A peer-reviewed open-access journal
PhytoKeys 92: 1–15 (2018)
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
doi: 10.3897/phytokeys.92.21831
RESEARCH ARTICLE
http://phytokeys.pensoft.net
1
Launched to accelerate biodiversity research
A new species and two new records of Quercus
(Fagaceae) from northern Vietnam
Hoang Thi Binh1,2, Nguyen Van Ngoc1,2, Trinh Ngoc Bon3,
Shuichiro Tagane4, Yoshihisa Suyama5, Tetsukazu Yahara1,4
1 Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
2 Department of Biology, Dalat University, 01 – Phu Dong Thien Vuong, Dalat, Vietnam 3 Department of
Forest Phytodiversity, Silviculture Research Institute, Vietnamese Academy of Forest Sciences, Hanoi, Vietnam
4 Centre for Asian Conservation Ecology, Kyushu University, 744 Motooka, Fukuoka, 819-0395, Japan
5 Kawatabi Field Science Center, Graduate School of Agricultural Science, Tohoku University, 232-3 Yomogida, Naruko-onsen, Osaki, Miyagi 989-6711, Japan
Corresponding author: Hoang Thi Binh (binhht@dlu.edu.vn)
Academic editor: H. Schaefer | Received 24 October 2017 | Accepted 20 December 2017 | Published 9 January 2018
Citation: Binh HT, Ngoc NV, Bon TN, Tagane S, Suyama Y, Yahara T (2018) A new species and two new records of
Quercus (Fagaceae) from northern Vietnam. PhytoKeys 92: 1–15. https://doi.org/10.3897/phytokeys.92.21831
Abstract
A new species, Quercus xuanlienensis Binh, Ngoc & Bon, is described from Xuan Lien Nature Reserve,
Vietnam. The new species is morphologically similar to Q. edithiae Skan, in having 8–11 pairs of secondary veins, bowl-shaped cupules and ellipsoid to cylindrical-ellipsoid and basally convex nuts. It differs in
having serrulate leaf margins only at apical 1/5–1/7, almost entire margins of bracts on cupule and much
longer nuts. The species is also similar to Q. fleuryi Hickel & A. Camus in having leaves glabrous on both
surfaces with only an apically serrulate margin but differs in having shorter petioles, cupules enclosing
1/5 of the nut and much longer nuts. In addition, Q. disciformis Chun & Tsiang. and Q. bella Chun &
Tsiang., previously known from China, are newly recorded from Ba Vi National Park, Vietnam.
Keywords
Ba Vi National Park, DNA barcoding, Fagaceae, Quercus, Taxonomy, Vietnam, Xuan Lien Nature Reserve
Introduction
Quercus L. comprises ca. 400–500 species (Nixon 1993, Valencia-A et al. 2016)
and has been divided into two subgenera, Quercus subgenus Cyclobalanopsis (Oerst.)
Schneider (ring-cup oaks) characterised by stigma capitate to subcapitate or discoid
Copyright Hoang Thi Binh 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.
2
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
stigma, cupule bracts being connate or forming concentric or spiral rings and Quercus
subgenus Quercus (scale-cup oaks) characterised by usually linear ampliate or broadly
ampliated stigma, free and imbricate cupule bracts (Nixon 1993, Manos et al. 1999).
In Vietnam, according to Ho (2003) and Ban (2005), a total of 43 Quercus species
were recorded, amongst which 37 species belong to subgenus Cyclobalanopsis and six
species belong to subgenus Quercus. Recently, the following two species were reported
and the species of Quercus in Vietnam rose to 45 species: Q. lineata Blume of subgenus
Cyclobalanopsis (Li et al. 2016) and Q. trungkhanhensis Binh & Ngoc of subgenus
Quercus (Binh et al. in press).
To widen our knowledge on the Fagaceae of Vietnam, field surveys were undertaken by the authors for 13 conservation areas (national parks, nature reserves and conservation area) in Vietnam and a total of 105 Quercus samples were collected. Amongst
them, during the field surveys in Xuan Lien Nature Reserve and Ba Vi National Park
(Fig. 1), we discovered three unknown species of the subgenus Cyclobalanopsis which
were not identical to any of the 38 species of Cyclobalanopsis previously recorded from
Vietnam (Ho 2003, Ban 2005, Li et al. 2016, Binh et al. in press).
Xuan Lien Nature Reserve, Thuong Xuan District, Thanh Hoa Province, North
Central Coast of Vietnam, was established in 1999 with a total area of 21,000 ha.
Until now, 1,142 species of vascular plants belonging to 620 genera and 180 families
have been recorded (Xuan Lien Nature Reserve 2017). In Fagaceae, 31 species including 17 Lithocarpus species (55%), 10 species of Castanopsis (32%) and four species of
Quercus (13%) have been recorded (Xuan Lien Nature Reserve 2017). Ba Vi National
Park, Ha Noi Capital, northern Vietnam was established in 1991 with a total area of
7,377 ha (Fig. 1). In this national park, located in the Ba Vi mountain range, 1,201
vascular plant species of 649 genera and 160 families including 19 species of Fagaceae
are recorded (Ba Vi National Park 2008).
