Syzygium megistophyllum Merr. & L.M.Perry

Craven, L. A., Damas, K. Q. & Cowley, K. J., 2021, Studies in Papuasian Syzygium (Myrtaceae): 2. The furfuraceous species of subg. Syzygium, Blumea 66 (1), pp. 57-81 : 73

25. Syzygium megistophyllum Merr. & L.M.Perry — Fig. 2 : 2.3–2.7; Map 7

Syzygium megistophyllum Merr. & L.M.Perry (1942) 279. — Type: Brass 13340 (holo A n.v. photo seen; iso BRI!, L n.v. photo seen), Indonesia, Papua Province, Idenburg River, 4 km SW of Bernhard Camp, Agathis forest, alt. c. 900 m, Mar. 1939.

Tree to 7 m tall, to 10 cm dbh; bark orange-brown or grey to dark grey, smooth or rough. Vegetative branchlet terete or quadrangular, rounded or winged, 8‒12 mm diam; bark dull or dull-glossy, smooth, slightly glandular-verrucose, persistent. Leaf lamina narrowly elliptic to ovate, 43‒87 by 12‒34 cm, 2.5‒4.3 times as long as wide; base cordate; apex acuminate; acumen flat; margin revolute; cartilaginous or coriaceous; primary and secondary venation generally similar with all or nearly all secondaries joining the intramarginal vein; primary veins 35‒60 on each side of the midrib, in median part of lamina at a divergence angle of 70–80° and 10‒20 mm apart; intramarginal vein present, 1–3 mm from leaf margin, secondary intramarginal vein absent (rarely a weak secondary intramarginal vein is evident). Petiole 0‒3 mm long (leaves sessile to subsessile). Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, cauline, few-flowered, paniculate, up to 9 by 7 cm, major axis c. 3 mm thick at the midpoint, bark furfuraceous; bracts caducous; bracteoles subtending each flower, persistent. Flower buds with the apex acuminate. Flowers white, red or brown. Hypanthium dull, furfuraceous, not visibly gland-dotted, plane; stipitate; shortly stipitate-cylindrical or stipitately very narrowly obconic, c. 25 by 4‒5 mm, stipe c. 0.5 mm long. Calyx calyptrate (the lobes connate). Petals obsolete, forming a calyptra that is adherent to the calycine calyptra and falls with it. Staminal disc descending ( Fig. 2 : intermediate between 2.3 and 2.7). Stamens c. 55, 7‒21 mm long. Style c. 18 mm long (style is deeply inserted within the hypanthium tube of c. 20 mm long). Placentation axile-median; placenta a flattened, narrowly elliptic cushion. Ovules c. 15 per locule, ascending, arranged irregularly. Mature fruit red, furfuraceous, wrinkled (when dry), lageniform, 45‒70 by c. 75 mm excluding the calyx, with the hypanthium rim not appreciably expanding in fruit and 8‒10 mm diam; seed ellipsoid, up to 18 mm across, cotyledons collateral.

Distribution — Indonesia (Papua Province), Papua New Guinea.

Habitat & Ecology — Shale ridge, lowland forest on side of ridge, lower montane rainforest, forest on hillslope, Agathis - forest. Altitude 30‒1100 m.

Note — Syzygium pseudomegistophyllum W.N.Takeuchi is very close to S. megistophyllum . Infructescence axes of Takeuchi & Kulang 11601 (identified by Takeuchi (2002) as being S. megistophyllum ) are very short (up to c. 2 cm long) and may be a link between the sessile inflorescences of S. pseudomegistophyllum and S. megistophyllum in which the infructescence may be as much as 9 cm long ( Merrill & Perry 1942). Some of the primary veins in the proximal one-third of the leaf blade in Takeuchi & Kulang 11601 and NGF 22045 slightly ‘dip’ before running to the margin but the other veins are more regularly curved to the margin. These two collections, both from south of the main New Guinea cordillera (whereas all the other collections are from north of the cordillera), also have quadrangular and winged branchlets (but see Takeuchi 2002). In the non-furfuraceous S. recurvovenosum (Lauterb.) Diels all the primary veins have a strongly dipped (i.e., recurved) curvature. Further collections are required from both sides of the cordillera so that the significance of the several similarities and differences can be properly assessed. It may be that the southern collections represent a species distinct from both S. megistophyllum and S. pseudomegistophyllum and that the last two species are conspecific.

Figures

Fig. 2 Staminal disc types in Syzygium species. Series 1: Flat; series 2: descending; series 3: ascending; series 4: raised.