowers with short stamens and styles The morphology of the newly described species justifies its taxonomic placement in Camellia section Thea series Sinenses Keywords: Key Words: Bidoup-Nui Ba National Park, cool-temperate evergreen forest, Hon Giao Mountain, Taxonomy Camellia L is the largest genus of Theaceae with more than 300 species (Chang & Bartholomew, 1984; Mabberley, 2017; Gao et al., 2005) The genus is distinguished within the family by large seeds and dehiscent, capsular fruit, with wide spreading, but persistent valves (Sealy, 1958) China and Vietnam are major centers of diversity for Camellia (Sealy, 1958; Chang & Bartholomew, 1984; Macoboy, 1998; Ninh, 2002) Over the last 20–30 years many new species of Camellia have been described from these two countries (Rosmann, 1995; Chang, 1996; Rosmann et al., 1998; Chang & Ren, 1999; Rosmann, 1999; Chang, 2000; Orel, 2006; Ninh et al., 2012; Orel et al., 2012; Ninh & Luong, 2013; Luu et al., 2015; Ninh & Ninh, 2015; Orel & Curry, 2015; Ninh & Luong, 2016; Ninh et al., Received 13 December 2019; accepted 30 October 2020 2017; Orel & Curry, 2017; Nguyen et al., 2018; Orel & Curry, 2019; Pham et al., 2019) These discoveries and their subsequent publication have contributed greatly to the scientific knowledge of the Camellia floras of both China and Vietnam, as well as highlighting the need for further fieldwork and research As part of a field trip to Hon Giao Mountain, Khanh Hoa Province, Vietnam in July 2019, Messrs Van Dung Luong and Truong Quang Cuong discovered a population of a distinctive Camellia species The specimens had relatively small leaves, short pedicels and very small flowers with short stamens, and styles These morphological features suggested that the specimens they collected represented a Camellia species new to science A herbarium study of closely related species was not conducted by the authors However, the three taxonomic classificatory systems (i.e., Sealy, 1958; Chang & Bartholomew, 1984; Ming & Bartholomew, 2007) currently Brittonia, XX(X), pp 1–9 © 2021, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A BRITTONIA in use for Camellia were consulted for the analysis of this putative new species Our study was grounded primarily by the taxonomic treatment of Sealy (1958), as we believe it to be relatively well-substantiated and complete Chang and Bartholomew (1984), a progression from Sealy’s treatment, was also consulted, especially for species collected since 1958, and the assignment of the new species to subgenus, section, and series followed their intersectional taxonomy The works of Wen (2004)-onwards, Gao et al (2005) and Ming and Bartholomew (2007) were consulted for additional data Taxonomic treatment Camellia flosculora Curry, V S Le, C Q Truong & V D Luong, sp nov Type: Vietnam, Lam Dong Province, Bidoup-Nui Ba National Park., Hon Giao Mountain, [precise locality details are held by DLU but have been suppressed for conservation reasons], 1740 m elevation, 20 Jul 2019 [fl, fr], Truong Quang Cuong, Luong Van Dung, DL 190701 (holotype: DLU; isotype: HNU) (Figs and 2.) Diagnosis: Camellia flosculora is placed in C sect Thea ser Sinenses Chang due to its possession of 3-loculed, pubescent ovaries and 3-parted, free styles (Chang & Bartholomew, 1984) It is readily distinguished from other species of sect Thea (L.) Dyer ser Sinenses Chang by its small leaf blades (3– × 1.5–2.5 cm), short pedicels (0.3–0.4 mm), very small flowers (0.5–0.7 cm diameter), short stamens (2–3 mm) and short styles (1.5–1.7 mm) Small to medium-sized, evergreen tree, 3–8 m tall; branches pubescent when young, becoming glabrous Leaves stalked, lanceolate to oblong-ovate, 3–7 × 1.5–2.5 cm, thickly coriaceous, the apex acuminate or narrowly acuminate, the base nearly rounded or broadly obtuse, the margins regularly serrate, dark green and shiny above, paler green below, glabrous on both sides except the midrib, the midrib and lateral veins sunken above, protruding below, the secondary venation pinnate, with 7–10 pairs of lateral veins; petiole slightly curved-falcate, terete, pale green, 4– mm long, pubescent Flowers solitary or [VOL geminate, axillary, 5–7 mm diameter; pedicel 3–4 mm long, pubescent, light green to yellowish green; bracts 2(−3), the scales 0.5–1 × 0.5–1 mm, light green, pubescent