PNGTreesKey – Hopea iriana Slooten


Barry Conn (NSW) & Kipiro Damas (LAE).
Guide to trees of Papua New Guinea
Copyright held by the authors, National Herbarium of New South Wales, and Papua New Guinea National Herbarium

Hopea iriana Slooten

Reinwardtia Vol. 2: 28 (1952)

Family: Dipterocarpaceae

Timber Group: Major exportable hardwood

Field Characters: Large canopy tree (30-40 m high); Bole cylindrical (to slightly spurred, c. 0.6 m diam.); straight (bole up to 30 m long); buttresses rarely buttresses present or usually buttresses absent; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots absent; Bark dark grey or brown, slightly rough or smooth, scaly or flaky or fissured; Subrhytidome (under-bark) brown; less than 25 mm thick, 15.0 (c.); bark blaze consisting of one layer; faintly to non-aromatic; outer blaze pink or pale brown, markings absent, fibrous; inner blaze pink or pale brown, markings absent, fibrous; bark exudate (sap) absent; terminal buds not enclosed by leaves.

Indumentum: Complex hairs absent; stinging hairs absent; mature twig indumentum (hairs) absent (small lenticels present).

Leaves: Leaves spaced along branches, spiral (leaves occurring singly at a node and arranged spirally up the branchlet), simple (a leaf composed of a single blade); petiole present, not winged, attached to base of leaf blade, not swollen; leaves broadest at or near middle or broadest below middle, 8.0-11.0 cm, 3.0-4.0 cm; symmetric (mostly (slightly asymmetric), entire, not dissected or lobed, acuminate, venation pinnate, secondary veins open, prominent, intramarginal veins absent; leaves lower surface pale green, upper surface dark green, indumentum (hairs) absent; absent; domatia absent; stipules absent.

Flowers: Inflorescence terminal or axillary, flowers on a branched axis, cones absent; flowers bisexual, stalked, flowers slightly asymmetric or with one plane of symmetry, 4.0-5.0 mm long, diameter small (up to10 mm diam.) (c. 5 mm diam.); perianth present, with distinct sepals and petals whorls, inner perianth white or cream-coloured; 5, some or partly joined (at base); stamens 10 (c.), present (broad at base), free of each other, joined to the perianth (at base and falling with petals); ovary superior, carpels joined (when more than one), locules 2; styles solitary, 1 (thickened to form a stylopodium).

Fruits: Infrutescence arranged on branched axis, fruit 10.0 (c.) mm long, 8.0 (c.) mm diam., brown, not spiny, non-fleshy, simple, dehiscent, capsule (often referred to as a nut, but splitting at germination into more or less 3 regular valves); seeds 1, about 10 mm long (c. 8 mm long), not winged, broad (as wide as long), seed 1-10 mm diam. (c. 8 mm diam.).

Distribution: West Sepik, East Sepik, Morobe, Western & Milne Bay.

Hopea iriana
Botanical records
in PNGplants database

Map details