Syzygium hooglandii Craven & Damas, 2021

18. Syzygium hooglandii Craven & Damas View in CoL , sp. nov. — Fig. 2 View Fig : 1.8; Map 6

From Syzygium buettnerianum (K.Schum.) Nied. it differs in having the primary and secondary venation generally similar with all or nearly all secondaries joining the intramarginal vein (in S. buettnerianum the primary and secondary venation is distinctly different with the secondaries relatively little developed and not or rarely joining the intramarginal vein); the terminal flower in a triad ebracteolate (all flowers apparently bracteolate in S. buettnerianum ); 5‒10 ovules per locule, arranged radially in one row (5‒12 per locule and arranged irregularly in S. buettnerianum ). — Type: Hoogland & Pullen 5961 (holo CANB!; iso LAE !, A, BM, BRI, G, K, L, MEL, US, all n.v.), Papua New Guinea, Western Highlands Province, c. 5 km SE of Mt Hagen, near Wankl village on mountain slope, in tall largely secondary forest on steep slope, alt. c. 2050 m, 18 Aug. 1956.

Etymology. The specific epithet honours Ruurd Dirk Hoogland (1922‒ 1994), a collector of numerous, high quality specimens of Papuasian and Australian plants, and a botanical bibliographer. Ru joined the New Guinea Surveys team of the then CSIRO Division of Land Use and Regional Survey in 1952. He established excellent standards for the collection of herbarium specimens in New Guinea, and trained newly appointed staff in his methods.

Tree to 45 m tall (often 21–27 m), to 135 cm dbh; bark pale orange-brown, grey, whitish yellow-brown, pinkish grey, light grey brown, smooth, flaky or papery. Vegetative branchlet terete or sometimes compressed or rounded-quadrate, rounded, 2‒5.5 mm diam; bark dull, smooth and finely cracked or sub- furfuraceous, not glandular-verrucose, persistent. Leaf lamina narrowly elliptic, elliptic or broadly elliptic, 5‒10 by 2.5‒6 cm, 1.4‒2.4 times as long as wide; base attenuate, cuneate or obtuse; apex acuminate to long acuminate; acumen recurved; margin revolute; chartaceous to subcartilaginous; primary and secondary venation generally similar with all or nearly all secondaries joining the intramarginal vein; primary veins 27‒33 on each side of the midrib; major veins in median portion of lamina 1.5‒3 mm apart; intramarginal vein present, weakly arched, 2‒3 mm from margin, secondary intramarginal vein present. Petiole 4‒10 mm long. Reproductive seasonal growth unit with distinct vegetative and reproductive zones. Inflorescence leafless or leafy, terminal or distal axillary, corymbose, up to 3‒13 by 4.5‒13 cm, major axis 2.5‒4 mm thick at the midpoint, bark furfuraceous; bracts caducous or persistent; bracteoles subtending lateral flowers of a triad but with the terminal flower without bracteoles; persistent. Flower buds with the apex rounded to obtuse. Flowers purple, red or maroon. Hypanthium glossy or dull-glossy; striate-glandular, visibly gland-dotted; stipitate; goblet-shaped or stipitate-cup-shaped, 2.5‒4.25 by 2–3.75 mm, stipe 0.5‒1 mm long. Calyx a rim of tissue, lobes if distinguishable 4 or 5 and very depressedly triangular or depressedly triangular and 0.2–0.5 mm long including the rim. Petals 4, calyptrate (coherent and falling as a cap). Staminal disc flat ( Fig. 2 View Fig : 1.8). Stamens 2.5‒5 mm long. Style 2.5‒4 mm long. Placentation axile-median; placenta a small cushion. Ovules 5‒10 per locule, spreading, arranged radially in one row. Mature fruit blue, smooth, depressed spheroid, c. 10 by 10‒14 mm wide excluding the calyx; seed depressed spheroid, 8–12 mm across, cotyledons collateral.

Distribution — Papua New Guinea.

Habitat & Ecology — Tall and largely secondary forest on steep slope, mossy fagaceous forest on hillside, mid mountain oak forest, associated with Garcinia L. ( Clusiaceae ), Terminalia L. ( Combretaceae ) and Palaquium Blanco ( Sapotaceae ) in montane rainforest, secondary succession in creek gully, dry rainforest in gully. Altitude 760‒2130 m.

Notes — 1. Syzygium hooglandii additionally differs from S. buettnerianum in the reticulate leaf venation being more prominent, and in the inflorescences being shorter and stouter with the bracteoles more persistent. There is some variation in the placentation among the specimens assigned to S. hooglandii , i.e., NGF 17337 has c. 5 ovules in one row, Hoogland & Pullen 5961 c. 10 in one row, whereas NGF 15429 has c. 13 ovules/locule arranged irregularly on the placenta. NGF 15429 was collected at c. 760 m while NGF 17337 and Hoogland & Pullen 5961 were collected at c. 2130 and c. 2050 m, respec- tively. It may be that NGF 15429 is transitional with respect to S. buettnerianum or represents another taxon.

2. A distinction between primary and secondary veins may be artificial and this species may in fact have very few secondary veins per se. In robust seasonal growth units, the proximal inflo- rescence branchlets are subtended by leaves but in non-robust seasonal growth units the inflorescence per se is leafless.