Syzygium prolatum Craven & Damas, 2021

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 : 75

29. Syzygium prolatum Craven & Damas , sp. nov. — Fig. 2 : 1.5; Map 7

From Syzygium branderhorstii Lauterb. it differs in the leaf lamina lacking a secondary intramarginal vein (secondary intramarginal vein present in S. branderhorstii ); and the corolla in late bud approximating the hypanthium in length (corolla very much shorter in bud in S. branderhorstii ). — Type: NGF (Womersley) 19301 (holo CANB!; iso A, BO, BRI, K, L, LAE !, SING, all n.v.), Papua New Guinea, Milne Bay Province, headwaters of Gumini River, Cameron Plateau, ridge top in forest, 11 June 1964.

Etymology. The specific epithet is derived from the Latin, prolatus, extended,elongate,in reference to the long flower buds of this species relative to those of others of the section.

Tree to 33 m tall; bark pale brown, papery. Vegetative branchlet terete or slightly compressed, rounded, 2‒3 mm diam, dull; bark smooth or slightly furfuraceous, not glandular-verrucose, persistent. Leaf lamina obovate or rarely elliptic, 4.5‒10 by 3.5‒6 cm, 1.2‒1.6 times as long as wide; base cuneate; apex obtuse, rounded or retuse; acumen flat; margin flat; coriaceous; primary and secondary venation distinctly different with secondaries relatively little developed and not or rarely joining the intramarginal vein; primary veins 17‒19 on each side of the midrib, in median part of lamina at a divergence angle of 70‒80° and 2‒5 mm apart; intramarginal vein present, weakly arched, 1‒1.5 mm from margin, secondary intramarginal vein absent. Petiole 3‒4 mm long. Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, on branchlets below the leaves, paniculate, up to 15 by 14 cm, major axis c. 1.5 mm thick at the midpoint, branchlets predominantly smooth but patches of furfuraceous epidermis occur; bracts persistent; bracteoles subtending each flower, persistent. Flower buds with the apex rounded to obtuse. Flowers white. Hypanthium dull, glandular-verrucose, visibly gland-dotted; minutely but distinctly wrinkled and ribbed; not stipitate; goblet-shaped, 2.5‒3 by c. 2.5 mm. Calyx lobes 4, transversely narrowly semi-elliptic or very depressedly triangular, c. 0.3 mm long. Petals 5, calyptrate (coherent and falling as a cap). Staminal disc flat ( Fig. 2 : 1.5). Stamens c. 100. Placentation axile-median; placenta a narrowly oblong cushion. Ovules 10‒12 per locule, ascending, arranged irregularly. Open flowers and fruit not seen.

Distribution — Papua New Guinea.

Habitat & Ecology — Forest on ridge top.

Notes — 1. The material available is in late bud and open flowers have not been seen. The branchlets predominantly are smooth but patches of furfuraceous epidermis may occur. The primary and secondary venation is distinctly different. In late bud the petals approximate the hypanthium in length, unlike all other furfuraceous species that have been examined in the late bud stage in which the petals are short relative to the hypanthium.

2. The species is known from the type collection only.

Figures

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