Corresponding author: Hoang Thi Binh (binhht@dlu.edu.vn)
Academic editor: H. De Boer
The taxonomy of
Binh HT, Ngoc NV, Tagane S, Toyama H, Mase K, Mitsuyuki C, Strijk JS, Suyama Y, Yahara T (2018) A taxonomic study of
The genus
In this study, specimens of the
Recently, molecular studies of the genus
The purpose of this paper is to revise the taxonomy of the
The field surveys were carried out in 13 conservation areas (national parks, nature reserves and conservation areas) in Vietnam and one national park in Cambodia (Fig.
Collection sites in Vietnam and Cambodia in this study, including eight national parks, four nature reserves and two conservation areas.
Altitudinal distribution of
Altitude (m) | |
---|---|
1498 | |
1336 | |
1204 | |
1021 | No |
919 | No |
617 | |
400 | |
225 |
Amongst the collections of
In this study, 46 samples including 9 species of the
DNA was isolated from each silica-gel dried sample by the CTAB method (
DNA regions of the large subunit of ribulose-1,5-biphosphate carboxylase oxygenase (
For 105 samples, thousands of short sequences (loci) were amplified from each genome using primers designed for “multiplexed
For classical phylogenetic analyses, a phylogenetic tree was constructed by combining nucleotide sequences of the three DNA regions comprising
For MIG-seq, raw data were pretreated from 105 samples and quality control was completed following
The collections contain considerable numbers of sterile specimens including those from young trees that are often morphologically different from adult trees. Thus, after phylogenetic trees were obtained, morphological traits of leaves and shoots were carefully re-examined as well as reproductive organs if available and species were distinguished. If two OTUs are morphologically distinguishable and also not monophyletic on phylogenetic trees, these were regarded as two distinct species. Then, these were identified by a thorough literature review and comparisons with type specimen images available online (e.g. JSTOR Global Plants,
In Hon Ba Nature Reverse, tree diversity was examined in eight plots of 100 m × 5 m and four species of
In Bidoup-Nui Ba National Park, approximately 100 km west of Mt. Hon Ba, tree diversity was examined in two plots at 1,553 m and 1,807 m altitude and
In Ba Na Nature Reserve and Son Tra Natural Conservation Area, central Vietnam,
In the top plateau of Mt. Bokor, Cambodia,
A total of 2,034 bases consisting of three DNA regions (657 bp for
Summary statistics of datasets used for phylogenetic inference comprising
Regions |
|
Combined data | ||
---|---|---|---|---|
Aligned sequence length | 657 | 834 | 543 | 2034 |
Variable DNA sites | 9 | 35 | 98 | 142 |
Parsimony-informative sites | 3 | 9 | 44 | 56 |
Bayesian phylogeny of 29 samples of
Trees based on single gene sequences gave lower resolution but the
A neighbour-joining (
The results of the three gene tree (Bayesian tree) and MIG-seq tree (
Comparison of
The consistent topology of three gene and MIG-seq trees (Figs
Although the topologies of the three gene and MIG-seq tree are mostly consistent, there are some notable differences, particularly in Clade 2 and Clade M3 containing the
A comparison, based on morphological characters both in the field and from dried specimens of the herbarium and the molecular evidence for the
Morphological comparison of
Characters |
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---|---|---|---|---|---|---|---|---|---|---|
Young shoot | Almost glabrous | Golden tomentose | Curly hairy | Golden tomentose | Straight hairy | Golden tomentose | Almost glabrous | |||
Leaf margin | Undulate, distinctly serrate in upper 1/2 | Not undulate, almost entire or with a few low teeth in upper 1/4 | Not undulate, distinctly serrate in upper 1/3 | Not undulate, distinctly serrate in upper 5/6–3/4(–2/3) | Not undulate, distinctly serrate in upper 1/3 | Not undulate, distinctly serrate in upper 1/2 | Not undulate, distinctly serrate in upper 1/3 | |||
