Two new species of Oreocharis (Gesneriaceae) from Fan Si Pan, the highest mountain in Vietnam
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Two new species of Oreocharis (Gesneriaceae) from Fan Si Pan, the highest mountain in Vietnam
Wen Hong Chen 0
Quang Hieu Nguyen
Run Zheng Chen 0
Tien Hiep Nguyen
Sinh Khang Nguyen
Van Tap Nguyen
Michael Möller
David J. Middleton
Yu-Min Shui 0
0 Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences , 132 Lanhei Road, Kunming 650201, Yunnan , China 2 Centre for Plant Conservation of Vietnam (CPC), Vietnam Union of Science and Technology Associations , 25/32 Lane 191, Lac Long Qua Road, Hanoi, Vietnam 3 Karst Conservation Initiative of Yunnan, 132 Lanhei Road, Kunming 650201, Yunnan , China 4 Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology , 18 Hoang Quoc Viet Road, Hanoi, Vietnam 5 Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh EH3 5LR , UK 6 Herbarium , Singapore Botanic Gardens , National Parks Board , 1 Cluny Road , Singapore 259569
Two new species of Oreocharis Benth. from Fan Si Pan, the highest mountain in Vietnam (Sa Pa) are described and illustrated. Oreocharis grandiflora W.H.Chen, Q.H.Nguyen & Y.M.Shui, is similar to O. flavida Merr. from Hainan province, China, but differs mainly by its larger and infundibuliform corolla, stamens adnate to the base of the corolla tube and stamens coherent in two pairs. The second, Oreocharis longituba W.H.Chen, Q.H.Nguyen & Y.M.Shui, is similar to O. hirsuta Barnett, endemic to northern Thailand, but mainly differs in its pubescence, coherent stamens and glabrous filaments.
eol>Biogeographical affinis; Sino-Himalayan forest subkingdom; Southeastern Asia; Oreocharis with yellow or orange flowers
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Copyright Wen Hong Chen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC
BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Introduction
Fan Si Pan is a species-rich diversity hotspot in Indochina, the flora of which is still
incompletely known. Fan Si Pan (in Vietnamese: Phan Xi Păng), the highest
mountain in Vietnam (3143 m elevation), is situated in the northwest of the country and
its orogeny is linked to the Himalayan Mountain chain
(Nguyen and Harder 1996;
Tapponnier et al. 1990, 2001)
. It also has the highest recorded levels of biodiversity
in Indo-China and is part of one of the 25 world’s biodiversity hotspots
(Takhtajan
1986; Myers et al. 2000)
. With more than 100 years of collecting and research in
Fan Si Pan, a rich flora of 1659 species in 723 genera and 228 families has been
recorded
(Nguyen and Nguyen 1998)
. According to the floristic subdivision of Eastern
Asia, Fan Si Pan is floristically related to the Sino-Himalayan forest subkingdom (=
Sino-Himalaya Floristic Region in the past)
(Nguyen and Harder 1996, Wu and Wu
1996)
. Even after a century of research, Fan Si Pan still yields new species. Over the
last few decades several new species have been described, such as Abies fansipanensis
Xiang et al. and Manglietia crassifolia Vu et al., adding to our understanding of its
floristic affinities
(Xiang et al. 1997; Vu and Xia 2010; Vu et al. 2011)
.
The genus Oreocharis Benth. now includes over 90 species after its recent
re-circumscription
(Möller et al. 2011)
. Since then, several new taxa have been described
from China and the genus now includes over 106 species
(Möller et al. 2016)
. The
genus is distributed predominantly in China, with few species in Thailand, Myanmar,
Bhutan, NE India, Japan and Vietnam
(Möller et al. 2011; Möller and Clark 2013;
Möller et al. 2014, 2016)
. Most Oreocharis species occur in relatively restricted and
geographically isolated localities with very few widely distributed, such as O. aurea
Dunn, occurring from South Yunnan in China (type locality) to North Vietnam
(Pellegrin 1930; Wang et al. 1990, 1998; Li 1991; Ho 2000)
. No new species of Oreocharis
were described from Vietnam from 1908 until recently when three new species were
discovered
(Do et al. 2017; Chen et al. 2017)
.
During a joint Sino-Vietnamese botanical survey in Fan Si Pan in November 2012,
two of the authors (QHN and YMS) collected several specimens of Gesneriaceae.
These included two collections of fruiting specimens. From the vegetative habit and
fruit characters, they were identified as belonging to Oreocharis. In September 2013,
cultivated plants of the two collections produced flowers unlike any of the described
species in the genus (Figs 1 and 2). After consulting the relevant literature from China
and Vietnam
(Barnett 1961; Ho 2000; Wang et al. 1990, 1998; Li and Wang 2004;
Chen et al. 2017; Do et al. 2017)
, it was confirmed that the two species were new to
science. On examination of other recent and historic unidentified collections from
Vietnam, a number of other specimens of one of the species were also found. Here,
they are descri (...truncated)