In this study, a new species is reported from Xuan Lien Nature Reserve and two
species are newly recorded from Ba Vi National Park. A new species is described as
Quercus xuanlienensis Binh, Ngoc & Bon. The two newly recorded species to the country are Q. disciformis Chun & Tsiang. and Q. bella Chun & Tsiang.
In addition to the morphological examination, DNA sequences and phylogenetic
analyses are helpful for delimiting species (Hebert and Gregory 2005, Dick and Webb
2012). Here, DNA sequences of the three species were compared with those of 20 species
in Vietnam to confirm that the three species are divergent and thus distinct from the other species. First, two DNA barcode regions were sequenced, the partial genes for the large
subunit ribulose-1,5-bisphosphate carboxylase oxygenase (rbcL) and maturase K (matK)
as basic DNA barcodes (CBOL Plant Working Group 2009). However, those sequences
show limited divergence in the genus Quercus and thus multiple gene markers (Hubert et
al. 2014, Simeone et al. 2016), RAD-seq (Cavender-Bares et al. 2015, Fitz-Gibbon et al.
2017) and MIG-seq (Suyama and Matsuki 2015, Binh et al. in review) have been used
to determine phylogenetic relationships in Quercus. In particular, Binh et al. (in review)
successfully used MIG-seq to determine the phylogenetic relationship in the Quercus
langbianensis complex in Vietnam and revise its taxonomy. In this study, the authors
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
3
Figure 1. Collection sites of Quercus xuanlienensis Binh, Ngoc & Bon, Quercus disciformis Chun & Tsiang.
and Quercus bella Chun & Tsiang.
compared the MIG-seq of Q. xuanlienensis, Q. disciformis and Q. bella with those of 18
Quercus species studied by Binh et al. (in review) and two additional species Q. platycalyx
Hickel & A.Camus and Q. quangtriensis Hickel & A.Camus that have cupules similar to
Q. disciformis and Q. bella, to determine their identities and phylogenetic relationships.
Materials and methods
Morphological observations
The validity of a new species and the identities of newly recorded species were examined based on literature of the genus Quercus in Vietnam and its surrounding countries (Camus 1936–1954, Soepadmo 1972, Ho 2003, Huang et al. 1999, Ban 2005,
Phengklai 2008, Li et al. 2016, Binh et al. in press), authentic specimens including
types by visiting the herbaria DLU, HN, FU, P and VNM and using images available
on the web of JSTOR Global Plants (https://plants.jstor.org/) and Chinese Virtual
Herbarium (http://www.cvh.org.cn/).
4
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
DNA extraction
DNA was isolated from silica-gel dried leaf materials following the CTAB method
(Doyle and Doyle 1987) with minor modifications, as in Toyama et al. (2016). Before
the DNA extraction, dry leaf material was milled by QIAGEN TissueLyser to obtain fine powder and the powder was washed up to five times by 1 ml buffer (0.1 M
HEPES, pH 8.0; 2% Mercaptoethanol; 1% PVP; 0.05 Ascorbic acid).
DNA barcoding
DNA regions of the large subunit of ribulose-1,5-bisphosphate carboxylase oxygenase
(rbcL) and maturase K (matK) were amplified and sequenced following the protocols
of Kress et al. (2009) and Dunning and Savolainen (2010), respectively.
Next generation DNA sequencing – MIG-seq
DNA products were used from 105 Quercus spp. as templates to amplify thousands of
short sequences (loci) from a wide variety of genomes using primers designed for “multiplexed ISSR genotyping by sequencing” (MIG-seq, Suyama and Matsuki 2015). Then
presence/absence of each locus in each sample was used for phylogenetic tree reconstruction regardless of whether it has SNP or not. According to the MIG-seq protocol
of Suyama and Matsuki (2015) with minor modifications as in Binh et al. (in review),
the 1st PCR, multiple non-repetitive regions from various inter-simple-sequence repeat
(ISSR) are amplified from genomic DNA by multiplexed PCR with tailed ISSR primers. The 2nd PCR step was performed based on products from the 50 times dilution
for each 1st PCR product with deionised water. Then, 3 µl of each 2nd PCR product
was pooled as a single mixture library and purified. Subsequently, the Pippin Prep DNA
size selection system (Sage Science, Beverly, MA, USA) was used to selected fragments
in the size range 350–800 bp. A SYBR green quantitative PCR assay (Library Quantification Kit; Clontech Laboratories, Mountain View, CA, USA) was used to measure
the concentration of the size-selected library with approximately 10 pM of libraries.
Finally, 10 pM of libraries were used for sequencing on an Illumina MiSeq Sequencer
(Illumina, San Diego, CA, USA), using a MiSeq Reagent Kit v3 (150 cycle, Illumina).
Phylogenetic analyses
In MIG-seq, raw data from 105 samples were pretreated and quality control completed
following Suyama and Matsuki (2015) as described in Binh et al. (in review). Subsequently, a list of loci obtained was used for the next steps. This list of loci was detected at
least in one individual (1/105=0.01) with the following settings: all samples belong to the
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
5
same population and threshold frequency of haplotype count in a population (r) = 0.001,
a threshold one-order higher than 0.01. Presence/absence (1/0) data of loci were used to
compute a distance matrix, construct a neighbour-joining (NJ) tree and the reliability of
the tree topology was examined by bootstrapping with 1000 replicates using PHYLYP ver.