Length of petioles | 1.3–2 cm | 1–1.6 cm | 1–2.2 cm | 1.2–2(–2.9) cm | 0.8–1 cm | 1–1.4 cm | 0.9–1.8 cm | 1–2 cm | 0.4–1 cm | 1–2 cm |
Number of secondary veins | 10–13 pairs | 8–13 pairs | 7–11 pairs | (9–)10–14(–16) pairs | 12–14 pairs | 8–13 pairs | 9–12(–14) pairs | (7–)10–13 pairs | 10–12 pairs | |
Cupule shape | Obconical | Cup-shaped | Obconical | Bowl-shaped | Cup-shaped | |||||
Cupule coverage | Enclosing 1/3 of the nut | Enclosing <1/2 of the nut | Enclosing 2/3 of the nut | Enclosing 1/3–1/2 of the nut | Enclosing 1/2 of the nut | Enclosing 1/3 of the nut | ||||
Cupule bract | 5–6 rings | 6 rings | 7–8 rings | 6–8 rings | 5–6 rings | 6–9 rings | ||||
Cupule bract margin | Entire | Sparsely dissected in the lower rings | Distinctly toothed in two lower rings | Undulate | Distinctly toothed in all rings | Nearly entire, not undulate | ||||
Nut shape | Ovoid | Subglobose | Ovoid | Obovoid to ellipsoid | Subglobose | Ovoid | Subglobose | Ovoid-ellipsoid | Obovoid to ellipsoid | |
Nut scar | Convex | Flat | Convex | Convex | Flat | Convex | ||||
Nut hairiness | Glabrous | Densely hairy | Sparsely hairy | Densely hairy | Sparsely hairy | Densely hairy |
While
1 | Leaves undulate, distinctly serrate in the upper 1/2. Cupules obconical, enclosing 1/3 of the nut, bracts set in 5–6 rings, margin entire. Nut ovoid, scar convex |
|
– | Leaves not undulate |
|
2 | Leaves almost entire or with a few low teeth. Cupule cup-shaped, enclosing <1/2 of nut, bracts set in 6–8 rings, margin undulate at least in the lower rings. Nut subglobose, scar convex or flat |
|
– | Leaves distinctly serrate in the upper 5/6 to 1/3 of margin |
|
3 | Cupule distinctly narrowed at base, bracts set in 6 rings, sparsely dissected in the lower rings. Nut scar convex |
|
– | Cupule not distinctly narrowed at base, bracts set in 7–8 rings, margin distinctly toothed in two lower rings. Nut scar flat |
|
4 | Cupule obconical |
|
– | Cupule cup-shaped or bowl-shaped |
|
5 | Margin distinctly serrate in the upper 1/3; secondary veins 7–11 pairs; petioles 1.2–2(–2.9) cm long; Cupules enclosing 2/3 of the nut. Nut ovoid |
|
– | Margin distinctly serrate in the upper 5/6–3/4(–2/3); secondary veins (9–)10–14(–16) pairs; petioles 0.8–1 cm long. Cupules enclosing 1/3–1/2 of the nut. Nut obovoid to ellipsoid |
|
6 | Cupule bowl-shaped, enclosing about 2/3 of nut, bracts set in 7 rings, bract margin distinctly toothed in all rings. Nut subglobose |
|
– | Cupule cup-shaped, enclosing 1/3–2/3 of nut, bracts set in 5–9 rings, bract margin nearly entire |
|
7 | Cupules enclosing 2/3 of the nut. Nut ovoid. Young shoots covered with straight whitish hairy. Leaves distinctly serrate in the upper 1/3 |
|
– | Cupules enclosing 1/3–1/2 of the nut. Nut subglobose, ovoid-ellipsoid, obovoid to ellipsoid. Young shoots covered with golden tomenose or almost glabrous. Leaves regularly distinctly serrate in the upper 1/3–1/2 |
|
8 | Cupules enclosing 1/2 of the nut, bracts set in 5–6 rings. Leaves regularly distinctly serrate in the upper 1/3. Nut subglobose, scar convex |
|
– | Cupules enclosing 1/3 of the nut, bracts set in 6–9 rings. Leaves regularly distinctly serrate in the upper 1/2 or upper 1/3. Nut scar flat or convex |
|
9 | Leave regularly distinctly serrate in the upper 1/2; petiole 0.4–1 cm long. Nut ovoid–ellipsoid, scar flat, sparsely hairy |
|
– | Leave regularly distinctly serrate in the upper 1/3; petiole 1–2 cm long. Nut obovoid to ellipsoid, scar convex, densely hairy |
|
VIETNAM. “Mont Bani, in the main coast range about 25 kilometres from Tourane”, 4–13 June, 1927,
VIETNAM. Da Nang Province: Ba Na Nature Reserve. In this study, this species was found along the roadside and edge of evergreen forest, at 707 and 789 m altitude.
