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ຫວ້າພູ || Syzygium phoukhaokhouayense Soulad., Tagane & Yahara
in Tagane, Dang, Souladeth, Nagamasu, Toyama, et al., 2018.
Photographs: S. Tagane
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Abstract
Five new species of Syzygium (Myrtaceae), Syzygium honbaense, S. phamhoangii and S. yersinii from Khanh Hoa Province, Vietnam, S. phoukhaokhouayense from Phou Khao Khouay National Protected Area, Vientiane Province, Laos, and S. scabrum from Bung Khla, Phu Wua Wildlife Sanctuary, Buengkan Province, Thailand, are described and illustrated. Photographs, vernacular names and preliminary conservation assessments are provided for them.
Five new species of Syzygium (Myrtaceae), Syzygium honbaense, S. phamhoangii and S. yersinii from Khanh Hoa Province, Vietnam, S. phoukhaokhouayense from Phou Khao Khouay National Protected Area, Vientiane Province, Laos, and S. scabrum from Bung Khla, Phu Wua Wildlife Sanctuary, Buengkan Province, Thailand, are described and illustrated. Photographs, vernacular names and preliminary conservation assessments are provided for them.
Keywords: Flora, Laos, Myrtales, new species, Thailand, taxonomy, Vietnam, Eudicots
Syzygium honbaense Tagane, V.S.Dang & Yahara, sp. nov.
TYPE:— VIETNAM. Khanh Hoa Province, Mt. Hon Ba, ...
Syzygium honbaense is distinct from all the other Syzygium species in the region by having terminal inflorescences with 3 to 5 reddish flowers, ca. 1.1 cm long hypanthium and relatively smaller leaves, to 7.2 × 2.7 cm
Distribution:—Vietnam (so far only known from the type locality, Mt. Hon Ba).
Habitat and Ecology:—Hill evergreen forest, at ca. 1200 m elevation.
Etymology:— The new species is named after the type locality, Hon Ba Nature Reserve in Khanh Hoa Province of Vietnam.
Vernacular name:— Trâm hòn bà.
Note:— Among the Syzygium species having relatively large (hypanthium > 1 cm in diam.) and reddish to purplish flowers in Indochina, S. honbaense is easily distinguished from the other species by a combination of its smallest leaves ((1.7–)2.6–7.2 cm long vs. longer than (6–)12 cm) and terminal inflorescences.
Syzygium phamhoangii Tagane, V.S.Dang & Yahara, sp. nov.
TYPE:—VIETNAM. Khanh Hoa Province, Mt. Hon Ba, ...
Syzygium phamhoangii is similar to Syzygium balsameum (Wight 1841: 16) Walpers (1843: 179) in the shape of leaves and axillary inflorescences but distinguished by its obtuse to slightly cordate leaf base (vs. cuneate to long attenuate), shorter petioles ((1–)2–4 mm long vs. 4–15 mm long), larger hypanthium (3.5–4 mm long vs. 2.5–3.5 mm long) and more ovules per locule in ovary (12–16 ovules vs. 3–8 ovules).
Distribution:—Vietnam (so far only known from the type locality, Mt. Hon Ba).
Habitat and Ecology:—Hill evergreen forest, at ca. 920 m elevation.
Etymology:— The specific epithet is chosen in honor of the excellent Vietnamese botanist Prof. Dr. Phạm Hoàng Hộ, who significantly contributed to the study of the flora of Vietnam.
Vernacular name:— Trâm phạm hoàng hộ.
Syzygium yersinii Tagane, V.S.Dang & Yahara, sp. nov.
TYPE:— VIETNAM. Khanh Hoa Province, Mt. Hon Ba, ...
Syzygium yersinii is similar to S. chantaranothaianum Soh & Parnell (2012: 558) in ovate-oblong leaf shape, very short petioles and terminal inflorescences but differs in having larger and thicker leaves (thickly coriaceous in S. yersinii vs. subcoriaceous in S. chantaranothaianum), reticulate tertiary vein (vs. scalariform) and larger flowers (hypanthium 1.8 cm long vs. 0.8–1 cm long).
Distribution:— Vietnam (so far only known from the type locality, Mt. Hon Ba).
Habitat and Ecology:— Hill evergreen forest, at 890–920 m elevation.
Etymology:— This species is named after Dr. Alexandre Emile Jean Yersin (1863–1943), a Swiss-French, for his contributions to the exploration of the Hon Ba mountain.
Vernacular name:—Trâm yersin.
Note:— Lee et al. (2014: 398) identified this species as Syzygium formosum (Wallich 1831: 108) Mason (1851: 554) but S. yersinii is easily distinguished from S. formosum by its opposite leaves (vs. usually whorled in S. formosum) and terminal inflorescences (vs. in the axils of fallen leaves). The leaf texture and venation when dry is very similar to S. grande (Wight 1841: 17) Walpers (1843: 180), but differs from S. grande in its small habit (4 m tall vs. usually more than 20 m tall), subsessile leaves (vs. petiolate in S. grande) and more or less slightly cordate leaf base (vs. cuneate).
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FIGURE 4. Syzygium phoukhaokhouayense Soulad., Tagane & Yahara.