abaxially, persistent Sepals 5–6, orbicular or subglobose, 1.5–2 × 1–1.5 cm, light green, pubescent abaxially, the margins ciliate, persistent Petals 5(−6), orbicular or broadly obovate, white, 4–5 × 2.5–3.5 mm, glabrous, united for about 0.2 mm at the base with the outermost filaments Androecium of 60– 70 stamens in series; filaments 2–3 mm long, white, glabrous, the outer filaments united for about 0.5 mm from the base; anthers light yellow Gynoecium 3-locular; ovary ovate, 1.2–1.5 × 1–1.2 mm, pubescent; styles 3-parted, free to base, 1.5–1.7 mm long, pubescent Capsule asymmetrically globose, dehiscent, pubescent, the apex acute, 7– 12 mm wide, 1-loculed with seed per locule, columella abortive, pericarp thinly leathery Seeds globose, 6–10 mm wide, glabrous Distribution and habitat.— Under dense, cooltemperate evergreen forest, at elevations between 1600 and 1700 m, Hon Giao Mountain, BidoupNui Ba National Park, Lam Dong Province, Vietnam (Fig 3) Phenology.— The species was observed flowering between September and November, and fruiting between April and May Etymology.— The specific epithet refers to the tiny flowers of this species Common name.— Trà hoa nhỏ (Trà = Camellia; hoa nhỏ = flosculora) Conservation status.– This species is known only from the type locality near the border of Bidoup-Nui Ba National Park A thorough search of the area around the type locality found about 50 individual plants in an area of about As the type population is situated near the boundary of the national park some degree of protection is afforded this species However, due to the small population size, limited known area of occupancy, recent fluctuations in monsoonal weather patterns, poaching, traditional plant collecting and cutting by ethnic minority peoples, as well as the encroachment of agriculture along the border of the national park, the IUCN category of Endangered (EN B2 D) is considered appropriate for this species (IUCN, 2012; see also Beech et al., 2017) 2021] LE ET AL.: CAMELLIA FLOSCULORA (THEACEAE) FIG Camellia flosculora A Leaf B Part of upper surface of leaf C Part of lower surface of leaf D Developing flower bud E Flower F Sepals (abaxial sides) G Petals H Stamens I Pedicel, bracts, sepals, and gynoecium J Capsule K Seed (Drawn from the holotype, DL 190701, by Luong Van Dung.) We assign the new species to subgenus Thea (L.) Dyer due to its possession of the characteristics of the section as described by Chang and Bartholomew (1984), including one or two axillary, pedicellate, medium to relatively small flowers; the bracts and sepals usually BRITTONIA [VOL FIG Camellia flosculora A Branches with leaves B Leaf (adaxial view) C Leaf (abaxial view) D, E Buds F, G, H Flowers I Petals J Sepals K Petals with gynoecium L Fruits M Dehisced capsule N Seed (Images from the holotype, DL 190701, by Luong Van Dung.) differentiated; five or six persistent sepals; persistent or deciduous bracts; free stamens in series, with the outer whorl connate; 3parted, free styles; a 3-locular ovary; and capsules with columellae The capsules, however, have only a single locule due to the abortion of two of the ovary locules during development (Table I) 2021] LE ET AL.: CAMELLIA FLOSCULORA (THEACEAE) FIG Collection site: Bidoup-Nui Ba National Park, southern Vietnam (Adapted from Binh et al., 2018) Within subgenus Thea, Chang and Bartholomew (1984) recognized eight sections based on the morphology of the ovary; number, differentiation and persistence of the bracts and sepals; number of flowers per inflorescence and whether they are sessile or pedicellate; number and morphology of the styles; arrangement of stamens into series and whether the filaments are free or connate into a short tube; number of locules in the ovary; and type of dehiscence of the capsules The following features align the new species with section Thea: 1–2, small, axillary, pedicellate, bracteolate flowers, 5–6, persistent sepals, 5–6 petals, stamens in series, outer filaments basally shortly connate, a 3-locular ovary, 3-parted, free styles, and capsules dehiscent from the apices with columellae Within section Thea, Chang and Bartholomew (1984) recognized four series based on features of the ovaries and styles (Table II) The morphological characteristics of Camellia flosculora, namely 3-loculed, pubescent ovaries