PNGTreesKey – Macaranga inermis Pax & K.Hoffm.


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

Macaranga inermis Pax & K.Hoffm.

in Engler, H.G.A., Das Pflanzenreich Vol. 63: (1914)

Family: Euphorbiaceae

Timber Group: Non-timber species

Field Characters: Small sub-canopy tree or Large canopy tree (up to 30 m high); Bole markedly fluted (up to c. 40 cm diam.); buttresses buttresses present; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots absent; Bark brown, rough, pustular, lenticels elongated vertically; Subrhytidome (under-bark) red or green; less than 25 mm thick, 8.0-10.0; bark blaze consisting of one layer; strongly aromatic; pleasant; outer blaze red, with stripes, fibrous; inner blaze red, with stripes, fibrous; bark exudate (sap) present, colourless, not readily flowing (spotty), colour changing on exposure to air, to red (pale (pinkish red), not sticky; terminal buds not enclosed by leaves.

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

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, swollen (at both base and tip); leaves broadest at or near middle, 8.0-14.0 cm, 3.0-5.5 cm; symmetric, entire, not dissected or lobed, acuminate, venation pinnate, secondary veins open, prominent, intramarginal veins absent; leaves lower surface pale green, upper surface green, indumentum (hairs) absent; absent; domatia absent; stipules present, free, laterally placed, not encircling the twig, collar-like, fringed, large, persistent.

Flowers: Inflorescence axillary, flowers on a branched axis, cones absent; flowers unisexual, unisexual with male and female flowers on the same plant, not stalked or stalked (shortly), flowers with many planes of symmetry, 1.0 (c.) mm long, diameter small (up to10 mm diam.) (c. 1 mm diam.); perianth present, with all sepals and/or petals (hence tepals) similar, inner perianth yellow or green; 1-(cup-like in female flowers); (male flowers)-4, some or partly joined; stamens 10 (c.), absent, free of each other, free of the perianth; ovary superior, carpels joined (when more than one), locules 3; styles free, 3.

Fruits: Infrutescence arranged on branched axis, fruit 3.0 (c.) mm long, 3.0 (c.) mm diam., red, not spiny, non-fleshy, simple, dehiscent, capsule; seeds 1, barely visible (to 1 mm long) (c. 1 mm long), not winged, broad (as wide as long), seed 1-10 mm diam. (c. 1 mm diam.).

Distribution: West Sepik, Morobe, Western Highlands, Southern Highlands, Northern & Bougainville.

Macaranga inermis
Botanical records
in PNGplants database

Map details