Phytotaxa 480 (1): 085–090 https://www.mapress.com/j/pt/ Copyright © 2021 Magnolia Press 

ISSN 1179-3155 (print edition) 

Article 

https://doi.org/10.11646/phytotaxa.480.1.8 

PHYTOTAXA 

Rediscovery of Camellia langbianensis (Theaceae) in Vietnam

QUACH VAN HOI1,2,8, ROMAN V. DOUDKIN2,7,9, TRUONG QUANG CUONG3,10, LE VAN SON3,11, LUONG VAN 

DUNG4,12*, SOO-YONG KIM5,13 & SHI-XIONG YANG6,14* 

1 Tay Nguyen Institute for Scientific Research, Vietnam Academy of Science and Technology, Xo Viet NgheTinh str. 116, Dalat, 66107, Vietnam.

2 School of Natural Sciences, Far Eastern Federal University, Sukhanova str. 8, Vladivostok, 690090, Russia.

3 Bidoup Nui Ba National Park, Tran Hung Dao str. 5E, Dalat, 66116, Vietnam. 

4 Faculty of Biology, Dalat University, Phu Dong ThienVuong str. 01, Dalat, 66106, Vietnam.

5 International Biological Material Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 34141, Republic of Korea.

6 CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.

7 Botanical Garden-Institute, Far-East Branch, Russian Academy of Sciences, Makovskii str. 142, Vladivostok, 690024, Russia.

8 quachvanhoi@gmail.com; https://orcid.org/0000-0002-3691-941X

9 r_doudkin@mail.ru; https://orcid.org/0000-0002-5528-7729

10 forestek36a@yahoo.com; https://orcid.org/0000-0001-9159-1018

11 leson1502@gmail.com; https://orcid.org/0000-0003-0151-0646

12 luongvandungdl@gmail.com; https://orcid.org/0000-0001-5985-1975

13 soodole@kribb.re.kr; https://orcid.org/0000-0002-4608-644X

14 shxyang@mail.kib.ac.cn; https://orcid.org/0000-0001-8472-1275

*Corresponding authors: shxyang@mail.kib.ac.cn, luongvandungdl@gmail.com 

Abstract 

Camellia langbianensis is a species endemic to southern Vietnam. It was described by Gagnepain based on the collection of Poilane and was rediscovered about 80 years since published. The complete descriptions and illustrations are provided for this species. A comment on the affinities with closely related species C. vidalii is also shown. It is accessed to be Critically Endangered (CR) according to IUCN categories and criteria. 

Keywords: 

Dankia langbianensis, morphology, taxonomy, Lam Dong province, Bidoup Nui Ba National Park 

Introduction 

Camellia langbianensis (Gagnep.) Phamhoang in Ho (1991: 573) was first published as Dankia langbianensis Gagnepain (1939: 131) in the monotypic genus Dankia Gagnepain (1939: 131). The type specimen (Poilane18648) of D. langbianensis was collected in “B-dlé” and Dankia, Langbian, Vietnam. At that time, Gagnepain (1939) placed D. langbianensis as a member of the family Bixaceae. From a photocopy of a letter to Sleumer from Kobuski on 9 September 1955, which is attached on the sheet K000704329, it was indicated that Sleumer was the first to suggest this taxon to be a member of Theaceae and Kobuski further suggested that it is a member of Camellia Linnaeus (1753: 698). However, in a photocopy of a letter to Sleumer from Sealy on 20 September 1955, which is attached on the same sheet, it was indicated that Sealy considered its uncertain placement due to Gagnepain’s unreliable description and lacking of the material by hand. This species was not mentioned in subsequent revisions of the genus Camellia (Sealy 1958, Chang & Ren 1998, Ming & Bartholomew 2007). Later, Ho (1991) merged Dankia with Camellia without a clear explanation, but, the descriptions of the flowers and fruits of Dankia are consistent with Camellia in five sepals, numerous stamens, capsule dehiscent with five valves and a central placenta. Ho (1991, 1999) provided a short Vietnamese description and an illustration for C. langbianensis, but he failed to provide any information on the fruit. Even in the original description, Gagnepain (1939) did not mention the flower colour because the type specimens (Poilane 18648) bear only a few flower buds. Zhao et al. (2017) designated a lectotype for the name. Afterwards, Zhao (2019) reduced C. vidalii Rosmann (1999: 319) to the synonymy of C. langbianensis. However, this reduction should be re-evaluated because lacking of the complete information of C. langbianensis. 