3.695 (Shimada and Nishida 2017) as follows; 1000 times re-sampling with Seqboot, distance computation with Restdist, tree construction with NJ and consensus tree construction with Censense. In addition, FigTree v1.4.3 (http://tree.bio.ed.ac.uk/software/figtree/)
was used to visualise the resulting tree. A phylogenetic tree for 105 samples including 43
Quercus species amongst 44 species previously recorded in Vietnam (data not shown) was
constructed and subsequently reduced to 28 samples by focusing on the clades containing
Q. xuanlienensis, Q. disciformis, Q. bella and the additional 20 Quercus species following
Binh et al. (in review). A total of 19,916 loci were used for the final phylogenetic tree.
Results
Morphological comparison of a new species and two newly recorded species with
similar species
The unknown species (Quercus xuanlienensis) collected from Xuan Lien Nature Reserve was
not morphologically assignable to any of the species recognised in Vietnam and its surrounding countries. According to Flora of China (Huang et al. 1999) and Illustrated Flora
of Vietnam (Ho 2003), Q. xuanlienensis is most similar to Q. edithiae in leaf size (7–15 ×
3–5.8 cm), leaf base (cuneate), petiole length (1.5–2.8 cm long), number of secondary veins
(8–11 pairs), cupule shape (bowl-shaped) and nut shape (ellipsoid to cylindrical-ellipsoid).
However, Q. xuanlienensis is distinct from Q. edithiae in having a leaf margin serrated only
along its upper 1/5–1/7 (vs. upper 2/3), entire margin of cupule bracts (vs. denticulate except basal 2 or 3 rings) and longer nut (5–6 cm long vs. 4–4.5 cm long) (Table 1). Quercus
xuanlienensis is also morphologically similar to Q. fleuryi Hickel & A. Camus in leaf shape
and texture, leaf margin serrulate only at apical 1/5–1/7, entire margin of cupule bracts, basally convex nuts, but Q. fleuryi (type: Fleury 37831, P [P00753925, P00753926]) showed
much larger leaves (14–22 × 5–9 cm) than Q. xuanlienensis ((6–)8–11 × 3–4.5 cm)). In addition, Q. xuanlienensis is distinct from Q. fleuryi in having an ellipsoid bud (vs. ovate), shorter
petiole (1.5–2 cm long vs. 2.5–4 cm long), smaller and bowl-shaped cupule, (1.3–1.7 cm
high, 1.9–2.1 cm in diam. vs. campanulate to cylindrical, 3.6–3.7 cm high, 3.5 cm in
diam.), fewer cupule bracts (7–8 rings vs. 10–13 rings), cupules covering 1/4 to 1/3 of a nut
(vs. 2/3) and ellipsoid to cylindrical-ellipsoid (vs. ovoid to cylindrical-ellipsoid) and longer
nuts (5–6 cm high, 2–2.3 cm in diam. vs. 3–4.5 cm high, 2–3 cm in diam.) (Table 1).
According to the key and descriptions in the Flora of China (Huang et al. 1999), the
other two unknown taxa from Ba Vi National Park were identified as Q. disciformis and
Q. bella. Excluding slightly thinner leaves and lower teeth, one species is identical with
Q. disciformis in the following diagnostic characters: leaf blade oblong to obovate-elliptic
(6–13 × 2.5–4 cm), margin serrate in the upper 2/3, glabrous on both surfaces when ma-
6
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
ture; lateral veins 11–13 pairs; petiole ca. 2 cm long; cupule discoid, rim flat when ripe,
3–4 cm in diam., covering base of the nut, scales arranged in 8–10 rings, margin of rings
denticulate except apical 2 or 3 entire; nuts oblate 1.5–2 cm high, 2 cm in diam., apex
flattened densely appressed hairy. Another species was identified as Q. bella having the
following characteristics: leaf blade oblong-elliptic to lanceolate (8–15 cm × 2–3.5 cm),
base slightly oblique, margin serrate in the upper 1/2; lateral veins 12 pairs of lateral veins;
petiole 1–2 cm long; cupule discoid (ca. 0.5 cm × 2.5–3 cm), covering base of the nut,
scales arranged in 6–8 rings, margin of rings irregular denticulate; nut oblate nut 1.5–2
cm high and 2.2–3 cm in diam.
DNA barcoding and MIG-seq
The rbcL and matK sequences of Q. xuanlienensis showed 100% (627/627 bp) and
99% (907/910 bp) homologies with Q. donnaiensis and Q. austrocochinchinensis, respectively. The rbcL and matK sequences of Q. disciformis and Q. bella showed that
100% (696/696 bp) and 100% (833/833 bp) homologies with each other, respectively.
