PNGTreesKey – Horsfieldia hellwigii (Warb.) Warb. var. hellwigii
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
Nova Acta Academiae Caesareae Leopoldino-Carolinae Germanicae Naturae Curiosorum. Abhandlungen der Kaiserlichen Leopoldinisch-Carolinischen Deutschen Akademie der Naturforscher Vol. 68: 343 (1897)
Other Literature: W.J.J.O. de Wilde, Flora Malesiana, Series 1 125-126 (2000) Fig. 17.
Timber Group: Minor hardwood
Field Characters: Large canopy tree (up to 30 m high) or Small sub-canopy tree; Bole cylindrical (up to 50 cm diam.); straight (bole mostly up to 15 m long); buttresses buttresses absent; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots absent; Bark grey, rough, fissured; Subrhytidome (under-bark) dark red; less than 25 mm thick, 10.0-12.0; bark blaze consisting of one layer; faintly to non-aromatic; outer blaze white, pale yellow, pale red, or pale brown, markings absent; inner blaze white, pale yellow, pale red, or pale brown, markings absent; bark exudate (sap) present, red, flowing, colour not changing on exposure to air, not sticky; terminal buds not enclosed by leaves.
Indumentum: Complex hairs absent; stinging hairs absent; mature twig indumentum (hairs) present, hairs dense (with rusty-coloured more or less woolly 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 slightly broadest below middle or equally broad throughout much of length, 17.0-40.0 (-50.0) cm, 5.0-14.0 cm; symmetric, entire, not dissected or lobed, acuminate (shortly), venation pinnate, secondary veins open, prominent, intramarginal veins absent; leaves lower surface green, brown, or red (slightly (rusty-coloured hairs), upper surface dark green (glossy), indumentum (hairs) present (on lower surface), indumentum (hairs) dense; present; domatia absent; stipules absent.
Flowers: Inflorescence axillary (amongst lower leaves or leaf scars), flowers on a branched axis, cones absent; flowers unisexual, unisexual with male and female flowers on different plants, stalked (shortly), flowers with many planes of symmetry or slightly asymmetric, 1.0-3.0 (-4.0) mm long, diameter small (up to10 mm diam.) (c. 3 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-) 12-18, absent, joined (to form a central staminal column), free of the perianth; ovary superior, carpels joined (when more than one), locules 1; styles absent.
Fruits: Infrutescence arranged on branched axis, fruit 16.0-28.0 mm long, yellow or orange, not spiny, non-fleshy (leathery) or slightly fleshy, simple, dehiscent, capsule (dehiscing by 2-valves); seeds 1, about 10 mm long (10-18 mm long), not winged, broad (as wide as long) (10-12 mm diam.), seed more than 10 mm diam.
Distribution: West Sepik, Madang, Morobe, Central, Northern, Milne Bay, Papuan Islands & New Britain.
in PNGplants database
Notes: Notes Horsfieldia hellwigii var. hellwigii has ellipsoid to fusiform fruits that are 16-28 mm long whereas var. brachycarpa has shorter ellipsoid to almost globose fruits (12-15 mm long). The fruits of the other variety, var. lignosa, are slightly asymmetrical and subglobose with a thick woody pericarp (4-8 mm thick). The pericarp of the former two varieties are thinner, about 2 mm thick.