VIETNAM. Ba Na Nature Reserve,
VIETNAM. Lam Dong Province: Bao Lam District, B40 Pass, roadside and edge of evergreen forest,
Tree, 6–8 m tall. Young twigs almost glabrous except near bud, 1–1.2 mm in diam., sometimes sulcate. Old twigs glabrous, brownish-black when dry, lenticellate. Stipules linear, 3–5 mm long, hairy on both surfaces, caducous. Leaf blades elliptic to elliptic-lanceolate or rarely oblanceolate, (5.2–)9–15 × 1.7–4.5 cm, thinly coriaceous, glossy adaxially, pale green abaxially, acuminate at apex, cuneate at base, margin regularly distinctly serrate in the upper 1/2, having 9–12 teeth per side, glabrous on both surfaces; midrib slightly prominent adaxially, prominent abaxially, lateral veins (7–)10–13 pairs, straight and running into the teeth of margin, slightly prominent adaxially, prominent abaxially, at an angle of 40–45 degrees from midrib, tertiary veins scalariform-reticulate, visible on both surfaces; petioles 0.4–1 cm long, whitish hairy when young, glabrescent. Male and female inflorescences not seen. Infructescences axillary or terminal, erect spike, rachis 0.5–1.4 cm long, 1–3 mm in diam., tomentose when young, glabrescent when mature. Mature fruits ca. 2.9 cm high (including cupule), usually 1 (or 2) per infructescence, sessile; cupules obconical, 1.2 cm high, 1.5 cm in diam., enclosing 1/3 of the nut, wall comprising bracts, arranged in 7 rings, margin of rings nearly entire; nut ovoid-ellipsoid, 2.5 cm high, 1.5 cm in diam., apex nearly flat, sparsely hairy except densely appressed hairy around stylopodia, stylopodia up to 4 mm long, basal scar flat, 0.8 cm in diam., glabrous.
Fruiting specimens were collected in June.
VIETNAM. Lam Dong Province: Bao Lam District. At present, this species is known only from the type locality. Only one individual was found along the roadside and edge of evergreen forest, at 1,000 m altitude.
The specific epithet is derived from the name of its type locality, Bao Lam District.
Similar to
VIETNAM. Lam Dong Province: Bidoup-Nui Ba National Park, hill evergreen forest dominated by the species of
Tree, 8 m tall. Buds oblong to ellipsoid, ca. 2–4 mm high, ca. 1–2 mm in diam., scales 6–7 rows, imbricate, ovate-riangular, ca. 3 × 2.5 mm, apex obtuse, margin ciliate, densely hairy or glabrous outside, glabrous inside. Twigs greyish, glabrous, lenticellate. Leaf blades oblong-lanceolate, (7.5–)10–13 × 2.5–4 cm, thinly coriaceous, blackish-brown adaxially, pale brown abaxially when dry, glabrous on both surfaces, acuminate at apex, cuneate at base, margin undulate, distinctly serrate in the upper 1/2; midrib sunken adaxially, prominent abaxially, lateral veins 10–13 pairs, slightly prominent adaxially, prominent abaxially, at an angle of 45–50 degrees from midrib and running into the teeth of margin, tertiary veins scalariform-reticulate, slightly prominent, visible on both surfaces; petioles 1.3–2 cm long, blackish when dry, glabrous. Male and female inflorescences and infructescences not seen. Fruits 2.6 cm high (including cupule); cupules obconical, 1.3–1.5 cm high, 1.3–1.7 cm in diam., enclosing 1/3 of nut when mature, outside tomentose with whitish hairs to glabrous, inside villous with erect whitish hairs, wall ca. 2–3 mm thick, bracts arranged in 5–6 rings, margin of rings entire (without scale-like structure); nut ovoid, 2.2 cm high, 1.4 cm in diam., blackish, apex acute, basal scar 0.9 cm in diam., convex, glabrous. Fruits characters were obtained from the fallen materials.
