Discovery of a new plant species Syzygium triflorum in Vietnam

During the implementation of the scientific and technological project “Research on the potential distribution of native plant species for the restoration of tropical forest ecosystems in Gia Lai Province”, a research team from the Institute of Tropical ecology, under the Joint Vietnam-Russia Tropical Science and Technology Research Center has identified a plant species new to science.

The newly discovered species, Syzygium triflorum (commonly known as Trâm ba hoa in Vietnamese), belongs to the genus Syzygium, family Myrtaceae. This species was found in the Kon Chu Rang Nature Reserve, located in Gia Lai province, Central Highlands of Vietnam.

The species epithet “triflorum” is derived from its distinctive morphological feature - inflorescences typically comprising three flowers.

The species was encountered along a forest patrol trail connecting the Bai Chay and Dak Hla ranger stations within the Kon Chu Rang Nature Reserve. Syzygium triflorum is characterized as a small tree growing beneath the canopy of secondary mixed forests, which are in the process of natural regeneration following past fire disturbances. These forests are primarily dominated by tropical coniferous species such as Dacrydium elatum and Dacrycarpus imbricatus.

This species favors partially open habitats, typically found in areas with 30-40% canopy cover. Flowering and fruiting were recorded in July 2024, during the rainy season. The flowers and fruits were observed during the rainy season in July 2024; at that time, the fruits had not yet fully ripened.

Taxonomic description of Syzygium triflorum: Young branches quadrangular, grayish-red; leaves opposite, narrowly elliptic, gradually tapering at the apex, 7.5-8.5 x 2.0-2.2 cm, upper surface glossy green, lower surface light green with glandular dots, 26-30 pairs of secondary veins. Inflorescences axillary only (not terminal), usually with 3 flowers; bracts ovate-lanceolate; flowers 2.8-3.2 x 1.8-2.0 mm, pale green, sessile or with very short pedicels (0-0.5 mm); hypanthium funnel-shaped, inverted-conical; calyx lobes 4, broadly triangular; petals 4, nearly round; stamens 18-28, arranged in a single whorl, anthers elliptic; ovary 2-locular, with many ovules per locule; young fruit globose, 4.0 x 4.0 mm.

Conservation status: The species is currently known only from a few populations, each with approximately 30-40 individuals distributed over a total area of about 10 hectares (0.01 km²). The main natural threat in the area could be spontaneous forest fires, which may cause drastic fluctuations in mature population size. However, this risk is considered low due to the area’s strict protection and well-maintained fire prevention patrols. No fires have been recorded in these forests for at least the past 30 years. Therefore, the species is considered safe within this habitat for the time being.

According to the IUCN criteria, although there is insufficient direct or indirect information about the species' current condition or potential threats, due to the very small known population, restricted to a limited area, and only about 200 mature individuals, Syzygium triflorum is provisionally assessed as Endangered (EN) under Criterion D (IUCN 2012).

Prior to this discovery, 49 species of Syzygium had been recorded in Vietnam, making it the country with the highest species diversity of this genus in the Indochina region. This finding provides valuable scientific data to support ongoing and future plant conservation efforts in the region. Moreover, given the known economic and medicinal significance of many Syzygium species - particularly in the fields of essential oil extraction, food, and traditional medicine - further studies are warranted to investigate the potential applications of this newly described species.

Figure 1: Syzygium triflorum. A, B. Immature fruits. C, D. Floral receptacle and style (after petals and stamens have fallen). E, F. Inflorescence (three flowers per cluster). G. Branch bearing leaves. H. Leaf, adaxial (upper) and abaxial (lower) surfaces.

Figure 2: Dried flowers of Syzygium triflorum. A. Inflorescence. B. Adaxial (upper) surface of petal. C. Stamen. D. Longitudinal section of flower (placenta positioned centrally).

Source: Cuong DH, Thanh NTK, Hiep NH, Huyen DN, Hoang TT, Tagane S (2025) Syzygium triflorum (Myrtaceae), a new species from Vietnam. PhytoKeys 255: 75-83. https://doi.org/10.3897/phytokeys.255.143043

Nguyen Huu Hiep (Institute of Tropical Ecology)

Ngoc Nguyen translated