taxonID	type	description	language	source
039D87D0FF928D17FF45CEFEDF3DFBD6.taxon	materials_examined	TYPE: — VIETNAM. Khanh Hoa Province, Mt. Hon Ba, 12 ° 07 ′ 29.45 ″ N, 108 ° 57 ′ 51.11 ″ E, elev. 1204 m, 21 July, 2013, Tagane S., Yahara T., Nagamasu H., Fuse K., Toyama H., Tran H., Dang V. S., Loi X. N., Thach N. D., Cuong Q. N., Hieu P. N. H. & Thach K. N. V 612 [fl.] (holotype KYO!, isotypes KAG!, VNM, the herbarium of Hon Ba Nature Reserve). 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. Tree, 10 m tall. Young twigs terete, grayish brown, glabrous, ca. 1 mm in diam., old twigs grayish brown, internode (0.5 –) 1.2 – 2.6 cm long. Leaves opposite, blade elliptic, elliptic-oblong, rarely obovate, (1.7 –) 2.6 – 7.2 × (0.8 –) 1.2 – 2.7 cm, 1.8 – 3.2 times longer than wide, coriaceous, dark yellowish green to grayish green adaxially, dull brownish yellow abaxially, glabrous on both surfaces, base cuneate, apex acuminate or acute, margin entire, slightly recurved when dry, midrib sunken adaxially, prominent abaxially, secondary veins 8 – 10 pairs, prominent on both surfaces, intersecondary veins distinct adaxially, intramarginal veins 1 (rarely 2, faintly visible), 1 – 2 mm apart from margin; petiole (0.4 –) 0.8 – 1 cm long, concave adaxially, rounded abaxially, grayish green to yellowish brown, glabrous. Inflorescences terminal, racemose, 3 - to 5 - flowered, rarely solitary, peduncle 0.8 – 1.4 cm long, rachis and lateral branches terete or occasionally slightly compressed; bracteoles caducous, not seen. Flower buds subglobose, ca. 1.1 cm in diam., reddish purple (in vivo). Hypanthium funnel-shaped, ca. 1.1 cm long, glabrous, pseudostipe indistinct, or very short to 1 mm long. Sepals 4, depressed ovate, 2.5 – 4 × 7 – 8 mm, apex rounded, margin fringed with whitish, membranous part, petals 4, suborbicular, ca. 9 mm in diam., membranous, with ca. 180 gland dots per petal. Stamens many, more than 340, 1.1 – 1.5 cm long, anthers 0.8 – 0.9 mm long, filaments reddish purple (in vivo), glabrous. Style ca. 1.4 – 1.7 cm long, glabrous, ovary 2 - locular, ovules 18 – 20 per locule. Fruit and seeds not seen.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF928D17FF45CEFEDF3DFBD6.taxon	distribution	Distribution: — Vietnam (so far only known from the type locality, Mt. Hon Ba). Habitat and Ecology: — Hill evergreen forest, at ca. 1200 m elevation. Phenology: — Flowering specimens were collected in July.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF928D17FF45CEFEDF3DFBD6.taxon	etymology	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. Preliminary conservation assessment: — Critically Endangered (CR). During our intensive botanical surveys in Mt. Hon Ba from 2011 to 2013, only one flowering individual was found at the edge of the evergreen forest, along the road to the summit of Mt. Hon Ba. This situation satisfies the CR (critically endangered) status in criterion D of IUCN Red List Categories (IUCN 2012). 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.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF938D14FF45CC4CD949FEEB.taxon	materials_examined	TYPE: — VIETNAM. Khanh Hoa Province, Mt. Hon Ba, 12 ° 06 ′ 46.88 ″ N, 108 ° 58 ′ 14.43 ″ E, elev. 919 m, 20 Feb. 2014, Toyama H., Dang V. S., Tagane S., Fuse K., Yahara T., Nagamasu H., Tran H., Nguyen V. N., Nguyen Q. C., Do N. T. & Ho N. P. H. V 909 [fl.] (holotype KYO!, isotypes FOF!, KAG!, VNM!, the herbarium of Hon Ba Nature Reserve).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF938D14FF45CC4CD949FEEB.taxon	distribution	Distribution: — Vietnam (so far only known from the type locality, Mt. Hon Ba). Habitat and Ecology: — Hill evergreen forest, at ca. 920 m elevation. Phenology: — Flowering specimens were collected in February.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF938D14FF45CC4CD949FEEB.taxon	etymology	Etymology: — The specific epithet is chosen in honor of the excellent Vietnamese botanist Prof. Dr. Ph ạm Hoàng H ộ, who significantly contributed to the study of the flora of Vietnam. Vernacular name: — Trâm ph ạm hoàng h ộ. Preliminary conservation assessment: — Critically Endangered (CR). Syzygium phamhoangii is known only from a single population in Mt. Hon Ba, at ca. 900 m above the sea level. The population with fewer than 15 mature individuals is very close to the road and can be easily affected by human disturbance. Therefore, this species is qualified as CR under criterion D (IUCN 2012).