Syzygium araucariarum 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

2. Syzygium araucariarum Craven & Damas , sp. nov. — Fig. 2 : 1.6; Map 1

From Syzygium furfuraceum Merr. & L.M.Perry it differs in having the leaf lamina obovate, elliptic or broadly elliptic with the acumen recurved and the base attenuate or narrowly cuneate (broadly oblong or sometimes obovate, the acumen flat and the base obtuse in S. furfuraceum ); inflorescences on branchlets below the leaves or on branches (cauline in S. furfuraceum ); and the hypanthium not furfuraceous and usually with 4 obvious ribs (furfuraceous and unribbed in S. furfuraceum ). — Type: NGF (Floyd) 7460 (holo CANB!; iso LAE !), Papua New Guinea, Morobe Province,Bulolo,1955 planting area, alt. c. 1100 m, 9 June 1955.

Etymology. The specific epithet is derived from Araucaria , a genus of

Araucariaceae .

Tree to 42 m tall, to 150 cm dbh; bark red brown, flaky or fissured (often described as flaky or papery and scaly). Vegetative branchlet terete or compressed, rounded, 2‒3 mm diam; bark dull-glossy, smooth, slightly or not glandular-verrucose, persistent. Leaf lamina obovate, elliptic or broadly elliptic, 10.5‒13 by 5‒8.5 cm, 1.5‒2.6 times as long as wide; base attenuate or narrowly cuneate; apex roundly acuminate or short acuminate; acumen recurved; margin flat to minutely revolute; coriaceous or 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 15‒16 on each side of the midrib, in median part of lamina at a divergence angle of 60‒75° and 3‒8 mm apart; intramarginal vein present, weakly arched, 1‒3.5 mm from margin, secondary intramarginal vein present. Petiole 5‒10 mm long. Reproductive seasonal growth unit with a reproductive zone only. Inflorescence leafless, on branchlets below the leaves or on branches, paniculate, up to 18 by 20‒22 cm, major axis c. 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 cream. Hypanthium glossy or dull-glossy, smooth, visibly gland-dotted, usually with 4 obvious ribs; stipitate, goblet-shaped, c. 6 by 5 mm; stipe c. 1 mm long. Calyx is an irregular rim c. 0.1 mm high with 4 weakly developed lobes c. 0.25 mm long (lobe length includes the rim length). Petals 4, calyptrate (coherent or partly connate and falling as a cap). Staminal disc flat ( Fig. 2 : 1.6). Stamens c. 170. Style c. 3 mm long. Placentation axile-basal; placenta a cushion. Ovules c. 12‒20 per locule, ascending, arranged irregularly. Fruit not seen.

Distribution — Papua New Guinea.

Habitat & Ecology — Upper mid-mountain forest, logging area with mostly Fagaceae , Class 1 rainforest on steep slopes with southern aspect. Altitude 910‒2130 m.

Note — Many of the studied collections are noted by col- lectors to have been growing in areas that were either being logged for, or being cleared for planting, Araucaria hunsteinii K.Schum. (Klinki pine), an important timber tree in the Bulolo region of Papua New Guinea.

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.