and 3-parted, free styles, support placement of the new species in series Sinenses Chang Within series Sinenses, the new species appears to be most like Camellia sinensis (L.) [VOL BRITTONIA Table MORPHOLOGICAL COMPARISONS BETWEEN CAMELLIA FLOSCULORA AND OTHER SPECIES OF SERIES SINENSES Feature Leaf length (cm) Leaf width (cm) Leaf shape C angustifolia C fangchensis C flosculora C parvisepala C ptilophylla 7–11 13.5–29 3–7 11–19 12–21 9–19 (4–)5–9–10 1.8–2.8 5.5–12.5 1.5–2.5 5–8 4–6.8 2.8–5.4 (1.6–)2–3–4 Lanceolate Elliptic or oblong elliptic Serrate Lanceolate to oblongovate Regularly serrate Obovate Oblong Elliptic Serrulate Serrulate Oval or oblong to oblanceolate Bluntly serrulate Abruptly acute or obtuse Acuminate or narrowly acuminate Acute, with long acumenb Acuminate, acumen obtuse Obtuse to rounded Broadly cuneate or rounded Obtuse or slightly roundedb Broadly cuneate Acuminate or caudateacuminate Cuneate 10–13 8–10 7–8 7–9a 0.8–1 0.5–0.7 0.4–0.7a 1–2 1–3(−7) Leaf margin Serrulate Leaf apex Acuminate, acumen slightly cuneate Obtuse Leaf base Pairs of lateral veins Petiole length (cm) Flower number Position of flower Flower diam (cm) Pedicel (cm) 6–8 11–17 Nearly rounded or broadly obtuse 7–10 0.5–0.8 0.3–1 0.4–0.5 0.4–0.7 ? 1–2 1–2 1(−3)c b C pubicosta C sinensis Bluntly serrulate to sinuateserrulate Obtuse to rounded cuspidate ? Axillary Axillary Axillary Terminal Axillary Axillary ? 2.1–3.5 0.5–0.7 1.5–2.2b 2.5–3a 1.5 2.5–3.5a 0.3–0.4, pendulous 0.3–0.5, erect 0.8–1, pendulousa 0.7–0.8, erect (0.6–)0.8–1, pendulous ? 0.5–1, pendulous/ recurvedc 2–3 2–3 2–3 5 5–6 5–6 ? 5(−6) 6–7 7–8 ? 7.5–10 2–3 7–9 8–10 10 8–13 ? Glabrous Glabrous Glabrous Glabrous Glabrous Glabrous ? Outer whorl basally slightly connate Free Nearly free Outer united at base for mm Adnate with petals, connate for 1–2 mm Ovary ? Subglobose, densely white pubescent Outer filaments united for ca 0.5 mm from base Ovate, pubescent Grey pubescent Pubescent Subglobose, densely yellowtomentose Locule number 3 3 3 Orbicular, densely hairy, or rarely sparsely hairy 3(−2–1) Bract number Sepal number Petal number Stamen length (mm) Filament hairiness Filaments LE ET AL.: CAMELLIA FLOSCULORA (THEACEAE) 2021] Table Continued Feature C angustifolia C fangchensis C flosculora C parvisepala C ptilophylla C pubicosta C sinensis Length of stamen to style ? Equal to or longer than styles Stamens longer than styles Stamens longer than styles Shorter than or equal to styles Stamens about equal to styles Styles ? 3-parted for 1/3 their length, 6– 10 mm long, bases pubescent 3-parted, free to base, 1.5– 1.7 mm long, pubescent 3-parted, free to base, mm long, glabrousb 3-cleft, 10 mm long, glabrous Stamens slightly longer than styles 3-parted, free to base, 8–9.5 mm long, hairy almost to apex Distribution China China Southern Vietnam China China c Northern Vietnam 3-fid for 2– 3(−4) mm; 8–12 mm long, glabrous to sparsely hairy China All data from Sealy (1958) and Chang and Bartholomew (1984) except: a from Wen (2004 onwards); b from Gao et al (2005); from Ming and Bartholomew (2007) Kuntze, the type species of the series The two species share relatively small leaves, axillary, white flowers, pendulous pedicels, similar numbers of bracts and sepals, glabrous filaments, and a 3-locular ovary Camellia flosculora differs from C sinensis in having smaller leaves, regularly serrate leaf margins (vs bluntly serrulate to sinuate-serrulate in C sinensis), shorter pedicels, smaller flower diameter, fewer petals, shorter stamens which are longer than the styles (vs equal to, or slightly longer) and 3-parted and free (vs 3fid), and shorter, pubescent (vs glabrous, or rarely sparsely hairy) styles (Table I) Camellia flosculora also has many traits in common with C parvisepala Chang, including similar petiole length, axillary, white flowers, similar sepal and petal numbers, glabrous filaments, stamens longer than styles, and a pubescent ovary However, it differs in having larger leaves with more pairs of lateral veins, larger diameter flowers, pendulous pedicels (vs erect in C parvisepala), longer stamens and longer styles, which are 3-parted, free, and pubescent (vs 3-cleft and glabrous) (Table I) Another species of ser Sinenses, C angustifolia Chang was described by Chang (1981) from an incomplete specimen