Syzygium rubrocarpum I.Martian., M.R.Hariri & A.S.D.Irsyam, 2025

Syzygium rubrocarpum I.Martian., M.R.Hariri & A.S.D.Irsyam , sp. nov. ( Fig. 1‒2 View FIGURE 1 ).

Type:— Cultivated at Bogor Botanic Gardens-BRIN from material collected in the wild Acc. No. B199307391 ex Indonesia: Southeast Sulawesi Province, Kolaka Regency [orig. coll. 2 September 1996, R. Subekti P. Cs. (201)], voucher 15 October 2024, I Martiansyah s.n. ( holotype FIPIA!; isotype BO!) .

Diagnosis: — Syzygium rubrocarpum is similar to Syzygium polycephalum (Miquel) Merrill & L.M.Perry (1939: 153) [basionym:— Eugenia polycephala Miquel (1850: 19) ] but differs in having narrowly elliptic or oblong-elliptic to subfalcate leaf shape (vs. leaves oblong, oblong-lanceolate to subobovate), with 13‒15 lateral veins (vs. 10‒13), cauliflorous inflorescences on main stem (vs. ramiflorous), flowers in cymes (vs. panicles), with pink-colored petals and stamens (vs. white petals and stamens), and red berries (vs. dark purple berries).

Description: —Perennial tree, up to 8 m in height. Leaves opposite, subsessile or shortly petiolate; petioles when present 2‒5 mm long, green; leaf blade narrowly elliptic or oblong-elliptic to subfalcate, 10‒30 × 2.5‒7.5 cm, base cuneate to subcordate, apex acuminate, acumen 1‒2 mm long, adaxial surface glossy green, abaxial surface glossy yellowish green, midrib impressed adaxially, prominent abaxially, lateral veins 13‒15 pairs, intramarginal vein present, 2‒15 mm from the margin, conspicuous. Inflorescences cauliflorous cymes on main stem; pedicels 2‒4 mm long, green. Calyx tube campanulate-turbinate ca. 5 mm long, greenish white; calyx lobes 4, broadly ovate-triangular, 2–4 mm long, pinkish white; petals 4, free, rounded to oblate, 3‒6 × 6‒7 mm, pinkish white, early caducous; stamens numerous, caducous; filaments filiform, 12‒16 mm long, pink at base, white at apex; anthers flat, dorsifixed, yellow; ovary 1-locular with 1 ovule; style pink, ca. 21 mm long. Berries 1-seeded, globose, 1.5–3.5 cm in diam., shiny red. Seeds globose, white with red patches or pinkish white.

Etymology: —The epithet ‘ rubrocarpum ’ refers to the red-colored ripe fruit of the new species.

Distribution: —Kendari and Kolaka.

Vernacular name: — Ruruhi.

Paratype: — INDONESIA: Southeast Sulawesi, Kendari, December 2023, M.R. Hariri s.n. (FIPIA-DEP103!).

Proposed conservation status: —Only two populations of S. rubrocarpum have been observed, with the exact number of individuals remaining unclear. This species is known to occur only in Kendari and Kolaka, though we speculate that additional populations may exist. Due to insufficient field investigations, the full natural range of this species in the wild remains unknown. Consequently, we recommend classifying this species as ‘Data Deficient’ (DD) ( Le Breton et al. 2019).

Note: —In this study, DNA analysis was conducted to determine the taxonomic position of S. rubrocarpum . Genomic DNA was extracted and amplified using the internal transcribed spacer (ITS) region, following the protocol of Sun et al. (1994). The resulting sequence was analyzed through a BLAST search to identify homologous sequences in the NCBI database ( Stover & Cavalcanti 2017). The results revealed that S. rubrocarpum exhibits distinct sequence differences from S. polycephalum , despite their morphological similarities. Additional sequences from Calyptranthes Swartz (1788: 79) , Eugenia P.Micheli ex Linnaeus (1753: 470) , Myrcia de Candolle ex Guillaume de la Guéroue (1827: 401) , and Syzygium were retrieved and used to construct a phylogenetic tree using the Neighbor-Joining method with the Kimura 2-parameter model model and 1000× bootstraps executed in MEGA X ( Kumar et al. 2018). The analysis placed S. rubrocarpum within the S. jambos (Linnaeus) Alston (1931: 115) branch with a bootstrap value of 63, supporting its status as a distinct species. These molecular findings confirm that S. rubrocarpum is genetically separate from both S. polycephalum and S. jambos . Therefore, S. rubrocarpum occupies a stable position within the Syzygium clade ( Fig. 3 View FIGURE 3 ), thereby refuting its previous identification as a member of Eugenia in the Bogor Botanic Gardens.