and it was discovered by the author in 1972 at similar elevations, around 1800 m, on nearby G. Rabong (collected as specimens FRI 20671, 20632). It has never been proved that this variation is not clinal or phenotypic. The author visited a stand on Bukit Retak in Ulu Temburong, Brunei where half the trees were like this and half with large leaves like lowland
Agathis (TCW 3056-3060). Kostermans (Kostermans 12820, 12897) has made collections from a similarly polymorphic population at 700 m on Mt. Palimasan in north east Kalimantan.