Edgeworthia tomentosa (Thunb.) Nakai. (Thymelaeaceae): A NEWLY RECORDED SPECIES FOR THE FLORA OF VIETNAM

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Nguyễn Thị Vân và Đtg Tạp chí KHOA HỌC & CÔNG NGHỆ 180(04): 49 - 52

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Edgeworthia tomentosa (Thunb.) Nakai. (Thymelaeaceae): A NEWLY RECORDED SPECIES FOR THE FLORA OF VIETNAM

Nguyen Thi Van¹, Tran Duc Binh², Sy Danh Thuong³, Bui Hong Quang²*

1Bacgiang Agriculture and Forestry University,

2Institite of Ecology and Biological Resources - Vietnam Academy of Science and Technology,

3TNU- University of Education

SUMMARY

Thymelaeaceae has 48 genera and ca. 650 species, widely distributed in both hemispheres.

Edgeworthia is a small genus of Thymelaeaceae, about 5 species, only distribution in Asia (Bhutan, China, India, Japan, Myanmar, Nepal, Vietnam). Among 5 species, there are 3 endemic species in China. In Vietnam, this genus has only 1 species - E. gardneri (Wall.) Meisn., only distribution in Khanh Hoa. In this paper, E. tomentosa (Thunb.) Nakai., a new record of Thymelaeaceae, is described and color photographs from the material collected in Sang Ma Sao Village, Muong Hum Commune, Bat Xat District, Lao Cai Province, Vietnam. So far, this species only distributes in China (forests, shrubby slopes and also cultivated in Fujian, Guangdong, Guangxi, Guizhou, Henan, Hunan, Jiangxi, Yunnan, Zhejiang) and Japan (cultivated and naturalized). This paper also mentions the conservation status of the species and discussion on different morphological characters between E. tomentosa and E. gardneri.

Key words: Edgeworthia, Edgeworthia tomentosa, Lao Cai, new record, Vietnam

INTRODUCTION^*

So far, the genus Edgeworthia Meisner and the species E. tomentosa (Thunb.) Nakai.

belong to Thymelaeaceae, was known including about 4 species and distributed in Asia (China, Japan) [3], [4], [7]. So far, there is only one species (E. tomentosa (Thunb.) Nakai.) in Vietnam [1], [5]. In 2017, during investigation in Bat Xat District, Lao Cai Province, Vietnam, we found a Edgeworthia plant small tree, an interesting species of Thymelaeaceae was encountered. Hence, we report this species as a new distributional record for the flora of Vietnam, with a single population found in the primary broad-leaved evergreen closed forest, nearby waterfall in Lao Cai Province, not common in the studied areas. More extensive field surveys are needed to find more E. tomentosa populations that probably exist somewhere in similar habitats in this studied areas. This work will provide insight for conservation and management of rare and threatened plant species in Vietnam. The taxonomic description, color photographs, distribution,

*Tel: 0982 166390; Email: bhquang78@gmail.com

ecology, phenology and conservation of this species are provided to facilitate its easy identification (fig. 1). This species is morphologically most similar to E.

tomentosa, in having erect small tree to 2 - 3 m tall, leaves membranaceous, elliptic to obovate. However, this species can be differentiated from the inflorescences;

peduncle 1 - 2 cm, grayish white hirsute;

bracts ca. 10, pilose; flowers fragrant; calyx yellow inside, 13 - 20 × 4 - 5 mm, tube exterior densely white sericeous, lobes 4, ovate-lanceolate, ca. 3.5 × 3 mm. In E.

gardneri: inflorescences peduncle pendulous, 2 - 2.5 (-5) cm, white sericeous at anthesis, glabrescent; bracts caducous, leaflike, narrowly lanceolate; calyx ca. 15 mm) [7]

(see table 1).

MATERIALS AND METHODS

Materials: Plants mentioned in this paper were collected during field studies in 2017.

Herbarium specimens of each studied species are presently housed in Hanoi.

Methods: Observations of flowers were made mostly on living plants in their habitats.

Additionally, flowers were preserved in spirit

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for subsequent studies and preparation of herbarium specimens. They were fixed and preserved in 50 - 60% ethanol. Measurements of floral parts for description were made on both living and liquid-preserved materials.

Fresh flowers or floral parts were found to shrink up to ca 15 - 20% in size in the drying process of making herbarium specimens. This was taken into account when dried herbarium specimens were identified. In describing quantitative characters, infrequent extreme values (i.e. rarely occurring minimum and maximum values) of a variation range are parenthesized before and after a normal variation range respectively.

RESULTS AND DISCUSSION Key species Edgeworthia in Vietnam

1a. Leaves deciduous, absent at flowering………..1. E. tomentosa 1b. Leaves evergreen or biennial, present at flowering……….2. E. gardneri Taxonomic Treatment:

Edgeworthia tomentosa (Thunb.) Nakai in Bot. Mag. Tokyo 33: 206. 1919, et in Journ.

