Corresponding author: Shuichiro Tagane (
Academic editor: Irina Belyaeva
Tagane S, Nguyen VH, Ngoc NV, Son HT, Toyama H, Yang C-J, Yahara T (2016)
In Vietnam, 11 species of
Vu Quang National Park covers an area of ca. 56,000 ha containing an elevation gradient of over 2,000 m, from 30 m in the lowlands to 2,286 m at the summit of Mt. Rao Co (Rào CÓ), on the border with Laos (
Location of Vu Quang National Park, Vietnam.
During our botanical inventory in Vu Quang National Park in July 2015, we discovered a previously undescribed species of the genus
Similar to
VIETNAM. Ha Tinh Province; Vu Quang National Park; along the trail to the summit; in hill forest, alt. 453 m,
Small tree, 9 m tall, DBH 15.6 cm; bark gray-brown; branchlets very sparsely pubescent, soon glabrous, with many lenticels, which are narrow to broadly elliptic, 0.3–0.9 × 0.1–0.25 mm, whitish; young twigs blackish when dry, old twigs grey-brown. Leaves: simple, alternate, petiole 2.5–5 mm long, sparsely pubescent when young, blackish when dry; leaf blade ovate to elliptic-ovate or oblong-ovate, (2.4–)3.5–9.8 × (1.0–)1.2–3.1 cm, papery, very sparsely pubescent on both surfaces, apex acuminate to acute, rarely obtuse, with a gland on tip, base cuneate, with 2–5 pairs of stalked glands at border with petiole, margin crenulate with glandular teeth; midribs prominent on both surfaces, glabrescent, secondary veins 6–7 pairs, arising at an angle of 40–45 degrees from the midrib, slightly prominent on both surfaces, tertiary veins reticulated, visible when dry. Stipules narrowly triangular, ca. 5 × 1 mm, thinly papery, with 4–6 glandular teeth per side, glands often stalked, apex acute, with a gland on tip, blackish when dry, very sparsely pubescent, caducous. Inflorescences axillary, pendant, racemes or racemiform panicles with flowers borne singly on rachis or in clusters of up to 3 sometimes on short branches, 4–9 cm long, 7–20 flowered; rachis densely pubescent with spreading hairs except glabrous and lenticellate basally; bracts caducous, not seen. Pedicels 2.5–3.5 mm long, densely pubescent with spreading hairs; bracteoles narrowly ovate, 2.5–3 mm long, margin with 3–5 stalked glands per side, glabrous except near base, caducous. Flowers fragrant, 6–8 mm in diam.; calyx tube ca. 2.5 mm long, densely pubescent with spreading hairs; sepals 8, narrowly oblanceolate, ca. 3 × 0.5 mm long, membranous, with conspicuous midvein, light green
So far known only from the type locality.
Rare in hill evergreen forest, at alt. 453 m. Flowering specimens were collected in July.
The specific epithet ‘
Data Deficient. Only one flowering individual was found in a protected area of Vu Quang National Park. Further efforts for finding additional individuals/populations are needed to evaluate its conservation status.
In Vu Quang National Park, another species of
1a | Stamens solitary before each petal |
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1b | Stamens 2 or more before each petal |
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2a | Styles dentiform, less than 1 mm long |
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2b | Styles filiform, 2–5 mm long |
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3a | Petals less than 2 mm long |
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3b | Petals 3–4 mm long |
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4a | Stipules, leaf bases and bracts with stalked glands |
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4b | Stipules, leaf bases and bracts without stalked glands |
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5a | Petioles 8–15 mm long; leaves with acumen ca. 10 mm or more; leaf blade drying blackish brown |
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5b | Petioles less than 7 mm long; leaves with acumen 9 mm or less; leaf blade not drying blackish (i.e. reddish brown to dark greyish brown) |
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6a | Inflorescences glabrescent or pubescent only with short appressed hairs |
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6b | Inflorescences pubescent with spreading trichomes |
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7a | Abaxial surface of leaf pubescent on midrib and lateral veins only |
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7b | Abaxial surface of leaf sparsely to densely pubescent throughout |
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8a | Stamens partly inserted on the lower part of the petals; sepals manifestly accrescent after anthesis |
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8b | Stamens inserted strictly between the disk glands; sepals not or slightly accrescent after anthesis |
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9a | Bracts lanceolate-oblong, 4–8 mm long, caducous |
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9b | Bracts ovate-flabelliform, 5–6 mm long, persistent |
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10a | Stamens consistently 2 before each petal |
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10b | Stamens at least partly in fascicles of 3 or more |
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11a | Flowers with distinct pedicles of 3–5 mm long; calyx tube same length as the petals |
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11b | Flowers subsessile; calyx tube more than twice as long as petals |
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The authors cordially thank the Vietnam Administration of Forestry and Vu Quang National Park for permitting our botanical inventory in the protected area. We thank the curators and staff of