Syzygium gillisonii 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 : 68-69

15. Syzygium gillisonii Craven & Damas , sp. nov. — Fig. 2 : 3.4; Map 5

From Syzygium pyrocarpum (Greves) Merr.& L.M.Perry it differs in having a cordate base to the leaf lamina (cuneate in S. pyrocarpum ); 18‒24 primary veins on each side of the midrib (35‒48 in S. pyrocarpum ); a petiole up to 0.5 mm long (2‒10 mm in S. pyrocarpum ); and bright mauve, non-furfura- ceous fruit (red and furfuraceous in S. pyrocarpum ). — Type: NGF (Gillison)

25344 (holo CANB!; iso LAE !, BRI, L, both n.v.), Papua New Guinea, Milne Bay Province, ridge top rainforest, Rossel Island, Ulanga Bay, Mt Te , alt. c. 450 m, 11 June 1966 .

Etymology. The specific epithet honours Andrew Napier Gillison (1937‒), the collector of the type.Andy worked in Papua New Guinea between 1957 and 1972, initially in the Department of Agriculture, Stock and Fisheries and from 1964 in the Department of Forests.

Tree to 12 m tall, to 12.5 cm dbh; bark slightly smooth to papery. Vegetative branchlet terete or in the young branchlets compressed, rounded, 5‒6 mm diam; bark dull-glossy, smooth, not glandular-verrucose, bark persistent. Leaf lamina broadly elliptic or sometimes obovate, 18.5‒26.7 by 11.1‒14 cm, 1.6‒1.9 times as long as wide; base cordate; apex acute to sometimes obtuse; acumen flat; margin flat; coriaceous to cartilaginous; primary and secondary venation generally similar with all or nearly all secondaries joining the intramarginal vein, primary veins 18‒24 on each side of the midrib, in median part of lamina at a divergence angle of 60‒70° and 10‒20 mm apart; intra- marginal vein present, strongly arched, 3‒6 mm from margin, secondary intramarginal vein absent. Petiole up to 0.5 mm long. Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, cauline, paniculate, up to 13 by 8 cm, major axis c. 4.5 mm thick at the midpoint, bark furfuraceous; bracts caducous; bracteoles subtending each flower, caducous. Flowers white. Hypanthium dull or dull-glossy, appearing smooth but actually minutely subspiculate, not visibly gland-dotted, ribbed; not stipitate, elongated cup-shaped, 9‒11 by 5.5‒7 mm. Calyx lobes 4, transversely semi-elliptic, c. 2 mm long. Staminal disc ascending ( Fig. 2 : 3.4). Style c. 9.5 mm long. Placentation axile-median; placenta a more or less elliptic cushion. Ovules c. 12 per locule, ascending, arranged irregu- larly. Fruit bright mauve, more or less smooth, ribbed, lageniform or ellipsoid, 20‒25 by 12‒15 mm excluding the calyx, with the hypanthium rim not appreciably expanding in fruit and c. 7 mm diam, cotyledons collateral. Flower buds, petals and stamens not seen.

Distribution — Papua New Guinea.

Habitat & Ecology — Associated with Myristica Gronov. ( Myristicaceae ) and Calophyllum L. ( Clusiaceae ) in ridge-top rainforest. Altitude c. 450 m.

Notes — 1. The material seen is in the late flower-early fruit stage of development and is lacking petals and stamens. Although the collector’s notes suggest the fruit is mature, in the examined material the seeds were immature.

2. The species is known from two collections only.

Figures

Map 5 Distribution of Syzygium furfuraceum Merr. & L.M.Perry (●), S. gillisonii Craven & Damas (■).

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