Syzygium kampotense Chantar., 2024

Chantaranothai, Pranom, 2024, Notes on the genus Syzygium (Myrtaceae) from Cambodia, Thailand, Vietnam, China and Taiwan, PhytoKeys 244, pp. 151-161 : 151-161

Syzygium kampotense Chantar. sp. nov.

Figs 1 , 2 , 3

Diagnosis.

Syzygium kampotense resembles S. championii (Benth.) Merr. & L. M. Perry and S. claviflorum (Roxb.) Wall. ex Steud. , in the clavate hypanthium shape, cuneate leaf base, small leaves and short petioles. The new species differs from both species in having thickly coriaceous leaves with strongly revolute leaf margins, an acute or obtuse leaf apex and fewer secondary veins (Fig. 1 , Table 1 ).

Type.

Cambodia: Kampot Province, Kampot District, southern summit of Phnom Bokor, vicinity of Bokor , 1–2 km NE of artificial on near Church toward Prek Kaoh Toch, 13 May 1997, McDonal et al. 5676 (holotype AAU, isotype QBG) .

Description.

Shrub ca. 1 m tall; branching sparingly, bark corky, whitish grey or reddish. Leaves with petiole 2–3 mm long, wrinkled; lamina thickly coriaceous, 4–6.5 × 1.7 – 3 cm, elliptic or elliptic-oblong, base broadly cuneate, apex acute or obtuse, margin strongly revolute; midrib impressed on the upper surface, rounded with sparse pustules on the lower surface; secondary veins in ca. 12 pairs, indistinct on upper surface and distinct on lower surface; intramarginal vein 1. Inflorescence not seen. Hypanthial cup 13–15 mm long, clavate. Pseudostipe absent. Sepals red 4, ca. 1 × 1.5 mm, triangular. Petals not seen. Stamens numerous, white. Ovary 2 - locular, ca. 9 ovules per locule. Fruit purple, 8–10 mm in diameter, globose or ellipsoid, crowned with remnant of calyx lobes.

Distribution.

Endemic to Cambodia.

Ecology.

Dense sclerophyllous, short-tree forest, canopy 2–4 m tall, some emergent to 7 m tall; associates include Ardisia , Lithocarpus , Elaeocarpus , Melastoma , Schima , Syzygium and Vaccinum.

Conservation status.

The species is only known from the type locality. It should be categorised as Critically endangered [CR, B 1 ab (iii)] according to the IUCN Red List Criteria and Categories version 3.1 ( IUCN 2012). The Extent of Occurrence is estimated to be less than 20 km 2 and this species is found in a restricted area on open limestone hills which is a threatened ecosystem.

Etymology.

The name of this species is given based on the location where the plant was collected.

Notes.

The new species most likely belongs to Syzygium subgenus Perikion Craven & Biffin ( Craven and Biffin 2010; Hatt et al. 2023, because of its clavate hypanthium shape and ellipsoid, obovoid or globose fruit. These characteristics resemble S. claviflorum , the type of this subgenus.

Additional specimens examined.

Cambodia, Kampot Province, Bokor National Park, near field station, near top of plateau , 10 ° 20.38 ' N, 104 ° 01.4 ' E, alt. 1,045 m, 10 Mar. 2001, Midlleton & Monyrak 660 (P [ P 00589160 ]); Bokor, Dy Phon 1130 (P [ P 04658853 ]) .

New Records

Figures

Figure 1. Syzygium kampotense Chantar.: holotype, McDonal et al. 5676 (AAU). In set leaf, hypanthial cups and fruit. Photographed by B. Boonsuk.

Figure 2. Syzygium kampotense Chantar., showing leaf, hypanthial cups and fruit. Photographed by B. Boonsuk.

Figure 3. Syzygium kampotense A habit B lower surface of leaf C calyx tube (side view) D longitudinal section of calyx tube and ovary, showing two locules E fruit (from McDonald et al. 5676; drawn by N. Triyutthachai).