Corresponding author: Junhao Chen (
Academic editor: Thomas L.P. Couvreur
Two new species of
Chen J, Eiadthong W (2020) New species and new records of
Herbarium specimens are easily assigned to
Although Thailand is considered to be well known botanically, there remains an upward trend in the number of plant species described from Thailand (
The material studied include herbarium specimens of
The conservation status of the new species was assessed using the criteria stipulated in the IUCN Red List (
Distinct from
Peninsular Thailand. Surat Thani Province: Ban Na San District, Tai Rom Yen National Park, Dat Fa Waterfall, 730 m elev., 25 February 2006,
Climbers, to ca. 10 m tall. Twigs drying light brown to brownish black, glabrous, epidermis non-flaky. Leaf laminas 8.5–15 cm long, 2.9–7.7 cm wide, elliptic to oblong-elliptic, chartaceous, glabrous above and below; base cuneate or decurrent on petiole; apex acute to acuminate, acumen up to 5 mm long; midrib raised to flush above, prominent below; secondary veins 7–12 pairs per leaf, raised to flush above and below; tertiary venation reticulate, visible on both surfaces; petiole 2–8 mm long, 1–1.5 mm in diameter, glabrous. Inflorescences 1–15-flowered, peduncles recurved (often laterally compressed and hook-like), glabrous, lateral branches condensed, pedicels 8–16 mm long, ca. 1 mm in diameter, subglabrous. Sepals 3, free, valvate, ca. 1.5 mm long, 1.5–2 mm wide, ovate, glabrous inside, sparsely puberulent outside, apex acute, green in vivo. Petals 6, free, valvate, sparsely appressed-pubescent to glabrous on both surfaces except the glabrous base inside, membranous, greenish yellow in vivo, blade often curly, base concave. Outer petals 3, 35–45 mm long, claw 2–2.5 mm wide, blade 1–2 mm wide, linear, apex acute. Inner petals 3, 32–40 mm long, claw 1.5–2 mm wide, blade 1–1.5 mm wide, linear, apex acute. Stamens 25–35, ca. 1 mm long, ca. 1 mm wide, oblong, anther connective apex truncate. Carpels 8–10, ovary ca. 1 mm long, ca. 0.5 mm wide, stigma ca. 0.5 mm long, cylindrical. Fruit of up to 8 monocarps borne on a glabrous pedicel 19–22 mm long, ca. 4 mm in diameter. Monocarps ca. 26 mm long, 18–20 mm wide, broadly ellipsoid, rough, glabrous, apex weakly beaked (ca. 1 mm long) or rounded, sessile, colour in vivo unknown, drying brownish black, pericarp thickness unknown. Seeds not seen.
Flowering specimens collected in February and August; fruiting specimens collected in May.
So far only known from peninsular Thailand (Fig.