A phylogenetic tree, inferred using MIG-seq, showed that Q. xuanlienensis, Q. disciformis and Q. bella are not identical with any of the 20 species from Vietnam. The
neighbour-joining (NJ) tree based on MIG-seq data for 28 sample of Quercus recognised two major clades using Trigonobalanus as an outgroup (Fig. 2). Clade 1 with 82%
bootstrap value consists of three species of subgenus Quercus (Q. lanata, Q. setulosa and
Q. trungkhanhensis) and Clade 2 with 99% bootstrap value consists of 20 species of subgenus Cyclobalanopsis including Q. bella, Q. disciformis and Q. xuanlienensis. These three
species were clustered with Q. quangtriensis, Q. neglecta and Q. platycalyx and a clade of
those six species was strongly supported (74% bootstrap value). Amongst the six species,
Q. xuanlienensis was separated from the other five species forming a clade with a 74%
bootstrap value. Four samples of Q. disciformis and three samples of Q. bella formed two
distinct clades, each supported by 100% bootstrap value. Quercus disciformis was sister
to Q. bella and the clade of those two species had an 84% bootstrap value.
Discussion
The results of the NJ tree, based on MIG-seq data, showed that Q. disciformis is sister
to but well differentiated from Q. bella. These two species were collected in Ba Vi National Park where they co-occur with similar in leaf and nut morphologies, but differ
in the coverage of the cupule (Fig. 4, less than 1/8 in Q. disciformis vs. Fig. 5, basal
1/8 to 1/4 in Q. bella). According to the Flora of China (Huang et al. 1999), Q. bella
is recorded from Guangdong, Guangxi and Hainan provinces, whereas Q. disciformis
is distributed in SW Guangdong, Guangxi, Guizhou, Hainan and Hunan provinces.
Ba Vi National Park is located in northern Vietnam, neighbouring Guangxi province
and therefore the occurrences of Q. disciformis and Q. bella there are understandable.
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
7
Table 1. Morphological comparison amongst Quercus xuanlienensis Binh, Ngoc & Bon, sp. nov., Quercus
edithiae Skan and Quercus fleuryi Hickel & A. Camus.
Characters
Buds shape
Q. xuanlienensis
Ellipsoid
Twigs
Tomentose then
glabrous
Stipules
Leaf margin
Leaf surface
Leaf base
Leaf size
Length of petioles
Number of
secondary veins
Infructescence
Cupule shape and
size
Linear-lanceolate,
10–14 mm long
Serrate on upper
1/5–1/7 of lamina
Glabrous on both
surfaces
Cuneate
(6–)8–11(–15) ×
3–4.5(–5) cm
1.5–2 cm long
8–11 pairs
0.8–1 cm long, each
infructescence with
(1 or) 2 acorns
Bowl-shaped,
1.3–1.7 cm high,
1.9–2.1 cm in diam.
Number of rings on
7–8 rings
cupule
Margin of rings on
Entire
cupule
Nut enclosure by
Enclosing 1/5 of the nut
cupule
Ellipsoid to cylindricNut shape and size ellipsoid, 5–6 cm high,
2–2.3 cm in diam.
Convex, 9–10 mm in
Base of the nut
diam.
Q. edithiae (1,2,5)
Ellipsoid to ovoid
Densely yellowish brown
tomentose when young, later
glabrous
Q. fleuryi (3,4,5)
Ovoid
Densely orange-brown
tomentose when young,
later glabrous
Caducous, not seen
Caducous, not seen
Serrate on the upper 2/3 of
lamina
Glabrous on upper surface,
reddish brown pubescent on
lower surface
Cuneate
Undulate and serrulate on
upper 1/6–1/7 of lamina
Glabrous on both surfaces
Broadly cuneate
7–15 × 3–5.8 cm
14–22 × 5–9 cm
1.7–2.8 cm long
2.5–4 cm long
9–10 pairs
10–12 pairs
0.8–1.5 cm long, each
infructescence with (2 or) 3 acorns
Bowl-shaped, 1.5–1.7 cm high,
2.3 cm in diam.
0.8–1 cm long, each
infructescence with (2 or)
3 acorns
Campanulate to cylindric,
3.6–3.7 cm high, 3.5 cm
in diam.
6–8 rings
10–13 rings
Almost denticulate except basal
2 or 3 which are entire
Entire
Enclosing 1/4 to 1/3 of the nut
Enclosing 2/3 of the nut
Ellipsoid to cylindrical-ellipsoid,
4–4.5 cm high, 2.1 cm in diam.
Ovoid to cylindricalellipsoid, 3–4.5 cm high,
2–3 cm in diam.
Slightly convex, ca. 7 mm in diam. Convex, ca. 12 mm in diam.