Am. Arb. 5: 82. 1924 (Fig. 1)

- E. gardneri auct non Meisn: Hook. f. Fl, Brit. Ind. 5: 195. 1886, p. p. ; Hemsl. in Journ. Linn. Soc. Bot. 26: 396. 1891.

- E. papyrifera (Sieb.) Sieb. et Zucc. in Abh. Bay. Akad. Wiss. Math. Phys. 4 (3):

199. 1846.

Shrubs or tree to 1.5 - 2 m tall, deciduous, branching usually trichotomous. Branchlets brown, strong, stout, usually pubescent when young. Leaves falling before anthesis; leaf blade oblong, lanceolate, or oblanceolate, 8 - 20 × 2.5 - 5.5 cm, both surfaces whitish gray sericeous, more densely in abaxially; base gradually narrowed, cuneate; apex apiculate;

lateral veins 10 - 13 pairs, slender, curved, pubescent. Inflorescences terminal and axillary, capitate, 30 - 50 flowered; peduncle 1 - 2 cm, grayish white hirsute; bracts ca. 10,

pilose. Flowers fragrant. Calyx yellow inside, 13 - 20 × 4 - 5 mm; tube exterior densely white sericeous; lobes 4, ovate-lanceolate, ca.

3.5 × 3 mm. Anthers subovoid, ca. 2 mm.

Disk shallowly cup-shaped, margin irregular.

Ovary ovoid, ca. 4 × 2 mm, apex sericeous;

style glabrous, ca. 2 mm; stigma globose, ca.

3 mm. Drupe ellipsoid, ca. 8 × 3.5 mm, apex pubescent.

Flowering: (Mar-April), Fruit (April-May) Distribution: North Vietnam: Lao Cai (Bat Xat: Sang Ma Sao); South China (Fujian, Guangdong, Guangxi, Guizhou, Henan, Hunan, Jiangxi, Yunnan, Zhejiang);

cultivated and naturalized in Japan.

Ecology and habitat: Primary broad-leaved evergreen closed forest, on steep shady slope, humid area, nearby waterfall, at the elevation of 2547 m asl.

Specimens examined: North Vietnam, Lao Cai Province: Bat Xat District, 06th April, 2017, B. H. Quang 300 (HN), at elevation about 2547 m a.s.l. around point 22°24’28.5N 103°44’58.1E, locally not common.

Notes: E. tomentosa is morphologically similar to E. gardneri, a rare species on the in west north of Vietnam, and might be mistaken for the same at the first sight. The main differences between the two taxa are mentioned below (Table 1).

Conservation status: So far, there is a single distribution site recorded in Vietnam. The E.

tomentosa has Area of Occupancy (AOO) estimated less than 20 km² and number of matured individuals unknown. Moreover, this species with limitation of typical habitat characterized by primary forest, on steep shady slope, humid area, nearby waterfall, at a certain elevation (above 2000 m.a.s.l.), is not common in the studied areas. Therefore, according to the IUCN Red List criteria (IUCN, 2001) [2], E. tomentosa is proposed to be listed as Vulnerable under criterion D2.

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51 Table 1. Morphological comparison of E. tomentosa with E. gardneri

Morphological characters

E. tomentosa E. gardneri*

Leaves Blade oblong, lanceolate or oblanceolate, 8 - 20 × 2.5 - 5.5 cm, both surfaces whitish gray sericeous, more densely in abaxially; base gradually narrowed, cuneate; apex apiculate;

lateral veins 10 - 13 pairs, slender, curved, pubescent

blade narrowly elliptic to elliptic- lanceolate, 6 - 10 × 2.5 - 3.4 cm, both surfaces appressed pubescent; base cuneate; apex acute; lateral veins 8 or 9 pairs, conspicuous

Inflorescences Peduncle 1 - 2 cm, grayish white hirsute peduncle pendulous, 2 - 2.5 (-5) cm, white sericeous at anthesis, glabrescent

Bracts bracts ca. 10, pilose bracts caducous, leaflike,

narrowly lanceolate

Calyx Calyx yellow inside, 13 - 20 × 4 - 5 mm; tube exterior densely white sericeous, lobes 4, ovate-lanceolate, ca. 3.5 × 3 mm

Calyx ca. 15 mm, exterior densely white sericeous; lobes 4, yellow adaxially, ovate, ca. 3.5 × 2.5 mm, abaxially densely sericeous, apex acute or rounded

Ovary Ovary ovoid, ca. 4 × 2 mm, apex sericeous;

style glabrous, ca. 2 mm; stigma globose, ca.