FIGURE 1. Distribution map of Camellia langbianensis (mark) 

During the period of 2016–2019, researchers from the Dalat University and the Tay Nguyen Institute for Scientific Research carried out many field surveys around the mountain Langbian, the type locality of C. langbianensis (Fig. 1). By thoroughly comparison with the protologue and the types in K as well as the digital images of P and L, some collections can be identified as C. langbianensis. This is the rediscovery of this specie over the past 80 years so that it is possible to give a complete description and re-evaluated its relationship with C. vidalii. 

Taxonomic treatment 

Camellia langbianensis (Gagnep.) Phamhoang in Ho (1991: 537). ≡ Dankia langbianensis Gagnepain (1939: 131). (Figs. 2 & 3). 

Types:—VIETNAM. Lam Dong province: between B.-dle and Dankia commune, Langbian mountain, 1200–1300 m, 26 October 1930, Poilane 18648 (lectotype designated by Zhao et al. (2017: 173): P [P00754831]; isolectopypes: K [K000704329], L [L0012339], P [P00754832]). the image of the lectotype is available at https://science.mnhn.fr/institution/mnhn/collection/p/item/p00754831 

Description:

—Small evergreen tree, 3–5 m tall; branches pubescent when young and then glabrescent. Leaves alternate; petiole falcate, slightly curved, terete, 7–10 mm long, sparsely pubescent when young and then glabrescent; blades oblong, 20–32 cm long, 5–8 cm wide, coriaceous, apex acuminate, margin shallow serrate, base broadly cuneate or obtuse, above dark green, shiny and glabrous, below paler green, sparsely pubescent, lateral veins 15–20 pairs, impressed above, prominent below. Flowers solitary or 2–3 clustered, axillary, nodding, 5–6 cm diameter; pedicel 3.0–4.5 cm long, sparsely pubescent, light green; bracteoles 2(–3), scale-like, 2.0–2.5 mm long, 2.5–3.0 mm wide, light green, pubescent on both surfaces, persistent. Sepals 5(–6), orbicular or suborbicular, 5.0–9.0 mm long, 6.5–13 cm wide, light green, pubescent on both surfaces, margin membranous and ciliate, persistent. Petals 10–11(–12), suborbicular to pentagonal, light yellow, pink pigmentation on edges, 1.4–3.4 cm long, 1.9–3.5 cm wide, tomentose on the both surfaces, innermost ones united 2.0–3.0 mm at base. Stamens 220–250 in 3–4 series; filaments 1.8–2.7 mm long, yellow, inner ones pubescent at base, outer ones glabrous, united for 3–4 mm from base and adnate to innermost petals for 2.0–3.0 mm at base; anthers 2.0–2.5 mm long, 1.5–2.0 mm wide, light yellow. Gynoecium 5-locular, ovary superior, oblate spherical, ribbed, 3.0–3.5 mm long, 4.0–5.0 mm wide, tomentose; style 5, free, 2.0–2.4 cm long, tomentose. Capsule corky, 1.8–2.1 cm high, 4.5–5.5 cm wide, sparse pubescent, dehiscing distally into 5 valves, pericarp 1.5–2.0 mm thin, 1–2 seed per locule; columella stout, 1.1–1.3 cm long. Seed semispherical, 1.5–1.8 cm long, 1.0–1.2 cm wide, russety, glabrous. 

Distribution and habitat:

—Camellia langbianensis is endemic to Vietnam, occurring in provinces of Lam Dong and Ning Thuan. It grows in evergreen broad-leaved forest at 1100–1300 m altitude. 

