Agapetes putaoensis, a Newly Recorded Species of Agapetes (Ericaceae) from China

YANG Bin, LI Jianwu, LI Haitao, ZHOU Lumen, TAN Yunhong*

(1 Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences, Yezin, Nay Pyi Taw 05282, Myanmar; 2 Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; 3 Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences, Mengla, Yunnan 666303, China; 4 Yunnan Branch, Institute of Medicinal Plant, Chinese Academy of Medical Sciences/Yunnan Key Laboratory of Southern Medicinal Resources, Jinghong, Yunnan 666100, China; 5 Management and Conservation Bureau of Yunnan Huangliangshan National Nature Reserve, Lüchun, Yunnan 662599, China)

Abstract: Agapetes putaoensis Y. H. Tong & N. H. Xia was originally described from Putao District, Kachin State, northeast Myanmar in 2014. The present authors collected it from Lüchun County, Yunnan, China in 2018 and 2020. Here, it is reported as a newly recorded species for China. This species is described and illustrated with a colour plate for identification. Supplementary description of its fruits is also provided. The voucher specimens are deposited in the Herbarium of Xishuangbanna Tropical Botanical Garden (HITBC) and the Yunnan Branch, Institute of Medicinal Plant, Chinese Academy of Medical Sciences (IMDY).

Key words: Agapetes; Ericaceae; Agapetes putaoensis; new record; Myanmar

The genusAgapetesD. Don ex G. Don (Ericaceae: Vaccinioideae: Vaccinieae), comprises approximate 100 recognized species, most of which are distributed from the eastern Himalayas through Southwest China and Indochina to Southeast Asia[1]. In China, 55 species and 2 varieties are currently recognized, including the recently publishedA.xianaY. H. Tong andA.yingjiangensisY. H. Tong, B. M. Wang & N. H. Xia[1-4].

During the traditional Chinese Medicine resource and floristic surveys of southeastern Yunnan, China in 2018 and 2020, we collected some specimens of anAgapetesspecies. After a detailed examination of the morphological characters of our material and related literatures, we identified it asAgapetesputaoensisY. H. Tong & N. H. Xia which was recently described by Tong and Xia[5]from Kachin state, Northern Myanmar. It therefore represents a newly recorded species for the flora of China, which was reported herein.

葡萄树萝卜(新拟，图版Ⅰ)

AgapetesputaoensisY.H.Tong&N.H.Xia,Phytotaxa184(1):39,2014.(Plate Ⅰ)

Type: Myanmar. Kachin State: Putao, Renan, epiphytic on trees, 27°42′6″N, 98°2′14″E, elevation 970 m, 15 March 2009, Ayeyarwady Expedition 2416 (holotype: IBSC; isotypes: CDBI, IBSC).

Shrubs epiphytic, ca. 2.5 m tall. Twigs longitudinal-striate, glabrous. Leaves spirally scattered; petiole 4-6 mm long, glabrous; blades elliptic-lanceolate, 5-11.3 × 1.1-2.9 cm, thinly leathery, glabrous, midveins raised on both surfaces, secondary veins 3-5 pairs, with fine veins slightly conspicuous on both surfaces, base attenuate to cuneate, margin entire, slightly revolute, apex caudate-acuminate. Inflorescences axillary or on leafless stem, 1-5-flowered; peduncle very short, 1-2 mm long; bracts triangular, ca. 0.5 mm long, glabrous; pedicels 1.2-2.0 cm long, glabrous, expanded upwards. Calyx tube white, tubular, 2.5-3.0 × ca. 2 mm, glabrous; lobes triangular, ca. 1 mm long, glabrous, apex acute. Corolla reddish white, cylindric-conical, 0.8-1.0 × 0.2-0.3 cm, glabrous; lobes triangular-lanceolate, 5-6 mm long, strongly reflexed at late flowering. Stamens 10, 0.9-1.0 cm long; filaments flat, ca. 1 mm long, margin white pubescent; thecae 1.5-2.0 mm long, papillate; tubules 6.0-6.5 mm long, with 2 spurs abaxially, spurs ca. 1 mm long. Style glabrous, ca. 1 cm long. Fruit subglobose, greyish-white when mature, 4-5 mm in diameter.

Distribution: China (Yunnan) (new record); Myanmar (Kachin).

Specimensexamined: China(中国). Yunnan(云南): Lüchun County(绿春县), Qimaba Village(骑马坝乡), Huangliangshan National Nature Reserve(黄连山国家级自然保护区), 22°50′30.75″N, 102°14′41.15″E, 1 100 m, 11 April 2020, Li Jianwu(李剑武) 5402 (HITBC); Sanmeng(三猛乡), Lagu(腊姑村), 1 500 m, 10 April 2018, Lüchun Team(绿春考察队)5326310565 (IMDY).

Discussion: The comparative analysis of the floristic similarities showed that the flora of Dulongjiang has closer affinity with the flora of SE Yunnan than others although it is distant away from SE Yunnan[6-7]. One of the possible ways to explain the closer floristic affinity between Dulongjiang and southeastern Yunnan is from the geology and the tectonic theory of these regions. Meanwhile, the geological history of SE Asia revealed that the west and South Yunnan could be derived from fragments of Gondwana[8]. During the proceeding of the northward thrusting of Indian plate to Asian continental plate and the uplift of the Himalayas and the Hengduan Mountains, the Gondwana fragment of Yunnan had turned clockwise. Dulongjiang area and Northeast Myanmar belong to the same geographic area, therefore it could be possible that this species occurs in the disjunctive areas of Northeast Myanmar and SE Yunnan.

Additionalspecimensexamined: Myanmar(缅甸). Kachin State(克钦邦): Putao township(葡萄镇), Wasadam, 29 April 2016, Tan Y. H.(谭运洪)& Zhou S. S.(周仕顺), M201634 (HITBC); Putao(葡萄), on the way from the mountain top to Namti, 14 May 2017, Tan Y. H.etal.(谭运洪等), M1777(HITBC), Putao(葡萄), Northwest of Zeyadam, on the way from Camp 1 to Zeyadam, 12 May 2017, Zhou S. S.(周仕顺)& Zeng X. D.(曾晓东), M2123 (HITBC).

AcknowledgmentsWe are very grateful to the reviewers for their valuable comments and suggestions. The first author thanks Dr. Song Yu and Mr. Li Kunju for their help in the field.

图版Ⅰ葡萄树萝卜 A和D.果枝；B和E.花；C和F.花解剖；A-C拍自云南省绿春县；D-F拍自缅甸克钦邦葡萄；A由李剑武拍摄；B由李海涛拍摄；C由杨斌拍摄；D-F由谭运洪拍摄
PlateⅠAgapetesputaoensisY. H. Tong & N. H. Xia A & D. Fruiting branches; B & E. Flowers; C & F. Dissected flowers; Photos A-C taken from Lüchun, Yunnan, China; D-F taken from Putao, Kachin, Myanmar; A by LI Jianwu; B by LI Haitao; C by YANG Bin; D-F by TAN Yunhong.