(1)
From the material Ford 623 (K)
From the original description in Hooker’s Icon. Pl. 27: t. 2661 1901
(3)
From the material Fleury 37831 (P)
(4)
From the original description in Bull. Mus. Natl. Hist. Nat. 29: 600 1923
(5)
From the description in flora of China (Huang et al. 1999)
(2)
The two species are similar to Q. platycalyx and Q. quangtriensis in having oblong
to oblong-elliptic leaves, usually serrate along leaf margins in the upper 1/2 to 2/3,
glabrous on both surfaces when mature, and cupules covering less than 1/3 of the nut
and oblate to ovoid nuts (Huang et al. 1999, Phengklai 2008, Ho 2003). The MIGseq tree showed that those four species are related; the monophyly of a clade including
8
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
Figure 2. NJ tree of 28 samples of Quercus and one Trigonobalanus (outgroup) based on presence/absence data of 19,916 MIG-seq loci. Branches are labelled with bootstrap support (% of 1000 replicates).
the four species and Q. neglecta was supported by a 77% bootstrap value, although the
support for the monophyly of the four species is weaker. The affinity of the four species
and Q. neglecta was unexpected because Q. neglecta is an easily distinguished species
having linear leaves and small nuts (Huang et al. 1999, Ho 2003).
The MIG-seq tree showed that Q. xuanlienensis is related to the above four species and Q.
neglecta that is morphologically distinct from the other Quercus species. From the four species
(Q. disciformis, Q. bella, Q. quangtriensis and Q. platycalyx), Q. xuanlienensis is clearly distinguished by the leaf margin (leaf margin serrulate only at apical 1/5–1/7 in Q. xuanlienensis vs.
serrate in upper 1/2 to 2/3 in the four species) and nut shape (ellipsoid to cylindrical-ellipsoid
vs. oblate to ovoid). Thus, Q. xuanlienensis is separated as a distinct species from them.
Whereas Q. edithiae is morphologically most similar to Q. xuanlienensis, the type
specimens of Q. edithiae collected from Hong Kong (type: Ford 623, K [K000832101,
K000832102]) are morphologically distinct from Q. xuanlienensis in having distinct
serrations, denticulate cupule bracts and smaller nuts and the description of Q. edithiae
in Flora of China (Huang et al. 1999) agrees with the type specimen. The morphological differences between Q. edithiae and Q. xuanlienensis are as distinct as those
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
9
between related species of Quercus in Vietnam and its surrounding countries. Huang
et al. (1999) recorded Q. edithiae in Guangdong, Guangxi, Hainan and Vietnam, but
no specimen could be found of Q. edithiae collected from Vietnam in any herbarium
in Vietnam or on the Chinese Virtual Herbarium website (http://www.cvh.org.cn/).
Further studies are needed to confirm the occurrence of Q. edithiae itself in Vietnam.
The MIG-seq tree (Fig. 2) was very helpful in deriving the conclusions contained in
this paper. As Q. disciformis and Q. bella are morphologically similar and were collected
from the same locality, it was difficult to ascertain whether these are in fact two distinct
species and not variants of a single species without the support of the MIG-seq data. Also,
the separation of Q. xuanlienensis from the other species in Fig. 2 supported the conclusion that it is a new species. The authors also obtained sequences data of rbcL and matK
but the informative content of those sequences was too low to resolve the relationships
amongst such closely related species of Quercus. Difficulties were faced in determining
the sequences of ITS for Q. disciformis, Q. bella and Q. xuanlienensis, most likely due to
the low quality of the authors’ samples. MIG-seq is applicable to low quality samples and
provides finer resolution of the relationship amongst closely related species (Suyama and
Matsuki 2015, Binh et al. in review). Further studies using MIG-seq would be fruitful to
elucidate the diversity of Quercus in Vietnam, a centre of oak species richness in SE Asia.
Taxonomic treatments
Quercus xuanlienensis Binh, Ngoc & Bon, sp. nov.
urn:lsid:ipni.org:names:77174819-1
Fig. 3
Diagnosis. Quercus xuanlienensis is morphologically similar to Q. edithiae of China
and Vietnam in leaf size (7–15 × 3–5.8 cm), cuneate leaf base, petiole length (1.5–
2.8 cm long), number of secondary veins (8–11 pairs), bowl-shaped cupule, ellipsoid
to cylindrical-ellipsoid nut and basally convex nut but differs in leaf margin serrulate
only at apical 1/5–1/7 (vs. serrate in the upper 2/3), entire bracts of cupule (vs. almost
denticulate except basal 2 or 3 rings which is entire), cupule enclosing 1/5 of the nut
(vs. enclosing 1/4–1/3 of the nut) and longer nut (5–6 cm long vs. 4–4.5 cm long).
Type. VIETNAM. Thanh Hoa Province, Thuong Xuan District, Xuan Lien
Nature Reserve, in evergreen forest around waterfall, alt. 810 m, 19°52'46.7"N,
105°11'34.4"E, 6 Mar. 2017, Binh HT, Ngoc NV, Bon TN V6967 (holotype KYO!;
isotypes DLU!, FU!, P!, VNM!).