3 mm

Ovary ellipsoid, ca. 5 mm, uniformly densely grayish white sericeous; style pubescent, ca. 2 mm; stigma globose, ca. 3 mm

*Morphological characters following Yinzheng et al. (2013) [7]

CONCLUSION

E. tomentosa, a new record for the Flora of Vietnam, with a single population found in the primary broad-leaved evergreen closed forest, on steep shady slope, humid area, nearby waterfall, at the elevation of 2547 m.

a.s.l. in Lao Cai Province, is preliminarily assessed conservation status of Vulnerable under criterion D2 (VU D2). More extensive field surveys are needed to find more E.

tomentosa populations that probably exist somewhere in similar habitats in the studied areas. This work will provide insight for conservation and management of rare.

Acknowledgements

We are thankful to the curators of herbarium of Institute of Ecology and Biological Resources (HN) and herbarium of South China Botanical Garden, (IBSC) for allowing us to study the vouchers.

REFERENCES

1. Nguyen Tien Ban (2003), Thymelaeaceae. In:

Checklist of Plant Species of Vietnam 2, Agricultural Publishing House, Hanoi, pp. 467-470.

2. IUCN. (2015), IUCN Red List Categories and Criteria, Version 3.1. IUCN Species Survial Commission, Gland, Switzerland, and Cambridge, United Kingdom, 30 pp.

3. Murata J. (1999), “Thymelaeaceae”. In K.

Iwatsuki Flora of Japan, 2c, pp. 146–151.

4. Nakai Takenoshin (1919), Botanical Magazine, Tokyo 33: 206.

5. Pham Hoang Ho (1999), An Illustrated Flora of Vietnam. Vol. 2, Young Publishing house, Ho Chi Minh, Vietnam, pp. 117.

6. Ministry of Science and Technology (2007), Vietnam red list data book, part II. Plant, Natural science and Technology Publishing house, Hanoi.

7. Yinzheng Wang, Michael G. Gilbert, Brian F.

Mathew, Christopher Brickell & Lorin I. Nevling (2007), “Flora of China (Clusiaceae through Araliaceae)”, Science Press & Missouri Botanical Garden Press, Beijing & St. Louis, 13, pp. 1-548.

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Figuge 1. 1. Habitas; 2,3. Inflorescence; 4,5,6. Flowers; 7. Fruit (All photo by Bui Hong Quang)

TÓM TẮT

GHI NHẬN MỚI LOÀI Edgeworthia tomentosa (Thunb.) Nakai.

Họ (Thymelaeaceae) CHO HỆ THỰC VẬT VIỆT NAM

Nguyễn Thị Vân¹, Trần Đức Bình², Sỹ Danh Thường³, Bùi Hồng Quang^2*

1Trường Đại học Nông Lâm Bắc Giang,

2Viện sinh thái và Tài nguyên sinh vật - Viện Hàn lâm Khoa học và Công nghệ Việt Nam,

3Trường Đại học sư phạm – ĐH Thái Nguyên Họ Trầm (Thymelaeaceae) bao gồm 48 chi, khoảng 650 loài, phân bố rộng rãi ở cả 2 bán cầu. Chi Edgeworthia là một chi nhỏ thuộc họ Trầm (Thymelaeaceae), bao gồm 5 loài, phân bố ở châu Á (Bhutan, Trung Quốc, Ấn Độ, Nhật Bản, Myanmar, Nepal, Việt Nam). Trong số 5 loài thuộc chi này, có 3 loài là đặc hữu của Trung Quốc. Ở Việt Nam, chi này chỉ có 1 loài là E. gardneri (Wall.) Meisn., chỉ phân bố ở Khánh Hòa. Trong bài báo này, E. tomentosa (Thunb.) Nakai, một loài bổ sung mới cho hệ thực vật Việt Nam thuộc họ Trầm (Thymelaeaceae) đã được mô tả và chụp ảnh màu từ vật liệu thu thập được ở thôn Sàng Ma Sao, xã Mường Hum, huyện Bát Xát, tỉnh Lào Cai, Việt Nam. Trước đây, loài này chỉ phân bố ở Trung Quốc (trong rừng, thảm cây bụi dốc và được trồng ở một số tỉnh như Phúc Kiến, Quảng Đông, Quảng Tây, Quý Châu, Hà Nam, Hồ Nam, Giang Tây, Vân Nam, Chiết Giang) và được nhập và trồng ở Nhật Bản. Bài báo cũng đề cập đến tình trạng bảo tồn và thảo luận các đặc điểm hình thái khác nhau giữa E. tomentosa và E. gardneri, cung cấp đầy đủ mô tả hình thái học, hình ảnh, phân bố và sinh thái học của loài này.

Từ khóa: Edgeworthia, Edgeworthia tomentosa, Lao Cai, new record, Vietnam Ngày nhận bài: 26/02/2018; Ngày phản biện: 12/3/2018; Ngày duyệt đăng: 27/4/2018

*Tel: 0982 166390; Email: bhquang78@gmail.com