PNGTreesKey – Arthrophyllum macranthum Philipson


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

Arthrophyllum macranthum Philipson

Bulletin of the British Museum (Natural History) Botany Vol. 1: 18 (1951)

Other Literature: W.R. Philipson, Handbooks of the Flora of Papua New Guinea 4-6 (1995) Fig. 1.

Family: Araliaceae

Timber Group: Non-timber species

Field Characters: Large canopy tree (up to 25 m high, rarely to 30 m) or Small sub-canopy tree (up to 8 m high); Bole cylindrical (c. 25 mm diam.); straight (often branching near base, with bole up to c. 5 m long); buttresses buttresses absent; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots absent; Bark grey, smooth; Subrhytidome (under-bark) pale brown; less than 25 mm thick; bark blaze consisting of one layer; faintly to non-aromatic; outer blaze white (cream-coloured), with stripes; inner blaze white (cream-coloured), with stripes; bark exudate (sap) present, brown, colour not changing on exposure to air; terminal buds not enclosed by leaves.

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

Leaves: Leaves clustered at end of branches, spiral (leaves occurring singly at a node and arranged spirally up the branchlet), compound (a leaf made up from two or more leaflets); petiole present, not winged, attached to base of leaf blade, not swollen or swollen; leaves with three leaflets (trifoliate) or pinnate (unbranched with more than three leaflets); petiolule not swollen; rachis present, absent, absent; leaves with a terminal leaflet (the number of leaflets odd - imparipinnate), broadest at or near middle or broadest below middle, 9.0-13.0 cm, 3.5-5.0 cm, leaflets opposite, symmetric, terminal developing leaflet buds straight; venation pinnate, secondary veins open, not prominent, but visible, intramarginal veins absent; leaves lower surface dull green, upper surface dark green (glossy), indumentum (hairs) present, indumentum (hairs) sparse; absent; domatia absent; stipules absent.

Flowers: Inflorescence terminal, flowers on a branched axis, cones absent; flowers bisexual, stalked, flowers with many planes of symmetry, 6.0-7.0 mm long, diameter small (up to10 mm diam.) (c. 6 mm diam.); perianth present, with distinct sepals and petals whorls, inner perianth yellow or green; 5, free; stamens 4, present, free of each other, free of the perianth; ovary inferior, carpels joined (when more than one), locules 1; styles absent (stigma sessile).

Fruits: Infrutescence arranged on branched axis, fruit 10.0-12.0 mm long, 8.0 (c.) mm diam., dark green, not spiny, fleshy, simple, indehiscent, drupe; seeds 1, about 10 mm long (c. 8 mm long), not winged, narrow (longer than wide), seed 1-10 mm diam. (5-6 mm diam.).

Distribution: West Sepik, Morobe, Western Highlands, Eastern Highlands, Southern Highlands, Western, Central & Milne Bay.

Arthrophyllum macranthum
Botanical records
in PNGplants database

Map details