Description. Tree, ca. 18 m tall. Buds ellipsoid, ca. 9 mm long, ca. 4 mm in diam.,
scales imbricate, in 4–5 rows, ovate-triangular, ca. 3 × 2.5 mm, apex obtuse, margin ciliate, appressed whitish to yellowish brown hairy on both surfaces. Twigs glabrous when
old, lenticellate. Stipules linear-lanceolate, 10–14 mm long, densely appressed hairy, glabrescent outside, glabrous inside. Leaves alternate; blade leathery, oblong-elliptic or obovate, (6–)8–11(–15) × 3–4.5(–5) cm, apex acuminate, acumen up to 0.6 cm long, base
10
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
Figure 3. Quercus xuanlienensis Binh, Ngoc & Bon. A Leafy twig B Adaxial side of mature leaf C Stipules D Bud E, F Inside and outside of bud scale G Mature fruit H, I Inside and outside of cupule J Basal
scar of the nut. Scale bars: C 5 mm D 3 mm. Materials from Binh et al. V6967.
cuneate, margin recurved, serrulate in the upper 1/5–1/7, pale brown on the upper surface, yellowish brown to reddish brown on the lower surface when dry, glabrous on both
surfaces; midribs ±flat on upper surface, prominent and distinct on lower surface, lateral
veins 8–11 pairs, prominent on lower surface, at an angle of 40–45 degrees from midrib,
straight and running into the margin, tertiary veins scalariform, indistinct on upper surface, prominent and distinct on lower surface; petioles 1–2 cm long, glabrous. Male and
female inflorescences not seen. Infructescences axillary or terminal, erect, rachis 8–10
mm long, 4–5 mm in diam., glabrous, brownish red when fresh, blackish when dried.
Fruits 6–6.5 cm high (including cupule), solitary or twin, sessile; cupules bowl–shaped,
1.3–1.7 cm high, 1.9–2.1 cm in diam., enclosing ca. 1/5 of the nut when mature, outside
whitish to yellowish brown tomentose to glabrous, inside densely appressed yellowish
brown hairy, wall ca. 1–2 mm thick, comprising of bracts, bracts arranged in 7–8 rings,
margin of rings entire; nuts ellipsoid to cylindrical-ellipsoid, 5–6 cm high, 2–2.3 cm in
diam., apex acute, densely appressed yellowish brown hairy around stylopodia, with stylopodia up to 4 mm long, basal scar 9–10 mm in diam., convex, to 3 mm high, glabrous.
Distribution. Vietnam. Thanh Hoa Province, Thuong Xuan District, Xuan Lien
Nature Reserve.
Ecology in Vietnam. At present, only one individual was found in evergreen forest, at 810 m altitude.
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
11
Etymology. The specific epithet is derived from the district name of the type locality, Xuan Lien Nature Reserve, Thuong Xuan District, Thanh Hoa Province, North
Central Coast of Vietnam.
Phenology. Fruiting specimens were collected in March.
GenBank accession no. Binh et al. V6967: LC331257 (rbcL), LC331254 (matK).
Preliminary conservation status. Quercus xuanlienensis is known for only one
individual inside the protected area of Xuan Lien Nature Reserve. According to the
criterion D of the IUCN Red List criteria (IUCN 2012), this species is qualified as
Critically Endangered (CR).
Quercus disciformis Chun & Tsiang., J. Arnold Arbor. 28: 324 (1947)
Fig. 4
Cyclobalanopsis disciformis (Chun & Tsiang) Y.C. Hsu & H.W. Jen, Acta Bot. Yunnan.
1: 148 (1979).
Type. CHINA. “Hsin-I Hsien, Ling-Tung Pao, Chung-Tung”, 3 Aug. 1931, C. Wang
31087 (holotype-IBK [catalogue no. IBK00081941, image!], isotype-IBSC [catalogue
no. 0117316, image!]).
Specimens examined in Vietnam. Ha Noi, Ba Vi District, Ba Vi National Park, in
evergreen forest: alt. 737 m, 21°04'33.88"N, 105°22'03"E, 12 Sept. 2016, Binh et al.
V 6052, V6053, V6058 [fr.] (FU); alt. 1172 m, 21°03'34.1"N, 105°21'54.1"E,
11 Sep. 2016, Binh et al. V6040 [fr.] (FU).
Distribution. China (Guangdong, Guangxi, Guizhou, Hainan, Hunan) and Vietnam (Ba Vi National Park).
Ecology in Vietnam. In the field survey, only three individuals were found at an
altitude of 737 m and one at 1172 m; in evergreen forest.
Phenology. Flowering from March to April, fruiting from August to September in
China (Huang 1999). Fruiting in September in Vietnam.
GenBank accession no. Binh et al. V6058: LC331258 (rbcL), LC331255 (matK).
Preliminary conservation status. Quercus disciformis is widely distributed from
Guizhou to Guangdong and Hainan in China and not recorded as a threatened species
in IUCN (2017). The Vietnamese population in Ba Vi National Park extends its distribution range, representing the south western limit. Given the situation, the population
in Vietnam is locally important but the category Least Concern (LC) (IUCN 2012,
Ban et al. 2007) would be appropriate for this species.
Quercus bella Chun & Tsiang., J. Arnold Arbor. 28: 326 (1947)
Fig. 5
Cyclobalanopsis bella (Chun & Tsiang) Chun ex Y.C. Hsu & H.W. Jen., J. Beijing Forest. Univ. 15(4): 45 (1993).
12
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
Figure 4. Image of Quercus disciformis Chun & Tsiang. from Binh et al. V6058 (FU) A Leafy twig
B Abaxial side of mature leaf C–D Infructescence and mature fruit E Nut F Cupule G Bottom of nut
H Vertical section of nut.
