Syzygium saundersii Craven, 2019

Craven, L. A., 2019, Studies in Papuasian Syzygium (Myrtaceae): 1. Subgenus Perikion revised, Blumea 64 (2), pp. 115-122 : 120-121

7. Syzygium saundersii Craven , sp. nov. — Fig. 1 ; Map 4

From Syzygium claviflorum (Roxb.) Steud. it differs in the obtuse, rounded or truncate leaf lamina apex; the glossy, non-stipitate and 8–10 mm long hypanthium; the 7–11 mm long stamens; the 5–5.5 mm long style; and the c. 10 ovules per locule. (In S. claviflorum the leaf lamina apex is long acuminate or acuminate,the hypanthium is dull, stipitate and 9.8–23 mm long,the stamens are 3–8 mm long, and there are 9–16 ovules per locule.) — Type: Saunders 663 (holo CANB!; iso A, BISH, BM, BO, BRI, G, K, L, LAE, MEL, US, all n.v.), Papua New Guinea, Western Highlands Province, c. 800 m S of Tomba, forest, alt. c. 2440 m, 2 July 1957.

Etymology. The species is named in honour of John Campbell Saunders (1930–2001), forest botanist in the CSIRO Division of Land Research & Regional Survey’s New Guinea survey team and its successors from 1954 to 1995. John’s herbarium collections are sometimes scanty as they were collected as vouchers for his many wood samples; the type of the present species is a notable exception.He encouraged CSIRO herbarium collectors such as R.D. Hoogland,R. Pullen,R. Schodde and LAC to also collect wood samples and is directly responsible for the significant CSIRO contribution to Papua New Guinean wood samples,deposited primarily in FPAw and PMPw.

Tree to 26 m tall (bole to 15 m), to 45 cm dbh; bark grey. Vegetative branchlet quadrangular to compressed, angled to slightly winged, 2– 6 mm diam; bark dull, smooth, not glandular-verrucose, persistent. Leaf lamina 4.5–13 by 2.7–8 cm, 1.3–1.7 times as long as wide, broadly obovate, obovate or broadly elliptic; base attenuate or cuneate; apex truncate, rounded or obtuse; margin revolute; cartilaginous; primary and secondary venation distinctly different with secondaries relatively little developed and not or rarely joining the intramarginal vein (secondary veins are few); primary veins 10–16 on each side of the mid-rib, in median part of the lamina at a divergence angle of 65–75°, 3–10 mm apart; intramarginal vein present, weakly arched, 1.5–3 mm from margin, secondary intramarginal vein absent. Petiole 12–27 mm long. Reproductive seasonal growth unit with distinct vegetative and reproductive zones, or with a reproductive zone only (the vegetative zone is weakly developed and consists at most of a few pairs of leaves (that often are reduced in size). Inflorescence terminal or distal axillary, few- to many-flowered, paniculate, up to 3.5–12 by 2.5–9 cm, major axis 2–3 mm thick at the midpoint; bark smooth; bracts deciduous; bracteoles subtending each flower, caducous. Flowers calyptrate (petals coherent and falling as a cap). Hypanthium glossy, smooth (in sicco strongly wrinkled but this presumably is an artefact of drying), visibly but not strongly gland-dotted; not stipitate (tapering evenly to the base or truncate or rounded); thickly narrowly obconic; 8–10 by 3.5–4.5 mm. Calyx lobes 4, transversely semielliptic or semielliptic, 1–2 mm long. Petals 4; caducous (falling at anthesis); coherent (outer petal apparently falls separately but inner 3 seemingly fall as a unit), 5.5 mm long. Staminal disc flat ( Fig. 1 : 1.9). Stamens c. 55, 7–11 mm long. Style 5–5.5 mm long. Placentation axile-median; placenta apparently more or less oblong and not very prominent. Ovules c. 10 per locule, ascending, arranged in two longitudinal rows (one row on each placental lobe) or possibly arranged irregu- larly. Fruit not seen.

Distribution — Papua New Guinea.

Habitat & Ecology — Forest, mountain forest on steep slope, mixed montane forest. Altitude 2440–2600 m.

Note — The relationships of this species may lie with S. bicolor .

Figures

Map 4 Distribution of Syzygium saundersii Craven (●), S. sleumeri Craven (■), S. subamplexicaule Merr. & L.M.Perry (▲) and S. suberosum Craven (♦).

Fig. 1 Diagrams of staminal disc types occurring in Syzygium subg. Perikion species, showing staminal discs that are flat (1.1–1.10), descending (2.5), ascending (3.2) and raised (4.2). Within the flat staminal disc type, structure may differ in the degree of ‘lip’ projection at the inner edge of hypanthium apex (1.4, 1.5, 1.6 and 1.9) and the presence of a grooved petal insertion point (1.10).