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D14FF45C940DF00F8C7.taxon	materials_examined	TYPE: — LAOS. Vientiane Province, Thoulakhom district, Ban Pa Paek, Phou Khao Khouay National Protected Area, 18 ° 22 ′ 35.28 ″ N, 102 ° 51 ′ 29.46 ″ E, 905 m elev., 26 December 2017, Yahara T., Tagane S., Souladeth P., Nagamasu H., Naiki A., Chayer S. & Kongxaisavath D. L 1827 [fl.] (holotype FOF!, isotypes BKF, KAG, KYO!, NHL!, P).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D14FF45C940DF00F8C7.taxon	distribution	Distribution: — Laos (so far only known from Phou Khao Khouay National Protected Area). Habitat and Ecology: — Open pine forest, at 905 m elevation. Phenology: — Flowering specimens were collected in December. DNA barcodes: — LC 381851 (rbcL), LC 381854 (matK); sequenced from Tagane et al. L 1827.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D14FF45C940DF00F8C7.taxon	etymology	Etymology: — The species epithet refers to the geographical location of the find, Phou Khao Khouay National Protected Area. Vernacular name: — ຫວາພ (Wa Phou). Preliminary conservation assessment: — Critically Endangered (CR). At present, Syzygium phoukhaokhouayense is known from only a single individual in the Phou Khao Khouay National Protected Area, at 905 m elev. The area is close to the Vientiane Capital, and has been relatively intensively surveyed by many botanists (e. g. Newman et al. 2007, Souladeth & Meesawat 2012, Lucas et al. 2013). However, we could not find any specimen of this species in the major herbaria (BKF, FOF, HN, KAG, NHL, P, RUPP, TNS, VNM), indicating that this is a rare species. This situation is qualified as CR according to IUCN Red List criteria D (IUCN 2012). Note: — The matK sequence of S. phoukhaokhouayense is identical with S. syzygioides (783 / 783 bp for GenBank accession no. AB 924771 and AB 925281, 780 bp for AB 924710 and AB 924734, 768 / 768 bp for AB 924947). 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.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D1AFF45CF25DB8BF89A.taxon	materials_examined	TYPE: — THAILAND. Buengkan Province, Bung Khla, Phu Wua Wildlife Sanctuary, 22 Nov. 2015, Phonsena P., de Wilde W. J. J. O & Duyfjes B. E. E 7280 [fl. & fr.] (holotype BKF!, isotypes BK, KKU).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D1AFF45CF25DB8BF89A.taxon	description	Paratypes: — LAOS. Vientiane Province: Thoulakhom District, Phou Khao Khouay National Protected Area, Ban Tha Heua, 18 ° 21 ′ 15.82 ″ N, 102 ° 48 ′ 07.35 ″ E, 769 m elev., 22 May 2011, Souladeth P. 91 [fl.] (FOF, KKU!); ibid., 26 Dec. 2017, Yahara T., Tagane S., Souladeth P., Nagamasu H., Naiki A., Chayer S. & Kongxaisavath D. L 1438 [fr.] (BKF, FOF!, KYO!, NHL); ibid., 18 ° 23 ′ 19.08 ″ N, 102 ° 54 ′ 40.61 ″ E, elev. 695 m, Yahara T., Tagane S., Souladeth P., Nagamasu H., Naiki A., Chayer S. & Kongxaisavath D. L 1727 (FOF, KYO!); ibid., 23 Apr. 2011, Souladeth P. 86 [fr.] (FOF!, KKU); Phou Khao Khouay, 29 Oct. 1971, Vidal 5969 [fr.] (P [P 00589453], image!). THAILAND. Nakhon Phanom Province, Ban Phaeng, Phu Langka National Park, Tat Kham Fall, 17 ° 57 ′ 00 ″ N, 104 ° 09 ′ 44 ″ E, elev. 150 m, 25 Aug. 2001, Pooma R., de Wilde W. J. J. O., Duyfjes B. E. E., Chamchumroon V. & Phattarahirankanok K. 2613 [fl.] (BKF!).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D1AFF45CF25DB8BF89A.taxon	distribution	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. Phenology: — Flowering specimens collected in August and November, fruiting in October to December. DNA barcodes: — LC 381850 (rbcL), LC 381853 (matK); sequenced from Yahara et al. L 1438.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF908D1AFF45CF25DB8BF89A.taxon	etymology	Etymology: — The species epithet refer to its nature of roughened (scabrid) surfaces of twigs and leaves caused by dense hairs. Vernacular name: — หวาขน (Wa Khon) (Thailand); ຫວາຂນ (Wa Khon) (Laos). Preliminary conservation assessment: — Endangered (EN). Based on collections and our field observations, S. scabrum is considered to be widely distributed in forests at lower to high elevations (150 – 800 m) in Northeast Thailand and Central Laos, and the area of occupancy (AOO) of this species calculated based on the collection localities is less than 2200 km 2 with some disturbed localities in Laos. Therefore we qualify this species as EN according to the IUCN criteria of B 1 a & b (IUCN 2012). 