Syzygium sleumeri Craven, 2019

Craven, L. A., 2019, Studies in Papuasian Syzygium (Myrtaceae): 1. Subgenus Perikion revised, Blumea 64 (2), pp. 115-122 : 121

8. Syzygium sleumeri Craven , sp. nov. — Fig. 1 ; Map 4

From Syzygium claviflorum (Roxb.) Steud. it differs in the winged branchlets; the obtuse, rounded or retuse leaf lamina apex; the glandular-verrucose, ribbed, and 10 mm long hypanthium; the 6–9 mm long stamens; and 8–10 ovules per locule. (In S. claviflorum the branchlets are rounded or angled; the leaf lamina apex is long acuminate or acuminate; the hypanthium is minutely wrinkled and generally plane, and 9.8–23 mm long; the stamens are minutely wrinkled, generally plane, and 3–8 mm long; and there are 9–16 ovules per locule.) — Type: Sleumer & Vink BW 14247 (holo CANB!; iso L n.v., MAN n.v.), Indonesia, Papua Barat, Mt Gwamongga,Anggi Gigi Lake, fire-vegetation of Ericaceae and Baeckea on clay, alt. 2250 m, 21 Jan. 1962.

Etymology. The species is named in honour of Hermann Otto Sleumer (1906–1993), a prolific author on the taxonomy of several plant families and an expert in Ericaceae in particular.

Shrub to 2 m tall. Vegetative branchlet quadrangular, winged, 0.6–1.3 mm diam; bark dull-glossy, smooth, not glandular-verrucose, persistent. Leaf lamina 1.5–3.5 by 0.7–1.6 cm, 1.6–2.4 times as long as wide, elliptic, narrowly elliptic, broadly elliptic or obovate; base cuneate or narrowly cuneate; apex obtuse, rounded or occasionally retuse; margin flat to revolute; cartilaginous; primary and secondary venation obscure; primary veins 5–8 on each side of the mid-rib, in median part of the lamina at a divergence angle of c. 60°, 1–3 mm apart; intramarginal vein present (often obscure), weakly arched, 0.2–0.5 mm from margin. Petiole 0.5–0.7 mm long. Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, terminal or distal axillary (sometimes terminal and distal axillary), 1- to few-flowered, racemose, up to 1–3 by 1.5–2 cm, major axis 0.4–0.5 mm thick at the midpoint; bark glandular-verrucose; bracts caducous or deciduous, bracteoles subtending each flower; deciduous. Flowers white (noted as calyx lobes red, petals and filaments white), calyptrate (petals coherent and falling as a cap). Hypanthium dull, glandular-verrucose, visibly gland-dotted, weakly ribbed; stipitate; generally elongated goblet-shaped (at the apex curved slightly), 10 by 3–3.3 mm wide; stipe 2.5–3 mm long. Calyx lobes 4; transversely narrowly semielliptic, 0.5 mm long. Petals 7, coherent and caducous, 2.3 mm long. Staminal disc flat (intermediate between Fig. 1 : 1.2, 1.6). Stamens c. 75, 6–9 mm long. Style 8.5 mm long. Placentation axile-median; placenta is an obscure, flattened and narrowly obovate structure (bilobed in the distal part). Ovules c. 8–10 per locule, pendulous, arranged in two longitudinal rows (one row on each placental lobe). Fruit not seen.

Distribution — Indonesia (Papua).

Habitat & Ecology — Fire-vegetation of Ericaceae and Baeckea , steppe. Altitude 50–2250 m.

Additional specimen examined. INDONESIA, Papua, Misool, Sorong, between Fakal and Tip, Pleyte 897.

Note — The shrub habit is characteristic, if not diagnostic. The inflorescence is a racemose structure, 1- to c. 6-flowered, terminal and/or distal axillary. The flowers are in monads or triads, or sometimes clustered in 4’s and then always at the apex of the inflorescence.

Figures

Map 4 Distribution of Syzygium saundersii Craven (●), S. sleumeri Craven (■), S. subamplexicaule Merr. & L.M.Perry (▲) and S. suberosum Craven (♦).

Fig. 1 Diagrams of staminal disc types occurring in Syzygium subg. Perikion species, showing staminal discs that are flat (1.1–1.10), descending (2.5), ascending (3.2) and raised (4.2). Within the flat staminal disc type, structure may differ in the degree of ‘lip’ projection at the inner edge of hypanthium apex (1.4, 1.5, 1.6 and 1.9) and the presence of a grooved petal insertion point (1.10).