PNGTreesKey – Pinus strobus L.


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

Pinus strobus L.

Species Plantarum 1 000 (1753)

Family: Pinaceae

Timber Group: Softwood or Plantation species Tradename: White Pine, Weymouth Pine

Field Characters: Large canopy tree (20-45 m high, mostly shorter in Papua New Guinea); Bole cylindrical (c. 20 cm diam.); straight (branching from near base); buttresses buttresses absent; spines spines absent; aerial roots aerial roots absent; stilt roots stilt roots absent; Bark grey, rough (near base of older trees) or smooth (on young trees throughout or often remaining smooth distally on older trees), scaly or flaky or furrowed cork (at base of older trees); Subrhytidome (under-bark) brown; less than 25 mm thick (10 mm thick), 10.0 (c.); bark blaze with two layers (outer layer of dead cork); strongly aromatic; resinous/linament-like or pine-like; outer blaze brown, with stripes (layers of cork), corky; inner blaze white, markings absent, fibrous; bark exudate (sap) present, colourless, not readily flowing (spotty), colour not changing on exposure to air, sticky; terminal buds not enclosed by leaves.

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

Leaves: Leaves clustered at end of branches or spaced along branches, whorled (with more than two leaves at one node of a branchlet) or spiral (leaves occurring singly at a node and arranged spirally up the branchlet) (arranged in leaf bundles, with basal sheath c. 15 mm long, soon falling off), 4-(per bundle)-5, simple (a leaf composed of a single blade); petiole absent; leaves equally broad throughout much of length (needle-like), 7.0-12.0 cm, 0.5 cm; symmetric, entire or crenate (very finely toothed), not dissected or lobed, acute, venation parallel-veined, secondary veins closed, not prominent, but visible, intramarginal veins absent (resin canals marginal - view in cross-section); leaves lower surface blue-green or pale green, upper surface blue-green or pale green (note: the upper surface consists of two inner surfaces, each with stomatic lines), indumentum (hairs) absent; absent; domatia absent; stipules absent.

Flowers: Inflorescence terminal or axillary, flowers on an unbranched axis, flowers arranged in a cone (strobilus) (male flowers in narrowly cylindrical strobili, strobili in clusters around base of young shoots); flowers unisexual, unisexual with male and female flowers on the same plant, not stalked, flowers with one plane of symmetry; perianth absent; stamens 1, absent, free of each other; ovary superior, carpels separate (when more than one), locules 2; styles absent.

Fruits: Infrutescence arranged on unbranched axis, arrangement of fruits present (sub-terminal, pendulous, cylindrical, often curved, often with white resin), cone 100.0-150.0 mm, 30.0 mm, pale brown; seeds 100 (2 per scale), about 10 mm long (c. 8 mm long), winged (wing narrow, 22-25 mm long), narrow (longer than wide) (red-brown, mottled with black), seed 1-10 mm diam. (c. 4 mm diam.).

Distribution: Morobe (not successful as a Plantation species in this province).

Pinus strobus
Botanical records
in PNGplants database

Map details