Type. CHINA. “Fang-Cheng Hsien, Shi-Wan-Ta Shan”, alt. 200–250 m, in sparsely
wooded ravine along stream on moist sites, 24 Mar. 1944, S.H. Chun 4772 (IBSC
[catalogue no. 0039624, image!]).
Specimens examined in Vietnam. Ha Noi, Ba Vi District, Ba Vi National Park, in
evergreen forest: alt. 600 m, 21°04'40.6"N, 105°22'17.2"E, 11 Sep. 2016, Binh et al.
V 6044, V6038 [fr.] (FU); alt. 703m, 21°04'59.6"N, 105°22'03.6"E, 21 Sep. 2017,
Yahara et. al. V6981 [fr.] (DLU, FU); alt. 1023 m, 21°03'33.7"N, 105°21'39.4"E, 11
Sep. 2016, Binh et al. V6031 [fr.] (FU).
Distribution. China (Guangdong, Guangxi, Hainan) and Vietnam (Ba Vi National Park, Fig. 1).
Ecology in Vietnam. Quercus bella was found on the slopes in evergreen forests in
Ba Vi National Park: at alt. 600–1172 m.
Phenology. Flowering from February to April, fruiting from October to December (Huang et al. 1999). Flowering and fruiting specimens were collected from
Vietnam in September.
GenBank accession no. Binh et al. V6038: LC331259 (rbcL), LC331256 (matK).
Preliminary conservation status. Quercus bella was only previously known as an
endemic species to China and distributed in Guangdong, Guangxi and Hainan. The
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
13
Figure 5. Image of Quercus bella Chun & Tsiang. A Leafy twig B Adaxial side of mature leaf C Abaxial
side of mature leaf D Infructescense and mature fruit (A–D from Yahara et al. V6981 (DLU, FU)) E Inside
of cupule F Bottom of nut (E–F from Binh et al. V6038 (FU))
species is not recorded as a threatened species in IUCN (2017). Although only three
fruiting individuals of Q. bella were collected in Ba Vi National Park, more individuals
are expected to occur there and the habitat in the Ba Vi National Park is currently wellprotected from anthropogenic activities under the law. Thus, it is appropriate to place
this species under the category Least Concern (LC) following IUCN Red List (IUCN
2012) and Vietnam Red Data book (Ban et al. 2007).
Acknowledgements
We wish to thank Dr. Chika Mitsuyuki in Tohoku University for supporting our
MIG-seq analysis. We also thank the curators and staff of the following herbaria DLU,
FU, K, P, VNM for making their materials accessible. This study was supported by
the Environment Research and Technology Development Fund (S9 & 4-1601) of
the Ministry of the Environment, Japan, MEXT/JSPS KAKENHI (Grant Numbers
JP15H02640 & JP16H02553), and JSPS Core-to-Core Program, A. Advanced Research Networks.
14
Hoang Thi Binh et al. / PhytoKeys 92: 1–15 (2018)
References
Ba Vi National Park (2008) Plants of Ba Vi National Park. http://vuonquocgiabavi.com.vn/
he-thuc-vat-vqg-ba-vi [In Vietnamese; Accessed 20 September, 2017]
Ban NT (2005) Vietnam plant checklist, Vol. 2. Agriculture Publishers, Hanoi National University. [In Vietnamese]
Ban NT, Ly DT, Tap N, Dung VV, Thin NN, Tien VN, Khoi KN (2007) Vietnam Red Data
Book Part II. Plants. Natural Sciences and Technology Publishers, Hanoi. [In Vietnamese]
Binh HT, Ngoc NV, Tai VA, Son HT, Tagane S, Yahara T (in press) Quercus trungkhanhensis
(Fagaceae), a new species from Cao Vit Gibbon Conservation Area, Cao Bang Province,
north-eastern Vietnam. Acta Phytotaxonomica et Geobotanica.
Binh HT, Ngoc NV, Tagane S, Toyama H, Mase K, Mitsuyuki C, Strijk JS, Suyama Y, Yahara
T (in review) A taxonomic study of Quercus langbianensis complex based on morphology,
and DNA barcodes of classic and next generation sequences. Phyto Keys.
Camus A (1936–1954) Les Chênes. Monographie du genre Quercus et Monographie du genre
Lithocarpus. Paul Lechevalier Edition, Paris.
Cavender‐Bares J, González‐Rodríguez A, Eaton DA, Hipp AA, Beulke A, Manos PS (2015)
Phylogeny and biogeography of the American live oaks (Quercus subsection Virentes):
a genomic and population genetics approach. Molecular Ecology 24(14): 3668–3687.
https://doi.org/10.1111/mec.13269
Dick CW, Webb CO (2012) Plant DNA barcodes, taxonomic management, and species discovery in tropical forests. In: Kress WJ, Erickson DL (Eds) DNA Barcodes. Methods and
Protocols 858: 379–393. https://doi.org/10.1007/978-1-61779-591-6_18
Doyle JJ, Doyle JL (1987) A rapid DNA isolation procedure for small quantities of fresh leaf
tissue. Phytochemical Bulletin 19: 11–15.
