Syzygium bowersiae 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 : 62-63

3. Syzygium bowersiae Craven & Damas , sp. nov. — Fig. 2 : 1.6, 2.7, 3.2, 3.3; Map 1

From Syzygium furfuraceum Merr. & L.M.Perry it differs in having the leaf lamina broadly elliptic or elliptic with the base attenuate or cuneate (broadly oblong or sometimes obovate and the base obtuse in S. furfuraceum ); inflorescences on branchlets below the leaves or on branches (cauline in S. furfuraceum ); placentation axile-median with the ovules spreading (axile-basal and ascending in S. furfuraceum ); and fruit obovoid and flat distally or olliform, 9‒10 mm long (fruit depressedly spheroid and c. 15 mm long in S. furfuraceum ). — Type: NGF (Vandenberg, Katik & Kairo) 40090 (holo CANB!; iso LAE !,A, BISH, BO, BRI, K, L, NSW,PNH, SING, all n.v.), Papua New Guinea, Southern Highlands Province, Mendi Subprovince, Hagen- Mendi road, in rainforest c. 5 km from Kagaba camp site, alt. c. 2700 m, 22 Sept. 1968.

Etymology. This species is named in honour of Nancy Bowers (1928‒ 2006), an American anthropologist,who carried out ethnobotanical research in the Upper Kaugel Valley of the then Western Highlands District (later Province) in Papua New Guinea for two main periods, 1961‒1963 and 1968‒1969, and many subsequent visits. Her extensive plant collections from there include a collection of the present species (Bowers 795).

Tree to 30 m tall, to 60 cm dbh; bark brown or orange brown, smooth or scaly. Vegetative branchlet terete or compressed, rounded, 2‒2.5 mm diam; bark dull or dull-glossy, smooth, slightly glandular-verrucose, persistent. Leaf lamina broadly elliptic or elliptic, 8‒17.5 by 4.5‒10 cm, 1.7‒1.8 times as long as wide; base attenuate or cuneate; apex short acuminate, retuse, or roundly acuminate; acumen flat; margin flat; cartilaginous; primary and secondary venation distinctly different with secondaries relatively little developed and not or rarely joining the intramarginal vein, or generally similar with all or nearly all secondaries joining the intramarginal vein; primary veins 15‒18 on each side of the midrib, in median part of lamina at a divergence angle of 60‒70° and 3‒8 mm apart; intramarginal vein present, weakly arched, 1.5‒5 mm from margin, secondary intramarginal vein present. Petiole 5‒14 mm long. Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, on branchlets below the leaves or on branches, paniculate, up to 11‒20 by 10‒20 cm, major axis 3‒4 mm thick at the midpoint, bark furfuraceous; bracts caducous; bracteoles subtending each flower, caducous. Flower buds with the apex rounded to obtuse. Flowers white or yellowish. Hypanthium dull or dull-glossy, sometimes weakly furfuraceous (‘platelets’ readily caducous), minutely (but distinctly) wrinkled, weakly glandular-verrucose (rough), visibly gland-dotted or not, ribbed or not, sometimes angled laterally (i.e., 2-costate); stipitate or not (then tapering evenly to the base or truncate or rounded); stipitate-obconic, broadly clavate, stipitate-olliform or goblet-shaped, 5‒7 by 3.5‒5 mm; stipe 0‒2 mm long. Calyx an irregular rim of tissue with 4 weakly developed lobes, lobes transversely semi-elliptic,very depressedly triangular or depressedly triangular, 0.25‒1 mm long (including the rim). Petals 4; calyptrate (coherent and falling as a cap). Staminal disc variable, flat, descending or ascending ( Fig. 2 : 1.6, 2.7, 3.2, 3.3). Stamens 35‒150, 4‒12.5 mm long. Style 4.5‒6 mm long. Placentation axile-median; placenta a small roundish cushion or a truncately narrowly obovate cushion. Ovules 15‒20 or 25‒30 per locule, spreading, arranged irregularly. Mature fruit dark red, obovoid and flat distally or olliform, 9‒10 by 7‒8 mm excluding the calyx, with the hypanthium rim appreciably expanding in fruit and 5‒6 mm diam, glandular-verrucose, wrinkled; mature seeds not seen, cotyledons collateral.

Distribution — Papua New Guinea.

Habitat & Ecology — Rainforest, disturbed lower montane rainforest, forest on alluvial flats, mixed montane forest.Altitude 1350‒2700 m.

Note — The staminal disc form and stamen number in S. bowersiae are quite variable and further collections are needed to ascertain if the differences are correlated with other morphological character states; if so, the circumscription of the species may require reconsideration with additional species being recognised.

Figures

Map 1 Distribution of Syzygium aporematum Craven & Damas (●), S. araucariarum Craven & Damas (■), S. bowersiae Craven & Damas (▲).

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