NGUYEN Khang Sinh 溫放

Abstract：Raphiocarpus Chun is a small genus includes all species from China to Indo-China Peninsula， and mainly distributes from southern and southwestern China to northern and central Vietnam. However， there are only three species can be found in both countries formerly. Raphiocarpus begoniifolius （Lévl.） Burtt was once considered as an endemic species of China， and it is distributed in China （northwestern Guangxi， southwestern Guizhou， southeastern Yunnan and northwestern Hubei）， but there is not reported on flora of Vietnam. This species is here reported as the first record for the flora of Vietnam， so it makes the codistributed species number of Raphiocarpus in both countries has been risen from three to four. Notes on taxonomy and distinguishable discussion from its congener， Raphiocarpus macrosiphon （Hance） Burtt， are provided. The further improved key to species of Raphiocarpus in Vietnam is showed here. According to the field studies by both countries， respectively and/or jointly， we also discussed the endangered status of Raphiocarpus begoniifolius so that it furnishes direct evidence for the conservation of this species and， even， this genus in China and Vietnam. The voucher specimens are hold in Herbarium of Institute of Ecology and Biological Resources （HN）.

Key words：North Vietnam， Raphiocarpus Chun， flora of Vietnam， flora of China

摘 要：漏斗苣苔屬（Raphiocarpus Chun）是分布于中國(guó)至中南半島一帶的小屬，主要產(chǎn)于中國(guó)華南西南抵越南北部至中部，但之前中越兩國(guó)共有分布的該屬物種僅有3個(gè)種。大苞漏斗苣苔[Raphiocarpus begoniifolius （Lévl.） Burtt]一度被認(rèn)為是中國(guó)的特有種，僅分布在中國(guó)的廣西西北部、貴州西南部、云南東南部和湖北西北部，尚未見有在越南的相關(guān)研究報(bào)道。該文首次報(bào)道了越南植物區(qū)系中大苞漏斗苣苔的國(guó)家級(jí)分布新記錄，使得中越兩國(guó)共有分布的該屬物種上升到了4個(gè)種，并著重討論了大苞漏斗苣苔與其近緣種長(zhǎng)筒漏斗苣苔[Raphiocarpus macrosiphon （Hance） Burtt]的區(qū)別特征，進(jìn)一步完善了越南所分布的漏斗苣苔屬植物檢索表。根據(jù)中越兩國(guó)的各自與聯(lián)合野外考察工作對(duì)該種的瀕危現(xiàn)狀進(jìn)行了討論，為中越兩國(guó)開展該種乃至該屬植物的保育提供了直接證據(jù)。憑證標(biāo)本保存于越南生物資源與生態(tài)研究所標(biāo)本館（HN）中。

關(guān)鍵詞：越南北部， 漏斗苣苔屬， 越南植物區(qū)系， 中國(guó)植物區(qū)系

1 Introduction

The genus，Raphiocarpus Chun， originally described as a monotypic genus （Chun， 1946）. It was merged into Didissandra C. B. Clarke by Wang （1980） after three decades. However， the results showed that the Sino-Vietnamese species of Didissandra are not congeneric with the Malesian species （which themselves had to be split into two genera， Didissandra and Ridleyandra A.Weber & B.L.Burtt） （Weber & Burtt， 1998）. Thus， according to presently understanding， Raphiocarpus should include all species from China and Vietnam formerly placed in Didissandra. Further up， these species of the redefined Raphiocarpus are generally very ill-known and are quite possible that those species do not form a homogeneous group （Weber & Burtt 1998， 1997; Sontag & Weber， 1998; Vitek et al， 1998）. In other words， the genus may prove artificial， when the species （and adjacent genera） are better known （Weber & Skog， 2007）.