Additional specimens examined:—Vietnam. Lam Dong: Lam Ha District, Phu Son Commune, R’tieng village, 1000 m elev., 12 February 2017, L. V. Dung, T. Q. Cuong, N. V. Quyet, DL.170201 (DLU); Dam Rong District, Da Long Commune, 1100 m elev., 21 January 2019, L. V. Dung, T. Q. Cuong, DL19010 (DLU); Dam Rong District, Da Long Commune, 1180 m elev., 15 April 2019, L. V. Dung, T. Q. Cuong, DL190401 (DLU). Ninh Thuan: Ninh Son district, Phuoc Binh municipalite, 1300–1400 m, 2 April 1997, L. Averyanov et al. VH 3561 (HN). 

FIGURE 2. The morphology of Camellia langbianensis. A. Leaf, adaxial view; B. Venation detail of leaf (lower surface); C. Flower, lateral view; D, E. Flower, top view; F. Inner surface of bractlets; G. Inner surface of sepals; H. Inner surface of petals; I. Androecium; J. Stamens; K. Sepals and gynoecium; L. Cross section of ovary; M. Fruit; N. Dehisced capsule; O. Seeds. Draw by Luong Van Dung. 

FIGURE 3. Camellia langbianensis. A. Habitat; B. Young branches; C. Flower bud; D. Adaxil surface of leaf blade; E. Abaxial surface of leaf blade; F. Flower, back view; G. Flower, top view; H. Petals; I. Androecium; J. Sepals and gynoecium; K, L, M. Fruits; N. Dehisced capsule; O. Seeds. Photoed by Truong Quang Cuong (A–C), Luong Van Dung (D–O). 

Conservation status:

—The species is found in three locations (two in Lam Dong and one in Ninh Thuan) and has an extent of occurrence of less than 100 km2. It is known that the mountain Langbian has suffered from habitat loss, degradation and fragmentation in places. The main reason is due to tourism activities and deforestation for agricultural production. It was estimated that fewer than 200 individuals are in three populations. Therefore, it would be assessed as Critically Endangered (CR) according to IUCN categories and criteria (IUCN 2019). 

Taxonomic affinities:

—According to the classification of Ming & Bartholomew (2007), C. langbianensis may be placed into section Piquetia (Pierre 1887: 119) Sealy (1958: 108) in the charecters of its leaves stalked, blades oblong, more than 20 cm long, flowers pedicellate, solitary or 2–3, in axillary or terminal, persistent bracteoles 2–3, persistent sepals 5, petals 5(–6), styles 3–5, capsule flattened, globose, with 5 indehiscent secondary ridges, 1–2 ovules per locule. 

FIGURE 4. Morphological comparison between Camellia langbianensis and C. vidalii. A, D. Indumentum of pedicel; B, E. Indumentum of abaxial bracteole; C, F. Indumentum of adaxial bracteole; G, J. Indumentum of abaxial sepal; H, K. Indumentum of adaxial sepal; I, L. Indumentum of abaxial petal; M, P. Indumentum of adaxial petal; N, Q. Indumentum at the base of inner filaments; O, R. Indumentum of the style. C. langbianensis: A–C, G–I, M–O photoed by L. V. Dung from V. D Luong. & Q. C. Truong DL190401 (DLU); C. vidalii: D–F, J–L, P–R photoed by S. X. Yang from S. X. Yang et al. 6237 (KUN). 

Zhao (2019) reduced C. vidalii to the synonym of C. langbianensis. However, by careful comparison of the protologues and type specimens as well as our new collections including fresh materials, it is indicated that C. vidalii differs from C. langbianensis in the morphological characters of leaves and flowers (Table 1; Fig. 4). It is better to treat them as independent species at moment, and the further studies is necessary. 

TABLE 1. Morphological differences between C. langbianensis and C. vidalii. 

Acknowledgements 

This work was supported by the KRIBB Initiative Program of the Republic of Korea and the National Natural Science Foundation of China (grant no. 31770219). We would thank Dr. Zhen-Wen Liu (KUN) for his help to prepare the plates. 

References 

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