Unknown. Fallen fruits were collected in February.
VIETNAM. Lam Dong Province: Bidoup-Nui Ba National Park. At present, this species is known only from the type locality.
Vietnam. Lam Dong Province, Lan Tranh,
The specific epithet “
VIETNAM. “Station agricole de Blao, province du haut Donaï”, 800 m, 25 Apr. 1933,
VIETNAM. Khanh Hoa Province: Hon Ba Nature Reserve. This species was found in hill evergreen forest at 225 m and 1067 m altitude.
VIETNAM. Khanh Hoa Province: Hon Ba Nature Reserve,
CAMBODIA. ‘‘Mont. De Elephant, sol argileux tourbeu’’, 1,000 m, 6 Aug. 1919,
CAMBODIA. Kampot Province, Bokor National Park.
CAMBODIA. Kampot Province, Bokor National Park:
VIETNAM. Annam [Trung Ky]: ‘‘Pres de Nha-trang, massif de Honba,’’ 1,000–1,500 m, 18–20 Sep. 1918,
VIETNAM. Khanh Hoa Province: Hon Ba Nature Reserve.
VIETNAM. Khanh Hoa Province, Hon Ba Nature Reserve,
VIETNAM. “Tonkin: Km. 8 du col de Lo qui Ho près de Chapa”, 1800 m, 29 July 1926,
VIETNAM. Lao Cai Province: Lo Qui Ho Pass, Chapa.
In the original publication of
VIETNAM. “Annam: Près de Sapoum, près station agricole de Blao, prov. du Haut Donai”, 1000–1100 m, 9 Jan. 1935,
VIETNAM. Lam Dong Province: Lan Tranh wards. In this study,
VIETNAM. Lam Dong Province, Lan Tranh wards,
VIETNAM. Khanh Hoa Province: Hon Ba Nature Reserve, evergreen forest along river,
Tree, 12 m tall. Buds ovoid, ca. 3–4 mm high, ca. 2–3 mm in diam., scales in 4–6 rows, imbricate, ovate-triangular, ca. 1 × 1.5 mm, apex obtuse, margin yellowish-brown ciliate, appressed hairy on both surfaces. Young twigs greyish-brown, 1–1.2 mm in diam., curly hairy, sometimes sulcate, old twigs greyish-brown, glabrous, lenticellate. Leaf blades lanceolate to oblanceolate, (3.6–)11–16.5 × (1.4–)2–5.2 cm, acute at apex, cuneate at base, margin regularly distinctly serrate in the upper 5/6–3/4(–2/3), glabrous on both surfaces; midrib slightly prominent adaxially, prominent abaxially, lateral veins (9–)10–14(–16) pairs, straight and running into the teeth of margin, slightly prominent adaxially, prominent abaxially, at an angle of 40–45 degrees from midrib, tertiary veins scalariform-reticulate, faintly visible on both surfaces; petioles 0.8–1 cm long, tomentose when young, soon glabrous. Male and female inflorescences not seen. Infructescences axillary, erect, rachis 0.5–1.4 cm long, 1–2 mm in diam., glabrous. Mature fruits 2–3.5 cm high (including cupule), usually 1 (or 2) per infructescence, sessile; cupules obconical, 1.4–1.6 cm high, 1.5–1.8 cm in diam., enclosing 1/3–1/2 of the nut, wall covered with densely whitish- to yellowish-brown hairs, bracts arranged in 6–8 rings, margin of the ring undulate; nut obovoid to ellipsoid, 2.3–2.8 cm high, 1.3–1.7 cm in diam., apex obtuse, sparsely hairy except densely appressed hairy around stylopodia and basal scar, stylopodia up to 3 mm long, basal scar 0.7–0.8 cm in diam., convex.
