SYZYGIUM TRIFLORUM (MYRTACEAE), A NEW SPECIES FROM VIETNAM

Dang Hung Cuong¹, Nguyen Thi Kim Thanh², Nguyen Huu Hiep¹, Dang Ngoc Huyen¹,
Thanh Truong Hoang³, Shuichiro Tagane⁴

¹Institute of Tropical Ecology, Joint Vietnam-Russia Tropical Center and Technology Research Center, Hanoi, Vietnam

²Faculty of Biology, University of Science, Vietnam National University, Hanoi, Vietnam

³Forest Science Institute of Central Highlands and South of Central Vietnam (FSIH), Lam Dong, Vietnam

⁴Kagoshima University Museum, Kagoshima University, Korimoto, Kagoshima, Japan

Corresponding author: Truong Hoang Thanh (truonghoangthanhld@gmail.com)

Abstract
Syzygium triflorum T.T.Hoang, Kim Thanh, S.Tagane & D.H.Cuong, sp. nov., from Kon Chu Rang Nature Reserve, Vietnam, is described and illustrated. The new species is distinguished from related species, Syzygium skiophilum, by its having 4-angled and reddish-grey twigs, oblong leaves with an attenuate apex, less secondary veins of 26– 30 pairs, exclusively axillary inflorescences, lanceolate-ovate bracts, sessile flowers, obconical hypanthium (slightly pyriform in flower buds) and more stamens of 18–28. The flowers and fruits were observed in the rainy season, July 2024. This new species grows under a mixed broad-leaved and coniferous forest dominated by Dacrydium elatum and Dacrycarpus imbricatus.

Keywords: Flora, Indochina, Kon Chu Rang Nature Reserve, Myrtales

Sources: PhytoKeys 255: 75–83 (2025)

Figure 1. Syzygium triflorum T.T.Hoang, Kim Thanh, S.Tagane & D.H.Cuong A immature fruit in lateral view

B immature fruits in top view C hypanthia in lateral view (after petals and most stamens had fallen off) D hypanthia with calyx disc and styles in top view (after petals and most stamens had fallen off) E inflorescence in top view, showing flowers before anthesis (left and right) F inflorescence in lateral view (3 flowers in cluster) G leafy branches H leaves, adaxial (upper) and abaxial (bottom) surface. Photos: H. T. Truong and H. C. Dang.