A) Flowering branch, B) Portion of lower leaf surface, C) Bark, D) Young shoot, E & F) Flowers.
Photographs: A–F for Yahara et al. L1827,
taken by S. Tagane on 26 Dec. 2017.
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Syzygium phoukhaokhouayense Soulad., Tagane & Yahara, sp. nov.
TYPE:—LAOS. Vientiane Province, Thoulakhom district, Ban Pa Paek, Phou Khao Khouay National Protected Area, ...
Syzygium phoukhaokhouayense is similar to S. syzygioides (Miquel 1855: 431) Merrill & Perry (1938: 109) but differs in having coriaceous leaves (vs. chartaceous to subcoriaceous in S. syzygioides), longer petiole (7–12 mm long vs. 3–5 mm long), larger and reddish-purple hypanthium (4.1–4.5 mm long vs. ca. 3 mm long, greenish), longer styles (ca. 5 mm long vs. ca. 8.3 mm long) and fewer ovules per locule in ovary (4–5 per locule in S. phoukhaokhouayense vs. 10–14 per locule in S. syzygioides). Also, it is apparently similar to S. lineatum (De Candolle 1828: 287) Merrill & Perry (1938: 109) but easily distinguished by having more secondary veins (28–32 pairs in S. phoukhaokhouayense vs. 16–20 pairs in S. lineatum) and single intramarginal veins (vs. 2).
Distribution:—Laos (so far only known from Phou Khao Khouay National Protected Area).
Habitat and Ecology:—Open pine forest, at 905 m elevation.
Etymology:— The species epithet refers to the geographical location of the find, Phou Khao Khouay National Protected Area.
Vernacular name:— ຫວ້າພູ (Wa Phou).
Note:— The matK sequence of S. phoukhaokhouayense is identical with S. syzygioides (783/783 bp for GenBank accession no. AB924771 and AB925281, 780 bp for AB924710 and AB924734, 768/768 bp for AB924947). However, S. phoukhaokhouayense is easily distinguished from S. syzygioides by the diagnostic characters mentioned above, such as the differences in leaf thickness, length of petiole and style, and colour of hypanthium.
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FIGURE 5. Syzygium scabrum Tagane, Soulad. & Yahara.
A) Leafy twig, B) Portion of lower leaf surface, C) Inflorescence, D) Flowers and flower buds, E) Young fruit, F) Fruit and seed.
Photographs: A & B for Yahara et al. L1727, taken by S. Tagane on Dec. 2017;
C & D for Souladeth 86, taken by P. Sutthisaksopon on 24 May 2011;
E & F for Phonsena et al. 7280 taken by P. Phonsena on 22 Nov. 2015.
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Syzygium scabrum Tagane, Soulad. & Yahara, sp. nov.
TYPE:—THAILAND. Buengkan Province, Bung Khla, Phu Wua Wildlife Sanctuary, ...
Syzygium scabrum is similar to S. vestitum Merrill & Perry (1938: 110) in having reddish brown hairs on twigs, leaves and hypanthium, but differs in having more or less cordate leaf base (vs. broadly cuneate to rounded in S. vestitum), scabrid on both sides of leaf surfaces (vs. glabrous except on veins on abaxial side, never scabrid on adaxial side), more secondary veins (16–30 pairs vs. 10–16 pair) and longer styles (8–15.5 mm long vs. 6 mm long).
Distribution:— Laos (Vientiane Province: Phou Khao Khouay National Protected Area), Thailand (Nakhon Phanom Province: Phu Langka National Park, Buengkan Province: Phu Wua Wildlife Sanctuary).
Habitat and Ecology:—In hill evergreen forest, at altitudes of 690–770 m in Laos, and in dry evergreen forest at an altitude of 150 m in Thailand.
Etymology:—The species epithet refer to its nature of roughened (scabrid) surfaces of twigs and leaves caused by dense hairs.
Vernacular name:— หว้าขน (Wa Khon) (Thailand); ຫວ້າຂົນ (Wa Khon) (Laos).
Note 1:—This species has been confused with S. vestitum (type: Mt. Bana, Vietnam, J. & M.S. Clemens 3296, K, image!) by Souladeth & Meesawat (2012), Chantaranothai (2014), and Soh & Parnell (2015), but it is clearly distinguished from S. vestitum by the above diagnostic characters. Syzygium vestitum is restricted to northern to central Vietnam and southern China (southeast Yunnan) (Hô 2003, Chen & Craven 2007, from our field observations in SE Asia). The sequence of matK region of S. scabrum (GenBank accession no. LC381853) differs 7 bp of the total 760 bp from the S. vestitum (LC381852: Tagane et al. V2522 (FU!) from Bach Ma National Park, Central Vietnam, ca. 25 km apart from the type locality of S. vestitum), supporting the separation of the two species.
Shuichiro Tagane, Van-Son Dang, Phetlasy Souladeth, Hidetoshi Nagamasu, Hironori Toyama, Akiyo Naiki, Kengo Fuse, Hop Tran , Cheng -Jui Yang, Amornrat Prajaksood and Tetsukazu Yahara. 2018. Five New Species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa. 375(4); 247–260. DOI: 10.11646/phytotaxa.375.4.1
