Pinus merkusii Jungh. & De Vriese

Large tree 40-50 m tall, occasionally to 70 m. Pyramidal with heavy horizontal branches and thick fissured bark in most areas but in some regions trees have more slender, somewhat ascending branches and much thinner, smoothish bark resembling that in the upper crown of thick-barked populations. These two types hold true in artificial plantings. The reddish bark of young trees changes to dark brown weathering to gray on older trees. Foliage buds long and narrow with awl-shaped scales. Needles in pairs, 16-19 cm by 1 mm, abruptly pointed, stomata on all faces, falling in the second year. Basal sheath 12-18 mm long, reddish. Pollen cones 18-25 by 5 mm. Seed cone cylindrical before opening, 5-11 by 3 cm and twice as thick after opening, generally falling soon after shedding seeds. Apophysis broadly tetragonal in shape with a smooth, almost depressed umbo. Seed 7.5 by 4.5 mm, with a deciduous wing 25 by 8 mm.

From low elevations to 2000 m, generally on poor quality acid podzolic soils over sandstone or fresh volcanic ash, sometimes on deeply leached acid basalt, rarely successfully competing on richer forest soils. Most stands show a clear relationship to fire or other disturbance and the pine can be seen to be expanding in recently disturbed areas. In Sumatra the habitat experiences heavy year-round precipitation, but the pine areas themselves definitely favour the drier sites. The Tapanuli populations, which have thin bark, are more sensitive to fire and do not descend below 1000 m. Elsewhere, including the Philippine islands, this pine grows in strongly seasonal environments.

The tender layer of the stem just beneath the bark is eaten.

Can be grown by seedlings. Seeds needs soaking.