Peninsular Thailand. Nakhon Si Thammarat Province: Lan Saka District, Khao Luang National Park, Karom Waterfall, 100 m elev., 11 August 2006,
Distinct from other
Peninsular Thailand. Surat Thani Province: Vibhavadi District, Khlong Yan Wildlife Sanctuary, trail from headquarters, ca. 200 m elev., 31 August 2002,
Climbers, to ca. 5 m tall. Twigs drying light brown to greyish black, sparsely to densely erect-pubescent, becoming glabrous, epidermis non-flaky. Leaf laminas 9–19 cm long, 3.7–7.5 cm wide, oblong-elliptic to oblong-obovate, chartaceous, glabrous above except the sparsely erect-pubescent midrib and secondary veins, sparsely to densely erect-pubescent below; base oblique; apex caudate to acuminate, acumen up to 15 mm long; midrib sunken above, prominent below; secondary veins 8–13 per side, sunken to flush above, raised below; tertiary venation reticulate, visible on both surfaces; petiole 3–10 mm long, 1–1.5 mm in diameter, erect-pubescent. Inflorescences 1-flowered (rarely 2-flowered), peduncles recurved (often laterally compressed and hook-like), sparsely erect-pubescent, lateral branches condensed, pedicels 5–15 mm long, ca. 1 mm in diameter, sparsely to densely erect-pubescent. Sepals 3, free, valvate, 6–10 mm long, 5–6 mm wide, ovate, sparsely puberulent inside, densely puberulent outside, apex acute, green in vivo. Petals 6, free, valvate, sparsely to densely puberulent on both surfaces except the glabrous base inside, chartaceous, yellow in vivo, blade flat, base concave. Outer petals 3, 17–29 mm long, claw 6–8 mm wide, blade 6–12 mm wide, oblong-ovate, apex acute. Inner petals 3, 16–28 mm long, claw 4–6 mm wide, blade 3–6 mm wide, oblong-elliptic, apex acute. Stamens 20–30, ca. 2 mm long, ca. 1 mm wide, oblong, anther connective apex apiculate. Carpels 10–14, ovary ca. 3 mm long, ca. 0.5 mm wide, stigma ca. 2 mm long, cylindrical. Fruit of up to 10 monocarps borne on a subglabrous pedicel 8.5–20 mm long, 2–2.5 mm in diameter. Monocarps 23–27 mm long, 10–13 mm wide, ellipsoid, smooth, glabrous, apex weakly beaked (ca. 1 mm long), base contracted into a stipe 1.5–4 mm long, green in vivo, drying brownish black, pericarp ca. 2 mm thick. Seeds 15.5–17.8 mm long, 9.4–10.7 mm wide, 4.6–5.2 mm thick, generally smooth with wrinkled area on sides, light yellowish brown.
Flowering and fruiting specimens collected in August and September. Fruiting specimens also collected in February and June.
So far only known from peninsular Thailand (Fig.
The specific epithet was given in honour of Mr Tawee Insura, whose prolific collection of
Peninsular Thailand. Narathiwat Province: Sukhirin District, Hala-Bala Wildlife Sanctuary, 7 September 2006,
This species is most similar to
Peninsular Malaysia and peninsular Thailand (Fig.
Peninsular Thailand. Songkhla Province: Rattaphum District, Boripat Forest Park, 4 July 1986,
This species was hitherto known from Malacca, Kedah and Perak in Peninsular Malaysia (
Singapore, Peninsular Malaysia, peninsular Thailand (Fig.
Distributions of
Peninsular Thailand. Trang Province: Palian District, Lam Plok Waterfall, ca. 20 m elev., 4 May 2010,
The protologue for
1 | Axillary shoots often with thorns; leaf apex retuse, truncate, rounded or mucronate (rarely acute); riparian plants |
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– | Axillary shoots without thorns; leaf apex acute, acuminate or caudate (rarely or never retuse, truncate, rounded or mucronate); forest plants |
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2 | Young twigs erect-pubescent; leaves erect-pubescent below |
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– | Young twigs appressed-pubescent, puberulent or glabrous; leaves glabrous or appressed-pubescent below |
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3 | Leaves coriaceous, apex acute to acuminate (never caudate), base cuneate; petals coriaceous; carpels 25–29 per flower; monocarps up to 22 per fruit, 15–20 mm wide |
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– | Leaves chartaceous, apex caudate to acuminate, base rounded or oblique (rarely cuneate); petals chartaceous; carpels 10–18 per flower; monocarps up to 12 per fruit, 10–15 mm wide |
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4 | Leaf base rounded, rarely cuneate; petal blades three-angled; anther connective apex truncate; monocarps sessile, apex strongly beaked (2–5 mm long) |
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– | Leaf base oblique; petal blades flat; anther connective apex apiculate; monocarp base contracted into a stipe 1.5–4 mm long, apex weakly beaked (ca. 1 mm long) |
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5 | Young twigs, flower pedicels and lower surface of sepals with a dense covering of long appressed hairs (visible with the naked eye) |
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– | Young twigs, flower pedicels and lower surface of sepals glabrous or with a sparse covering of short appressed hairs (visible with hand lens) |