Dunning LT, Savolainen V (2010) Broad-scale amplification of matK for DNA barcoding plants, a
technical note. Botanical Journal of the Linnean Society 164(1): 1–9. https://doi.org/10.1111/
j.1095-8339.2010.01071.x
Fitz-Gibbon S, Hipp AL, Pham KK, Manos PS, Sork VL (2017) Phylogenomic inferences
from reference-mapped and de novo assembled short-read sequence data using RADseq
sequencing of California white oaks (Quercus section Quercus). Genome 60(9): 743–755.
https://doi.org/10.1139/gen-2016-0202
Hebert PDN, Gregory TR (2005) The promise of DNA barcoding for taxonomy. Systematic
Biology 54: 852–859. https://doi.org/10.1080/10635150500354886
Ho PH (2003) An Illustrated Flora of Vietnam, Vol. 2. Young Publishers, Ho Chi Minh City.
[In Vietnamese]
Huang CJ, Zhang YT, Bartholomew B (1999) Fagaceae. In: Zhengyi W, Raven PH, Deyuan H
(Eds) Flora of China. Volume 4, 333–369. [http://www.e oras.org]
Hubert F, Grimm GW, Jousselin E, Berry V, Franc A, Kremer A (2014) Multiple nuclear genes
stabilize the phylogenetic backbone of the genus Quercus. Systematics and Biodiversity
12(4): 405–423. http://dx.doi.org/10.1080/14772000.2014.941037
IUCN (2012) IUCN Red List Categories and Criteria: Version 3.1. Second edition. Gland, Switzerland and Cambridge, UK. http://jr.iucnredlist.org/documents/redlist_cats_crit_en.pdf
[accessed 10 December 2017]
A new species and two new records of Quercus (Fagaceae) from northern Vietnam
15
IUCN (2017) The IUCN Red List of Threatened Species. Version 2017-2. http://www.iucnredlist.
org [Downloaded on 10 December 2017]
Kress WJ, Erickson DL, Jones FA, Swenson NG, Perez R, Sanjur O, Bermingham E (2009)
Plant DNA barcodes and a community phylogeny of a tropical forest dynamics plot in
Panama. Proceedings of the National Academy of Sciences of the United States of America
106(44): 18621–18626. https://doi.org/10.1073/pnas.0909820106
Li Q, Zhang J, Coombes A (2016) Quercus lineata (Fagaceae): new distribution records
from China and Vietnam and its leaf anatomical features. Phytotaxa 266(3): 226–230.
https://doi.org/10.11646/21580
Linnaeus C (1753) Species Plantarum, 2. Stockholm.
Manos PS, Doyle JJ, Nixon KC (1999) Phylogeny, biogeography, and processes of molecular
differentiation in Quercus subgenus Quercus (Fagaceae). Molecular phylogenetics and evolution 12(3): 333–349. https://doi.org/10.1006/mpev.1999.0614
Nixon KC (1993) Infrageneric classification of Quercus (Fagaceae) and typification of sectional names. Annales des Sciences Forestières 50: 25s–34s. https://doi.org/10.1051/
forest:19930701
Phengklai C (2008) Fagaceae. Flora of Thailand 9(3): 179–410.
Shimada MK, Nishida T (2017) A modification of the PHYLIP program: A solution for the
redundant cluster problem, and an implementation of an automatic bootstrapping on
trees inferred from original data. Molecular Phylogenetics and Evolution 109: 409–414.
https://doi.org/10.1016/j.ympev.2017.02.012
Simeone MC, Grimm GW, Papini A, Vessella F, Cardoni S, Tordoni E, Piredda R, Franc A,
Denk T (2016) Plastome data reveal multiple geographic origins of Quercus Group Ilex.
PeerJ 4: e1897. https://doi.org/10.7717/peerj.1897 [eCollection 2016]
Soepadmo E (1972) Fagaceae. Flora Malesiana Series I, Volume 7(2). Noordho-Kol N.V., Djakarta, 265–403.
Suyama Y, Matsuki Y (2015) MIG-seq: an effective PCR-based method for genome-wide single-nucleotide polymorphism genotyping using the next-generation sequencing platform.
Scientific Reports 5: 16963. https://doi.org/10.1038/srep16963
Toyama H, Tagane S, Chhang P, Nagamasu H, Yahara T (2016) Flora of Bokor National Park,
Cambodia IV: A New Section and Species of Euphorbia Subgenus Euphorbia. Acta Phytotaxonomica et Geobotanica 67(2): 83–96.
Valencia-A S, Rosales JLS, Arellano OJS (2016) A new species of Quercus, section Lobatae (Fagaceae) from the Sierra Madre Oriental, Mexico. Phytotaxa 269(2): 120–126.
http://dx.doi.org/10.11646/phytotaxa.269.2.5
Xuan Lien Nature Reserve (2017 onwards) Diversity of plants of Xuan Lien Nature Reserve.
http://xuanlien.org.vn/default.aspx?c=home&l=vi&nid=Da_dang_loai_va_khu_he_
thuc_vat&gid=120 [In Vietnamese; Accessed September 15, 2017]