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. LC 381853) differs 7 bp of the total 760 bp from the S. vestitum (LC 381852: Tagane et al. V 2522 (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. Note 2: — The specimens Souladeth P. 86, Souladeth P. 91 and Yahara T. et al. L 1438 were collected from the same tree.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF9E8D18FF45CF88DED3F9DE.taxon	materials_examined	TYPE: — VIETNAM. Khanh Hoa Province, Mt. Hon Ba, 12 ° 06 ′ 46.88 ″ N, 108 ° 58 ′ 14.43 ″ E, elev. 919 m, 19 Feb. 2014, Toyama H., Dang V. S., Tagane S., Fuse K., Yahara T., Nagamasu H., Tran H., Nguyen V. N., Nguyen Q. C., Do N. T. & Ho N. P. H. V 786 [fl. bud] (holotype KYO!, isotypes FOF!, KAG!, VNM!, the herbarium of Hon Ba Nature Reserve). 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). Shrubs, 4 m tall. Young twigs terete, yellowish brown to grayish brown, glabrous, old twigs grayish brown to very pale creamy brown, glabrous, internode 2 – 13 cm long. Leaves opposite, blade ovate-oblong, 12.2 – 21.4 × 5.4 – 8.3 cm, 1.8 – 2.9 times longer than wide, thickly coriaceous, apex acuminate, acumen to 1.2 cm long, base slightly cordate to cordate, margin entire, recurved when dry, glabrous, midrib sunken adaxially, prominent abaxially, secondary veins 20 – 24 pairs, 0.6 – 1.5 cm apart, prominent and distinct on both surfaces, intersecondary veins prominent and distinct on both surfaces, tertiary veins reticulate, prominent on both surfaces, intramarginal veins 2, outer one ca. 0.6 mm apart from margin, inner one 2 – 3.5 mm apart from margin; petiole to 1.3 mm long, blackish when dry, glabrous. Inflorescence terminal, racemose, 3 to 5 - flowered, peduncle 3 mm long, glabrous, bracteoles caducous, not seen. Flower buds ca. 2.2 cm long, 1.1 cm in diam., light yellowish green (in vivo). Hypanthium funnel shaped, ca. 1.8 cm long, glabrous, pseudostipe 4 – 7 mm long. Sepals 4, semi-circular, 4 – 5 × 6 – 8 mm, petals 5 – 6, orbicular, depressed ovate, depressed obovate, 7 – 10 × 7 – 14 mm, white (in vivo), chartaceous, with many glands. Stamens more than 480, 2 – 10 mm long, anthers 1 – 1.2 mm long, filaments 1.8 – 9 mm long, glabrous. Style 1.1 – 1.3 cm long, glabrous (floral measurements were made from rehydrated flower buds). Ovary 2 - locular, ovules 8 – 10 per locule. Fruits globose, ca. 3.2 cm in diam., Seed 1, subglobose, 2.2 cm in diameter. Paratypes: — VIETNAM. Khanh Hoa Province: Mt. Hon Ba, 12 ° 06 ′ 51.31 ″ N, 108 ° 58 ′ 23.34 ″ E, elev. 890 m, 21 July 2013, Tagane et al. V 638 [fr.] (FU!, VNM, the herbarium of Hon Ba Nature Reserve); 12 ° 06 ′ 46.88 ″ N, 108 ° 58 ′ 14.43 ″ E, elev. 919 m, 20 Feb. 2014, Toyama H., Dang V. S., Tagane S., Fuse K., Yahara T., Nagamasu H., Tran H., Nguyen V. N., Nguyen Q. C., Do N. T. & Ho N. P. H. V 750 [ster.] (FU!, VNM, the herbarium of Hon Ba Nature Reserve).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF9E8D18FF45CF88DED3F9DE.taxon	distribution	Distribution: — Vietnam (so far only known from the type locality, Mt. Hon Ba). Habitat and Ecology: — Hill evergreen forest, at 890 – 920 m elevation. Phenology: — Flowering specimens collected in February.	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
039D87D0FF9E8D18FF45CF88DED3F9DE.taxon	etymology	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. Preliminary conservation assessment: — Endangered (EN). According to our observations in the field in Mt. Hon Ba and its adjacent areas (six times, from lowland to the summit of Mt. Hon Ba (ca. 1560 m elev.) in 2013 – 2017), Syzygium yersinii is endemic to Mt. Hon Ba and known only from the narrow range of Mt. Hon Ba, around 900 m elevation. We estimate the number of mature individuals to be fewer than 150, suggesting the situation is qualified as EN according to IUCN Red List criteria D (IUCN 2012). The forest in Hon Ba Nature Reserve is currently well protected from anthropogenic activities and therefore the population is seemingly stable. 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).	en	Tagane, Shuichiro, Dang, Van-Son, Souladeth, Phetlasy, Nagamasu, Hidetoshi, Toyama, Hironori, Naiki, Akiyo, Fuse, Kengo, Tran, Hop, Yang, Ceng-Jui, Prajaksood, Amornrat, Yahara, Tetsukazu (2018): Five new species of Syzygium (Myrtaceae) from Indochina and Thailand. Phytotaxa 375 (4): 247-260, DOI: 10.11646/phytotaxa.375.4.1, URL: http://dx.doi.org/10.11646/phytotaxa.375.4.1