from Guangxi Zhuang Autonomous Region, China, and its flowers are unknown However, that species differs from C flosculora in having larger leaves with fewer lateral veins, a longer petiole, and serrulate margins (vs serrate), and longer, erect (vs pendulous) pedicels (Table I) Table FEATURES OF THE FOUR SERIES OF CAMELLIA SECTION THEA Featurea Ovary Styles Distribution a I Quinquelocularis 4–5-locular, glabrous 4–5(−7)-cleft species in China II Pentastylae 4–5-locular, pilose free, or apices 5-cleft species in China and Vietnam Adapted from Chang and Bartholomew (1984) III Gymnogynae 3-locular, glabrous 3-cleft species in China IV Sinenses 3-locular, pilose 3-cleft, or 3-parted, free species in China and Vietnam BRITTONIA [VOL Key to the species of Camellia section Thea series Sinenses Styles 3-parted, free to base Styles glabrous…… … ………………… …………… …… … C parvisepala Styles pubescent or long-hairy almost to the apex Styles 1.5–1.7 mm long………… …………… …………………………… C flosculora Styles 8–9.5 mm long……………………… .… …………………………….… C pubicosta Styles 3-parted but not free to base, 3-cleft or 3-fid Styles pubescent or hairy, 6–10 mm long Leaves 7–11 × 1.8–2.8 cm with 6–8 pairs of lateral veins… ……….………… C angustifolia Leaves 13.5–29 × 5.5–12.5 with 11–17 pairs of lateral veins……… .………… C fangchensis Styles glabrous, or rarely sparsely hairy Flowers terminal .………………… ………… ……………………………C ptilophylla Flowers axillary Number of sepals 5; number of petals 6……… .…………………………C parvisepala Number of sepals 5–6, number of petals 7–8… …… ……………… ………C sinensis Acknowledgements We give special thanks to the management and staff of the Bidoup-Nui Ba National Park and Dalat University for their cooperation and support throughout the fieldwork that resulted in the discovery of Camellia flosculora We also thank the manuscript reviewers for their constructive feedback Literature cited Beech, E., M Barstow & M Rivers 2017 The Red List of Theaceae Botanic Gardens Conservation International, Richmond, Surrey, UK Binh, H T., N V Ngoc, S Tagane, H Toyama, K Mase, C Mitsuyuki, J S Strijk, Y Suyama & T Yahara 2018 A taxonomic study of Quercus langbianensis complex based on morphology and DNA barcodes of classic and next generation sequences PhytoKeys 95: 37–70 https:// phytokeys.pensoft.net/article/21126/ Chang, H T 1981 A taxonomy of the genus Camellia Acta Scientiarum Naturalium Universitatis Sunyatseni, monograph series 1: 96 Chang, H T 1996 New species of genus Camellia from Jinshajiang Valley International Camellia Journal 28: 79– 85 Chang, H T 2000 New species of Chinese Theaceae International Camellia Journal 32: 95–100 Chang, H T & B Bartholomew 1984 Camellias Timber Press, Portland, Oregon Chang, H T & S Ren 1999 New species of Theaceae from Tropical Asia International Camellia Journal 31: 127–129 Gao, J., C R Parks & D Yueqiang 2005 Collected species of the genus Camellia: an illustrated outline Zhejiang Science and Technology Publishing House, Zhejiang IUCN 2012 IUCN Red List categories and criteria: version 3.1 IUCN, Species Survival Commission, Gland, Switzerland https://www.iucnredlist.org/resources/categoriesand-criteria Luu, H T., V D Luong, Q D Nguyen & T Q T Nguyen 2015 Camellia sonthaiensis (Theaceae), a new species from Vietnam Annales Botanici Fennici 52(5–6), 289– 295 https://bioone.org/journals/annales-botanici-fennici/ volume-52/issue-5%e2%80%936/085.052.0502/ Camelliasonthaiensis-Theaceae-a-New-Species-fromVietnam/10.5735/085.052.0502.short (Accessed 07/09/ 2019) Mabberley, D J 2017 The Plant Book 4th Edition Cambridge University Press Cambridge, UK Macoboy, S 1998 Stirling Macoboy’s What Camellia is that? 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CAMELLIA FLOSCULORA (THEACEAE) FIG Camellia flosculora A Leaf B Part of upper surface of leaf C Part of lower surface of leaf D Developing flower bud E Flower F Sepals (abaxial sides) G Petals H Stamens... Camellia section Piquetia (Theaceae) from Vietnam Novon 16: 244–247 Orel, G & A S Curry 2015 In pursuit of hidden camellias: 32 new Camellia species from Vietnam and China Theaceae Exploration Associates... tuyenquangensis (Theaceae), a new species from Vietnam Korean Journal of Plant Taxonomy 47(2): 95–99 https:// www.researchgate.net/publication/318244114 _Camellia_ tuyenquangensis_Theaceae _a_ new_ species_ from_