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6 | Twigs with flaky outer layer; leaf blades 21–33 cm long, tertiary venation subscalariform; inflorescence lateral branches often elongate (up to 6 cm long) |
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– | Twigs usually with unbroken outer layer; leaf blades 5–20 cm long, tertiary venation reticulate; inflorescence lateral branches condensed or short (up to 2.5 cm long) |
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7 | Petals cream-white in vivo, blades terete; monocarps 1–2(–5) per fruit |
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– | Petals yellow, orange, beige, maroon or brown in vivo, blades not terete; monocarps 4–30 per fruit |
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8 | Petals 7–14 mm long |
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– | Petals 15–45 mm long |
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9 | Leaves lanceolate, base oblique or rounded; flower pedicels 3–6 mm long; outer petals ovate; monocarp base contracted into a stipe ca. 4 mm long |
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– | Leaves oblong-elliptic to oblong-obovate, base cuneate or decurrent on petiole; flower pedicels 7–10 mm long; outer petals deltoid; monocarps sessile or with base contracted into a stipe up to 2 mm long |
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10 | Leaf apex acuminate to caudate; outer petal blades flat, inner petal blades spathulate; monocarp apex strongly beaked (ca. 2 mm long) |
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– | Leaf apex acute; outer petal blades undulate, inner petal blades rhomboid; monocarp apex weakly beaked (less than 1 mm long) |
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11 | Anther connective apex apiculate |
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– | Anther connective apex truncate |
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12 | Sepals ca. 3 mm long, ca. 2.5 mm wide; petal blades 1–2 mm wide |
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– | Sepals 5–10 mm long, 5–8 mm wide; petal blades 5–18 mm wide |
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13 | Flower pedicels 5–9 mm long |
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– | Flower pedicels 15–32 mm long |
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14 | Leaf apex often caudate (sometimes acuminate); carpels ca. 10 per flower; monocarps up to 9 per fruit, 22–30 mm long, 15–20 mm wide, base contracted into a stipe 7–10 mm long |
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– | Leaf apex acute to acuminate (never caudate); carpels ca. 20 per flower; monocarps up to 17 per fruit, 18–20 mm long, 11–15 mm wide, base contracted into a stipe 3–4 mm long |
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15 | Leaves membranous; monocarp apex beaked (ca. 2 mm long), base contracted into a stipe 4–5 mm long; cultivated only |
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– | Leaves coriaceous; monocarp apex rounded (rarely weakly beaked), base contracted into a stipe 5–12 mm long; occurs in the wild |
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16 | Outer petal blades 11–14 mm wide, broadly elliptic; monocarps 8–10 mm wide, apex sharply beaked ca. 5 mm long |
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– | Outer petal blades 1–7 mm wide, ovate, lanceolate or linear; monocarps 15–28 mm wide, apex rounded or beaked up to 3 mm long |
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17 | Outer petals ovate; monocarp base contracted into a stipe 1–3 mm long |
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– | Outer petals lanceolate or linear; monocarps sessile |
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18 | Leaves chartaceous; inflorescences 10–20-flowered; carpels 15–20 per flower; monocarp apex rounded or weakly beaked; inhabits montane forests at 900–1700 m |
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– | Leaves coriaceous; inflorescences 3–5-flowered; carpels ca. 10 per flower; monocarp apex beaked ca. 3 mm long; inhabits lowland forests |
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19 | Leaves coriaceous; petals lanceolate, apex obtuse to acute; outer petals 18–30 mm long, blade 3–5 mm wide; inner petals 18–27 mm long, blade 2–4 mm wide |
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– | Leaves chartaceous; petals linear, apex acute; outer petals 35–45 mm long, blade 1–2 mm wide; inner petals 32–40 mm long, blade 1–1.5 mm wide |
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We thank Tawee Insura, Piya Chalermglin, Charan Leeratiwong and David Johnson for use of their photographs. We are also grateful to David Johnson and Charan Leeratiwong for their advice and assistance in taking measurements of