Fruiting specimens were collected in February.
VIETNAM. Khanh Hoa Province: Hon Ba Nature Reserve. This species is known only from the type locality. A few individuals were found in evergreen forest from 225–617 m elevation.
VIETNAM. Khanh Hoa Province: Hon Ba Nature Reserve,
The specific epithet “
VIETNAM. “Annam: massif du Lang-Bian, grand Piton Lang-Bian, près du village de Beneur”, 1500–2000 m, 15 Feb. 1914,
VIETNAM. Lam Dong Province: Bidoup-Nui Ba National Park. In this study,
VIETNAM. Bidoup-Nui Ba National Park,
We thank the curators and staff of the following herbaria DLU, FU, HN, HUH, P, PE, 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 and MEXT/JSPS KAKENHI (Grant Numbers JP15H02640 & 16H02553) and JSPS Core-to-Core Program, A. Advanced Research Networks. Funding was provided to JSS through the Flore du Cambodge, du Laos et du Viêtnam programme (MNHN, Paris & RBGE, Edinburgh) to study specimens in P.
Voucher information and GenBank accession numbers for samples used in this study (newly sequenced data).
Species | Vouchers | Elevation | GenBank accession no. | MIG-seq | ||
---|---|---|---|---|---|---|
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1850 m |
|
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+ |
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|
518 m |
|
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|
+ |
|
|
556 m |
|
|
– | + |
|
|
249 m |
|
|
|
+ |
|
|
340 m |
|
|
|
+ |
|
|
707 m |
|
|
|
+ |
|
|
789 m |
|
|
|
+ |
|
|
1000 m |
|
|
|
+ |
|
|
1695 m |
|
|
– | – |
|
|
1698 m |
|
|
|
+ |
|
|
225 m |
|
|
|
+ |
|
|
1067 m |
|
|
– | + |
|
|
1535 m |
|
|
|
+ |
|
|
1464 m |
|
|
|
+ |
|
|
888 m | – | – | – | – |
|
|
1014 m | – | – | – | – |
|
|
1014 m | – | – | – | – |
|
|
1043 m | – | – | – | – |
|
|
1000 m | – | – | – | – |
|
|
844 m |
|
|
|
+ |
|
|
1498 m | – | – | – | – |
|
|
1511 m |
|
|
– | – |
|
|
1336 m |
|
|
|
+ |
|
|
1695 m |
|
|
– | + |
|
|
1489 m | – | – | – | – |
|
|
N/A |
|
|
|
+ |
|
|
N/A |
|
|
|
+ |
|
|
1400 m |
|
|
|
+ |
|
|
1580 m |
|
|
|
+ |
|
|
367 m | – | – | – | – |
|
|
617 m |
|
|
– | – |
|
|
400 m |
|
|
– | – |
|
|
225 m |
|
|
– | – |
|
|
225 m |
|
|
|
+ |
|
|
833 m |
|
|
|
+ |
|
|
1533 m |
|
|
|
+ |
|
|
1533 m |
|
|
|
+ |
|
|
1533 m |
|
|
|
+ |
|
|
1472 m |
|
|
|
+ |
|
|
1376 m |
|
|
|
+ |
|
|
546 m |
|
|
|
+ |
|
|
1062 m |
|
|
|
+ |
|
|
1644 m |
|
|
|
+ |
|
|
1412 m |
|
|
|
+ |
|
|
1310 m |
|
|
|
+ |
|
1735 m |
|
|
|
+ |
(+): Used for analyses in this paper; (–): Not used for analyses in this paper. (*) From GenBank.
Figure S1, S2
Phylogenetic trees
Figure S1. Bayesian phylogeny of 29 samples of