PNGTreesKey – Horsfieldia irya (Gaertn.) Warb.


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

Horsfieldia irya (Gaertn.) Warb.

Nova Acta Academiae Caesareae Leopoldino-Carolinae Germanicae Naturae Curiosorum. Abhandlungen der Kaiserlichen Leopoldinisch-Carolinischen Deutschen Akademie der Naturforscher Vol. 68: 317 (1897)

Other Literature: W.J.J.O. de Wilde, Flora Malesiana, Series 1 132-135 (2000) Fig. 20.

Family: Myristicaceae

Timber Group: Minor hardwood

Field Characters: Large canopy tree (10-30 m high, rarely to 40 m) or Small sub-canopy tree; Bole cylindrical (often slightly fluted near base, up to c. 30 cm diam.); straight; buttresses buttresses present (occasionally buttresses up to 3 m high) or buttresses absent; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots present (occasionally with small prop roots present) or stilt roots absent; Bark brown, rough, slightly fissured, cracked, or slightly pustular, lenticels irregular; Subrhytidome (under-bark) red; less than 25 mm thick, 10.0; bark blaze consisting of one layer; faintly to non-aromatic; pleasant; outer blaze red, markings absent, fibrous; inner blaze red, markings absent, fibrous; bark exudate (sap) present, red, flowing, colour not changing on exposure to air, slightly sticky; terminal buds not enclosed by leaves.

Indumentum: Complex hairs absent; stinging hairs absent; mature twig indumentum (hairs) present, hairs dense (somewhat (minute, grey to rusty-coloured hairs).

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 sometimes broadest below middle or equally broad throughout much of length, 10.0-30.0 (-35.0) cm, (3.0-) 4.0-7.0 (-9.0) cm; symmetric, entire, not dissected or lobed, sub acute or slightly acuminate, venation pinnate, secondary veins open, prominent, intramarginal veins absent; leaves lower surface pale green, upper surface green, indumentum (hairs) absent or present when young, indumentum (hairs) sparse (early glabrescent); absent; domatia absent; stipules absent.

Flowers: Inflorescence axillary, flowers on a branched axis, cones absent; flowers unisexual, unisexual with male and female flowers on different plants, stalked, flowers with many planes of symmetry or slightly asymmetric, 1.0-2.5 mm long, diameter small (up to10 mm diam.) (1-2 mm diam.); perianth present, with all sepals and/or petals (hence tepals) similar, inner perianth pale yellow; 2, some or partly joined or all joined (almost (forming a shortly 2-lobed, globose to cup-shaped perianth); stamens 10-18, absent, joined (to form a central column), free of the perianth; ovary superior, carpels joined (when more than one), locules 1; styles absent.

Fruits: Infrutescence arranged on branched axis, fruit 40.0-45.0 mm long, orange, pale brown, or black (almost (when dry), not spiny, non-fleshy (leathery) or slightly fleshy, simple, indehiscent, drupe; seeds 1, about 10 mm long (12-20 mm long), not winged, broad (as wide as long), seed more than 10 mm diam.

Distribution: East Sepik, Madang, Morobe, Western, Gulf, Northern, Milne Bay, New Britain & Bougainville.

Horsfieldia irya
Botanical records
in PNGplants database

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