At present，Raphiocarpus with fourteen currently recognized species， has its main distribution from southern and southwestern China to northern and central Vetnam （Pellegrin， 1930; Ho， 2000; Li & Wang， 2004; Phuong， 2005; Zhang et al， 2010; Phuong & Xuyen， 2010; Phuong et al， 2012）. Raphiocarpus petelotii （Pellegr.） B. L. Burtt and Raphiocarpus sinicus Chun， do also occur in Vietnam （Li & Wang， 2004; Phuong， 2005; Phuong & Xuyen， 2010）. The distribution area of Raphiocarpus longipedunculatus （C. Y. Wu ex H. W. Li） B. L. Burtt， Raphiocarpus maguanensis Y. M. Shui & W. H. Chen and Raphiocarpus jinpingensis W. H. Chen & Y. M. Shui in Chinese Yunnan （Pingbian， Maguan， Jinping， Lüchun） are very close to the border of Vietnam and these species might be discovered in Vietnam in the future （Li & Wang， 2004; Wei et al， 2010; Zhang et al， 2010）. Recently， we recognized and identified some species of this genus from the specimens of Gesneriaceae in the Hanoi Herbarium （HN）. The ‘Checklist of plant species of Vietnam includes five species of Didissandra C. B. Clarke， now Raphiocarpus， in Vietnam. They are Raphiocarpus annamensis （Pellegr.） B. L. Burtt， Raphiocarpus asper （Drake） B.L.Burtt， Raphiocarpus clemensiae （Pellegr.） B.L.Burtt， Raphiocarpus evrardii （Pellegr.） B.L.Burtt， Raphiocarpus petelotii， Raphiocarpus sinicus and Raphiocarpus tamdaoensis V.X.Phuong， D.T.Xuyen & Y.G.Wei （Phuong， 2005; Phuong et al， 2012）. After consulting relevant literature （Pellegrin， 1930; Burtt， 1954; Burtt & Tan， 1984; Wang & Li ， 1992， 1998; Ho， 2000; Weber， 2004; Wei et al， 2010; Zhang et al， 2010， Phuong & Xuyen， 2010; Phuong et al， 2012）， as well as herbarium specimens in Vietnam and China， we considered that our unknown species from Vietnam should be Raphiocarpus begoniifolius （Lévl.） Burtt， which is a new record to Vietnam.

2 Results and Analysis

2.1 Taxonomy and specimens information

Raphiocarpus begoniifolius （Lévl.） Burtt in Beitr. Biol. Pflanze 70：173. 1998. —Didissandra begoniifolia Lévl. in Repert. Sp. Nov. 11：495. 1913; Burtt in Not. Bot. Gard. Edinb. 23（3）：100. 1960; Lauener & Burtt in l. c. 38（3）：467. 1980; K.Y. Pan in W. T. Wang， Fl. Reip. Pop. Sin. 69：231， tab. 59：5-9. 1990; W. T. Wang et al. in Z. Y. Wu & Raven， Fl. China 18：282. 1998. —Chirita chamydata W. W. Smith in Not. Bot. Gard. Edinb. 10：170. 1918. —Loxostigma begoniifolium （Lévl.） Anthony in l. c. 18：199. 134. Type：CHINA. Yunnan， Red River from manmer. J. Esquirol 972 （E， holo?。?

Additional specimens examined：Vietnam：Hà Giang prov.， Qun B distr.， Cao M P comm.， Vàng Chá Phìn vill.， subtropical evergreen broad-leaved forest on silicate mountain， around point 104°49′05.4″ E， 23°05′24.3″ N， elevation of 1 650-1 700 m a. s. l. perennial herb about 30-60 cm tall， flower purple， common in humid shaded areas of mountain slopes， Nguyen Khang Sinh， Nguyen Quang Hieu & Tu Bao Ngan， NSK 977， NSK 981， September 14， 2017.

2.2 Distribution and conservation

Ecology：Grows on wet humus-soil or crevices of rocks covered with humus under thickets and subtropical evergreen broad-leaved forest on slopes， at an elevation of 1 200-2 100 m above sea level. Flowering：August-September; Fruiting：September-October.

Distribution：China （Guangxi， Yunnan， Guizhou and Hubei） and new to Vietnam （Hà Giang prov.， Qun B distr.， Cao M P comm.）

Conservation status in China and Vietnam：Because the populations found in Guangxi， Guizhou， Yunnan and Hubei of China and North Vietnam， are growing well with abundant individuals in different po-pulations， we estimate that this species will not easily become extinct. During our field work， although we found that farmlands and fruit plantations were expanding in these areas， which would result in deforestation， habitat loss and fragmentation of this species， the individuals and populations of Raphiocarpus begoniifolius are abundant in two countries. Thus， following the IUCN （2017） red list categories and criteria， the conservation status of this species is Least Concern （LC）.

2.3 Notes on taxonomy and key of Raphiocarpus in Vietnam

The vegetative organs of Raphiocarpus begoniifolius （Lévl.） Burtt look similar to Raphiocarpus macrosiphon （Hance） Burtt if there is no flower， but the flowers of the latter are orange-red and are entirely different from the pale-purple or rusty lilac to purple flowers of the former. After a new species of Raphiocarpus， Raphiocarpus tamdaoensis， was published by Phuong et al（2012） and this new record was confirmed， there are nine species of Raphiocarpus in Vietnam in all. Here we present the further promoted identification key to all known species of Raphiocarpus occurring in Vietnam.

3 Acknowledgments

Authors would like to thank Prof. Wei Yigang from Guilin Botanical Garden and Dr. Michael Mller from Royal Botanical Garden Edinburgh to identify and confirm those specimens of Raphiocarpus begoniifolius.